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Sample records for higgs boson results

  1. Higgs boson discovery and recent results

    E-Print Network [OSTI]

    Martin Flechl; for the CMS collaboration

    2015-10-07

    After briefly discussing the discovery of a Higgs boson at the Large Hadron Collider, an overview of recent results in Higgs boson physics obtained with the CMS experiment is presented. The focus is on measurements of the properties of the recently discovered Higgs boson with a mass of about 125 GeV. A brief selection of results in searches for Higgs bosons beyond the standard model is given, and prospects of future Higgs boson measurements and searches are discussed.

  2. Review of Physics Results from the Tevatron: Higgs Boson Physics

    E-Print Network [OSTI]

    Thomas R. Junk; Aurelio Juste

    2015-03-05

    We review the techniques and results of the searches for the Higgs boson performed by the two Tevatron collaborations, CDF and DO. The Higgs boson predicted by the Standard Model was sought in the mass range 90 GeV$Higgs boson with a mass in the range 115 GeV$Higgs boson mass of $m_H=125$ GeV, studies of Higgs boson properties were performed, including measurements of the product of the cross section times branching the ratio in various production and decay modes, constraints on Higgs boson couplings to fermions and vector bosons, and tests of spin and parity. We also summarize the results of searches for supersymmetric Higgs bosons, and Higgs bosons in other extensions of the Standard Model.

  3. Review of physics results from the Tevatron: Higgs boson physics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Junk, Thomas R.; Juste, Aurelio

    2015-02-28

    We review the techniques and results of the searches for the Higgs boson performed by the two Tevatron collaborations, CDF and DO. The Higgs boson predicted by the Standard Model was sought in the mass range 90 GeV H (*), H ? ZZ (*), and H ? ??. An excess of events was seen in the H ? bb searches consistent withmore »a Standard Model Higgs boson with a mass in the range 115 GeV H H = 125 GeV, studies of Higgs boson properties were performed, including measurements of the product of the cross section times branching the ratio in various production and decay modes, constraints on Higgs boson couplings to fermions and vector bosons, and tests of spin and parity. We also summarize the results of searches for supersymmetric Higgs bosons, and Higgs bosons in other extensions of the Standard Model.« less

  4. Review of physics results from the Tevatron: Higgs boson physics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Junk, Thomas R. [Fermi National Accelerator Lab., Batavia, IL (United States); Juste, Aurelio [Institute de Fisica d'Altes Energies (IFAE), Barcelona (Spain)

    2015-02-28

    We review the techniques and results of the searches for the Higgs boson performed by the two Tevatron collaborations, CDF and DO. The Higgs boson predicted by the Standard Model was sought in the mass range 90 GeV H (*), H ? ZZ (*), and H ? ??. An excess of events was seen in the H ? bb searches consistent with a Standard Model Higgs boson with a mass in the range 115 GeV H H = 125 GeV, studies of Higgs boson properties were performed, including measurements of the product of the cross section times branching the ratio in various production and decay modes, constraints on Higgs boson couplings to fermions and vector bosons, and tests of spin and parity. We also summarize the results of searches for supersymmetric Higgs bosons, and Higgs bosons in other extensions of the Standard Model.

  5. Combined results of searches for the standard model Higgs boson in pp collisions at ?s = 7 TeV

    E-Print Network [OSTI]

    Alver, B.

    Combined results are reported from searches for the standard model Higgs boson in proton–proton collisions at ?s = 7 TeV in five Higgs boson decay modes: ??, bb, ?? , WW, and ZZ. The explored Higgs boson mass range is ...

  6. Searches for the Higgs Boson

    E-Print Network [OSTI]

    M. Herndon; for the Babar; CDF; DØcollaborations

    2008-10-20

    Searches for this Higgs boson are reaching an exciting time. This proceeding reports the progress on Standard Model Higgs boson searches at the Tevatron and the prospects for Higgs boson searches at the Large Hadron Collider. Also reported are the results of non Standard Model searches and prospects at the Tevatron, Large Hadron Collide and B factories. Included in this result are the first limits on the mass of the Standard Model Higgs boson at high masses beyond the kinematic reach of the Large Electron Positron collider.

  7. Charged Higgs Bosons in the LHCHXSWG

    E-Print Network [OSTI]

    S. Heinemeyer

    2014-11-26

    Searches for charged Higgs bosons are an integral part of current and future investigations at the LHC. The LHC Higgs Cross Section Working Group (LHCHXSWG) was created to provide cross sections, branching ratios, analysis strategies etc. for Higgs boson searches at the LHC. We briefly review progress and results for charged Higgs bosons in and for the LHCHXSWG.

  8. Results on the search for the standard model Higgs boson at CMS

    SciTech Connect (OSTI)

    Fabozzi, Francesco [INFN Sezione di Napoli, Complesso Univ. di Monte S. Angelo Via Cintia - 80126 Napoli (Italy) and Universita della Basilicata, Viale dell'Ateneo Lucano 10 - 85100 Potenza (Italy); Collaboration: CMS Collaboration

    2012-10-23

    A summary of the results from searches for the Standard Model Higgs Boson in the CMS experiment at LHC with data collected from proton-proton collisions at {radical}(s) = 7TeV is presented. The Higgs boson is searched in a multiplicity of decay channels using data samples corresponding to integrated luminosities in the range 4.6 - 4.8 fb{sup -1}. The investigated mass range is 110 - 600 GeV. Results are reported for each channel as well as for their combination.

  9. LHC Higgs Boson searches

    E-Print Network [OSTI]

    William Murray

    2012-01-22

    A summary of the Higgs boson searches by the ATLAS and CMS collabrations using 1 f b-1 of LHC data is presented, concentrating on the Standard Model Higgs boson. Both experiments have the sensitivity to exclude at 95% CL a Standard Model Higgs boson in most of the Higgs boson mass region between about 130 GeV and 400 GeV. The observed data allow the exclusion of a Higgs Boson of mass 155 GeV to 190 GeV and 295 GeV to 450 GeV (ATLAS) and 149 GeV to 206 GeV and 300 GeV to 440 GeV (CMS). The lower limits are not as constraining as might be expected due to an excess in both experiments of order 2-3{\\sigma} which could be related to a low mass Higgs boson or to a statistical fluctuation.

  10. Gravity wraps Higgs boson

    E-Print Network [OSTI]

    Durmus A. Demir

    2011-12-11

    It is shown that, under a conformal transformation with reference to the Higgs field, the Higgs boson can be completely decoupled from electroweak interactions with no apparent change in known properties of leptons, quarks and vector bosons. Higgs boson becomes part of a scalar-tensor gravity which can be relevant for Dark Energy. It interacts with matter sector via higher-dimensional terms (e.g. neutrino Majorana mass), and via the fields (of new physics) whose masses are not generated by the Higgs mechanism. Dark Matter and two-Higgs-doublet model are the simplest examples.

  11. Was the Higgs boson discovered?

    E-Print Network [OSTI]

    Nguyen Anh Ky; Nguyen Thi Hong Van

    2015-04-09

    The standard model has postulated the existence of a scalar boson, named the Higgs boson. This boson plays a central role in a symmetry breaking scheme called the Brout-Englert-Higgs mechanism (or the Brout-Englert-Higgs-Guralnik-Hagen-Kibble mechanism, for completeness) making the standard model realistic. However, until recently at least, the 50-year-long-sought Higgs boson had remained the only particle in the standard model not yet discovered experimentally. It is the last but very important missing ingredient of the standard model. Therefore, searching for the Higgs boson is a crucial task and an important mission of particle physics. For this purpose, many theoretical works have been done and different experiments have been organized. It may be said in particular that to search for the Higgs boson has been one of the ultimate goals of building and running the LHC, the world's largest and most powerful particle accelerator, at CERN, which is a great combination of science and technology. Recently, in the summer of 2012, ATLAS and CMS, the two biggest and general-purpose LHC collaborations, announced the discovery of a new boson with a mass around 125 GeV. Since then, for over two years, ATLAS, CMS and other collaborations have carried out intensive investigations on the newly discovered boson to confirm that this new boson is really the Higgs boson (of the standard model). It is a triumph of science and technology and international cooperation. Here, we will review the main results of these investigations following a brief introduction to the Higgs boson within the theoretical framework of the standard model and Brout-Englert-Higgs mechanism as well as a theoretical and experimental background of its search. This paper may attract interest of not only particle physicists but also a broader audience.

  12. The Hunt for the Higgs Boson

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    The Hunt for the Higgs Boson John Conway Univ. of California, Davis Haber-Dine Symposium January 4/files/199001194.pdf ALEPH - Dec. 1989 Search for Higgs boson using first 11k Z Covered the mass range 32, , qq #12;Result: SM Higgs boson excluded at 95% CL in range 32 MeV - 15 GeV I believe

  13. Higgs boson otherwise

    E-Print Network [OSTI]

    Renata Jora

    2009-05-03

    We propose an electroweak model based on the identification of the Higgs with the dilaton. We show that it is possible in this context to have a massless Higgs boson at tree and one loop levels without contradicting the main experimental and theoretical constraints.

  14. Discovery of the Higgs Boson Decaying to Two Photons /

    E-Print Network [OSTI]

    Palmer, Christopher Allan

    2014-01-01

    2 Standard Model and the Higgs Boson . . . . . . . . . . .Second Higgs Boson Search . . . . . . . . . . . . . . . .CMS combined SM Higgs boson search exclusion limits with

  15. Search for the Standard Model Higgs Boson Produced in Association with a Z Boson in the Electron-Muon Final State and the Higgs Boson Decaying into Bottom Quarks

    E-Print Network [OSTI]

    Bartek, Rachel A.

    2013-01-01

    Vector Boson Reconstruction . . . . . . . . . Higgs Bosoning fractions (right) of the SM Higgs boson. . . . . . . . .Higgs boson. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

  16. Supersymmetry and the Higgs boson

    E-Print Network [OSTI]

    van Suijlekom, Walter

    Supersymmetry and the Higgs boson: a better marriage after all Remco Castelijn Supervisor: Dr) bosons. Both fermionic and bosonic particles are merely excitations of fields that cover our whole

  17. Higgs Bosons Searches at CDF

    SciTech Connect (OSTI)

    Cuenca Almenar, Cristobal [University of California Irvine, CA 92697 (United States)

    2010-02-10

    Advanced analysis techniques together with increasing data samples are bringing the sensitivity of CDF to the Higgs boson very close to the SM predictions. These improvements translate into more stringent exclusions of parameter space in BSM Higgs sectors and of the SM mass range. The CDF Collaboration has a very active program on Higgs searches that comprises most accessible production mechanisms and decay channels in pp-bar collisions at sq root(s) = 1.96 TeV. This contribution will also review the combination of the different channels, data samples and analysis techniques that currently produces one of the most exciting experimental results in our field.

  18. A Higgs Boson Composed of Gauge Bosons

    E-Print Network [OSTI]

    F. J. Himpsel

    2015-02-24

    It is proposed to replace the Higgs boson of the standard model by a Lorentz- and gauge-invariant combination of SU(2) gauge bosons. A pair of Higgs bosons is identified with pairs of gauge bosons by setting their mass Lagrangians equal to each other. That immediately determines the mass of the composite Higgs boson. It becomes simply half of the vacuum expectation value of the standard Higgs boson, which matches the observed mass with tree-level accuracy (2%). The two parameters of the standard Higgs potential are replaced by five one-loop self-interactions of the SU(2) gauge bosons, derived from the fundamental gauge couplings. The Brout-Englert-Higgs mechanism of spontaneous symmetry breaking is generalized from scalars to vectors. Their transverse components acquire finite vacuum expectation values which generate masses for both gauge bosons and the Higgs boson. This concept leads beyond the standard model by enabling calculations of the Higgs mass and its potential without adjustable parameters. It can be applied to non-abelian gauge theories in general, such as grand unified models and supersymmetry.

  19. Higgs boson cosmology

    E-Print Network [OSTI]

    Ian G. Moss

    2015-07-21

    The discovery of the Standard Model Higgs boson opens up a range of speculative cosmological scenarios, from the formation of structure in the early universe immediately after the big bang, to relics from the electroweak phase transition one nanosecond after the big bang, on to the end of the present-day universe through vacuum decay. Higgs physics is wide-ranging, and gives an impetus to go beyond the Standard Models of particle physics and cosmology to explore the physics of ultra-high energies and quantum gravity.

  20. Higgs boson cosmology

    E-Print Network [OSTI]

    Moss, Ian G

    2015-01-01

    The discovery of the Standard Model Higgs boson opens up a range of speculative cosmological scenarios, from the formation of structure in the early universe immediately after the big bang, to relics from the electroweak phase transition one nanosecond after the big bang, on to the end of the present-day universe through vacuum decay. Higgs physics is wide-ranging, and gives an impetus to go beyond the Standard Models of particle physics and cosmology to explore the physics of ultra-high energies and quantum gravity.

  1. A Historical Profile of the Higgs Boson

    E-Print Network [OSTI]

    Ellis, John

    2013-01-01

    D. V. Nanopoulos, Higgs bosons from two gluon annihilationAssociated production of Higgs bosons and Z particles, Phys.Low-energy theorems for Higgs boson couplings to photons,

  2. A Historical Profile of the Higgs Boson

    E-Print Network [OSTI]

    Ellis, John

    2013-01-01

    Low-energy theorems for Higgs boson couplings to photons,Production of very massive Higgs bosons, Phys. Lett. B 136 (D. V. Nanopoulos, Higgs bosons from two gluon annihilation

  3. Frequently Asked Questions About the Higgs Boson

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Questions About the Higgs Boson What is a Higgs field? What is a Higgs boson? The Higgs field is like a giant vat of molasses spread throughout the universe. Most of the known...

  4. Higgs boson search at ATLAS

    E-Print Network [OSTI]

    Scott Snyder; for the ATLAS Collaboration

    2012-09-04

    The status of the ATLAS Higgs boson search using about 5 fb^-1 of data recorded in 2011 is summarized. Proceedings from Physics at the LHC 2012 (Vancouver).

  5. Lepton flavor violation in Higgs boson decays under the rare...

    Office of Scientific and Technical Information (OSTI)

    Lepton flavor violation in Higgs boson decays under the rare tau decay results Citation Details In-Document Search Title: Lepton flavor violation in Higgs boson decays under the...

  6. SciTech Connect: "higgs boson"

    Office of Scientific and Technical Information (OSTI)

    higgs boson" Find + Advanced Search Term Search Semantic Search Advanced Search All Fields: "higgs boson" Semantic Semantic Term Title: Full Text: Bibliographic Data: Creator ...

  7. A Higgs Boson Composed of Gauge Bosons F. J. Himpsel

    E-Print Network [OSTI]

    Himpsel, Franz J.

    A Higgs Boson Composed of Gauge Bosons F. J. Himpsel Department of Physics, University of Wisconsin to replace the Higgs boson of the standard model by a Lorentz- and gauge- invariant combination of SU(2) gauge bosons. A pair of Higgs bosons is identified with pairs of gauge bosons by setting their mass

  8. A Minimally Symmetric Higgs Boson

    E-Print Network [OSTI]

    Ian Low

    2015-06-10

    Models addressing the naturalness of a light Higgs boson typically employ symmetries, either bosonic or fermionic, to stabilize the Higgs mass. We consider a setup with the minimal amount of symmetries: four shift symmetries acting on the four components of the Higgs doublet, subject to the constraints of linearly realized SU(2)xU(1) electroweak symmetry. Up to terms that explicitly violate the shift symmetries, the effective lagrangian can be derived, irrespective of the spontaneously broken group G in the ultraviolet, and is universal in all models where the Higgs arises as a pseudo-Nambu-Goldstone boson (PNGB). Very high energy scatterings of vector bosons could provide smoking gun signals of a minimally symmetric Higgs boson.

  9. Dark side of the Higgs boson.

    SciTech Connect (OSTI)

    Low, I.; Schwaller, P.; Shaughnessy, G.; Wagner, C. E. M.

    2012-01-01

    Current limits from the Large Hadron Collider exclude a standard model-like Higgs mass above 150 GeV, by placing an upper bound on the Higgs production rate. We emphasize that, alternatively, the limit could be interpreted as a lower bound on the total decay width of the Higgs boson. If the invisible decay width of the Higgs is of the same order as the visible decay width, a heavy Higgs boson could be consistent with null results from current searches. We propose a method to infer the invisible decay of the Higgs by using the width of the measured h {yields} ZZ {yields} 4 {ell} line shape, and study the effect on the width extraction due to a reduced signal strength. Assuming the invisible decay product is the dark matter, we show that minimal models are tightly constrained by limits from Higgs searches at the LHC and direct detection experiments of dark matter, unless the relic density constraint is relaxed.

  10. Gauge Theories on an Interval: Unitarity Without a Higgs Boson

    E-Print Network [OSTI]

    Csaki, Csaba; Grojean, Christophe; Murayama, Hitoshi; Luigi, Pilo; Terning, John

    2004-01-01

    breaking without a Higgs boson. Gauge Theories on anscattering amplitude. The Higgs boson is localized at y = ?Rreal scalar ?eld, the Higgs boson. At tree level, the

  11. Higgs boson decays in the littlest Higgs model

    SciTech Connect (OSTI)

    Gonzalez-Sprinberg, G.A.; Martinez, R.; Rodriguez, J.-Alexis

    2005-02-01

    We calculate the two body Higgs boson decays in the framework of the littlest Higgs model. The decay H{yields}{gamma}Z is computed at one-loop-level and, using previous results, we evaluate the branching fractions in the framework of the littlest Higgs model. A wide range of the space parameter of the model is considered and possible deviations from the standard model are explored.

  12. Higgs boson parity. Discussion of the experiment

    E-Print Network [OSTI]

    Ilya Ginzburg

    2015-07-26

    Recently CMS and ATLAS announced that they have measured the Higgs boson parity. In fact, these results allow to define parity for a small class of models only. For the majority of models the used approach provides no information about Higgs parity.

  13. Higgs boson parity. Discussion of the experiment

    E-Print Network [OSTI]

    Ginzburg, Ilya

    2015-01-01

    Recently CMS and ATLAS announced that they have measured the Higgs boson parity. In fact, these results allow to define parity for a small class of models only. For the majority of models the used approach provides no information about Higgs parity.

  14. MSSM Higgs Boson Searches at LEP

    E-Print Network [OSTI]

    Andre Sopczak

    2006-02-15

    Final results from the MSSM Higgs boson searches from the LEP experiments ALEPH, DELPHI, L3 and OPAL are presented. The results are statistically combined and the statistical significance for signal and background hypotheses are given. Upper bounds on the production cross sections are set for several Higgs-like topologies. Interpretations for six benchmark scenarios in the MSSM, both for CP-conserving and CP-violating scenarios, are given. Limits on the tan(beta) parameter, and in some scenarios upper limits on the neutral Higgs boson masses are set.

  15. What is a Higgs Boson?

    ScienceCinema (OSTI)

    Lincoln, Don

    2014-08-12

    Fermilab scientist Don Lincoln describes the nature of the Higgs boson. Several large experimental groups are hot on the trail of this elusive subatomic particle which is thought to explain the origins of particle mass.

  16. What is a Higgs Boson?

    SciTech Connect (OSTI)

    Lincoln, Don

    2011-07-07

    Fermilab scientist Don Lincoln describes the nature of the Higgs boson. Several large experimental groups are hot on the trail of this elusive subatomic particle which is thought to explain the origins of particle mass.

  17. Higgs Boson Properties and BSM Higgs Boson Searches at LHC

    E-Print Network [OSTI]

    Wolfgang F. Mader

    2008-09-24

    At the end of 2008, the Large Hadron Collider (LHC) will come into operation and the two experiments ATLAS and CMS will start taking data from proton-proton collisions at a center-of-mass energy of \\sqrt{s}=14 TeV. In preparation for the data taking period, the discovery potential for Higgs bosons beyond the Standard Model has been updated by both experiments and is reviewed here. In addition, the prospects for measuring the properties of a Higgs boson like its mass and width, its CP eigenvalues and its couplings to fermions and gauge bosons are discussed.

  18. Supersymmetric Higgs Bosons in Weak Boson Fusion

    E-Print Network [OSTI]

    W. Hollik; T. Plehn; M. Rauch; H. Rzehak

    2008-04-17

    We compute the complete supersymmetric next-to-leading order corrections to the production of a light Higgs boson in weak boson fusion. The size of the electroweak corrections is of similar order as the next-to-leading order corrections in the Standard Model. The supersymmetric QCD corrections turn out to be significantly smaller than their electroweak counterparts. These higher--order corrections are an important ingredient to a precision analysis of the (supersymmetric) Higgs sector at the LHC, either as a known correction factor or as a contribution to the theory error.

  19. Charged Higgs boson searches with the ATLAS detector

    E-Print Network [OSTI]

    Gilles, Geoffrey; The ATLAS collaboration

    2015-01-01

    Charged Higgs bosons, H+, are predicted by many models with an extended Higgs sector. This presentation reports ATLAS studies and results of searches for charged Higgs bosons in various final states. Exclusion limits are given and interpreted in the context of the Minimal Supersymmetric extension of the Standard Model.

  20. Combined results of searches for the standard model Higgs boson in pp collisions at sqrt(s) = 7 TeV

    E-Print Network [OSTI]

    CMS Collaboration

    2012-02-07

    Combined results are reported from searches for the standard model Higgs boson in proton-proton collisions at sqrt(s)=7 TeV in five Higgs boson decay modes: gamma pair, b-quark pair, tau lepton pair, W pair, and Z pair. The explored Higgs boson mass range is 110-600 GeV. The analysed data correspond to an integrated luminosity of 4.6-4.8 inverse femtobarns. The expected excluded mass range in the absence of the standard model Higgs boson is 118-543 GeV at 95% CL. The observed results exclude the standard model Higgs boson in the mass range 127-600 GeV at 95% CL, and in the mass range 129-525 GeV at 99% CL. An excess of events above the expected standard model background is observed at the low end of the explored mass range making the observed limits weaker than expected in the absence of a signal. The largest excess, with a local significance of 3.1 sigma, is observed for a Higgs boson mass hypothesis of 124 GeV. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-600 (110-145) GeV is estimated to be 1.5 sigma (2.1 sigma). More data are required to ascertain the origin of this excess.

  1. Combined results of searches for the standard model Higgs boson in pp collisions at sqrt(s) = 7 TeV

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et al.

    2012-03-01

    Combined results are reported from searches for the standard model Higgs boson in proton-proton collisions at sqrt(s)=7 TeV in five Higgs boson decay modes: gamma pair, b-quark pair, tau lepton pair, W pair, and Z pair. The explored Higgs boson mass range is 110-600 GeV. The analysed data correspond to an integrated luminosity of 4.6-4.8 inverse femtobarns. The expected excluded mass range in the absence of the standard model Higgs boson is 118-543 GeV at 95% CL. The observed results exclude the standard model Higgs boson in the mass range 127-600 GeV at 95% CL, and in the mass range 129-525 GeV at 99% CL. An excess of events above the expected standard model background is observed at the low end of the explored mass range making the observed limits weaker than expected in the absence of a signal. The largest excess, with a local significance of 3.1 sigma, is observed for a Higgs boson mass hypothesis of 124 GeV. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-600 (110-145) GeV is estimated to be 1.5 sigma (2.1 sigma). More data are required to ascertain the origin of this excess.

  2. Complementarity between nonstandard Higgs boson searches and precision Higgs boson measurements in the MSSM

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Complementarity between nonstandard Higgs boson searches and precision Higgs boson measurements of the Higgs boson properties at the LHC provide relevant constraints on possible weak-scale extensions seem to suggest that all the additional, non-SM-like Higgs bosons should be heavy, with masses larger

  3. OVERVIEW OF HIGGS BOSON STUDIES AT THE TEVATRON

    SciTech Connect (OSTI)

    Zivkovic, Lidija

    2014-05-01

    The CDF and D0 experiments at the Tevatron p¯p Collider collected data between 2002 and 2011, accumulating up to 10 fb?1 of data. During that time, an extensive search for the standard model Higgs boson was performed. Combined results from the searches for the standard model Higgs boson with the final dataset are presented, together with results on the Higgs boson couplings and spin and parity.

  4. Overview of Higgs boson studies at the Tevatron

    E-Print Network [OSTI]

    Lidija Zivkovic

    2014-09-17

    The CDF and D0 experiments at the Tevatron $p\\bar{p}$ Collider collected data between 2002 and 2011, accumulating up to 10 $\\rm{fb^{-1}}$ of data. During that time, an extensive search for the standard model Higgs boson was performed. Combined results from the searches for the standard model Higgs boson with the final dataset are presented together with results on the Higgs boson couplings and spin and parity.

  5. Search for the Standard Model Higgs boson in the fully leptonic WW decay channel at CMS

    E-Print Network [OSTI]

    LeBourgeois, Matthew; LeBourgeois, Matthew

    2012-01-01

    of the Higgs boson . . . . . . . . . . . . . . . . . . . . .the Higgs boson . . . . . . . . . . . . . . . . . . . . . .5 Search for the Higgs Boson in the WW Decay Channel . . .

  6. Higgs boson decay to Ali Abbasabadi

    E-Print Network [OSTI]

    Repko, Wayne

    Higgs boson decay to #22;#22;#22; Ali Abbasabadi Department of Physical Sciences, Ferris State, East Lansing, Michigan 48824, USA (April 17, 2000) The Higgs boson decay, H ! #22;#22;#22; , is studied in the Standard Model at the tree and one-loop levels. It is shown that for Higgs boson masses above 110 Ge

  7. Introduction to the Physics of Higgs Bosons

    E-Print Network [OSTI]

    Sally Dawson

    1994-11-17

    A basic introduction to the physics of the Standard Model Higgs boson is given. We discuss Higgs boson production in $e^+e^-$ and hadronic collisions and survey search techniques at future accelerators. The Higgs bosons of the minimal SUSY model are briefly considered. Indirect limits from triviality arguments, vacuum stability and precision measurements at LEP are also presented.

  8. From the Standard Model Higgs boson towards Supersymmetry

    E-Print Network [OSTI]

    van Suijlekom, Walter

    From the Standard Model Higgs boson towards Supersymmetry: Improving Supersymmetry Searches number of events with Higgs boson(s) in cascades of supersymmetric origin

  9. Gravitational Interaction of Higgs Boson and Weak Boson Scattering

    E-Print Network [OSTI]

    Zhong-Zhi Xianyu; Jing Ren; Hong-Jian He

    2013-11-04

    With the LHC discovery of a 125 GeV Higgs-like boson, we study gravitational interaction of the Higgs boson via the unique dimension-4 operator involving Higgs doublet and scalar curvature, $\\,\\xi H^\\dag H R\\,$, with nonminimal coupling $\\,\\xi\\,$. This Higgs portal term can be transformed away in Einstein frame and induces gauge-invariant effective interactions in the Higgs sector. We study the weak boson scattering in Einstein frame, and explicitly demonstrate the longitudinal-Goldstone boson equivalence theorem in the presence of $\\,\\xi\\,$ coupling. With these, we derive unitarity bound on the Higgs gravitational coupling $\\,\\xi\\,$ in Einstein frame, which is stronger than that inferred from the current LHC Higgs measurements. We further study $\\xi$-dependent weak boson scattering cross sections at TeV scale, and propose a new LHC probe of the Higgs-gravity coupling $\\,\\xi\\,$ via weak boson scattering experiments.

  10. Higgs constraints from vector boson fusion and scattering

    E-Print Network [OSTI]

    John M. Campbell; R. Keith Ellis

    2015-02-10

    We present results on 4-lepton + 2-jet production, the partonic processes most commonly described as vector boson pair production in the Vector Boson Fusion (VBF) mode. This final state contains diagrams that are mediated by Higgs boson exchange. We focus particularly on the high-mass behaviour of the Higgs boson mediated diagrams, which unlike on-shell production, gives information about the Higgs couplings without assumptions on the Higgs boson total width. We assess the sensitivity of the high-mass region to Higgs coupling strengths, considering all vector boson pair channels, $W^-W^+$, $W^\\pm W^\\pm$, $W^\\pm Z$ and $ZZ$. Because of the small background, the most promising mode is $W^+ W^+$ which has sensitivity to Higgs couplings because of Higgs boson exchange in the $t$-channel. Using the Caola-Melnikov (CM) method, the off-shell couplings can be interpreted as bounds on the Higgs boson total width. We estimate the bound that can be obtained with current data, as well as the bounds that could be obtained at $\\sqrt{s}=13$~TeV in the VBF channel for data samples of 100 and 300 fb$^{-1}$. The CM method has already been successfully applied in the gluon fusion (GGF) production channel. The VBF production channel gives important complementary information, because both production and decay of the Higgs boson occur already at tree graph level.

  11. Higgs constraints from vector boson fusion and scattering

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Campbell, John M.; Ellis, R. Keith

    2015-04-07

    We present results on 4-lepton + 2-jet production, the partonic processes most commonly described as vector boson pair production in the Vector Boson Fusion (VBF) mode. This final state contains diagrams that are mediated by Higgs boson exchange. We focus particularly on the high-mass behaviour of the Higgs boson mediated diagrams, which unlike on-shell production, gives information about the Higgs couplings without assumptions on the Higgs boson total width. We assess the sensitivity of the high-mass region to Higgs coupling strengths, considering all vector boson pair channels, W?W?, W±W±, W±Z and ZZ. Because of the small background, the most promisingmore »mode is W?W? which has sensitivity to Higgs couplings because of Higgs boson exchange in the t-channel. Using the Caola-Melnikov (CM) method, the off-shell couplings can be interpreted as bounds on the Higgs boson total width. We estimate the bound that can be obtained with current data, as well as the bounds that could be obtained at ?s = 13TeV in the VBF channel for data samples of 100 and 300 fb?¹. The CM method has already been successfully applied in the gluon fusion (GGF) production channel. The VBF production channel gives important complementary information, because both production and decay of the Higgs boson occur already at tree graph level.« less

  12. Higgs Boson -- on Your Own

    E-Print Network [OSTI]

    T. Csorgo

    2013-03-12

    One of the highlights of 2012 in physics is related to two papers, published by the ATLAS and the CMS Collaborations, that announced the discovery of at least one new particle in pp collisions at CERN LHC. At least one of the properties of this new particle is found to be similar to that of the Higgs boson, the last and most difficult to find building block from the Standard Model of particle physics. Physics teachers are frequently approached by their media-educated students, who inquire about the properties of the Higgs boson, but physics teachers are rarely trained to teach this elusive aspect of particle physics in elementary, middle or junior high schools. In this paper I describe a card-game, that can be considered as a hands-on and easily accessible tool that allows interested teachers, students and also motivated lay-persons to play with the properties of the newly found Higgs-like particle. This new particle was detected through its decays to directly observable, final state particles. Many of these final state particles are represented in a deck of cards, that represent elementary particles, originally invented to popularize the physics of quark matter in the so-called Quark Matter Card Games. The Higgs decay properties can be utilized, playfully, in a Higgs boson search card game. The rules of this game illustrate also the need for some luck, to complement knowledge and memory, useful skills that this game also helps to develop. The paper is organized as a handout or booklet, that directly describes how to play the Higgs boson on Your Own card game.

  13. Higgs and Z-boson Signatures of Supersymmetry

    E-Print Network [OSTI]

    Konstantin T. Matchev; Scott Thomas

    1999-08-26

    In supersymmetric theories of nature the Higgsino fermionic superpartner of the Higgs boson can arise as the lightest standard model superpartner depending on the couplings between the Higgs and supersymmetry breaking sectors. In this letter the production and decay of Higgsino pairs to the Goldstone fermion of supersymmetry breaking and the Higgs boson, h, or gauge bosons, Z or $\\gamma$ are considered. Relatively clean di-boson final states, hh, $h \\gamma$, hZ, $Z \\gamma$, or ZZ, with a large amount of missing energy result. The latter channels provide novel discovery modes for supersymmetry at high energy colliders since events with Z bosons are generally rejected in supersymmetry searches. In addition, final states with real Higgs bosons can potentially provide efficient channels to discover and study a Higgs signal at the Fermilab Tevatron Run II.

  14. Searches for Exotic Higgs Boson Decays with the ATLAS and the CMS Experiment

    E-Print Network [OSTI]

    Lagouri, Theodota; The ATLAS collaboration

    2015-01-01

    This talk will summarize the searches for exotic Higgs boson decays. It should cover decays of the observed Higgs boson to dark sector bosons, lepton flavor violating and flavor changing decays, and decays to a light pseudoscalar neutral Higgs boson as predicted by the NMSSM. Prospects for the LHC run-2 should be given. The talk should cover the results from ATLAS and CMS.

  15. Limits on a Composite Higgs Boson

    E-Print Network [OSTI]

    R. Sekhar Chivukula; Nick Evans; Christian Hoelbling

    2000-06-06

    Precision electroweak data are generally believed to constrain the Higgs boson mass to lie below approximately 190 GeV at 95% confidence level. The standard Higgs model is, however, trivial and can only be an effective field theory valid below some high energy scale characteristic of the underlying non-trivial physics. Corrections to the custodial isospin violating parameter T arising from interactions at this higher energy scale dramatically enlarge the allowed range of Higgs mass. We perform a fit to precision electroweak data and determine the region in the (m_H, Delta T) plane that is consistent with experimental results. Overlaying the estimated size of corrections to T arising from the underlying dynamics, we find that a Higgs mass up to 500 GeV is allowed. We review two composite Higgs models which can realize the possibility of a phenomenologically acceptable heavy Higgs boson. We comment on the potential of improvements in the measurements of m_t and M_W to improve constraints on composite Higgs models.

  16. Status of Higgs Boson Couplings and Searches

    E-Print Network [OSTI]

    Onyisi, Peter; The ATLAS collaboration

    2015-01-01

    The status of Higgs sector studies at the Large Hadron Collider is reviewed. The latest extractions of couplings and properties of the 125 GeV Higgs boson from the Run 1 data of the ATLAS and CMS experiments are discussed. Searches for additional Higgs boson states beyond that of the Standard Model are presented.

  17. Searches for exotic Higgs boson decays with the ATLAS and CMS experiments

    E-Print Network [OSTI]

    Lagouri, Theodota; The ATLAS collaboration

    2015-01-01

    The observed Higgs boson offers an excellent opportunity to look for new physics at LHC. Selected searches for exotic Higgs boson decays with the ATLAS and CMS experiments are presented. The Higgs boson decays to dark vector bosons (Zdark), the Lepton Flavor Violating (LFV) decays, the Flavor Changing Neutral Current (FCNC) decays, the decays to a light pseudo-scalar neutral Higgs boson (a in NMSSM) and the exotic Higgs decays to photon and missing transverse energy signatures are described and their Run-I results are given from both experiments. All the above searches for exotic Higgs boson decays present an alternative way for discovery of Beyond Standard Model (BSM) physics.

  18. On the Trail of the Higgs Boson

    E-Print Network [OSTI]

    Peskin, Michael E

    2015-01-01

    I review theoretical issues associated with the Higgs boson and the mystery of spontaneous breaking of the electroweak gauge symmetry. This essay is intended as an introduction to the special issue of Annalen der Physik, "Particle Physics after the Higgs".

  19. On the Trail of the Higgs Boson

    E-Print Network [OSTI]

    Michael E. Peskin

    2015-08-12

    I review theoretical issues associated with the Higgs boson and the mystery of spontaneous breaking of the electroweak gauge symmetry. This essay is intended as an introduction to the special issue of Annalen der Physik, "Particle Physics after the Higgs".

  20. On the Trail of the Higgs Boson

    E-Print Network [OSTI]

    Michael E. Peskin

    2015-08-15

    I review theoretical issues associated with the Higgs boson and the mystery of spontaneous breaking of the electroweak gauge symmetry. This essay is intended as an introduction to the special issue of Annalen der Physik, "Particle Physics after the Higgs".

  1. On the Trail of the Higgs Boson

    E-Print Network [OSTI]

    Michael E. Peskin

    2015-06-26

    I review theoretical issues associated with the Higgs boson and the mystery of spontaneous breaking of the electroweak gauge symmetry. This essay is intended as an introduction to the special issue of Annalen der Physik, "Particle Physics after the Higgs".

  2. Searches for Higgs Boson(s) at the Upgraded Tevatron

    E-Print Network [OSTI]

    Gregorio Bernardi; for the CDF; D0 collaborations

    2005-07-14

    We summarize the status of Higgs boson searches at the upgraded Fermilab Tevatron performed by the DO and CDF collaborations. We report on three categories of searches, namely 1) the search for the Standard Model Higgs boson (p\\bar{p} --> H, WH or ZH, with H --> WW* and/or H --> b\\bar{b}), 2) the search for the minimal supersymmetric Higgs boson using p\\bar{p} --> hb\\bar{b} --> b\\bar{b}b\\bar{b} and p\\bar{p} --> hX --> tau tau X, 3) the search for doubly charged Higgs boson.

  3. Holographic theories of electroweak symmetry breaking without a Higgs Boson

    E-Print Network [OSTI]

    Burdman, Gustavo; Nomura, Yasunori

    2003-01-01

    Breaking without a Higgs Boson Gustavo Burdman a and1] or theories where the Higgs boson arises as a compositeto build models of a composite Higgs boson [4] and dynamical

  4. Disentangling Dimension Six Operators through Di-Higgs Boson Production

    E-Print Network [OSTI]

    Pierce, Aaron; Thaler, Jesse; Wang, Lian-Tao

    2008-01-01

    Six Operators through Di-Higgs Boson Production Aaron Piercethe production rate and branching ratios of the Higgs boson.Here, we show how Higgs boson pair production can yield

  5. Higgs boson mass and new physics

    E-Print Network [OSTI]

    Fedor Bezrukov; Mikhail Yu. Kalmykov; Bernd A. Kniehl; Mikhail Shaposhnikov

    2012-09-27

    We discuss the lower Higgs boson mass bounds which come from the absolute stability of the Standard Model (SM) vacuum and from the Higgs inflation, as well as the prediction of the Higgs boson mass coming from asymptotic safety of the SM. We account for the 3-loop renormalization group evolution of the couplings of the Standard Model and for a part of two-loop corrections that involve the QCD coupling alpha_s to initial conditions for their running. This is one step above the current state of the art procedure ("one-loop matching--two-loop running"). This results in reduction of the theoretical uncertainties in the Higgs boson mass bounds and predictions, associated with the Standard Model physics, to 1-2 GeV. We find that with the account of existing experimental uncertainties in the mass of the top quark and alpha_s (taken at 2sigma level) the bound reads M_H>=M_min (equality corresponds to the asymptotic safety prediction), where M_min=129+-6 GeV. We argue that the discovery of the SM Higgs boson in this range would be in agreement with the hypothesis of the absence of new energy scales between the Fermi and Planck scales, whereas the coincidence of M_H with M_min would suggest that the electroweak scale is determined by Planck physics. In order to clarify the relation between the Fermi and Planck scale a construction of an electron-positron or muon collider with a center of mass energy ~200+200 GeV (Higgs and t-quark factory) would be needed.

  6. The Higgs Boson for the Masses?

    SciTech Connect (OSTI)

    Quigg, Chris

    2012-04-04

    The Higgs boson is the object of one of the greatest campaigns in the history of particle physics and a pop-culture icon. But what is a Higgs boson, and what would we like it to do for us? What will we understand after a discovery that we don't understand before? How would the world be different if nothing did the job of the Higgs boson? We will explore all these questions and more through demonstration, simulation, and audience participation.

  7. The light pseudoscalar Higgs boson in NMSSM

    E-Print Network [OSTI]

    Abdesslam Arhrib; Kingman Cheung; Tie-Jiun Hou; Kok-Wee Song

    2006-11-16

    We study the associated production of a very light pseudoscalar Higgs boson with a pair of charginos. The novel signature involves a pair of charged leptons from chargino decays and a pair of photons from the pseudoscalar Higgs boson decay, plus large missing energy at the LHC and ILC. The signal may help us to distinguish the NMSSM from MSSM, provided that the experiment can resolve the two photons from the decay of the pseudoscalar Higgs boson.

  8. Distinguishing a SM-like MSSM Higgs boson from SM Higgs boson at muon collider

    E-Print Network [OSTI]

    Jai Kumar Singhal; Sardar Singh; Ashok K Nagawat

    2005-07-26

    We explore the possibility of distinguishing the SM-like MSSM Higgs boson from the SM Higgs boson via Higgs boson pair production at future muon collider. We study the behavior of the production cross section in SM and MSSM with Higgs boson mass for various choices of MSSM parameters tan \\beta and m\\sub A. We observe that at fixed CM energy, in the SM, the total cross section increases with the increase in Higgs boson mass whereas this trend is reversed for the MSSM case. The changes that occur for the MSSM case in comparison to the SM predictions are quantified in terms of the relative percentage deviation in cross section. The observed large deviations in cross section for different choices of Higgs mass suggest that the measurements of the cross section could possibly distinguish the SM-like MSSM Higgs boson from the SM Higgs boson.

  9. Highlights of the MCTP Symposium on Higgs Boson Physics

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Highlights of the MCTP Symposium on Higgs Boson Physics MCTP Higgs Symposium webpage: http Sharma #12;Pursuing the Higgs Boson in 2010--2011 · Present Experimental Limits on the Higgs Boson---status of the Tevatron search · Prospects for the Tevatron in 2010--2011 · The LHC Higgs boson search at s=7 TeV with 1

  10. Alternative implementation of the Higgs boson

    E-Print Network [OSTI]

    Robert Foot; Archil Kobakhidze

    2010-12-23

    We discuss an alternative implementation of the Higgs boson within the Standard Model which is possible if the renormalizability condition is relaxed. Namely, at energy scale $\\Lambda$ the Higgs boson interacts at tree-level only with matter fermions, while the full gauge invariance is still maintained. The interactions with the electroweak gauge bosons are induced at low energies through the radiative corrections. In this scenario the Higgs boson can be arbitrarily heavy, interacting with the Standard Model fields arbitrarily weakly. No violation of unitarity in the scattering of longitudinal electroweak bosons occurs, since they become unphysical degrees of freedom at energies $\\Lambda \\sim \\mathrm{TeV}$.

  11. Precision Higgs Boson Physics and Implications for Beyond the...

    Office of Scientific and Technical Information (OSTI)

    Precision Higgs Boson Physics and Implications for Beyond the Standard Model Physics Theories Citation Details In-Document Search Title: Precision Higgs Boson Physics and...

  12. Precision Higgs Boson Physics and Implications for Beyond the...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Precision Higgs Boson Physics and Implications for Beyond the Standard Model Physics Theories Citation Details In-Document Search Title: Precision Higgs Boson...

  13. Search for Higgs Bosons Predicted in Two-Higgs-Doublet Models via Decays to Tau Lepton Pairs in 1.96 TeV pp[over-bar] Collisions

    E-Print Network [OSTI]

    Bauer, Gerry P.

    We present the results of a search for Higgs bosons predicted in two-Higgs-doublet models, in the case

  14. Search for the Standard Model Higgs Boson Produced in Association with a Z Boson in the Electron-Muon Final State and the Higgs Boson Decaying into Bottom Quarks

    E-Print Network [OSTI]

    Bartek, Rachel A.

    2013-01-01

    Vector Boson Reconstruction . . . . . . . . . Higgs Boson4 The Search for the SM Higgs boson in eµb ¯ b final stateing fractions (right) of the SM Higgs boson. . . . . . . . .

  15. Search for neutral MSSM Higgs bosons at LEP

    E-Print Network [OSTI]

    Schael, S; Brunelière, R; De Bonis, I; Décamp, D; Goy, C; Jézéquel, S; Lees, J P; Martin, F; Merle, E; Minard, M N; Pietrzyk, B; Trocmé, B; Bravo, S; Casado, M P; Chmeissani, M; Crespo, J M; Fernández, E; Fernández-Bosman, M; Garrido, L; Martínez, M; Pacheco, A; Ruiz, H; Colaleo, A; Creanza, D; De Filippis, N; De Palma, M; Iaselli, G; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Barklow, T; Buchmüller, O L; Cattaneo, M; Clerbaux, B; Drevermann, H; Forty, R W; Frank, M; Gianotti, F; Hansen, J B; Harvey, J; Hutchcroft, D E; Janot, P; Jost, B; Kado, M; Mato, P; Moutoussi, A; Ranjard, F; Rolandi, Luigi; Schlatter, W D; Teubert, F; Valassi, A; Videau, I; Badaud, F; Dessagne, S; Falvard, A; Fayolle, D; Gay, P; Jousset, J; Michel, B; Monteil, S; Pallin, D; Pascolo, J M; Perret, P; Hansen, J D; Hansen, J R; Hansen, P H; Kraan, A C; Nilsson, B S; Kyriakis, A; Markou, C; Simopoulou, E; Vayaki, A; Zachariadou, K; Blondel, A; Brient, J C; Machefert, F; Rougé, A; Videau, H L; Ciulli, V; Focardi, E; Parrini, G; Antonelli, A; Antonelli, M; Bencivenni, G; Bossi, F; Capon, G; Cerutti, F; Chiarella, V; Mannocchi, G; Laurelli, P; Murtas, G P; Passalacqua, L; Kennedy, J; Lynch, J G; Negus, P; O'Shea, V; Thompson, A S; Wasserbaech, S R; Cavanaugh, R J; Dhamotharan, S; Geweniger, C; Hanke, P; Hepp, V; Kluge, E E; Putzer, A; Stenzel, H; Tittel, K; Wunsch, M; Beuselinck, R; Cameron, W; Davies, G; Dornan, P J; Girone, M; Marinelli, N; Nowell, J; Rutherford, S A; Sedgbeer, J K; Thompson, J C; White, R; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bouhova-Thacker, E; Bowdery, C K; Clarke, D P; Ellis, G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Pearson, M R; Robertson, N A; Smizanska, M; van der Aa, O; Delaere, C; Leibenguth, G; Lemaître, V; Blumenschein, U; Hölldorfer, F; Jakobs, K; Kayser, F; Müller, A S; Renk, B; Sander, H G; Schmeling, S; Wachsmuth, H W; Zeitnitz, C; Ziegler, T; Bonissent, A; Coyle, P; Curtil, C; Ealet, A; Fouchez, D; Payre, P; Tilquin, A; Ragusa, F; David, A; Dietl, H; Ganis, G; Hüttmann, K; Lütjens, G; Männer, W; Moser, H G; Settles, R; Villegas, M; Wolf, G; Boucrot, J; Callot, O; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacholkowska, A; Serin, L; Veillet, J J; Azzurri, P; Bagliesi, G; Boccali, T; Foà, L; Giammanco, A; Giassi, A; Ligabue, F; Messineo, A; Palla, F; Sanguinetti, G; Sciabà, A; Sguazzoni, G; Spagnolo, P; Tenchini, R; Venturi, A; Verdini, P G; Awunor, O; Blair, G A; Cowan, G; García-Bellido, A; Green, M G; Medcalf, T; Misiejuk, A; Strong, J A; Teixeira-Dias, P; Clifft, R W; Edgecock, T R; Norton, P R; Tomalin, I R; Ward, J J; Bloch-Devaux, B; Boumediene, D E; Colas, P; Fabbro, B; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Tuchming, B; Vallage, B; Litke, A M; Taylor, G; Booth, C N; Cartwright, S; Combley, F; Hodgson, P N; Lehto, M H; Thompson, L F; Böhrer, A; Brandt, S; Grupen, C; Hess, J; Ngac, A; Prange, G; Borean, C; Giannini, G; He, H; Pütz, J; Rothberg, J E; Armstrong, S R; Berkelman, K; Cranmer, K; Ferguson, D P S; Gao, Y; González, S; Hayes, O J; Hu, H; Jin, S; Kile, J; McNamara, P A; Nielsen, J; Pan, Y B; Von Wimmersperg-Töller, J H; Wiedenmann, W; Wu, J; Wu, S L; Wu, X; Zobernig, G; Dissertori, G; Abdallah, J; Abreu, P; Adam, W; Adzic, P; Albrecht, T; Alderweireld, T; Alemany-Fernandez, R; Allmendinger, T; Allport, P P; Amaldi, Ugo; Amapane, N; Amato, S; Anashkin, E; Andreazza, A; Andringa, S; Anjos, N; Antilogus, P; Apel, W D; Arnoud, Y; Ask, S; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Ballestrero, A; Bambade, P; Barbier, R; Bardin, D; Barker, G J; Baroncelli, A; Battaglia, M; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Ben-Haim, E; Benekos, N; Benvenuti, A C; Bérat, C; Berggren, M; Berntzon, L; Bertrand, D; Besançon, M; Besson, N; Bloch, D; Blom, M; Bluj, M; Bonesini, M; Boonekamp, M; Booth, P S L; Borisov, G; Botner, O; Bouquet, B; Bowcock, T J V; Boyko, I; Bracko, M; Brenner, R; Brodet, E; Brückman, P; Brunet, J M; Buschbeck, Brigitte; Buschmann, P; Calvi, M; Camporesi, T; Canale, V; Carena, F; Castro, N; Cavallo, F; Chapkin, M; Charpentier, P; Checchia, P; Chierici, R; Shlyapnikov, P; Chudoba, J; Chung, S U; Cieslik, K; Collins, P; Contri, R; Cosme, G; Cossutti, F; Costa, M J; Crennell, D J; Cuevas-Maestro, J; D'Hondt, J; Dalmau, J; Da Silva, T; Da Silva, W; Della Ricca, G; De Angelis, A; de Boer, Wim; De Clercq, C; De Lotto, B; De Maria, N; De Min, A; De Paula, L; Di Ciaccio, L; Di Simone, A; Doroba, K; Drees, J; Eigen, G; Ekelöf, T J C; Ellert, M; Elsing, M; Espirito-Santo, M C; Fanourakis, G K; Fassouliotis, D; Feindt, M; Fernández, J; Ferrer, A; Ferro, F; Flagmeyer, U; Föth, H

    2006-01-01

    The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric Standard Model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The combined LEP data show no significant excess of events which would indicate the production of Higgs bosons. The search results are used to set upper bounds on the cross-sections of various Higgs-like event topologies. The results are interpreted within the MSSM in a number of ``benchmark" models, including CP-conserving and CP-violating scenarios. These interpretations lead in all cases to large exclusions in the MSSM parameter space. Absolute limits are set on the parameter tanb and, in some scenarios, on the masses of neutral Higgs bosons.

  16. Z' Bosons, the NuTeV Anomaly, and the Higgs Boson Mass

    E-Print Network [OSTI]

    Chanowitz, Michael S

    2009-01-01

    NuTeV Anomaly, and the Higgs Boson Mass Michael S. Chanowitzpredicted value of the Higgs boson mass, from ? 60 to ? 120from an increase in the Higgs boson mass. There is a vast

  17. A Historical Profile of the Higgs Boson

    SciTech Connect (OSTI)

    Ellis, John; Gaillard, Mary K.; Nanopoulos, Dimitri V.

    2012-01-31

    The Higgs boson was postulated in 1964, and phenomenological studies of its possible production and decays started in the early 1970s, followed by studies of its possible productionin e{sup +} e{sup -}, {anti p}p and pp collisions, in particular. Until recently, the most sensitive searches for the Higgs boson were at LEP between 1989 and 2000, which have been complemented bysearches at the Fermilab Tevatron. The LHC has recently entered the hunt, excluding a Higgs boson over a large range of masses and revealing a tantalizing hint in the range 119 to125 GeV, and there are good prospects that the existence or otherwise of the Higgs boson will soon be established. One of the most attractive possibilities is that the Higgs bosonis accompanied by supersymmetry, though composite options have yet to be excluded. This article reviews some of the key historical developments in Higgs physics over the past half-century.

  18. A More Precise Higgs Boson Mass

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Quigg, Chris

    2015-05-14

    To learn what distinguishes electromagnetism from the weak interactions was an early goal of experiments at CERN’s Large Hadron Collider (LHC). A big part of the answer was given in mid-2012, when the ATLAS and CMS Collaborations at the LHC announced the discovery of the Higgs boson in the study of proton–proton collisions. Now the discovery teams have pooled their data analyses to produce a measurement of the Higgs boson mass with 0.2% precision. The new value they discovered enables physicists to make more stringent tests of the electroweak theory and of the Higgs boson’s properties.

  19. Constraining Bosonic Supersymmetry from Higgs results and 8 TeV ATLAS multi-jets plus missing energy data

    E-Print Network [OSTI]

    Ghosh, Kirtiman; Nandi, S

    2014-01-01

    The collider phenomenology of models with Universal Extra Dimensions (UED) is surprisingly similar to that of supersymmetric (SUSY) scenarios. For each level-1 bosonic (fermionic) Kaluza-Klein (KK) state, there is a fermionic (bosonic) analog in SUSY and thus UED scenarios are often known as bosonic supersymmetry. The minimal version of UED (mUED) gives rise to a quasi-degenerate particle spectrum at each KK-level and thus, can not explain the enhanced Higgs to diphoton decay rate hinted by the ATLAS collaboration of the Large Hadron Collider (LHC) experiment. However, in the non-minimal version of the UED (nmUED) model, the enhanced Higgs to diphoton decay rate can be easily explained via the suitable choice of boundary localized kinetic (BLK) terms for higher dimensional fermions and gauge bosons. BLK terms remove the degeneracy in the KK mass spectrum and thus, pair production of level-1 quarks and gluons at the LHC gives rise to hard jets, leptons and large missing energy in the final state. These final s...

  20. TASI 2004 Lecture Notes: Higgs Boson Physics

    E-Print Network [OSTI]

    L. Reina

    2005-12-30

    In these lectures I briefly review the Higgs mechanism of spontaneous symmetry breaking and focus on the most relevant aspects of the phenomenology of the Standard Model and of the Minimal Supersymmetric Standard Model Higgs bosons at both hadron and lepton colliders. Some emphasis is put on the perturbative calculation of both Higgs boson branching ratios and production cross sections, including the most important radiative corrections.

  1. Higgs Boson & Flavor at the ATLAS & CMS Experiments

    E-Print Network [OSTI]

    Okawa, Hideki; The ATLAS collaboration

    2015-01-01

    The ATLAS and CMS Collaborations have discovered a Higgs boson in 2012. Remaining questions are to understand the property of the Higgs sector with precision, and to search for signs of physics beyond the Standard Model. Flavor studies and search for rare decays of the Higgs boson are promising probes to search for new physics. Related studies beyond the Higgs sector are also mentioned. This talk presents an overview of the results of such studies at the ATLAS and CMS experiments in LHC Run-1.

  2. A Search for Dark Higgs Bosons

    SciTech Connect (OSTI)

    Lees, J.P.

    2012-06-08

    Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb{sup -1} of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the Standard Model-dark sector mixing angle and the dark sector coupling constant.

  3. LCPHSM2004005 Study of Higgs Boson Pair Production at

    E-Print Network [OSTI]

    LC­PHSM­2004­005 March 2004 Study of Higgs Boson Pair Production at Linear Collider K. Desch a , TV for the measurement of the neutral Higgs boson properties within the framework of the MSSM. The process of associated Higgs boson production with subsequent decays of Higgs bosons into b­quark and #­lepton pairs

  4. Is the Higgs Boson Composed of Neutrinos?

    E-Print Network [OSTI]

    Krog, Jens

    2015-01-01

    We show that conventional Higgs compositeness conditions can be achieved by the running of large Higgs-Yukawa couplings involving right-handed neutrinos that become active at $\\sim 10^{13}- 10^{14}$ GeV. Together with a somewhat enhanced quartic coupling, arising by a Higgs portal interaction to a dark matter sector, we can obtain a Higgs boson composed of neutrinos. This is a "next-to-minimal" dynamical electroweak symmetry breaking scheme.

  5. CDF Note 10796 Search for Standard Model Higgs Boson Production

    E-Print Network [OSTI]

    Fermilab

    CDF Note 10796 Search for Standard Model Higgs Boson Production in Association with a W± Boson present a search for the standard model Higgs boson produced in association with a W± boson. This search that at least one jet be identified to originate from a bottom quark. Discrimination between the Higgs boson

  6. Searches for exotic decays of the 125 GeV Higgs boson and the lightest neutral Higgs boson in NMSSM with the ATLAS detector

    E-Print Network [OSTI]

    Looper, Kristina Anne; The ATLAS collaboration

    2015-01-01

    We present the results of searches for non-Standard Model decays of the 125 GeV Higgs boson, including decays to dark sector bosons, lepton flavour violating and flavour changing decays, and decays to a light pseudoscalar neutral Higgs boson (a) predicted by the next-Minimal-Supersymmetric-Standard-Model.

  7. From the Big Bang to the Higgs Boson in Less Than an Hour

    E-Print Network [OSTI]

    Fygenson, Deborah Kuchnir

    From the Big Bang to the Higgs Boson in Less Than an Hour Jeffrey D H Higgs boson Gauge bosons (force field quanta) Higgs boson and vacuum expectation value Strong) photon Z boson W bosons H Higgs boson Gauge bosons (force field quanta) Higgs boson and vacuum

  8. Higgs bosons in supersymmetric model with CP-violating potential

    E-Print Network [OSTI]

    Oshimo, Noriyuki

    2015-01-01

    In the supersymmetric standard model which is not minimal, the Higgs potential does not conserve CP symmetry generally. Assuming that there exists an SU(2)-triplet Higgs field, we discuss resultant CP-violating effects on the Higgs bosons. The experimentally observed Higgs boson, which should be CP-even in the standard model, could decay into two photons of CP-odd polarization state non-negligibly. For the second lightest Higgs boson, in sizable region of parameter space, the dominant decay modes are different from those expected by the standard model. The two-photon decay could yield both even and odd CP final states at a ratio of oder of unity.

  9. Higgs bosons in supersymmetric model with CP-violating potential

    E-Print Network [OSTI]

    Noriyuki Oshimo

    2015-11-21

    In the supersymmetric standard model which is not minimal, the Higgs potential does not conserve CP symmetry generally. Assuming that there exists an SU(2)-triplet Higgs field, we discuss resultant CP-violating effects on the Higgs bosons. The experimentally observed Higgs boson, which should be CP-even in the standard model, could decay into two photons of CP-odd polarization state non-negligibly. For the second lightest Higgs boson, in sizable region of parameter space, the dominant decay modes are different from those expected by the standard model. The two-photon decay could yield both even and odd CP final states at a ratio of oder of unity.

  10. Hidden sector dark matters and elusive Higgs boson(s) at the LHC

    SciTech Connect (OSTI)

    Ko, P.

    2012-07-27

    We consider two types of hidden sector dark matters (DM's), with and without QCD-like new strong interaction with confinement properties, and their interplays with the Standard Model (SM) Higgs boson. Assuming the hidden sector has only fermions (and gauge bosons in case of strongly interacting hidden sector), we have to introduce a real singlet scalar boson S as a messenger between the SM and the hidden sector dark matters. This singlet scalar will mix with the SM Higgs boson h, and we expect there are two Higgs-like scalar bosons H{sub 1} and H{sub 2}. Imposing all the relevant constraints from collider search bounds on Higgs boson, DM scattering cross section on proton and thermal relic density, we find that one of the two Higgs-like scalar bosons can easily escape the detections at the LHC. Recent results on the Higgs-like new boson with mass around with 125 GeV from the LHC will constrain this class of models, which is left for future study.

  11. Higgs boson searches at the Tevatron

    E-Print Network [OSTI]

    Ben Kilminster

    2010-12-10

    We present combined CDF and D0 searches for the Standard Model (SM) and Minimal Supersymmetric Standard Model (MSSM) Higgs boson using up to 6.7 fb$^{-1}$ of integrated luminosity from 1.96 TeV proton-antiproton collisions at the Tevatron. Specialized searches for Higgs bosons produced via gluon fusion, associated boson production, and vector boson fusion, decaying to $b\\bar{b}$, $W^{+}W^{-}$, $\\tau^{+}\\tau^{-}$, and $\\gamma\\gamma$ are combined to produce 95\\% CL upper limits on SM Higgs production as a function of mass. Current Tevatron limits are shown, including a new exclusion for SM Higgs masses between 158 and 175 GeV$/c^2$. We also present prospects for future sensitivity.

  12. The future of the Higgs boson

    SciTech Connect (OSTI)

    Lykken, Joseph; Spiropulu, Maria

    2013-12-15

    Experimentalists and theorists are still celebrating the Nobel-worthy discovery of the Higgs boson that was announced in July 2012 at CERN’s Large Hadron Collider. Now they are working on the profound implications of that discovery.

  13. Standard Model Higgs Boson Combination at the Tevatron

    E-Print Network [OSTI]

    Wei-Ming Yao for the CDF; D0 Collaborations

    2012-01-24

    We present the recent results from combinations of searches for a standard model (SM) Higgs boson ($H$) by the CDF and D0 experiments at the Tevatron $p\\bar p$ collider at $\\sqrt{s}=1.96$ TeV. The data correspond to an integrated total luminosity of 8.2 (CDF) and 8.6 (D0) fb$^{-1}$. Compared to the previous Tevatron Higgs boson search combination more data have been added, additional channels have been added, and some previously used channels have been reanalyzed to gain sensitivity. No excess is observed above background expectation, and set 95% C.L. upper limits (median expected) on Higgs boson production at factors of 1.17 (1.16), 1.71 (1.16), and 0.48(0.57) times the SM predictions for Higgs bosons of mass $m_H$=115, 140, and 165 GeV/c$^2$, respectively. We exclude a standard-model Higgs boson in the mass range 156--177 GeV/c$^2$ at the 95% C.L, with an expected exclusion region 148--180 GeV/c$^2$. The absence of a Higgs boson signal also constrains some new physics such as $4^{th}$ generation models and other exotic models.

  14. Upper and lower Higgs boson mass bounds from a chirally invariant lattice Higgs-Yukawa model

    E-Print Network [OSTI]

    Upper and lower Higgs boson mass bounds from a chirally invariant lattice Higgs-Yukawa model of the Standard Model Higgs boson based on first principle calculations, in par- ticular not relying on additional for the intended Higgs boson mass determination. These are the complex Higgs doublet as well as the top and bottom

  15. On the trail of the Higgs boson

    SciTech Connect (OSTI)

    Peskin, Michael E.

    2015-09-11

    I review theoretical issues associated with the Higgs boson and the mystery of spontaneous breaking of the electroweak gauge symmetry. In addition, this essay is intended as an introduction to the special issue of Annalen der Physik, “Particle Physics after the Higgs”.

  16. Vector Higgs bosons and possible suppression of flavorchanging neutral current

    E-Print Network [OSTI]

    Xiao Yu Qian

    2006-10-17

    We replace the scalar Higgs doublet with a vector Higgs boson doublet to the unified electroweak W-S model and find most of important features of W-S model are kept unchanged only the Higgs boson now become vector bosons. Lorentz invariance has been carefully discussed. The most important challenge is there will be three massless vector Higgs bosons. The remarkable effect is the possible suppression of the flavorchanging neutral current compare to the multi-Higgs model.

  17. Higgs boson studies at the Tevatron

    E-Print Network [OSTI]

    Gomez-Ceballos, Guillelmo

    We combine searches by the CDF and D0 Collaborations for the standard model Higgs boson with mass in the range 90–200??GeV/c[superscript 2] produced in the gluon-gluon fusion, WH, ZH, t[¯ over t]H, and vector boson fusion ...

  18. Higgs boson studies at the Tevatron

    E-Print Network [OSTI]

    Baringer, Philip S.; Bean, Alice; Chen, G.; Clutter, Justace Randall; Wilson, Graham Wallace; Aaltonen, T.; Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.

    2013-11-27

    We combine searches by the CDF and D0 Collaborations for the standard model Higgs boson with mass in the range 90–200??GeV/c(2) produced in the gluon-gluon fusion, WH, ZH, tt-barH, and vector boson fusion processes, and decaying in the H?bb-bar, H...

  19. Search for an Invisibly Decaying Higgs Boson Produced via Vector Boson Fusion with ATLAS

    E-Print Network [OSTI]

    Bassalat, Ahmed; The ATLAS collaboration

    2015-01-01

    The recently discovered Higgs boson at a mass 125 GeV provides an excellent tool to probe beyond the Standard Model physics. Many extensions of the Standard Model predict the decay of the Higgs boson into weakly interacting or neutral particles which do not interact with the detector, that could be candidates for dark matter. Using proton-proton collision data collected by the ATLAS detector during Run 1, searches have been performed for an invisibly decaying Higgs boson in three production channels: via vector boson fusion (VBF). An upper bound of 0.28 is set on the branching fraction of H -> invisible at 95% confidence level, where the expected upper limit is 0.31. The results are interpreted in models of Higgs-portal dark matter and of supersymmetry with a compressed mass spectrum.

  20. Search for the Higgs boson in the all-hadronic final state using the full CDF data set

    E-Print Network [OSTI]

    Gomez-Ceballos, Guillelmo

    This paper reports the result of a search for the standard model Higgs boson in events containing four reconstructed jets associated with quarks. For masses below 135 GeV/c [superscript 2], the Higgs boson decays to ...

  1. Dilaton as the Higgs boson

    E-Print Network [OSTI]

    Robert Foot; Archil Kobakhidze; Kristian L. McDonald

    2009-03-01

    We propose a model where the role of the electroweak Higgs field is played by the dilaton. The model contains terms which explicitly violate gauge invariance, however it is shown that this violation is fictitious, so that the model is a consistent low energy effective theory. In the simplest version of the idea the resulting low energy effective theory is the same as the top mode standard model.

  2. Searches for invisible Higgs boson decays with ATLAS and CMS

    E-Print Network [OSTI]

    Calfayan, Philippe; The ATLAS collaboration

    2015-01-01

    The ATLAS and CMS experiments carried out searches for invisible decays of the Higgs boson. The analyses have been led in final states with missing energy in the transverse plane of the detector, in the case of typical signatures where the Higgs boson is produced in association with an electroweak vector boson, or via gluon-gluon or vector boson fusion. Upper bounds on the branching fraction of a Higgs boson decaying to invisible particles have been derived as function of the assumed mass of the Higgs boson. Additional interpretations have been considered in the context of Higgs-portal models, which resulted in constraints on the production of Dark Matter candidates. The searches are based on the complete datasets from the Run-1 of the Large Hadron Collider, which includes proton-proton collision at a center-of-mass energy of $\\sqrt{s}=7$ or $8\\,\\mathrm{TeV}$, with up to $20\\,\\mathrm{fb}^{-1}$ of integrated luminosity.

  3. Recent Higgs results from the ATLAS experiment

    SciTech Connect (OSTI)

    Brendlinger, Kurt; Collaboration: ATLAS Collaboration

    2014-06-24

    This paper presents recent results on the Higgs boson from the ATLAS experiment at the Large Hadron Collider. The Collaboration reports on measurements of the signal strength, couplings, and spin of the Higgs in several decay channels. We find all measurements to be consistent with Standard Model predictions. The Higgs branching fraction to invisible particles is constrained and no evidence of physics beyond the Standard Model is found.

  4. Comparison of LHC and ILC Capabilities for Higgs Boson Coupling

    Office of Scientific and Technical Information (OSTI)

    LHC and ILC Capabilities for Higgs Boson Coupling Measurements Peskin, Michael E.; SLAC 43 PARTICLE ACCELERATORS; ACCURACY; BOSONS; COUPLING CONSTANTS; DECOUPLING; FERMIONS;...

  5. Measurements of the properties of the Higgs boson using the ATLAS Detector

    E-Print Network [OSTI]

    Queitsch-maitland, Michaela; The ATLAS collaboration

    2015-01-01

    A review of Run 1 results on the mass, spin CP properties, and differential cross section  measurements of the Higgs boson using the ATLAS detector will be presented.

  6. QCD effects in Higgs boson production at hadron colliders

    E-Print Network [OSTI]

    M. Grazzini

    2010-01-21

    We present updated predictions for Higgs boson production at the Tevatron and the LHC and we review their corresponding uncertainties. We report on a study of the impact of QCD radiative corrections on the Higgs boson search at the Tevatron.

  7. Direct Discovery Prospects for the Light CP-odd Higgs Boson of NMSSM Ideal Higgs Scenarios

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Direct Discovery Prospects for the Light CP-odd Higgs Boson of NMSSM Ideal Higgs Scenarios Jack on the following papers with R. Dermisek: · New constraints on a light CP-odd Higgs boson and related NMSSM Ideal CP-odd Higgs boson at the Tevatron and LHC. Published in Phys.Rev.D81:055001,2010, arXiv:0911

  8. Constraints on new phenomena via Higgs boson couplings and invisible decays with the ATLAS detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aad, G.

    2015-11-30

    The ATLAS experiment at the LHC has measured the Higgs boson couplings and mass, and searched for invisible Higgs boson decays, using multiple production and decay channels with up to 4.7 fb-1 of pp collision data at ?s=7 TeV and 20.3 fb-1 at ?s=8 TeV. In the current study, the measured production and decay rates of the observed Higgs boson in the ??, ZZ, W W , Z?, bb, ? ? , and ?? decay channels, along with results from the associated production of a Higgs boson with a top-quark pair, are used to probe the scaling of the couplingsmore »with mass. The limits are set on parameters in extensions of the Standard Model including a composite Higgs boson, an additional electroweak singlet, and two-Higgs-doublet models. Together with the measured mass of the scalar Higgs boson in the ?? and ZZ decay modes, a lower limit is set on the pseudoscalar Higgs boson mass of m A > 370 GeV in the “hMSSM” simplified Minimal Supersymmetric Standard Model. Results from direct searches for heavy Higgs bosons are also interpreted in the hMSSM. Finally, direct searches for invisible Higgs boson decays in the vector-boson fusion and associated production of a Higgs boson with W/Z (Z ? ??, W/Z ? jj) modes are statistically combined to set an upper limit on the Higgs boson invisible branching ratio of 0.25. As a result, the use of the measured visible decay rates in a more general coupling fit improves the upper limit to 0.23, constraining a Higgs portal model of dark matter.« less

  9. Constraints on new phenomena via Higgs boson couplings and invisible decays with the ATLAS detector

    SciTech Connect (OSTI)

    Aad, G.

    2015-11-30

    The ATLAS experiment at the LHC has measured the Higgs boson couplings and mass, and searched for invisible Higgs boson decays, using multiple production and decay channels with up to 4.7 fb-1 of pp collision data at ?s=7 TeV and 20.3 fb-1 at ?s=8 TeV. In the current study, the measured production and decay rates of the observed Higgs boson in the ??, ZZ, W W , Z?, bb, ? ? , and ?? decay channels, along with results from the associated production of a Higgs boson with a top-quark pair, are used to probe the scaling of the couplings with mass. The limits are set on parameters in extensions of the Standard Model including a composite Higgs boson, an additional electroweak singlet, and two-Higgs-doublet models. Together with the measured mass of the scalar Higgs boson in the ?? and ZZ decay modes, a lower limit is set on the pseudoscalar Higgs boson mass of m A > 370 GeV in the “hMSSM” simplified Minimal Supersymmetric Standard Model. Results from direct searches for heavy Higgs bosons are also interpreted in the hMSSM. Finally, direct searches for invisible Higgs boson decays in the vector-boson fusion and associated production of a Higgs boson with W/Z (Z ? ??, W/Z ? jj) modes are statistically combined to set an upper limit on the Higgs boson invisible branching ratio of 0.25. As a result, the use of the measured visible decay rates in a more general coupling fit improves the upper limit to 0.23, constraining a Higgs portal model of dark matter.

  10. LCPHSM2001054 Measurement of the Higgs Boson Mass

    E-Print Network [OSTI]

    LC­PHSM­2001­054 Measurement of the Higgs Boson Mass and Cross Section with a Linear e + e \\Gamma for the measurement of the Higgs boson mass and produc­ tion cross section. An integrated luminosity of 500 fb \\Gamma1 is assumed. For Higgs boson masses of 120, 150 and 180 GeV the uncertainty on the Higgs boson mass

  11. Unparticle Effects on Unitarity Constraints from Higgs Boson Scattering

    E-Print Network [OSTI]

    Xiao-Gang He; Chung-Cheng Wen

    2008-06-10

    We study the effects of two-body Higgs boson scattering by exchanging unpsrticles. The unparticle contribution can change the standard model prediction for two-body Higgs boson scattering partial wave amplitude significantly leading to modification of the unitarity constraint on the standard model Higgs boson mass. For unparticle dimension $d_\\U$ between 1 and 2, the unitarity constraint on Higgs boson mass can be larger than that in the SM. Information on unparticle interaction can also be obtained.

  12. Tools for charged Higgs bosons

    E-Print Network [OSTI]

    Oscar Stål

    2010-12-13

    We review the status of publicly available software tools applicable to charged Higgs physics. A selection of codes are highlighted in more detail, focusing on new developments that have taken place since the previous charged Higgs workshop in 2008. We conclude that phenomenologists now have the tools ready to face the LHC data. A new webpage collecting charged Higgs resources is presented.

  13. Constraints on new phenomena via Higgs boson couplings and invisible decays with the ATLAS detector

    E-Print Network [OSTI]

    ATLAS Collaboration

    2015-09-02

    The ATLAS experiment at the LHC has measured the Higgs boson couplings and mass, and searched for invisible Higgs boson decays, using multiple production and decay channels with up to 4.7 fb$^{-1}$ of $pp$ collision data at $\\sqrt{s}=7$ TeV and 20.3 fb$^{-1}$ at $\\sqrt{s}=8$ TeV. In the current study, the measured production and decay rates of the observed Higgs boson in the $\\gamma\\gamma$, $ZZ$, $WW$, $Z\\gamma$, $bb$, $\\tau\\tau$, and $\\mu\\mu$ decay channels, along with results from the associated production of a Higgs boson with a top-quark pair, are used to probe the scaling of the couplings with mass. Limits are set on parameters in extensions of the Standard Model including a composite Higgs boson, an additional electroweak singlet, and two-Higgs-doublet models. Together with the measured mass of the scalar Higgs boson in the $\\gamma\\gamma$ and $ZZ$ decay modes, a lower limit is set on the pseudoscalar Higgs boson mass of $m_{A}>370$ GeV in the "hMSSM" simplified Minimal Supersymmetric Standard Model. Results from direct searches for heavy Higgs bosons are also interpreted in the hMSSM. Direct searches for invisible Higgs boson decays in the vector-boson fusion and associated production of a Higgs boson with $W/Z$ ($Z\\to ll$, $W/Z \\to jj$) modes are statistically combined to set an upper limit on the Higgs boson invisible branching ratio of 0.25. The use of the measured visible decay rates in a more general coupling fit improves the upper limit to 0.23, constraining a Higgs portal model of dark matter.

  14. SEARCHING FOR HIGGS BOSONS AND NEW PHYSICS AT HADRON COLLIDERS

    SciTech Connect (OSTI)

    Chung Kao

    2007-09-05

    The objectives of research activities in particle theory are predicting the production cross section and decay branching fractions of Higgs bosons and new particles at hadron colliders, developing techniques and computer software to discover these particles and to measure their properties, and searching for new phenomena and new interactions at the Fermilab Tevatron and the CERN Large Hadron Collider. The results of our project could lead to the discovery of Higgs bosons, new particles, and signatures for new physics, or we will be able to set meaningful limits on important parameters in particle physics. We investigated the the prospects for the discovery at the CERN Large Hadron Collider of Higgs bosons and supersymmetric particles. Promising results are found for the CP-odd pseudoscalar ($A^0$) and the heavier CP-even scalar ($H^0$) Higgs bosons with masses up to 800 GeV. Furthermore, we study properties of the lightest neutralino ($\\chi^0$) and calculate its cosmological relic density in a supersymmetric $U(1)'$ model as well as the muon anomalous magnetic moment $a_\\mu = (g_\\mu - 2)/2$ in a supersymmetric $U(1)'$ model. We found that there are regions of the parameter space that can explain the experimental deviation of $a_\\mu$ from the Standard Model calculation and yield an acceptable cold dark matter relic density without conflict with collider experimental constraints. % Recently, we presented a complete next-to-leading order (NLO) calculation for the total cross section of inclusive Higgs pair production via bottom-quark fusion ($b\\bar{b} \\to hh$) at the CERN Large Hadron Collider (LHC) in the Standard Model and the minimal supersymmetric model. We plan to predict the Higgs pair production rate and to study the trilinear coupling among the Higgs bosons. % In addition, we have made significant contributions in B physics, single top production, charged Higgs search at the Fermilab as well as in grid computing for both D0 and ATLAS.

  15. arXiv:hep-ph/9801422v128Jan1998 Bounds on the Standard Higgs Boson1

    E-Print Network [OSTI]

    Lath, Amitabh

    arXiv:hep-ph/9801422v128Jan1998 UPR­791­T Bounds on the Standard Higgs Boson1 Jens Erler and Paul on the extraction of the Higgs boson mass. Global fit results depend strongly on the used value for the hadronic (SM) were mainly focussed on constraining its mass, mt, while the Higgs boson mass, MH , was fixed

  16. Methods for Higgs boson production at N$^3$LO

    E-Print Network [OSTI]

    Hoff, Jens

    2015-01-01

    We discuss methods for the calculation of the total partonic Higgs boson production cross section via gluon fusion and the result for the contribution that stems from two quarks of different flavor in the initial state. Our calculation is exact in the Higgs boson mass and the partonic center-of-mass energy. The result is expressed in terms of iterated integrals, some of which are Harmonic Polylogarithms, whereas others are new iterated integrals. We comment on the methods relevant for the reduction to scalar integrals and new types of function that appear in the final result.

  17. BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT

    E-Print Network [OSTI]

    BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT A.RASPEREZA DESY, Notkestrasse 85, D­22607#erential luminosity spectrum measurements and beam energy spread on the precision of the Higgs boson mass measurement possible impact of the beam related systematic errors on the Higgs boson mass measurement is discussed

  18. BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT

    E-Print Network [OSTI]

    BEAM RELATED SYSTEMATICS IN HIGGS BOSON MASS MEASUREMENT A.RASPEREZA DESY, Notkestrasse 85, D-22607 and differential luminosity spectrum measurements and beam energy spread on the precision of the Higgs boson mass such as Higgs boson mass, decay branching fractions and production rate. However, most of these studies did

  19. LCPHSM2001055 Determination of the Higgs boson spin

    E-Print Network [OSTI]

    LC­PHSM­2001­055 Determination of the Higgs boson spin with a Linear e + e \\Gamma Collider M of a light Higgs boson is studied at threshold and compared to the expectation of several spin as­ sumptions luminosity of 20 fb \\Gamma1 allow confirmation of the scalar nature of the Higgs Boson. INTRODUCTION

  20. Standard and non standard ideas for the Higgs boson sector

    E-Print Network [OSTI]

    Abbondandolo, Alberto

    Standard and non standard ideas for the Higgs boson sector Riccardo Barbieri Johns Hopkins Workshop as the Higgs boson is in their low-energy spectrum We only know of approximate symmetries that can explain synoptic table Supersymmetric The SM Higgs boson TC-like Minimally extended Higgsless "Composite" 5

  1. Higgs Boson Digest and Discussion By Tony O'Hagan

    E-Print Network [OSTI]

    O'Hagan, Tony

    Higgs Boson ­ Digest and Discussion By Tony O'Hagan Introduction On July 10th 2012, I posted to consult this list in search of answers. We've heard a lot about the Higgs boson. The news reports say like (in the sense of having some of the right characteristics of) the elusive Higgs boson

  2. Homing in on the Higgs Boson Howard E. Haber

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Homing in on the Higgs Boson Howard E. Haber SPS Meeting at UCSC June 7, 2012 References: H.E. Haber, Viewpoint: Homing in on the Higgs Boson, Physics 5, 32 (2012). For additional links, see my webpage: http://scipp.ucsc.edu/~haber/ #12;#12;Outline · The Higgs boson explained in 60 seconds

  3. Search for the pseudoscalar Higgs boson "A" of two Higgs doublet models (2HDM) with the ATLAS detector

    E-Print Network [OSTI]

    Bauce, Matteo; The ATLAS collaboration

    2015-01-01

    We search for the pseudoscalar Higgs boson A of 2HDMs in the decay modes A-> tautau and A->Zh. In the latter case, h is the lightest neutral scalar Higgs boson and is assumed to be the newly discovered 125 GeV particle. The results are interpreted in the context of 2HDMs and the Minimal Supersymmetric Standard Model (MSSM).

  4. Discovery of the Higgs Boson, Measurements of its Production, and

    E-Print Network [OSTI]

    Discovery of the Higgs Boson, Measurements of its Production, and a Search for Higgs Boson Pair (UPenn) ATLAS Run I h February 18, 2015 3 / 9 #12;Higgs Discovery!! Saxon (UPenn) ATLAS Run I h / 9 #12;Differential Cross Sections Saxon (UPenn) ATLAS Run I h February 18, 2015 6 / 9 #12;Higgs

  5. Measurement of the properties of the Higgs boson at ATLAS

    SciTech Connect (OSTI)

    Bristow, Timothy; Collaboration: ATLAS Collaboration

    2014-03-05

    An update on the Higgs boson search in the decay channels H???, H?ZZ{sup (*)}?4l, H?WW{sup (*)}?lvlv, H??{sup +}?{sup ?} and H?bb{sup ¯} at the ATLAS detector is presented. Proton-proton collision data recorded by the ATLAS experiment corresponding to an integrated luminosity of up to 25/fb at centre-of-mass energies of 7 and 8 TeV are used for these results. The latest combined and individual channel measurements of the mass, signal strength, spin and parity, coupling constants and Higgs boson production are reported. Results on the measurements of the properties of the Higgs boson are all consistent with the Standard Model.

  6. Combined search for the Higgs boson with the D0 experiment

    E-Print Network [OSTI]

    D0 Collaboration

    2013-09-20

    We perform a combination of searches for standard model Higgs boson production in $p\\bar{p}$ collisions recorded by the D0 detector at the Fermilab Tevatron Collider at a center of mass energy of $\\sqrt{s}=1.96$ TeV. The different production and decay channels have been analyzed separately, with integrated luminosities of up to 9.7 fb$^{-1}$ and for Higgs boson masses $90\\leq M_H \\leq 200$ GeV. We combine these final states to achieve optimal sensitivity to the production of the Higgs boson. We also interpret the combination in terms of models with a fourth generation of fermions, and models with suppressed Higgs boson couplings to fermions. The result excludes a standard model Higgs boson at 95% C.L. in the ranges $90 Higgs boson of mass 125 GeV.

  7. High Mass Higgs Boson Searches at the Tevatron

    E-Print Network [OSTI]

    Bjoern Penning

    2010-12-02

    We present results from CDF and D0 on direct searches for high mass standard model (SM) Higgs boson (H) in ppbar collisions at the Fermilab Tevatron at \\sqrt(s) = 1.96 TeV. Compared to previous Higgs boson Tevatron combinations, more data and new channels (H -> W+W- -> lnujj, H -> WW -> l+tau + X and trilepton final states) have been added. Most previously used channels have been reanalyzed to gain sensitivity. Analyzing 5.9 fb^-1 of data at CDF, and 5.4-6.7 fb^-1 at D0, the combination excludes with 95% C.L. a standard model Higgs boson in the mass range of m_H = 158-175 GeV/c2.

  8. WORK PROJECT REPORT Search for degenerate Higgs bosons

    E-Print Network [OSTI]

    Heikkilae, Jaana Kristiina

    2013-01-01

    Degenerate Higgs bosons have been searched as a summer student project. The goal was to implement an algorithm which would help to understand if there could be two Higgs bosons with very similar masses from the matrix of measured signal strengths $(\\sigma\\cdot B)_\\mathrm{meas.}/(\\sigma\\cdot B)_\\mathrm{SM}$ in different final states. The statistical compatibility of the observed data with a matrix of rank 1 has been evaluated. Using CMS data from the $\\gamma\\gamma$ and $W^{+}W^{-}$ decay channels, a result compatible with a single Higgs boson at the level of 38% is obtained. A generalization of the algorithm to allow using all available data in the 5x4 signal strength matrix is also presented.

  9. Search for the Higgs boson in the ttH production channel using the ATLAS detector

    E-Print Network [OSTI]

    Bouffard, Julian; The ATLAS collaboration

    2015-01-01

    Since the discovery of a Higgs boson by the ATLAS and CMS experiments at the LHC, the emphasis has shifted towards measurements of its properties and the search for less sensitive channels in order to determine whether the new particle is the Standard Model (SM) Higgs boson. Of particular importance is the direct observation of the coupling of the Higgs boson to top quarks. In this talk a review of ATLAS results in the search for the Higgs boson in the ttH production mode.

  10. Composite Higgs Boson Pair Production at the LHC

    E-Print Network [OSTI]

    Ramona Grober; Margarete Muhlleitner

    2010-12-07

    The measurement of the trilinear and quartic Higgs self-couplings is necessary for the reconstruction of the Higgs potential. This way the Higgs mechanism as the origin of electroweak symmetry breaking can be tested. The couplings are accessible in multi-Higgs production processes at the LHC. In this paper we investigate the prospects of measuring the trilinear Higgs coupling in composite Higgs models. In these models, the Higgs boson emerges as a pseudo-Goldstone boson of a strongly interacting sector, and the Higgs potential is generated by loops of the Standard Model (SM) gauge bosons and fermions. The Higgs self-couplings are modified compared to the SM and controlled by the compositeness parameter $\\xi$ in addition to the Higgs boson mass. We construct areas of sensitivity to the trilinear Higgs coupling in the relevant parameter space for various final states.

  11. Lower Higgs boson mass bounds from a chirally invariant lattice Higgs-Yukawa model with overlap fermions

    E-Print Network [OSTI]

    P. Gerhold; K. Jansen

    2009-02-24

    We study the coupling parameter dependence of the Higgs boson mass in a chirally invariant lattice Higgs-Yukawa model emulating the same Yukawa coupling structure as in the Higgs-fermion sector of the Standard Model. Eventually, the aim is to establish non-perturbative upper and lower Higgs boson mass bounds derived from first principles, in particular not relying on vacuum stability considerations for the latter case. Here, we present our lattice results for the lower Higgs boson mass bound at several values of the cutoff and compare them to corresponding analytical calculations based on the effective potential as obtained from lattice perturbation theory. Furthermore, we give a brief outlook towards the calculation of the upper Higgs boson mass bound.

  12. Combined Higgs Boson Property Measurements using the ATLAS Detector

    E-Print Network [OSTI]

    Rados, Petar Kevin; The ATLAS collaboration

    2015-01-01

    The combined measurements of the properties of the Higgs boson using the ATLAS detector and up to 25 fb-1 of 7 TeV and 8 TeV pp collision data collected in 2011 and 2012, are discussed. The results are obtained combining all channels measured in run 1. They include the mass, strengths of production and decay modes, couplings to fermions and bosons, spin and CP properties.

  13. Stable Higgs Bosons - new candidate for cold dark matter -

    E-Print Network [OSTI]

    Yutaka Hosotani

    2010-03-31

    The Higgs boson is in the backbone of the standard model of electroweak interactions. It must exist in some form for achieving unification of interactions. In the gauge-Higgs unification scenario the Higgs boson becomes a part of the extra-dimensional component of gauge fields. The Higgs boson becomes absolutely stable in a class of the gauge-Higgs unification models, serving as a promising candidate for cold dark matter in the universe. The observed relic abundance of cold dark matter is obtained with the Higgs mass around 70 GeV. The Higgs-nucleon scattering cross section is found to be close to the recent CDMS II and XENON10 bounds in the direct detection of dark matter. In collider experiments stable Higgs bosons are produced in a pair, appearing as missing energies and momenta so that the way of detecting Higgs bosons must be altered.

  14. Unraveling the Higgs Boson Discovery - Rik Yoshida

    SciTech Connect (OSTI)

    Rik Yoshida

    2012-10-02

    Argonne physicist Rik Yoshida explains what the Higgs boson is and what its discovery means for physics, the universe, and life. The third of Argonne's "OutLoud" public lecture series, held at the lab on September 27, 2012. Find out when the next one is at http://www.anl.gov/community/outloud

  15. Unraveling the Higgs Boson Discovery - Rik Yoshida

    ScienceCinema (OSTI)

    Rik Yoshida

    2013-06-06

    Argonne physicist Rik Yoshida explains what the Higgs boson is and what its discovery means for physics, the universe, and life. The third of Argonne's "OutLoud" public lecture series, held at the lab on September 27, 2012. Find out when the next one is at http://www.anl.gov/community/outloud

  16. The Higgs boson: from the lattice to LHC

    E-Print Network [OSTI]

    Paolo Cea; Leonardo Cosmai

    2011-11-09

    We discuss the triviality and spontaneous symmetry breaking scenario where the Higgs boson without self-interaction coexists with spontaneous symmetry breaking. We argue that non perturbative lattice investigations support this scenario. Moreover, from lattice simulations we predict that the Higgs boson is rather heavy. We estimate the Higgs boson mass $m_H = 754 \\pm 20 {\\text{(stat)}} \\pm 20 {\\text{(syst)}} {\\text{GeV}}$ and the Higgs total width $\\Gamma(H) \\simeq 340 {\\text{GeV}}$.

  17. Ian Hinchliffe Answers Your Higgs Boson Questions

    SciTech Connect (OSTI)

    Hinchliffe, Ian

    2012-01-01

    contingent with the ATLAS experiment at CERN, answers many of your questions about the Higgs boson. Ian invited viewers to send in questions about the Higgs via email, Twitter, Facebook, or YouTube in an "Ask a Scientist" video posted July 3: http://youtu.be/xhuA3wCg06s CERN's July 4 announcement that the ATLAS and CMS experiments at the Large Hadron Collider have discovered a particle "consistent with the Higgs boson" has raised questions about what scientists have found and what still remains to be found -- and what it all means. If you have suggestions for future "Ask a Scientist" videos, post them below or send ideas to askascientist@lbl.gov

  18. Ian Hinchliffe Answers Your Higgs Boson Questions

    ScienceCinema (OSTI)

    Hinchliffe, Ian

    2013-05-29

    contingent with the ATLAS experiment at CERN, answers many of your questions about the Higgs boson. Ian invited viewers to send in questions about the Higgs via email, Twitter, Facebook, or YouTube in an "Ask a Scientist" video posted July 3: http://youtu.be/xhuA3wCg06s CERN's July 4 announcement that the ATLAS and CMS experiments at the Large Hadron Collider have discovered a particle "consistent with the Higgs boson" has raised questions about what scientists have found and what still remains to be found -- and what it all means. If you have suggestions for future "Ask a Scientist" videos, post them below or send ideas to askascientist@lbl.gov

  19. Search for Heavy Neutral MSSM Higgs Bosons with CMS: Reach and Higgs-Mass Precision

    E-Print Network [OSTI]

    S. Gennai; S. Heinemeyer; A. Kalinowski; R. Kinnunen; S. Lethi; A. Nikitenko; G. Weiglein

    2007-04-04

    The search for MSSM Higgs bosons will be an important goal at the LHC. We analyze the search reach of the CMS experiment for the heavy neutral MSSM Higgs bosons with an integrated luminosity of 30 or 60 fb^-1. This is done by combining the latest results for the CMS experimental sensitivities based on full simulation studies with state-of-the-art theoretical predictions of MSSM Higgs-boson properties. The results are interpreted in MSSM benchmark scenarios in terms of the parameters tan_beta and the Higgs-boson mass scale, M_A. We study the dependence of the 5 sigma discovery contours in the M_A-tan_beta plane on variations of the other supersymmetric parameters. The largest effects arise from a change in the higgsino mass parameter mu, which enters both via higher-order radiative corrections and via the kinematics of Higgs decays into supersymmetric particles. While the variation of $\\mu$ can shift the prospective discovery reach (and correspondingly the ``LHC wedge'' region) by about Delta tan_beta = 10, we find that the discovery reach is rather stable with respect to the impact of other supersymmetric parameters. Within the discovery region we analyze the accuracy with which the masses of the heavy neutral Higgs bosons can be determined. We find that an accuracy of 1-4% should be achievable, which could make it possible in favourable regions of the MSSM parameter space to experimentally resolve the signals of the two heavy MSSM Higgs bosons at the LHC.

  20. Supersymmetric Higgs Bosons and Beyond

    SciTech Connect (OSTI)

    Carena, Marcela; Kong, Kyoungchul; Ponton, Eduardo; Zurita, Jose; /Fermilab /Buenos Aires U.

    2010-08-26

    We consider supersymmetric models that include particles beyond the Minimal Supersymmetric Standard Model (MSSM) with masses in the TeV range, and that couple significantly to the MSSM Higgs sector. We perform a model-independent analysis of the spectrum and couplings of the MSSM Higgs fields, based on an effective theory of the MSSM degrees of freedom. The tree-level mass of the lightest CP-even state can easily be above the LEP bound of 114 GeV, thus allowing for a relatively light spectrum of superpartners, restricted only by direct searches. The Higgs spectrum and couplings can be significantly modified compared to the MSSM ones, often allowing for interesting new decay modes. We also observe that the gluon fusion production cross section of the SM-like Higgs can be enhanced with respect to both the Standard Model and the MSSM.

  1. What if Superluminal Neutrinos Exist but not Higgs Bosons?

    E-Print Network [OSTI]

    Burra G. Sidharth

    2015-02-23

    As 2011 ended, two results stood out which seemed to go against twentieth century ideas. The first was the OPERA superluminal neutrino observation contradicting Special Relativity. The second was lack of a definitive appearance of the Higgs Boson. While both these hopefully will be decided by the end of 2012, we investigate a single mechanism that explains both these anomalies.

  2. Searches for Beyond SM Higgs Boson at the Tevatron

    SciTech Connect (OSTI)

    Safonov, A.; /Texas A-M

    2006-05-01

    In the following, the authors describe preliminary results of searches for non-SM higgs bosons at the CDF and D0 experiments. Both experiments use data obtained in p{bar p} collisions at the Tevatron at {radical}s = 1.96 TeV.

  3. Upper and lower Higgs boson mass bounds from a lattice Higgs-Yukawa model with dynamical overlap fermions

    E-Print Network [OSTI]

    P. Gerhold; K. Jansen

    2009-12-02

    We study a lattice Higgs-Yukawa model emulating the same Higgs-fermion coupling structure as in the Higgs sector of the electroweak Standard Model, in particular, obeying a Ginsparg-Wilson version of the underlying SU(2) x U(1) symmetry, being a global symmetry here due to the neglection of gauge fields in this model. In this paper we present our results on the cutoff-dependent upper Higgs boson mass bound at several selected values of the cutoff parameter.

  4. The Importance of Silicon Detectors for the Higgs Boson Discovery and the Study of its Properties

    E-Print Network [OSTI]

    Bortoletto, D

    2015-01-01

    Recent studies are presented demonstrating the important role played by silicon detectors in the the discovery of the Higgs boson. CMS is planning to replace its in an extended technical stop of the LHC in the winter of 2016 . We present results showing that this replacement will significant increase the sample of Higgs bosons that will be reconstructed enabling precision studies of this particle.

  5. D0 Search for the Higgs Boson in Multijet Events

    E-Print Network [OSTI]

    Alex Melnitchouk; for the D0 Collaboration

    2006-01-24

    We present two searches for the Higgs boson in \\sqrt{s} = 1.96 TeV p\\bar{p}collisions using data taken with the \\dz detector during Run II of the Fermilab Tevatron collider. The first study is a search for neutral Higgs bosons produced in association with bottom quarks. We set upper limits on the production of neutral Higgs bosons in the mass range of 90 to 150 GeV.The second study is a search for the standard model Higgs boson produced in association with the Z boson. We study the p\\bar{p}\\to ZH \\to \

  6. The LHC Higgs Boson Discovery: Implications for Finite Unified Theories

    E-Print Network [OSTI]

    S. Heinemeyer; M. Mondragon; G. Zoupanos

    2014-12-18

    Finite Unified Theories (FUTs) are N = 1 supersymmetric Grand Unified Theories (GUTs) which can be made finite to all-loop orders, based on the principle of reduction of couplings, and therefore are provided with a large predictive power. We confront the predictions of an SU(5) FUT with the top and bottom quark masses and other low-energy experimental constraints, resulting in a relatively heavy SUSY spectrum, naturally consistent with the non-observation of those particles at the LHC. The light Higgs boson mass is automatically predicted in the range compatible with the Higgs discovery at the LHC. Requiring a light Higgs-boson mass in the precise range of M_h = 125.6 +- 2.1 GeV favors the lower part of the allowed spectrum, resulting in clear predictions for the discovery potential at current and future pp, as well as future e+e- colliders.

  7. Vacuum Stability and the Higgs Boson

    E-Print Network [OSTI]

    Jose R. Espinosa

    2013-11-08

    The discovery of the Higgs boson at the LHC, and especially the determination of its mass around 125 GeV, together with the absence of any trace of new physics make it conceivable that we live in a metastable (but long-lived) electroweak vacuum. I will describe the state-of-the-art calculation that leads to this conclusion, elaborate on possible implications as well as cures of this instability of the Higgs potential and discuss some possible lines of attack for lattice studies of such metastability.

  8. Search for Heavy Neutral MSSM Higgs Bosons with CMS: Reach and Higgs-Mass Precision

    E-Print Network [OSTI]

    Gennai, S; Kalinowski, A; Kinnunen, R; Lethi, S; Nikitenko, A; Weiglein, G

    2007-01-01

    The search for MSSM Higgs bosons will be an important goal at the LHC. We analyze the search reach of the CMS experiment for the heavy neutral MSSM Higgs bosons with an integrated luminosity of 30 or 60 fb^-1. This is done by combining the latest results for the CMS experimental sensitivities based on full simulation studies with state-of-the-art theoretical predictions of MSSM Higgs-boson properties. The results are interpreted in MSSM benchmark scenarios in terms of the parameters tan_beta and the Higgs-boson mass scale, M_A. We study the dependence of the 5 sigma discovery contours in the M_A-tan_beta plane on variations of the other supersymmetric parameters. The largest effects arise from a change in the higgsino mass parameter mu, which enters both via higher-order radiative corrections and via the kinematics of Higgs decays into supersymmetric particles. While the variation of $\\mu$ can shift the prospective discovery reach (and correspondingly the ``LHC wedge'' region) by about Delta tan_beta = 10, we...

  9. Searches for the Standard Model Higgs Boson at CMS

    E-Print Network [OSTI]

    Marco Pieri; for the CMS Collaboration

    2012-05-13

    We searched for the standard model Higgs boson in many different channels using approximately 5 fb-1 of 7 TeV pp collisions data collected with the CMS detector at LHC. Combining the results of the different searches we exclude at 95% confidence level a standard model Higgs boson with mass between 127.5 and 600 GeV. The expected 95% confidence level exclusion if the Higgs boson is not present is from 114.5 and 543 GeV. The observed exclusion is weaker than expected at low mass because of some excess that is observed below about 128 GeV. The most significant excess is found at 125 GeV with a local significance of 2.8 sigma. It has a global significance of 0.8 sigma when evaluated in the full search range and of 2.1 sigma when evaluated in the range 110-145 GeV. The excess is consistent both with background fluctuation and a standard model Higgs boson with mass of about 125 GeV, and more data are needed to investigate its origin.

  10. Resummation of transverse energy in vector boson and Higgs boson production at hadron colliders

    E-Print Network [OSTI]

    Andreas Papaefstathiou; Jennifer M. Smillie; Bryan R. Webber

    2010-02-23

    We compute the resummed hadronic transverse energy (E_T) distribution due to initial-state QCD radiation in vector boson and Higgs boson production at hadron colliders. The resummed exponent, parton distributions and coefficient functions are treated consistently to next-to-leading order. The results are matched to fixed-order calculations at large E_T and compared with parton-shower Monte Carlo predictions at Tevatron and LHC energies.

  11. Lineshape of the Higgs boson in future lepton colliders

    E-Print Network [OSTI]

    Jadach, S

    2015-01-01

    The effect of the photon emission (bremsstrahlung) in the cross section of the process of direct production of the Higgs boson in the future high luminosity electron and muon colliders is calculated. It was found that cross section at the top of the Higgs boson resonance peak is reduced by factor 0.347 for the electron collider and 0.548 for the muon collider. Machine spread of the centre of the mass energy of 4.2MeV (equal to the Higgs width) would reduce peak cross section further, by factor 0.170 and 0.256 (QED and energy spread) for electron and muon beams respectively. Possible uncertainties in the resummed QED calculations are discussed. Numerical results for the lineshape cross section including QED and many values of the machine energy spread are provided.

  12. Measuring Resonance Parameters of Heavy Higgs Bosons at TESLA

    E-Print Network [OSTI]

    Niels Meyer

    2003-08-13

    This study investigates the potential of the TESLA Linear Collider for measuring resonance parameters of Higgs bosons beyond the mass range studied so far. The analysis is based on the reconstruction of events from the Higgsstrahlung process e+e- -> HZ. It is shown that the total width, the mass and the event rate for Higgs production can be measured from the mass spectrum in a model independent fit. Also, the branching ratios to W- and Z-bosons can be measured, assuming these are the only relevant Higgs decay modes. The simulation includes realistic detector effects and all relevant Standard Model background processes. Results are given for mH=200-320 GeV assuming 500 fb^-1 integrated luminosity at collision energies of 500 GeV.

  13. Large invisible decay of a Higgs boson to neutrinos

    E-Print Network [OSTI]

    Seto, Osamu

    2015-01-01

    We show that the standard model (SM)-like Higgs boson may decay into neutrinos with a sizable decay branching ratio in one well-known two Higgs doublet model, so-called neutrinophilic Higgs model. This could happen if the mass of the lighter extra neutral Higgs boson is smaller than one half of the SM-like Higgs boson mass. The definite prediction of this scenario is that the rate of the SM-like Higgs boson decay into diphoton normalized by the SM value is about 0.9. In the case that a neutrino is Majorana particle, a displaced vertex of right-handed neutrino decay would be additionally observed. This example indicates that a large invisible Higgs boson decay could be irrelevant to dark matter.

  14. Higgs Boson Searches at Hadron Colliders (1/4)

    ScienceCinema (OSTI)

    None

    2011-10-06

    In these Academic Training lectures, the phenomenology of Higgs bosons and search strategies at hadron colliders are discussed. After a brief introduction on Higgs bosons in the Standard Model and a discussion of present direct and indirect constraints on its mass the status of the theoretical cross section calculations for Higgs boson production at hadron colliders is reviewed. In the following lectures important experimental issues relevant for Higgs boson searches (trigger, measurements of leptons, jets and missing transverse energy) are presented. This is followed by a detailed discussion of the discovery potential for the Standard Model Higgs boson for both the Tevatron and the LHC experiments. In addition, various scenarios beyond the Standard Model, primarily the MSSM, are considered. Finally, the potential and strategies to measured Higgs boson parameters and the investigation of alternative symmetry breaking scenarios are addressed.

  15. Higgs Boson Searches at Hadron Colliders (1/4)

    SciTech Connect (OSTI)

    2010-06-21

    In these Academic Training lectures, the phenomenology of Higgs bosons and search strategies at hadron colliders are discussed. After a brief introduction on Higgs bosons in the Standard Model and a discussion of present direct and indirect constraints on its mass the status of the theoretical cross section calculations for Higgs boson production at hadron colliders is reviewed. In the following lectures important experimental issues relevant for Higgs boson searches (trigger, measurements of leptons, jets and missing transverse energy) are presented. This is followed by a detailed discussion of the discovery potential for the Standard Model Higgs boson for both the Tevatron and the LHC experiments. In addition, various scenarios beyond the Standard Model, primarily the MSSM, are considered. Finally, the potential and strategies to measured Higgs boson parameters and the investigation of alternative symmetry breaking scenarios are addressed.

  16. Discovery of a Higgs Boson in the H to ZZ to 4 leptons channel /

    E-Print Network [OSTI]

    Vartak, Adish Pradeep

    2014-01-01

    1.2 History of Higgs Boson Searches . . . . . . . . . . .Implications of a 125 GeV Higgs Boson 7.7 Concluding1.3.4 Higgs Boson Decays . . . . . . . . . . . . . . 1.3.5

  17. Higgs Boson Decays into Single Photon plus Unparticle

    E-Print Network [OSTI]

    Kingman Cheung; Chong Sheng Li; Tzu-Chiang Yuan

    2007-11-21

    The decay of the standard model Higgs boson into a single photon and a vector unparticle through a one-loop process is studied. For an intermediate mass Higgs boson, this single photon plus unparticle mode can have a branching ratio comparable with the two-photon discovery mode. The emitted photon has a continuous energy spectrum encoding the nature of the recoil unparticle. It can be measured in precision studies of the Higgs boson after its discovery.

  18. Monte Carlo Tools for charged Higgs boson production

    E-Print Network [OSTI]

    K. Kovarik

    2014-12-18

    In this short review we discuss two implementations of the charged Higgs boson production process in association with a top quark in Monte Carlo event generators at next-to-leading order in QCD. We introduce the MC@NLO and the POWHEG method of matching next-to-leading order matrix elements with parton showers and compare both methods analyzing the charged Higgs boson production process in association with a top quark. We shortly discuss the case of a light charged Higgs boson where the associated charged Higgs production interferes with the charged Higgs production via t tbar-production and subsequent decay of the top quark.

  19. Search for the Higgs boson in the all-hadronic final state using the CDF II detector

    E-Print Network [OSTI]

    CDF Collaboration

    2011-08-09

    We report on a search for the production of the Higgs boson decaying to two bottom quarks accompanied by two additional quarks. The data sample used corresponds to an integrated luminosity of approximately 4\\,\\invfb\\, of \\ppbar\\, collisions at $\\sqrt{s}=1.96$\\,TeV recorded by the CDF II experiment. This search includes twice the integrated luminosity of the previous published result, uses analysis techniques to distinguish jets originating from light flavor quarks and those from gluon radiation, and adds sensitivity to a Higgs boson produced by vector boson fusion. We find no evidence of the Higgs boson and place limits on the Higgs boson production cross section for Higgs boson masses between 100\\,\\gevcc\\, and 150\\,\\gevcc\\, at the 95% confidence level. For a Higgs boson mass of 120\\,\\gevcc\\, the observed (expected) limit is 10.5\\,(20.0) times the predicted Standard Model cross section.

  20. Top Partners and Higgs Boson Production

    E-Print Network [OSTI]

    Chien-Yi Chen; S. Dawson; I. M. Lewis

    2014-11-04

    The Higgs boson is produced at the LHC through gluon fusion at roughly the Standard Model rate. New colored fermions, which can contribute to $gg\\rightarrow h$, must have vector-like interactions in order not to be in conflict with the experimentally measured rate. We examine the size of the corrections to single and double Higgs production from heavy vector-like fermions in $SU(2)_L$ singlets and doublets and search for regions of parameter space where double Higgs production is enhanced relative to the Standard Model prediction. We compare production rates and distributions for double Higgs production from gluon fusion using an exact calculation, the low energy theorem (LET), where the top quark and the heavy vector-like fermions are taken to be infinitely massive, and an effective theory (EFT) where top mass effects are included exactly and the effects of the heavy fermions are included to ${\\cal O}(1/M^2_X)$. Unlike the LET, the EFT gives an extremely accurate description of the kinematic distributions for double Higgs production.

  1. Got Questions About the Higgs Boson? Ask a Scientist

    SciTech Connect (OSTI)

    Hinchliffe, Ian

    2012-01-01

    Ask a scientist about the Higgs boson. There's a lot of buzz this week over new data from CERN's Large Hadron Collider (LHC) and the final data from Fermilab's Tevatron about the Higgs boson. It raises questions about what scientists have found and what still remains to be found -- and what it all means. Berkeley Lab's Ian Hinchliffe invites you to send in questions about the Higgs. He'll answer a few of your questions in a follow-up video later this week. Hinchliffe is a theoretical physicist who heads Berkeley Lab's sizable contingent with the ATLAS experiment at CERN. • Post your questions in the comment box • E-mail your questions to askascientist@lbl.gov • Tweet to @BerkeleyLab • Or post on our facebook page: facebook/berkeleylab Update on July 5: Ian responds to several of your questions in this video: http://youtu.be/1BkpD1IS62g Update on 7/04: Here's CERN's press release from earlier today on the latest preliminary results in the search for the long sought Higgs particle: http://press.web.cern.ch/press/PressReleases/Releases2012/PR17.12E.htm And here's a Q&A on what the news tells us: http://cdsweb.cern.ch/journal/CERNBulletin/2012/28/News%20Articles/1459460?ln=en CERN will present the new LHC data at a seminar July 4th at 9:00 in the morning Geneva time (3:00 in the morning Eastern Daylight Time, midnight on the Pacific Coast), where the ATLAS collaboration and their rivals in the CMS experiment will announce their results. Tevatron results were announced by Fermilab on Monday morning. For more background on the LHC's search for the Higgs boson, visit http://newscenter.lbl.gov/feature-stories/2012/06/28/higgs-2012/.

  2. Got Questions About the Higgs Boson? Ask a Scientist

    ScienceCinema (OSTI)

    Hinchliffe, Ian

    2013-05-29

    Ask a scientist about the Higgs boson. There's a lot of buzz this week over new data from CERN's Large Hadron Collider (LHC) and the final data from Fermilab's Tevatron about the Higgs boson. It raises questions about what scientists have found and what still remains to be found -- and what it all means. Berkeley Lab's Ian Hinchliffe invites you to send in questions about the Higgs. He'll answer a few of your questions in a follow-up video later this week. Hinchliffe is a theoretical physicist who heads Berkeley Lab's sizable contingent with the ATLAS experiment at CERN. ? Post your questions in the comment box ? E-mail your questions to askascientist@lbl.gov ? Tweet to @BerkeleyLab ? Or post on our facebook page: facebook/berkeleylab Update on July 5: Ian responds to several of your questions in this video: http://youtu.be/1BkpD1IS62g Update on 7/04: Here's CERN's press release from earlier today on the latest preliminary results in the search for the long sought Higgs particle: http://press.web.cern.ch/press/PressReleases/Releases2012/PR17.12E.htm And here's a Q&A on what the news tells us: http://cdsweb.cern.ch/journal/CERNBulletin/2012/28/News%20Articles/1459460?ln=en CERN will present the new LHC data at a seminar July 4th at 9:00 in the morning Geneva time (3:00 in the morning Eastern Daylight Time, midnight on the Pacific Coast), where the ATLAS collaboration and their rivals in the CMS experiment will announce their results. Tevatron results were announced by Fermilab on Monday morning. For more background on the LHC's search for the Higgs boson, visit http://newscenter.lbl.gov/feature-stories/2012/06/28/higgs-2012/.

  3. Maximum Entropy Principle and the Higgs Boson Mass

    E-Print Network [OSTI]

    Alves, Alexandre; da Silva, Roberto

    2014-01-01

    A successful connection between Higgs boson decays and the Maximum Entropy Principle is presented. Based on the information theory inference approach we determine the Higgs boson mass as $M_H= 125.04\\pm 0.25$ GeV, a value fully compatible to the LHC measurement. This is straightforwardly obtained by taking the Higgs boson branching ratios as the target probability distributions of the inference, without any extra assumptions beyond the Standard Model. Yet, the principle can be a powerful tool in the construction of any model affecting the Higgs sector. We give, as an example, the case where the Higgs boson has an extra invisible decay channel. Our findings suggest that a system of Higgs bosons undergoing a collective decay to Standard Model particles is among the most fundamental ones where the Maximum Entropy Principle applies.

  4. Maximum Entropy Principle and the Higgs Boson Mass

    E-Print Network [OSTI]

    Alexandre Alves; Alex G. Dias; Roberto da Silva

    2014-11-18

    A successful connection between Higgs boson decays and the Maximum Entropy Principle is presented. Based on the information theory inference approach we determine the Higgs boson mass as $M_H= 125.04\\pm 0.25$ GeV, a value fully compatible to the LHC measurement. This is straightforwardly obtained by taking the Higgs boson branching ratios as the target probability distributions of the inference, without any extra assumptions beyond the Standard Model. Yet, the principle can be a powerful tool in the construction of any model affecting the Higgs sector. We give, as an example, the case where the Higgs boson has an extra invisible decay channel. Our findings suggest that a system of Higgs bosons undergoing a collective decay to Standard Model particles is among the most fundamental ones where the Maximum Entropy Principle applies.

  5. Constraints on new phenomena via Higgs boson couplings and invisible decays with the ATLAS detector

    E-Print Network [OSTI]

    Aad, Georges; Abdallah, Jalal; Abdinov, Ovsat; Aben, Rosemarie; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agricola, Johannes; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; ?lvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baak, Max; Baas, Alessandra; Baca, Matthew John; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Balunas, William Keaton; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansil, Hardeep Singh; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James Baker; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Kathrin; Becker, Maurice; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Janna Katharina; Belanger-Champagne, Camille; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernard, Nathan Rogers; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, Carolyn; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bevan, Adrian John; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Biedermann, Dustin; Bieniek, Stephen Paul; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello

    2015-01-01

    The ATLAS experiment at the LHC has measured the Higgs boson couplings and mass, and searched for invisible Higgs boson decays, using multiple production and decay channels with up to 4.7 fb$^{-1}$ of $pp$ collision data at $\\sqrt{s}=7$ TeV and 20.3 fb$^{-1}$ at $\\sqrt{s}=8$ TeV. In the current study, the measured production and decay rates of the observed Higgs boson in the $\\gamma\\gamma$, $ZZ$, $WW$, $Z\\gamma$, $bb$, $\\tau\\tau$, and $\\mu\\mu$ decay channels, along with results from the associated production of a Higgs boson with a top-quark pair, are used to probe the scaling of the couplings with mass. Limits are set on parameters in extensions of the Standard Model including a composite Higgs boson, an additional electroweak singlet, and two-Higgs-doublet models. Together with the measured mass of the scalar Higgs boson in the $\\gamma\\gamma$ and $ZZ$ decay modes, a lower limit is set on the pseudoscalar Higgs boson mass of $m_{A}>370$ GeV in the ``hMSSM'' simplified Minimal Supersymmetric Standard Model...

  6. Search for a pseudoscalar boson decaying into a Z boson and the 125 GeV Higgs boson in llbb final states

    E-Print Network [OSTI]

    CMS Collaboration

    2015-07-23

    Results are reported on a search for decays of a pseudoscalar A boson into a Z boson and a light scalar h boson, where the Z boson decays into a pair of oppositely-charged electrons or muons, and the h boson decays into b anti-b. The search is based on data from proton-proton collisions at a center-of-mass energy sqrt(s)=8 TeV collected with the CMS detector, corresponding to an integrated luminosity of 19.7 inverse femtobarns. The h boson is assumed to be the standard model-like Higgs boson with a mass of 125 GeV. With no evidence for signal, upper limits are obtained on the product of the production cross section and the branching fraction of the A boson in the Zh channel. Results are also interpreted in the context of two Higgs doublet models.

  7. Higgs and Z-boson Signatures of Supersymmetry

    E-Print Network [OSTI]

    Matchev, K T; Matchev, Konstantin T.; Thomas, Scott

    2000-01-01

    In supersymmetric theories of nature the Higgsino fermionic superpartner of the Higgs boson can arise as the lightest standard model superpartner depending on the couplings between the Higgs and supersymmetry breaking sectors. In this letter the production and decay of Higgsino pairs to the Goldstone fermion of supersymmetry breaking and the Higgs boson, h, or gauge bosons, $Z$ or $\\gamma$ are considered. Relatively clean di-boson final states, hh, $h \\gamma$, hZ, $Z channels provide novel discovery modes for supersymmetry at high energy colliders since events with Z bosons are generally rejected in supersymmetry searches. In addition, final states with real Higgs bosons can potentially provide efficient channels to discover and study a Higgs signal at the Fermilab Tevatron Run II.

  8. Light Higgs Bosons in NMSSM at the LHC

    E-Print Network [OSTI]

    Guchait, Monoranjan

    2015-01-01

    The next-to-minimal supersymmetric standard model (NMSSM) with an extended Higgs sector offers one of the Higgs boson as the Standard model (SM) like Higgs with a mass around 125 GeV along with other Higgs bosons with lighter and heavier masses and not excluded by any current experiments. At the LHC, phenomenology of these non SM like Higgs bosons is very rich and considerably different from the other supersymmetric models. In this work, assuming one of the Higgs bosons to be the SM like, we revisit the mass spectrum and couplings of non SM like Higgs bosons taking into consideration all existing constraints and identify the relevant region of parameter space. The discovery potential of these non SM like Higgs bosons, apart from their masses, is guided by their couplings with gauge bosons and fermions which are very much parameter space sensitive. We evaluate the rates of productions of these non SM like Higgs bosons at the LHC for a variety of decay channels in the allowed region of the parameter space. Alth...

  9. Searches for a high mass Standard Model Higgs boson at the Tevatron

    E-Print Network [OSTI]

    S. Pagan Griso

    2009-05-13

    Higgs boson searches are commonly considered one of the main objectives of particle physics nowadays. The latest results obtained by the CDF and D0 collaborations are presented here when searching for Higgs boson decaying into a W-boson pair, currently the most sensitive channel for masses greater than 130 GeV. The presented results are based on an integrated luminosity that ranges from 3.0 to 4.2 fb^-1. No significant excess over expected background is observed and the 95% CL limits are set for a Standard Model (SM) Higgs boson for different mass hypotheses ranging from 100 GeV to 200 GeV. The combination of CDF and D0 results is also presented, which exclude for the first time a SM Higgs boson in the 160 < mH < 170 GeV mass range.

  10. Searches for BSM and Higgs boson at LHC

    SciTech Connect (OSTI)

    Jinnouchi, O. [Tokyo Institute of Technology, Department of Physics, Graduate School of Science and Engineering (Japan); Collaboration: ATLAS Collaboration; CMS Collaboration

    2012-07-27

    This article reviews the recent results from the two energy frontier experiments, ATLAS and CMS at the large hadron collider (LHC), using the data collected during 2011 corresponding up to 4.9 fb{sup -1} integrated luminosity of {radical}(s) = 7TeV proton proton collisions. The recent results of searches for the Standard Model Higgs boson, and searches for beyond Standard Model physics based on supersymmetry and other new exotic models are presented.

  11. Impersonating the Standard Model Higgs boson: Alignment without decoupling

    SciTech Connect (OSTI)

    Carena, Marcela; Low, Ian; Shah, Nausheen R.; Wagner, Carlos E. M.

    2014-04-03

    In models with an extended Higgs sector there exists an alignment limit, in which the lightest CP-even Higgs boson mimics the Standard Model Higgs. The alignment limit is commonly associated with the decoupling limit, where all non-standard scalars are significantly heavier than the Z boson. However, alignment can occur irrespective of the mass scale of the rest of the Higgs sector. In this work we discuss the general conditions that lead to “alignment without decoupling”, therefore allowing for the existence of additional non-standard Higgs bosons at the weak scale. The values of tan ? for which this happens are derived in terms of the effective Higgs quartic couplings in general two-Higgs-doublet models as well as in supersymmetric theories, including the MSSM and the NMSSM. In addition, we study the information encoded in the variations of the SM Higgs-fermion couplings to explore regions in the mA – tan ? parameter space.

  12. Impersonating the Standard Model Higgs boson: Alignment without decoupling

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Carena, Marcela; Low, Ian; Shah, Nausheen R.; Wagner, Carlos E. M.

    2014-04-03

    In models with an extended Higgs sector there exists an alignment limit, in which the lightest CP-even Higgs boson mimics the Standard Model Higgs. The alignment limit is commonly associated with the decoupling limit, where all non-standard scalars are significantly heavier than the Z boson. However, alignment can occur irrespective of the mass scale of the rest of the Higgs sector. In this work we discuss the general conditions that lead to “alignment without decoupling”, therefore allowing for the existence of additional non-standard Higgs bosons at the weak scale. The values of tan ? for which this happens are derivedmore »in terms of the effective Higgs quartic couplings in general two-Higgs-doublet models as well as in supersymmetric theories, including the MSSM and the NMSSM. In addition, we study the information encoded in the variations of the SM Higgs-fermion couplings to explore regions in the mA – tan ? parameter space.« less

  13. Higgs boson mass bounds in the presence of a heavy fourth quark family

    E-Print Network [OSTI]

    John Bulava; Philipp Gerhold; Karl Jansen; Jim Kallarackal; Attila Nagy

    2013-01-16

    We present Higgs boson mass bounds in a lattice regularization allowing thus for non-perturbative investigations. In particular, we employ a lattice modified chiral invariant Higgs-Yukawa model using the overlap operator. We show results for the upper and lower Higgs boson mass bounds in the presence of a heavy mass-degenerate quark doublet with masses ranging up to 700 GeV. We perform infinite volume extrapolations in most cases, and examine several values of the lattice cutoff. Furthermore, we argue that the lower Higgs boson mass bound is stable with respect to the addition of higher dimensional operators to the scalar field potential. Our results have severe consequences for the phenomenology of a fourth generation of quarks if a light Higgs boson is discovered at the LHC.

  14. Higgs boson resonance parameters and the finite temperature phase transition in a chirally invariant Higgs-Yukawa model

    E-Print Network [OSTI]

    John Bulava; Philip Gerhold; Karl Jansen; Jim Kallarackal; Attila Nagy

    2011-11-11

    We study a chirally invariant Higgs-Yukawa model regulated on a space-time lattice. We calculate Higgs boson resonance parameters and mass bounds for various values of the mass of the degenerate fermion doublet. Also, first results on the phase transition temperature are presented. In general, this model may be relevant for BSM scenarios with a heavy fourth generation of quarks.

  15. From the Big Bang to the Higgs Boson in Less Than an Hour

    E-Print Network [OSTI]

    Fygenson, Deborah Kuchnir

    From the Big Bang to the Higgs Boson in Less Than an Hour Jeffrey D neutrino Z0 W + W -g gluon (8) photon Z boson W bosons Quarks Leptons H Higgs boson Gauge bosons (force field quanta) Higgs boson and vacuum expectation value Strong force EM force Weak force #12;Par7cles

  16. Searches for the SM Higgs Boson in Association with Top Quarks at LHC

    E-Print Network [OSTI]

    Zanzi, Daniele; The ATLAS collaboration

    2015-01-01

    Summary of the Run-I results of the searches for the SM Higgs boson produced in associations with top quarks at the LHC. Results performed by both the ATLAS and CMS experiments are presented and include the searches for the Higgs boson produced in association with either a top quark pair or a single top quark. Measurements of the top Yukawa coupling from the combinations of all CMS and ATLAS Higgs boson measurements are also presented together with prospects for the LHC Run-II. Talk for the 25th International Workshop on Weak Interactions and Neutrinos (WIN2015), 08/06/15 in Heidelberg.

  17. The ALEPH Search for the Standard Model Higgs Boson

    E-Print Network [OSTI]

    J. A. Kennedy

    2001-11-01

    A search has been performed for the Standard Model Higgs boson in the data collected with the ALEPH detector in 2000. An excess of 3 sigma above the background expectation is found. The observed excess is consistent with the production of the Higgs boson with a mass close to 114 GeV/c2.

  18. Supersymmetric Higgs Production in Vector-Boson Fusion

    E-Print Network [OSTI]

    Michael Rauch; Wolfgang Hollik; Tilman Plehn; Heidi Rzehak

    2010-04-14

    We present a full calculation of the supersymmetric NLO corrections to Higgs boson production via vector-boson fusion. The supersymmetric QCD corrections turn out to be significantly smaller than the electroweak ones. These higher-order corrections are an important ingredient to a precision analysis of the Higgs sector at the LHC.

  19. Higgs Production via Gluon-Induced Weak Boson Fusion

    E-Print Network [OSTI]

    Jens Vollinga

    2008-09-22

    We present a calculation that allows for an estimation of the NNLO contributions to the Higgs production in the weak boson fusion channel. A possible deterioration of this important channel for the Higgs discoveries at the LHC can be ruled out by this calculation due to the small remaining cross section after the weak boson cuts.

  20. Higgs and W boson spectrum from lattice simulations

    E-Print Network [OSTI]

    Mark Wurtz; Randy Lewis

    2013-10-01

    The spectrum of energy levels is computed for all available angular momentum and parity quantum numbers in the SU(2)-Higgs model, with parameters chosen to match experimental data from the Higgs-W boson sector of the standard model. Several multi-boson states are observed, with and without linear momentum, and all are consistent with weakly-interacting Higgs and W bosons. The creation operators used in this study are gauge-invariant so, for example, the Higgs operator is quadratic rather than linear in the Lagrangian's scalar field.

  1. What we have learned about the Higgs boson from the bosonic decay channels and more inclusive combinations of data

    E-Print Network [OSTI]

    Yuan, Li; The ATLAS collaboration

    2015-01-01

    A review on the property measurements of the Higgs boson is presented in this report, especially on the measurements using bosonic decay channels from both ATLAS and CMS experiments at the Large Hadron Collider. The results include mass, spin/CP, couplings as well as the fiducial differential cross section measurements.

  2. Invisible Higgs Boson Decay into Massive Neutrinos of 4th Generation

    E-Print Network [OSTI]

    K. Belotsky; D. Fargion; M. Khlopov; R. Konoplich; K. Shibaev

    2002-10-09

    Results from several recent experiments provide inderect evidences in the favor of existence of a 4th generation neutrino. Such a neutrino of mass about 50 GeV is compatible with current physical and astrophysical constraints and well motivated in the framework of superstring phenomenology. If sufficiently stable the existence of such a neutrino leads to the drastic change of Higgs boson physics: for a wide range of Higgs boson masses the dominant mode of Higgs boson decay is invisible and the branching ratios for the most promising modes of Higgs boson search are significantly reduced. The proper strategy of Higgs boson searches in such a framework is discussed. It is shown that in the same framework the absence of a signal in the search for invisible Higgs boson decay at LEP means either that the mass of Higgs is greater than 113.5 GeV or that the mass difference between the Higgs mass and doubled neutrino mass is small.

  3. Higgs Boson Cross Section from CTEQ-TEA Global Analysis

    E-Print Network [OSTI]

    Sayipjamal Dulat; Tie-Jiun Hou; Jun Gao; Joey Huston; Pavel Nadolsky; Jon Pumplin; Carl Schmidt; Daniel Stump; C. -P. Yuan

    2014-08-19

    We study the uncertainties of the Higgs boson production cross section through the gluon fusion subprocess at the LHC (with $\\sqrt s=7, 8$ and $14$ TeV) arising from the uncertainties of the parton distribution functions (PDFs) and of the value of the strong coupling constant $\\alpha_s(M_Z)$. These uncertainties are computed by two complementary approaches, based on the Hessian and the Lagrange Multiplier methods within the CTEQ-TEA global analysis framework. We find that their predictions for the Higgs boson cross section are in good agreement. Furthermore, the result of the Lagrange Multiplier method supports the prescriptions we have previously provided for using the Hessian method to calculate the combined PDF and $\\alpha_s$ uncertainties, and to estimate the uncertainties at the $68\\%$ confidence level by scaling them from the $90\\%$ confidence level.

  4. Higgs Boson Cross Section from CTEQ-TEA Global Analysis

    E-Print Network [OSTI]

    Dulat, Sayipjamal; Gao, Jun; Huston, Joey; Nadolsky, Pavel; Pumplin, Jon; Schmidt, Carl; Stump, Daniel; Yuan, C -P

    2013-01-01

    We study the uncertainties of the Higgs boson production cross section through the gluon fusion subprocess at the LHC (with $\\sqrt s=7, 8$ and $14$ TeV) arising from the uncertainties of the parton distribution functions (PDFs) and of the value of the strong coupling constant $\\alpha_s(M_Z)$. These uncertainties are computed by two complementary approaches, based on the Hessian and the Lagrange Multiplier methods within the CTEQ-TEA global analysis framework. We find that their predictions for the Higgs boson cross section are in good agreement. Furthermore, the result of the Lagrange Multiplier method supports the prescriptions we have previously provided for using the Hessian method to calculate the combined PDF and $\\alpha_s$ uncertainties, and to estimate the uncertainties at the $68%$ confidence level by scaling them from the 90% confidence level.

  5. Light Higgs Bosons in NMSSM at the LHC

    E-Print Network [OSTI]

    Monoranjan Guchait; Jacky Kumar

    2015-09-08

    The next-to-minimal supersymmetric standard model (NMSSM) with an extended Higgs sector offers one of the Higgs boson as the Standard model (SM) like Higgs with a mass around 125 GeV along with other Higgs bosons with lighter and heavier masses and not excluded by any current experiments. At the LHC, phenomenology of these non SM like Higgs bosons is very rich and considerably different from the other supersymmetric models. In this work, assuming one of the Higgs bosons to be the SM like, we revisit the mass spectrum and couplings of non SM like Higgs bosons taking into consideration all existing constraints and identify the relevant region of parameter space. The discovery potential of these non SM like Higgs bosons, apart from their masses, is guided by their couplings with gauge bosons and fermions which are very much parameter space sensitive. We evaluate the rates of productions of these non SM like Higgs bosons at the LHC for a variety of decay channels in the allowed region of the parameter space. Although bb, {\\tau}{\\tau} decay modes appear to be the most promising, it is observed that for a substantial region of parameter space the two-photon decay mode has a remarkably large rate. In this work we emphasize that this diphoton mode can be exploited to find the NMSSM Higgs signal and can also be potential avenue to distinguish the NMSSM from the MSSM. In addition, we discuss briefly the various detectable signals of these non SM Higgs bosons at the LHC.

  6. Higgs Boson Production via Gluon Fusion: Soft-Gluon Resummation including Mass Effects

    E-Print Network [OSTI]

    Schmidt, Timo

    2015-01-01

    We analyze soft and collinear gluon resummation effects at the N$^3$LL level for Standard Model Higgs boson production via gluon fusion $gg\\to H$ and the neutral scalar and pseudoscalar Higgs bosons of the minimal supersymmetric extension at the N$^3$LL and NNLL level, respectively. We introduce refinements in the treatment of quark mass effects and subleading collinear gluon effects within the resummation. Soft and collinear gluon resummation effects amount to up to about 5% beyond the fixed-order results for scalar and pseudoscalar Higgs boson production.

  7. Higgs boson with a single generation in the bulk

    E-Print Network [OSTI]

    M. V. Libanov; E. Y. Nugaev

    2005-12-18

    We study Higgs boson properties in a model where three fermionic families of the Standard Model arise from a single generation in (5+1) dimensions. We demonstrate that, in spite of a non-trivial background, properties of the four-dimensional Higgs particle are almost indistinguishable from those in the Standard Model. We also argue that it is more natural to have a light Higgs boson in this model.

  8. Higgs Boson Searches at the Tevatron, PIC 2012

    E-Print Network [OSTI]

    E. W. Varnes

    2013-01-12

    The search for the Higgs boson, both in the context of the standard model and extensions to it, has been a key focus during Run II of the Tevatron. I report on the status of these searches, which are highlighted by evidence at the 3 standard deviation level for the SM Higgs in its $b\\bar{b}$ decay mode, the strongest direct evidence to date for fermionic couplings of the Higgs boson.

  9. Search for standard model Higgs boson production in association with a W boson at CDF

    SciTech Connect (OSTI)

    Aaltonen, T.; et al.

    2012-03-01

    We present a search for the standard model Higgs boson production in association with a $W$ boson in proton-antiproton collisions ($p\\bar{p}\\rightarrow W^\\pm H \\rightarrow \\ell\

  10. CDF/ANAL/EXOTIC/PUBLIC//11103 Tests of the Spin and Parity of the Higgs Boson with CDF

    E-Print Network [OSTI]

    Quigg, Chris

    CDF/ANAL/EXOTIC/PUBLIC//11103 Tests of the Spin and Parity of the Higgs Boson with CDF The CDF and parity of the Higgs boson using dedicated searches for two specific non-standard Higgs boson hypotheses: a pseudoscalar Higgs boson with JP = 0- and a graviton-like Higgs boson, with JP = 2+, both assuming a boson mass

  11. Search for a high mass neutral Higgs boson using the ATLAS detector

    E-Print Network [OSTI]

    Cree, Graham; The ATLAS collaboration

    2015-01-01

    The results of searches for high mass Higgs bosons decaying to diboson (ZZ,WW,yy) final states by the ATLAS experiment are reported. In absence of the presence of a signal in the data, exclusion limits are presented.

  12. Higgs Boson in RG running Inflationary Cosmology

    E-Print Network [OSTI]

    Yi-Fu Cai; Damien A. Easson

    2013-01-07

    An intriguing hypothesis is that gravity may be non-perturbatively renormalizable via the notion of asymptotic safety. We show that the Higgs sector of the SM minimally coupled to asymptotically safe gravity can generate the observed near scale-invariant spectrum of the Cosmic Microwave Background through the curvaton mechanism. The resulting primordial power spectrum places an upper bound on the Higgs mass, which for finely tuned values of the curvaton parameters, is compatible with the recently released Large Hadron Collider data.

  13. arXiv:hepex/0505096 Measurement of the Higgs Boson Mass

    E-Print Network [OSTI]

    ################ arXiv:hep­ex/0505096 v1 30 May 2005 Measurement of the Higgs Boson Mass for the measurement of the Higgs boson mass. An integrated luminosity of 500 fb 1 is assumed. For Higgs boson masses of 120, 150 and 180 GeV the uncertainty on the Higgs boson mass measurement is estimated to be 40, 65

  14. What we have learned about the Higgs boson from the bosonic channels and more inclusive combinations of data

    E-Print Network [OSTI]

    Yuan, Li; The ATLAS collaboration

    2015-01-01

    This talk will review the status of what has been learned from LHC run-1 about the properties of the observed Higgs boson mostly from the bosonic decay channels, but also from latest/final inclusive analyses of the coupling structure. The focus of the talk should be the measurement of the Higgs boson mass (with focus on the combination of ATLAS and CMS), the status of the spin and CP properties and the analysis of the coupling structure. The talk is aimed to present the final LHC run-1 results from ATLAS and CMS.

  15. Light Higgs Boson Production in Two Higgs Doublets Models type III

    E-Print Network [OSTI]

    Camilo Jimenez; R. Martinez; J. -Alexis Rodriguez

    2008-10-23

    By using the Cheng, Sher and Yuan's anzats, we study the light Higgs Boson production associated with $b$ quark production at TEVATRON using the 2HDM type III. We compare the simulations with experimental results coming from TEVATRON, finding valid ranges for the $bb$ coupling. By using these results, we calculate the cross section for the process $pp \\to b\\bar bh(b\\bar b)$ for the LHC collider.

  16. The Higgs boson mixes with an SU(2) septet representation

    E-Print Network [OSTI]

    Junji Hisano; Koji Tsumura

    2013-01-28

    We study a possibility of the Higgs boson, which consists of an SU(2) doublet and a septet. The vacuum expectation value of a septet with hypercharge Y=2 is known to preserve the electroweak rho parameter unity at the tree level. Therefore, the septet can give significant contribution to the electroweak symmetry breaking. Due to the mixing with the septet, the gauge coupling of the standard-model-like Higgs boson is larger than that in the standard model. We show the sizable VEV of the Higgs septet can be allowed under the constraint from the electroweak precision data. The signal strengths of the Higgs boson for the diphoton and a pair of weak gauge boson decay channels at the LHC are enhanced, while those for the fermonic decay modes are suppressed. The mass of additional neutral Higgs boson is also bounded by the current LHC data for the standard model Higgs boson. We discussed the phenomenology of the multiply charged Higgs bosons, which come from the septet.

  17. Search for exotic decays of a Higgs boson into undetectable particles and photons

    E-Print Network [OSTI]

    CMS Collaboration

    2015-07-01

    A search is presented for exotic decays of a Higgs boson into undetectable particles and one or two isolated photons in pp collisions at a center-of-mass energy of 8 TeV. The data correspond to an integrated luminosity of up to 19.4 inverse femtobarns collected with the CMS detector at the LHC. Higgs bosons produced in gluon-gluon fusion and in association with a Z boson are investigated, using models in which the Higgs boson decays into a gravitino and a neutralino or a pair of neutralinos, followed by the decay of the neutralino to a gravitino and a photon. The selected events are consistent with the background-only hypothesis, and limits are placed on the product of cross sections and branching fractions. Assuming a standard model Higgs boson production cross-section, a 95% confidence level upper limit is set on the branching fraction of a 125 GeV Higgs boson decaying into undetectable particles and one or two isolated photons as a function of the neutralino mass. For neutralino masses from 1 to 120 GeV an upper limit in the range of 7 to 13% is obtained. Further results are given as a function of the neutralino lifetime, and also for a range of Higgs boson masses.

  18. Search for the standard model Higgs Boson in the Z gamma channel

    E-Print Network [OSTI]

    Singh, Kevin

    2013-01-01

    The Higgs decay into a photon and a Z boson, with the Z boson decaying into an electron-positron pair (electron channel) or muon-antimuon pair (muon channel), allows for accurate reconstructions of the Higgs boson mass and ...

  19. Search for the Standard Model Higgs boson decaying to two W bosons at CMS

    E-Print Network [OSTI]

    Xie, Si, Ph. D. Massachusetts Institute of Technology

    2012-01-01

    In this thesis, we search for the production of the Standard Model Higgs boson at the Large Hadron Collider, through its decay mode to two W bosons, which each in turn decay into a charged lepton and a neutrino. The Higgs ...

  20. Tests of Higgs boson compositeness through the HHH form factor

    E-Print Network [OSTI]

    Gounaris, G J

    2015-01-01

    We show how the $q^2$-dependence of the triple Higgs boson HHH form factor can reveal the presence of various types of new physics contributions, like new particles coupled to the Higgs boson or Higgs boson constituents, without directly observing them. We compare the effect of such new contributions to the one of higher order SM corrections to the point-like HHH coupling, due to triangle, 4-leg and s.e. diagrams. We establish simple analytic expressions describing accurately at high energy these SM corrections, as well as the examples of new physics contributions.

  1. Tests of Higgs boson compositeness through the HHH form factor

    E-Print Network [OSTI]

    G. J. Gounaris; F. M. Renard

    2015-10-14

    We show how the $q^2$-dependence of the triple Higgs boson HHH form factor can reveal the presence of various types of new physics contributions, like new particles coupled to the Higgs boson or Higgs boson constituents, without directly observing them. We compare the effect of such new contributions to the one of higher order SM corrections to the point-like HHH coupling, due to triangle, 4-leg and s.e. diagrams. We establish simple analytic expressions describing accurately at high energy these SM corrections, as well as the examples of new physics contributions.

  2. The Higgs boson, Supersymmetry and Dark Matter: Relations and Perspectives

    E-Print Network [OSTI]

    Alexandre Arbey; Marco Battaglia; Farvah Mahmoudi

    2015-04-20

    The discovery of a light Higgs boson at the LHC opens a broad program of studies and measurements to understand the role of this particle in connection with New Physics and Cosmology. Supersymmetry is the best motivated and most thoroughly formulated and investigated model of New Physics which predicts a light Higgs boson and can explain dark matter. This paper discusses how the study of the Higgs boson connects with the search for supersymmetry and for dark matter at the LHC and at a future $e^+e^-$ collider and with dedicated underground dark matter experiments.

  3. Multi-boson spectrum of the SU(2)-Higgs model

    E-Print Network [OSTI]

    Mark Wurtz; Randy Lewis

    2013-10-03

    Lattice simulations are used to compute the spectrum of energy levels for all angular momentum and parity quantum numbers in the SU(2)-Higgs model, with parameters chosen to match experimental data from the Higgs-W boson sector of the standard model. Creation operators are constructed for all lattice irreducible representations, and a correlation matrix is formed from which the spectrum is extracted using a variational analysis. Many multi-boson states are observed and careful analysis reveals that all are consistent with weakly-interacting Higgs and W bosons.

  4. Search for the associated production of the Higgs boson with a top-quark pair

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, Vardan [Yerevan Physics Institute (Armenia)

    2014-09-01

    A search for the standard model Higgs boson produced in association with a top-quark pair (t?tH) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb?¹ and 19.7 fb?¹ collected in pp collisions at center-of-mass energies of 7 TeV and 8 TeV respectively. The search is based on the following signatures of the Higgs boson decay: H ? hadrons, H ? photons, and H ? leptons. The results are characterized by an observed t?tH signal strength relative to the standard model cross section, ?=?/?SM, under the assumption that the Higgs boson decays as expected in the standard model. The best fit value is ? = 2.8 ± 1.0 for a Higgs boson mass of 125.6 GeV.

  5. Search for the associated production of the Higgs boson with a top-quark pair

    SciTech Connect (OSTI)

    Khachatryan, Vardan [Yerevan Physics Institute (Armenia)

    2014-09-01

    A search for the standard model Higgs boson produced in association with a top-quark pair (t?tH) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb?¹ and 19.7 fb?¹ collected in pp collisions at center-of-mass energies of 7 TeV and 8 TeV respectively. The search is based on the following signatures of the Higgs boson decay: H ? hadrons, H ? photons, and H ? leptons. The results are characterized by an observed t?tH signal strength relative to the standard model cross section, ?=?/?SM, under the assumption that the Higgs boson decays as expected in the standard model. The best fit value is ? = 2.8 ± 1.0 for a Higgs boson mass of 125.6 GeV.

  6. Search for the associated production of the Higgs boson with a top-quark pair

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, Vardan

    2014-09-16

    A search for the standard model Higgs boson produced in association with a top-quark pair (t?tH) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb?¹ and 19.7 fb?¹ collected in pp collisions at center-of-mass energies of 7 TeV and 8 TeV respectively. The search is based on the following signatures of the Higgs boson decay: H ? hadrons, H ? photons, and H ? leptons. The results are characterized by an observed t?tH signal strength relative to the standard model cross section, ?=?/?SM, under the assumption that the Higgs boson decays as expected in themore »standard model. The best fit value is ? = 2.8 ± 1.0 for a Higgs boson mass of 125.6 GeV.« less

  7. Search for the associated production of the Higgs boson with a top-quark pair

    SciTech Connect (OSTI)

    Khachatryan, Vardan

    2014-09-16

    A search for the standard model Higgs boson produced in association with a top-quark pair (t?tH) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb?¹ and 19.7 fb?¹ collected in pp collisions at center-of-mass energies of 7 TeV and 8 TeV respectively. The search is based on the following signatures of the Higgs boson decay: H ? hadrons, H ? photons, and H ? leptons. The results are characterized by an observed t?tH signal strength relative to the standard model cross section, ?=?/?SM, under the assumption that the Higgs boson decays as expected in the standard model. The best fit value is ? = 2.8 ± 1.0 for a Higgs boson mass of 125.6 GeV.

  8. Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

    SciTech Connect (OSTI)

    ATLAS Collaboration,

    2013-10-01

    Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H???, H?ZZ{sup ?}?4? and H?WW{sup ?}?????. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of {radical s}=7 TeV and {radical s}=8 TeV, corresponding to an integrated luminosity of about 25 fb{sup ?1}. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson.

  9. Leptogenesis via Higgs condensate relaxation

    E-Print Network [OSTI]

    Yang, L; Pearce, L; Kusenko, A; Kusenko, A

    2015-01-01

    of neutrinos and Higgs bosons in the plasma produced by thevacuum. The Standard Model Higgs boson has a tree-level po-top quark mass and Higgs boson mass, loop corrections result

  10. Gauge-Higgs Unification: Stable Higgs Bosons as Cold Dark Matter

    E-Print Network [OSTI]

    Yutaka Hosotani

    2010-03-17

    In the gauge-Higgs unification the 4D Higgs field becomes a part of the extra-dimensional component of the gauge potentials. In the $SO(5) \\times U(1)$ gauge-Higgs unification in the Randall-Sundrum warped spacetime the electroweak symmetry is dynamically broken through the Hosotani mechanism. The Higgs bosons become absolutely stable, and become the dark matter of the universe. The mass of the Higgs boson is determined from the WMAP data to be about 70 GeV.

  11. Observation and examination of a Higgs boson in the ZZ to four lepton channel

    E-Print Network [OSTI]

    Ralph, Duncan (Duncan Kelley)

    2014-01-01

    Results are presented on 5.1 fb- 1 of proton-proton collisions at a center of mass energy of 7 TeV and 19.7 fb- 1 at 8 TeV in a search for decays of the Standard Model (SM) Higgs boson to two Z bosons to four charged ...

  12. Neutral Higgs Bosons in the Higgs Triplet Model with nontrivial mixing

    E-Print Network [OSTI]

    Fatemeh Arbabifar; Sahar Bahrami; Mariana Frank

    2012-11-29

    We revisit the neutral Higgs sector of the Higgs Triplet Model, with non-negligible mixing in the CP-even Higgs sector. We examine the possibility that one of the Higgs boson state is the particle observed at the LHC at 125 GeV, and the other is either the small LEP excess at 98 GeV; or the CMS excess at 136 GeV; or that the neutral Higgs bosons are (almost) degenerate and have both mass 125 GeV. We show that, under general considerations, an (unmixed) neutral Higgs boson cannot have an enhanced decay branching ratio into gamma gamma with respect to the Standard Model one. An enhancement is however possible for the mixed case, but only for the heavier of the two neutral Higgs bosons, and not for mass-degenerate Higgs bosons. At the same time the branching ratios into WW^*,ZZ^*, bb and tau tau are similar to the Standard Model, or reduced. We correlate the branching ratios of both Higgs states into Z gamma to those into gamma gamma for the three scenarios. The mixed neutral sector of the Higgs triplet model exhibits some features which could distinguish it from other scenarios at the LHC.

  13. Search for a standard model Higgs boson produced in association...

    Office of Scientific and Technical Information (OSTI)

    Search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks using a matrix element method Title: Search for a standard model...

  14. Search for a standard model Higgs boson produced in association...

    Office of Scientific and Technical Information (OSTI)

    standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks using a matrix element method Khachatryan, V. Yerevan Physics Inst. (YerPhI)...

  15. Search for the Standard Model Higgs Boson in Missing Transverse...

    Office of Scientific and Technical Information (OSTI)

    Search for the Standard Model Higgs Boson in Missing Transverse Energy and b-quark Final States Using Proton-Antiproton Collisions at 1.96 TeV Citation Details In-Document Search...

  16. Prospects for the Higgs Boson Searches with CMS

    E-Print Network [OSTI]

    Matteo Sani

    2010-12-01

    An overview on the prospects for Higgs Boson searches with the CMS detector is presented. Projections have been made to estimate the potential to a possible discovery or exclusion of the Higgs Boson during the run at a center of mass energy of 7 TeV at the LHC, with a recorded integrated luminosity of approximately 1 fb-1, conditions expected by the end of 2011

  17. The Higgs boson and the International Linear Collider

    E-Print Network [OSTI]

    Borzumati, Francesca

    2014-01-01

    The Higgs boson will be subject of intense experimental searches in future high-energy experiments. In addition to the effort made at the Large Hadron Collider, where it was discovered, it will be the major subject of study at the International Linear Collider. We review here the reasons for that and some of the issues to be tackled at this future accelerator, in particular that of the precision of the Higgs-boson couplings.

  18. The Higgs boson and the International Linear Collider

    E-Print Network [OSTI]

    Francesca Borzumati; Eriko Kato

    2014-07-08

    The Higgs boson will be subject of intense experimental searches in future high-energy experiments. In addition to the effort made at the Large Hadron Collider, where it was discovered, it will be the major subject of study at the International Linear Collider. We review here the reasons for that and some of the issues to be tackled at this future accelerator, in particular that of the precision of the Higgs-boson couplings.

  19. Exclusive search for Higgs boson to gamma-gamma decay via vector boson fusion production mechanism

    E-Print Network [OSTI]

    Rankin, Dylan Sheldon

    2012-01-01

    We perform an exclusive search for the Higgs boson to gamma-gamma decay via vector boson fusion. We utilize the characteristic features of vector boson fusion, such as the di-jet [Delta][eta] and mass, as well as the ...

  20. Higgs boson couplings as a probe of new physics

    E-Print Network [OSTI]

    Kei Yagyu

    2015-05-26

    Precise measurements of various coupling constants of the 125 GeV Higgs boson $h$ are one of the most important and solid methods to determine the structure of the Higgs sector. If we find deviations in the $h$ coupling constants from the standard model predictions, it can be an indirect evidence of the existence of additional Higgs bosons in non-minimal Higgs sectors. Furthermore, we can distinguish non-minimal Higgs sectors by measuring a pattern of deviations in various $h$ couplings. In this talk, we show patterns of the deviations in several simple non-minimal Higgs sectors, especially for the gauge $hVV$ and Yukawa $hf\\bar{f}$ couplings. This talk is based on the paper [1].

  1. Physics 5, 32 (2012) Homing in on the Higgs Boson

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    2012-01-01

    Physics 5, 32 (2012) Viewpoint Homing in on the Higgs Boson Howard E. Haber Department of Physics that is incorporated in the standard model of particle physics, predicts the existence of a particle called the Higgs be attributed to the symmetry-breaking mechanism). Three papers now ap- pearing in Physical Review Letters, two

  2. The Standard Model Higgs boson as the inflaton

    E-Print Network [OSTI]

    F. L. Bezrukov; M. E. Shaposhnikov

    2008-01-09

    We argue that the Higgs boson of the Standard Model can lead to inflation and produce cosmological perturbations in accordance with observations. An essential requirement is the non-minimal coupling of the Higgs scalar field to gravity; no new particle besides already present in the electroweak theory is required.

  3. Search for CP Violating neutral Higgs bosons in the MSSM at LEP

    E-Print Network [OSTI]

    Philip Bechtle

    2006-02-24

    The LEP collaborations ALEPH, DELPHI, L3 and OPAL have searched for the neutral Higgs bosons which are predicted within the framework of the Minimal Supersymmetric Standard Model (MSSM). The data of the four collaborations are statistically combined and show no signicant excess of events which would indicate the production of Higgs bosons. The search results are thus used to set upper bounds on the cross sections of various Higgs-like event topologies and limits on MSSM benchmark models, including CP-conserving and CP-violating scenarios. Here, the limits on the model parameters of the CP-violating benchmark scenario CPX and derivates of this scenario are shown.

  4. Search for CP Violating Neutral Higgs Bosons in the MSSM at LEP

    SciTech Connect (OSTI)

    Bechtle, Philip; /SLAC

    2006-03-13

    The LEP collaborations ALEPH, DELPHI, L3 and OPAL have searched for the neutral Higgs bosons which are predicted within the framework of the Minimal Supersymmetric Standard Model (MSSM). The data of the four collaborations are statistically combined and show no significant excess of events which would indicate the production of Higgs bosons. The search results are thus used to set upper bounds on the cross sections of various Higgs-like event topologies and limits on MSSM benchmark models, including CP-conserving and CP-violating scenarios. Here, the limits on the model parameters of the CP-violating benchmark scenario CPX and derivates of this scenario are shown.

  5. Higgs Boson Production and Decay in Little Higgs Models with T-parity

    E-Print Network [OSTI]

    Chuan-Ren Chen; Kazuhiro Tobe; C. -P. Yuan

    2006-11-01

    We study Higgs boson production and decay in a certain class of Little Higgs models with T-parity in which some T-parity partners of the Standard Model (SM) fermions gain their masses through Yukawa-type couplings. We find that the Higgs boson production cross section of a 120 GeV Higgs boson at the CERN LHC via gg fusion process at one-loop level could be reduced by about 45%, 35% and 20%, as compared to its SM prediction, for a relatively low new particle mass scale f = 600, 700 and 1000 GeV, respectively. On the other hand, the weak boson fusion cross section is close to the SM value. Furthermore, the Higgs boson decay branching ratio into di-photon mode can be enhanced by about 35% in small Higgs mass region in certain case, for the total decay width of Higgs boson in the Little Higgs model is always smaller than that in the SM.

  6. Higgs boson, renormalization group, and naturalness in cosmology

    E-Print Network [OSTI]

    A. O. Barvinsky; A. Yu. Kamenshchik; C. Kiefer; A. A. Starobinsky; C. F. Steinwachs

    2012-11-05

    We consider the renormalization group improvement in the theory of the Standard Model (SM) Higgs boson playing the role of an inflaton with a strong non-minimal coupling to gravity. At the one-loop level with the running of constants taken into account, it leads to a range of the Higgs mass that is entirely determined by the lower WMAP bound on the cosmic microwave background (CMB) spectral index. We find that the SM phenomenology is sensitive to current cosmological data, which suggests to perform more precise CMB measurements as a SM test complementary to the LHC program. By using the concept of a field-dependent cutoff, we show the naturalness of the gradient and curvature expansion in this model within the conventional perturbation theory range of the SM. We also discuss the relation of these results to two-loop calculations and the limitations of the latter caused by parametrization and gauge dependence problems.

  7. Double Higgs-boson bremsstrahlung from W and Z bosons at supercolliders

    SciTech Connect (OSTI)

    Barger, V.; Han, T.; Phillips, R.J.N.

    1988-11-01

    We calculate the production of two standard-model neutral Higgs bosons via bremsstrahlung from a single W or Z boson in pp or e/sup +/e/sup -/ collisions at supercollider energies. Observation of these processes would test the predicted HHH, HVV, and HHVV couplings (V = W or Z). For e/sup +/e/sup -/..-->..ZHH we extend previous cross-section calculations to a more comprehensive range of energies and Higgs-boson masses, that may be accessible to future machines; we also give final-particle distributions. In the pp case we present the first calculations of the processes pp..-->..HHVX; the cross sections are comparable to other double Higgs-boson production processes for a range of energies and masses. The presence of W or Z accompanying the Higgs-boson pair has distinct practical advantages for triggering and for separating the final state from backgrounds.

  8. Searching for Heavier Higgs Boson via Di-Higgs Production at LHC Run-2

    E-Print Network [OSTI]

    Lan-Chun Lü; Chun Du; Yaquan Fang; Hong-Jian He; Huijun Zhang

    2015-07-14

    The LHC discovery of a light Higgs particle $h^0$ (125GeV) opens up new prospect for searching heavier Higgs boson(s) at the LHC Run-2, which will unambiguously point to new physics beyond the standard model (SM). We study the detection of a heavier neutral Higgs boson $H^0$ via di-Higgs production channel at the LHC (14TeV), $H^0 \\to h^0h^0 \\to WW^*\\gamma\\gamma$. This directly probes the $Hhh$ cubic Higgs interaction, which exists in most extensions of the SM Higgs sector. For the decay products of final states $WW^*$, we include both pure leptonic mode $WW^* \\to \\ell\\bar{\

  9. Higgs boson coupling to a new strongly interacting sector

    E-Print Network [OSTI]

    Hernández, A E Cárcamo; Zerwekh, Alfonso R

    2015-01-01

    In the framework of strongly interacting dynamics for electroweak symmetry breaking, heavy composite particles may arise and cause observable effects, as they should couple strongly to the resulting Higgs boson and affect the signals that appear at one loop level. Here we study this expected behavior, contrasting it with current experimental knowledge. We work in a simple and generic scenario where the lowest lying composite states are the Higgs scalar doublet and a massive vector triplet. We use an effective chiral Lagrangian to describe the theory below the compositeness scale $\\Lambda$, assumed to be $4\\pi v \\simeq~3$ TeV. The effective theory contains the Standard Model spectrum and the extra composites. We determine the constraints on this scenario imposed by our current knowledge of the $Zb\\bar{b}$ vertex, the $T$ and $S$ oblique parameters, and the recently measured Higgs mass and its diphoton decay rate. We found that the $T$ and $S$ parameters as well as the Higgs diphoton decay do not provide import...

  10. Testing Minimal Universal Extra Dimensions Using Higgs Boson Searches at the LHC

    E-Print Network [OSTI]

    Genevieve Belanger; Alexander Belyaev; Matthew Brown; Mitsuru Kakizaki; Alexander Pukhov

    2012-12-13

    Large Hadron Collider (LHC) searches for the SM Higgs boson provide a powerful limit on models involving Universal Extra Dimensions (UED) where the Higgs production is enhanced. We have evaluated all one-loop diagrams for Higgs production from gluon fusion and decay to two photons within "minimal" UED (mUED), independently confirming previous results, and we have evaluated enhancement factors for Higgs boson production and decay over the mUED parameter space. Using these we have derived limits on the parameter space, combining data from both ATLAS and CMS collaborations for the most recent 7 TeV and 8 TeV LHC data. We have performed a rigorous statistical combination of several Higgs boson search channels which is important because mUED signatures from the Higgs boson are not universally enhanced. We have found that 1/R 1000 GeV) around m_h = 118 GeV are left. The latter is likely to be excluded as more data becomes available whereas the region around 125 GeV is where the recently discovered Higgs-like particle was observed and therefore where the exclusion limit is weaker. It is worth stressing that mUED predicts an enhancement for all channels for Higgs production by gluon fusion and decay while the vector boson fusion process WW/ZZ -> h -> AA is generically suppressed and WW/ZZ -> h -> WW*/ZZ* is standard. Therefore, as more 8 TeV LHC data becomes available, the information on individual Higgs boson production and decay processes provided by the CMS and ATLAS experiments can be effectively used to favour mUED or exclude it further.

  11. About the role of the Higgs boson in the early Fred Jegerlehner, DESY Zeuthen/Humboldt University Berlin

    E-Print Network [OSTI]

    Röder, Beate

    About the role of the Higgs boson in the early universe Fred Jegerlehner, DESY Zeuthen ­ April 16-17, 2014 5 #12;The Higgs is special! Ì the Higgs boson was invented 1964 by Higgs, Englert

  12. Search for a non-standard-model Higgs boson decaying to a pair of new light bosons in four-muon final states

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et al.

    2013-11-01

    Results are reported from a search for non-standard-model Higgs boson decays to pairs of new light bosons, each of which decays into the ?+?? final state. The new bosons may be produced either promptly or via a decay chain. The data set corresponds to an integrated luminosity of 5.3 fb?1 of proton–proton collisions at View the MathML source, recorded by the CMS experiment at the LHC in 2011. Such Higgs boson decays are predicted in several scenarios of new physics, including supersymmetric models with extended Higgs sectors or hidden valleys. Thus, the results of the search are relevant for establishing whether the new particle observed in Higgs boson searches at the LHC has the properties expected for a standard model Higgs boson. No excess of events is observed with respect to the yields expected from standard model processes. A model-independent upper limit of 0.86±0.06 fb on the product of the cross section times branching fraction times acceptance is obtained. The results, which are applicable to a broad spectrum of new physics scenarios, are compared with the predictions of two benchmark models as functions of a Higgs boson mass larger than 86 GeV/c2 and of a new light boson mass within the range 0.25–3.55 GeV/c2

  13. Study of Vector Boson Fusion Higgs in Atlas-LHC

    E-Print Network [OSTI]

    Dimitris Varouchas

    2008-05-26

    Within the framework of Standard Model, the production mode of Higgs boson through the fusion of the vector bosons $W$ or $Z$ (Vector Boson Fusion) is one of the most important production mechanisms, providing a specific detection signature. A detailed study regarding this issue is being undergone for ATLAS detector in LHC and some general features of this analysis are being presented in this note emphasizing in the study of Central Jet Veto.

  14. An Inclusive Search for the Higgs Boson in the Four Lepton Final State The Higgs boson is the last undiscovered particle of the Standard Model of Particle Physics (SM).

    E-Print Network [OSTI]

    Fermilab

    An Inclusive Search for the Higgs Boson in the Four Lepton Final State The Higgs boson is the last undiscovered particle of the Standard Model of Particle Physics (SM). A search for SM Higgs boson decays transverse energy. Our search is optimized for Higgs boson decays to Z-boson pairs but is sensitive, due

  15. Gluon distribution functions and Higgs boson production at moderate transverse momentum

    SciTech Connect (OSTI)

    Sun P.; Yuan F.; Xiao, B.W.

    2011-11-04

    We investigate the gluon distribution functions and their contributions to the Higgs boson production in pp collisions in the transverse momentum-dependent factorization formalism. In addition to the usual azimuthal symmetric transverse momentum-dependent gluon distribution, we find that the azimuthal correlated gluon distribution also contributes to the Higgs boson production. This explains recent findings on the additional contribution in the transverse momentum resummation for the Higgs boson production as compared to that for electroweak boson production processes. We further examine the small-x naive kt-factorization in the dilute region and find that the azimuthal correlated gluon distribution contribution is consistently taken into account. The result agrees with the transverse momentum-dependent factorization formalism. We comment on the possible breakdown of the naive kt-factorization in the dense medium region, due to the unique behaviors for the gluon distributions.

  16. Higgs boson mass bounds in the presence of a very heavy fourth quark generation

    E-Print Network [OSTI]

    P. Gerhold; K. Jansen; J. Kallarackal

    2010-11-07

    We study the effect of a potential fourth quark generation on the upper and lower Higgs boson mass bounds. This investigation is based on the numerical evaluation of a chirally invariant lattice Higgs-Yukawa model emulating the same Higgs-fermion coupling structure as in the Higgs sector of the electroweak Standard Model. In particular, the considered model obeys a Ginsparg-Wilson version of the underlying ${SU}(2)_L\\times {U}(1)_Y$ symmetry, being a global symmetry here due to the neglection of gauge fields in this model. We present our results on the modification of the upper and lower Higgs boson mass bounds induced by the presence of a hypothetical very heavy fourth quark doublet. Finally, we compare these findings to the standard scenario of three fermion generations.

  17. Effects of a potential fourth fermion generation on the upper and lower Higgs boson mass bounds

    E-Print Network [OSTI]

    Philipp Gerhold; Karl Jansen; Jim Kallarackal

    2010-10-28

    We study the effect of a potential fourth fermion generation on the upper and lower Higgs boson mass bounds. This investigation is based on the numerical evaluation of a chirally invariant lattice Higgs-Yukawa model emulating the same Higgs-fermion coupling structure as in the Higgs sector of the electroweak Standard Model. In particular, the considered model obeys a Ginsparg-Wilson version of the underlying ${SU}(2)_L\\times {U}(1)_Y$ symmetry, being a global symmetry here due to the neglection of gauge fields in this model. We present our results on the modification of the upper and lower Higgs boson mass bounds induced by the presence of a hypothetical very heavy fourth quark doublet. Finally, we compare these findings to the standard scenario of three fermion generations.

  18. Effects of a potential fourth fermion generation on the Higgs boson mass bounds

    E-Print Network [OSTI]

    P. Gerhold; K. Jansen; J. Kallarackal

    2010-10-29

    We study the effect of a potential fourth fermion generation on the upper and lower Higgs boson mass bounds. This investigation is based on the numerical evaluation of a chirally invariant lattice Higgs-Yukawa model emulating the same Higgs-fermion coupling structure as in the Higgs sector of the electroweak Standard Model. In particular, the considered model obeys a Ginsparg-Wilson version of the underlying $SU(2)_L\\times U(1)_Y$ symmetry, being a global symmetry here due to the neglection of gauge fields in this model. We present our results on the modification of the upper and lower Higgs boson mass bounds induced by the presence of a hypothetical very heavy fourth quark doublet. Finally, we compare these findings to the standard scenario of three fermion generations.

  19. How to Determine the Probability of the Higgs Boson Detection

    E-Print Network [OSTI]

    Alexander Unzicker

    2009-12-02

    The Higgs boson is the most important, though yet undiscovered ingredient of the standard model of particle physics. Its detection is therefore one of the most important goals of high energy physics that can guide future research in theoretical physics. Enormous efforts have been undertaken to prove the existence of the Higgs boson, and the physics community is excitedly awaiting the restart of the Large Hadron Collider at CERN. But how sure can we be that the Higgs exits at all? The German philosopher Immanuel Kant recommended betting at such controversial questions, and Stephen Hawking announced a $100 bet against the Higgs. But seriously, online prediction markets, which are a generalized form of betting, do provide the best possible probability estimates for future events. It is proposed that the scientific community uses this platforms for evaluation. See also an online description www.Bet-On-The-Higgs.com.

  20. The Higgs boson resonance width from a chiral Higgs-Yukawa model on the lattice

    E-Print Network [OSTI]

    Philipp Gerhold; Karl Jansen; Jim Kallarackal

    2012-03-20

    The Higgs boson is a central part of the electroweak theory and is crucial to generate masses for quarks, leptons and the weak gauge bosons. We use a 4-dimensional Euclidean lattice formulation of the Higgs-Yukawa sector of the electroweak model to compute physical quantities in the path integral approach which is evaluated by means of Monte Carlo simulations thus allowing for fully non perturbative calculations. The chiral symmetry of the model is incorporated by using the Neuberger overlap Dirac operator. The here considered Higgs-Yukawa model does not involve the weak gauge bosons and furthermore, only a degenerate doublet of top- and bottom quarks are incorporated. The goal of this work is to study the resonance properties of the Higgs boson and its sensitivity to the strength of the quartic self coupling.

  1. Neural Networks Search for Charged Higgs Boson of Two Doublet Higgs Model at the Hadrons Colliders

    E-Print Network [OSTI]

    Bakhet, Nady; Hussein, Tarek

    2015-01-01

    In this work, we present an analysis of a search for charged Higgs boson in the context of Two Doublet Higgs Model (2HDM) which is an extension of the Standard Model of particles physics. The 2HDM predicts by existence scalar sector with new five Higgs bosons, two of them are electrically charged and the other three Higgs bosons are neutral charged. Our analysis based on the Monte Carlo data produced from the simulation of 2HDM with proton antiproton collisions at the Tevatron $\\sqrt{s}=1.96$ TeV (Fermi Lab) and proton proton collisions at the LHC $\\sqrt{s}=14$ TeV (CERN) with final state includes electron , muon , multiple jets and missing transverse energy via the production and decay of the new Higgs in the hard process $pp(\\bar{p})\\rightarrow t\\bar{t}\\rightarrow H^{+}b H^{-}\\bar{b}$

  2. Neural Networks Search for Charged Higgs Boson of Two Doublet Higgs Model at the Hadrons Colliders

    E-Print Network [OSTI]

    Nady Bakhet; Maxim Yu. Khlopov; Tarek Hussein

    2015-07-23

    In this work, we present an analysis of a search for charged Higgs boson in the context of Two Doublet Higgs Model (2HDM) which is an extension of the Standard Model of particles physics. The 2HDM predicts by existence scalar sector with new five Higgs bosons, two of them are electrically charged and the other three Higgs bosons are neutral charged. Our analysis based on the Monte Carlo data produced from the simulation of 2HDM with proton antiproton collisions at the Tevatron $\\sqrt{s}=1.96$ TeV (Fermi Lab) and proton proton collisions at the LHC $\\sqrt{s}=14$ TeV (CERN) with final state includes electron , muon , multiple jets and missing transverse energy via the production and decay of the new Higgs in the hard process $pp(\\bar{p})\\rightarrow t\\bar{t}\\rightarrow H^{+}b H^{-}\\bar{b}$

  3. Discovery of the Higgs boson is being hailed as the most

    E-Print Network [OSTI]

    Baskaran, Mark

    Discovery of the Higgs boson is being hailed as the most significant event in physics in the past oversimplified, the Higgs boson is the particle responsible for giving mass to all other particles. WSU team

  4. On the Trail of the Higgs Boson (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    On the Trail of the Higgs Boson Citation Details In-Document Search Title: On the Trail of the Higgs Boson Authors: Peskin, Michael E. ; SLAC Publication Date: 2015-06-29 OSTI...

  5. Finding the Higgs boson in decays to Z ? using the matrix element...

    Office of Scientific and Technical Information (OSTI)

    Publisher's Accepted Manuscript: Finding the Higgs boson in decays to Z using the matrix element method at next-to-leading order Title: Finding the Higgs boson in decays to Z...

  6. N 3 LO Higgs boson and Drell-Yan production at threshold: The...

    Office of Scientific and Technical Information (OSTI)

    N 3 LO Higgs boson and Drell-Yan production at threshold: The one-loop two-emission contribution Citation Details In-Document Search Title: N 3 LO Higgs boson and Drell-Yan...

  7. Higgs-boson production through gluon fusion at NNLO QCD with...

    Office of Scientific and Technical Information (OSTI)

    Higgs-boson production through gluon fusion at NNLO QCD with parton showers Citation Details In-Document Search Title: Higgs-boson production through gluon fusion at NNLO QCD with...

  8. An Updated Historical Profile of the Higgs Boson

    E-Print Network [OSTI]

    John Ellis; Mary K. Gaillard; Dimitri V. Nanopoulos

    2015-04-27

    The Higgs boson was postulated in 1964, and phenomenological studies of its possible production and decays started in the early 1970s, followed by studies of its possible production in electron-positron, antiproton-proton and proton-proton collisions, in particular. Until recently, the most sensitive searches for the Higgs boson were at LEP between 1989 and 2000, which were complemented by searches at the Fermilab Tevatron. Then the LHC experiments ATLAS and CMS entered the hunt, announcing on July 4, 2012 the discovery of a "Higgs-like" particle with a mass of about 125~GeV. This identification has been supported by subsequent measurements of its spin, parity and coupling properties. It was widely anticipated that the Higgs boson would be accompanied by supersymmetry, although other options, like compositeness, were not completely excluded. So far there are no signs any new physics, and the measured properties of the Higgs boson are consistent with the predictions of the minimal Standard Model. This article reviews some of the key historical developments in Higgs physics over the past half-century.

  9. Higgs boson searches in CP-conserving and CP-violating MSSM scenarios with the DELPHI detector

    E-Print Network [OSTI]

    DELPHI Collaboration; J. Abdallah

    2008-01-23

    This paper presents the final interpretation of the results from DELPHI on the searches for Higgs bosons in the Minimal Supersymmetric extension of the Standard Model (MSSM). A few representative scenarios are considered, that include CP conservation and explicit CP violation in the Higgs sector. The experimental results encompass the searches for neutral Higgs bosons at LEP1 and LEP2 in final states as expected in the MSSM, as well as LEP2 searches for charged Higgs bosons and for neutral Higgs bosons decaying into hadrons independent of the quark flavour. The data reveal no significant excess with respect to background expectations. The results are translated into excluded regions of the parameter space in the various scenarios. In the CP-conserving case, these lead to limits on the masses of the lightest scalar and pseudoscalar Higgs bosons, h and A, and on tan(beta). The dependence of these limits on the top quark mass is discussed. Allowing for CP violation reduces the experimental sensitivity to Higgs bosons. It is shown that this effect depends strongly on the values of the parameters responsible for CP violation in the Higgs sector.

  10. Probing Extra Matter in Gauge Mediation Through the Lightest Higgs Boson Mass

    E-Print Network [OSTI]

    Jason L. Evans; Masahiro Ibe; Tsutomu T. Yanagida

    2011-08-17

    We discuss the implications of the excesses in LHC Higgs boson searches on the gauge mediated supersymmetric standard model, for the mass range 120-140\\,GeV. We find that a relatively heavy lightest Higgs boson mass in this range can be reconciled with light SUSY particles, $m_{\\rm gluino}Higgs boson. We also find that the mass of this extra matter can be predicted rather precisely in gauge mediation for a given Higgs boson and gluino mass.

  11. Search for invisible decays of the Higgs Boson at the LHC

    E-Print Network [OSTI]

    White, Andrew; The ATLAS collaboration

    2015-01-01

    The latest from ATLAS and CMS on the search for invisible decays of the Higgs Boson will be presented.

  12. CDF Note 9674 Combined Upper Limit on Standard Model Higgs Boson Production for Winter 2009

    E-Print Network [OSTI]

    Fermilab

    CDF Note 9674 Combined Upper Limit on Standard Model Higgs Boson Production for Winter 2009 The CDF of searches for the Standard Model Higgs boson at CDF. The six major analyses combined are the WH bV/c2 in steps of 5 GeV/c2 , assuming Standard Model decay branching fractions of the Higgs boson

  13. CDF/PUB/EXOTIC/PUBLIC/10737 Search for a Standard Model Higgs Boson Decaying Into Photons

    E-Print Network [OSTI]

    Fermilab

    CDF/PUB/EXOTIC/PUBLIC/10737 Search for a Standard Model Higgs Boson Decaying Into Photons at CDF) A search for the SM Higgs boson in the diphoton decay channel is reported using data corre- sponding are set on the production cross section times the H branching fraction for hypothetical Higgs boson

  14. CDF note 9642 Search for the Standard Model Higgs boson in the ET plus jets sample

    E-Print Network [OSTI]

    Fermilab

    CDF note 9642 Search for the Standard Model Higgs boson in the ET plus jets sample The CDF Collaboration URL http://www-cdf.fnal.gov (Dated: August 17, 2009) We search for the Higgs boson produced; the Higgs boson decays into a bb pair. This analysis is an update of the previous one to 3.6 fb-1 of CDF

  15. Present status and future prospects for a Higgs boson discovery at the Tevatron and LHC

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Present status and future prospects for a Higgs boson discovery at the Tevatron and LHC Howard E-mail: haber@scipp.ucsc.edu Abstract. Discovering the Higgs boson is one of the primary goals of both for the Higgs boson and its phenomenological consequences are examined. 1. Introduction The origin

  16. CDF/PUB/EXOTIC/PUBLIC/9586 Search for a Fermiophobic Higgs Boson with the Diphoton Final

    E-Print Network [OSTI]

    Quigg, Chris

    CDF/PUB/EXOTIC/PUBLIC/9586 Search for a Fermiophobic Higgs Boson with the Diphoton Final State for the Higgs boson in the di-photon decay channel is reported. The Standard Model branching fraction is small. INTRODUCTION Low mass Higgs boson searches at the Tevatron usually focus on the dominant b¯b decay channel

  17. arXiv:hepph/9905551 Diphoton Background to Higgs Boson Production at the LHC

    E-Print Network [OSTI]

    Schmidt, Carl

    arXiv:hep­ph/9905551 v2 27 Apr 2000 Diphoton Background to Higgs Boson Production at the LHC section of a light Higgs boson at the CERN Large Hadron Collider demand the accurate prediction--90526 I. INTRODUCTION The direct search for the Standard Model (SM) Higgs boson at the CERN LEP collider

  18. ROME1-1378/2004 Associated production of a light Higgs boson

    E-Print Network [OSTI]

    ROME1-1378/2004 Associated production of a light Higgs boson and a chargino pair in the MSSM In the Minimal Supersymmetric Standard Model (MSSM), we study the light Higgs- boson radiation o#11; a light or the pseudoscalar Higgs boson A. In particular, we compute the total cross section and the analytical form

  19. CDF Note 10625 Search for the Standard Model Higgs boson in +

    E-Print Network [OSTI]

    Fermilab

    CDF Note 10625 Search for the Standard Model Higgs boson in + - + jets final state with 8.3fb-1 a search for the Standard Model Higgs boson in + - + jets final state, using CDF Run II data with an integrated luminosity of 8.3 fb-1 . The Signal considered in this search is four Higgs boson production

  20. CDF Note 9999 Combined Upper Limit on Standard Model Higgs Boson Production

    E-Print Network [OSTI]

    Fermilab

    CDF Note 9999 Combined Upper Limit on Standard Model Higgs Boson Production The CDF Collaboration for the Standard Model Higgs boson at CDF. The six major analyses combined are the WH b¯b channels, the WH + ZH E Model decay branching fractions of the Higgs boson and that the ratios of the rates for the WH, ZH, gg

  1. Inclusive Higgs Boson Searches in Four-Lepton Final States at the LHC

    E-Print Network [OSTI]

    Evelyne Delmeire

    2007-05-15

    The inclusive search for the Standard Model Higgs boson in four-lepton final states with the ATLAS and CMS detectors at the LHC pp collider is presented. The discussion focusses on the H-> ZZ^(*)->4l+X decay mode for a Higgs boson in the mass range 120 ~Higgs boson properties is also given.

  2. CDF/PUB/TOP/PUBLIC/11068 Search for an Invisible Decaying Higgs Boson in

    E-Print Network [OSTI]

    Quigg, Chris

    CDF/PUB/TOP/PUBLIC/11068 Search for an Invisible Decaying Higgs Boson in Dilepton Events at CDF M Abstract We present the first search at the Tevatron for a Higgs boson decaying to an invisible final state fb at 95% credibility level for a Higgs boson mass of 125 GeV/c2. We perform this analysis across

  3. Search for the Standard Model Higgs Boson in the H ZZ + -

    E-Print Network [OSTI]

    Roma "La Sapienza", Università di

    Search for the Standard Model Higgs Boson in the H ZZ + - q¯q Decay Channel at CMS Scuola di. Search for the Standard Model Higgs Boson in the H ZZ + -q¯q Decay Channel at CMS. Ph.D. thesis Introduction vii 1 The Hunt for the Higgs Boson 1 1.1 The Standard Model

  4. The Assessment of Evidence in the Discovery of a Higgs Boson David A. van Dyk*

    E-Print Network [OSTI]

    Wolfe, Patrick J.

    The Assessment of Evidence in the Discovery of a Higgs Boson David A. van Dyk* Imperial College London, United Kingdom dvandyk@imperial.ac.uk The 2012-2013 discovery of a Higgs boson filled the last in a 40-year search that culminated in the discovery of a Higgs boson. This talk reviews these statistical

  5. Search for a Higgs Boson Decaying to Two W Bosons at CDF

    E-Print Network [OSTI]

    Makhoul, K.

    We present a search for a Higgs boson decaying to two W bosons in pp? collisions at ?s=1.96??TeV center-of-mass energy. The data sample corresponds to an integrated luminosity of 3.0??fb-1 collected with the CDF II detector. ...

  6. Search for standard model Higgs boson production in association with a W boson at CDF

    E-Print Network [OSTI]

    Bauer, Gerry P.

    We present a search for the standard model Higgs boson production in association with a W boson in proton-antiproton collisions (pp? ?W[superscript ±]H???bb? ) at a center of mass energy of 1.96 TeV. The search employs ...

  7. Higgs boson productions at LHC as a probe of different littlest Higgs models with T-parity

    E-Print Network [OSTI]

    Lei Wang; Jin Min Yang

    2007-10-26

    Higgs boson productions at the LHC will serve as a sensitive probe of various little Higgs models. In this work we comparatively study two littlest Higgs models with different T-parity constructions through examining their effects in three production processes of the Higgs boson at the LHC, namely the productions of a single Higgs, a Higgs-pair, as well as a Higgs boson associated with a pair of top and anti-top quarks. The two models are characterized by predicting a top partner canceling the Higgs mass quadratic divergence contributed by the top quark with even and odd T-parity, respectively. We find that both models can alter the SM cross sections sizably and their corrections also differ significantly. Therefore, the Higgs boson productions at the LHC may shed some light on these two models or even distinguish them.

  8. Combined Search for the Standard Model Higgs Boson Decaying to bb? Using the D0 Run II Data Set

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Askew, A.; et al

    2012-09-20

    We present the results of the combination of searches for the standard model Higgs boson produced in association with a W or Z boson and decaying into bb? using the data sample collected with the D0 detector in pp? collisions at ?s=1.96 TeV at the Fermilab Tevatron Collider. We derive 95% C.L. upper limits on the Higgs boson cross section relative to the standard model prediction in the mass range 100 GeV?MH?150 GeV, and we exclude Higgs bosons with masses smaller than 102 GeV at the 95% C.L. In the mass range 120 GeV?MH?145 GeV, the data exhibit an excessmore »above the background prediction with a global significance of 1.5 standard deviations, consistent with the expectation in the presence of a standard model Higgs boson.« less

  9. Combined Search for the Standard Model Higgs Boson Decaying to bb? Using the D0 Run II Data Set

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bose, T.; Brandt, A.; Brandt, O.; Brock, R.; Bross, A.; Brown, D.; Brown, J.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Chevalier-Théry, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Croc, A.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duggan, D.; Duperrin, A.; Dutt, S.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Facini, G.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garcia-Bellido, A.; García-González, J. A.; García-Guerra, G. A.; Gavrilov, V.; Gay, P.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Hagopian, S.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jeong, M. S.; Jesik, R.; Jiang, P.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kaadze, K.; Kajfasz, E.; Karmanov, D.; Kasper, P. A.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, D.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Naimuddin, M.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nguyen, H. T.; Nunnemann, T.; Orduna, J.; Osman, N.; Osta, J.; Padilla, M.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M.-A.; Podesta-Lerma, P. L. M.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Rangel, M. S.; Ranjan, K.; Ratoff, P. N.; Razumov, I.; Renkel, P.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Salcido, P.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schlobohm, S.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Shivpuri, R. K.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Smith, K. J.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Takahashi, M.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tschann-Grimm, K.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.

    2012-09-01

    We present the results of the combination of searches for the standard model Higgs boson produced in association with a W or Z boson and decaying into bb? using the data sample collected with the D0 detector in pp? collisions at ?s=1.96 TeV at the Fermilab Tevatron Collider. We derive 95% C.L. upper limits on the Higgs boson cross section relative to the standard model prediction in the mass range 100 GeV?MH?150 GeV, and we exclude Higgs bosons with masses smaller than 102 GeV at the 95% C.L. In the mass range 120 GeV?MH?145 GeV, the data exhibit an excess above the background prediction with a global significance of 1.5 standard deviations, consistent with the expectation in the presence of a standard model Higgs boson.

  10. Direct searches of extra Higgs boson at future colliders

    E-Print Network [OSTI]

    Yokoya, Hiroshi

    2015-01-01

    We study direct searches of additional Higgs bosons in multi-top-quarks events at the LHC with the collision energy of 14 TeV as well as the International Linear Collider (ILC) with the collision energy of 1 TeV. As a benchmark model, we consider two Higgs doublet models with a softly-broken discrete $Z_2$ symmetry, where the $t\\bar t$ decay mode of additional neutral Higgs bosons can be dominant if their masses are heavy enough. Thus, the multi-top-quarks events become an important probe of the extended Higgs sector at future colliders. We estimate the discovery reach at the LHC and the ILC, and find that the search at the ILC can survey the parameter regions where the LHC cannot cover.

  11. All-order Finiteness of the Higgs Boson Mass in the Dynamical Gauge-Higgs Unification

    E-Print Network [OSTI]

    Yutaka Hosotani

    2006-07-06

    In the dynamical gauge-Higgs unification, it is shown that the mass of the Higgs boson (4D scalar field) in U(1) gauge theory in $M^4 \\times T^n$ ($n=1,2,3,...$) is finite to all order in perturbation theory as a consequence of the large gauge invariance. It is conjectured that the Higgs boson mass is finite in non-Abelian gauge theory in $M^4 \\times S^1$, $M^4 \\times (S^1/Z_2)$ and the Randall-Sundrum warped spacetime to all order in the rearranged perturbation theory where the large gauge invariance is maintained.

  12. Results on SUSY and Higgs searches at CMS

    ScienceCinema (OSTI)

    None

    2011-04-25

    We present the results of searches for Supersymmetry and the Higgs boson performed using data collected in 2010 by the CMS experiment at the LHC in pp-collisions at a centre-of-mass energy of 7 TeV. Searches for Supersymmetry are performed in all-hadronic final states with jets and missing transverse energy and in final states including one or more isolated leptons or photons. No evidence for new physics is observed and limits are set on the predictions of a range of Supersymmetric scenarios. The results of searches for the Higgs boson are presented and limits set.

  13. Combination of Tevatron searches for the standard model Higgs boson in the W+W- decay mode

    SciTech Connect (OSTI)

    Aaltonen, T.; Abazov, V.M.; Gregores, E.M.; Mercadante, P.G.; Hebbeker, T.; Kirsch, M.; Meyer, A.; Sonnenschein, L.; Avila, C.; Gomez, B.; Mendoza, L.; /Andes U., Bogota /Argonne /Arizona U. /Athens U. /Barcelona, IFAE /Baylor U. /Bonn U. /Boston U. /Brandeis U.

    2010-01-01

    We combine searches by the CDF and D0 collaborations for a Higgs boson decaying to W{sup +}W{sup -}. The data correspond to an integrated total luminosity of 4.8 (CDF) and 5.4 (D0) fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron collider. No excess is observed above background expectation, and resulting limits on Higgs boson production exclude a standard-model Higgs boson in the mass range 162-166 GeV at the 95% C.L.

  14. Search for a fermiophobic Higgs boson in pp collisions at sqrt(s) = 7 TeV

    E-Print Network [OSTI]

    CMS Collaboration

    2013-01-28

    Combined results are reported from searches for a fermiophobic Higgs boson in the gamma-gamma, WW, and ZZ decay modes in proton-proton collisions at sqrt(s) = 7 TeV. The explored Higgs boson mass range is 110-300 GeV. The data sample corresponds to an integrated luminosity of 4.9-5.1 inverse femtobarns. A fermiophobic Higgs boson is excluded at 95% confidence level in the mass range 110-194 GeV, and at 99% confidence level in the mass ranges 110-124.5 GeV, 127-147.5 GeV, and 155-180 GeV.

  15. Measuring the Higgs boson mass in dileptonic W-boson decays at hadron colliders

    E-Print Network [OSTI]

    Barr, Alan; Gripaios, Ben; Lester, Christopher G.

    2009-01-01

    Ju l 2 00 9 Cavendish-HEP-09/04 Measuring the Higgs boson mass in dileptonic W -boson decays at hadron colliders Alan J. Barr,1, ? Ben Gripaios,2, † and Christopher G. Lester3, ‡ 1Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH, United Kingdom 2... CERN PH-TH, Geneva 23, 1211 Switzerland 3Cavendish Laboratory, Dept of Physics, JJ Thomson Avenue, Cambridge, CB3 0HE, United Kingdom (Dated: July 22, 2009) It is expected that hadron collider measurements of the Higgs boson mass using the decay h ? W...

  16. Cosmological Bounds on an Invisibly Decaying Higgs Boson

    E-Print Network [OSTI]

    O. Bertolami; M. C. Bento; R. Rosenfeld

    2001-11-21

    We derive bounds on the Higgs boson coupling $g^{\\prime}$ to a stable light scalar which is regarded as a collisional dark matter candidate. We study the behaviour of this scalar, that we refer to as phion ($\\phi$), in the early Universe for different ranges of its mass. We find that a phion in the mass range of $100 \\mev$ is excluded, while if its mass is about $1 \\gev$, a rather large coupling constant, $g^{\\prime} \\gsim 2$, and $m_h \\lsim 130 \\gev$ are required in order to avoid overabundance. In the latter case, the invisible decay mode of the Higgs boson is dominant.

  17. The Discovery of the Higgs Boson: America's Role

    ScienceCinema (OSTI)

    None

    2014-05-30

    The discovery of the Higgs boson was an international endeavor, involving thousands of physicists from across the world. While the accelerator at which the experimental work was done is located on Europe, the US supplied more physicists than any other single country. America had a very large role in the discovery of the Higgs particle and continues to have a leading role in the ongoing studies of the boson's properties. This video describes some of the contributions of U.S. universities and laboratories.

  18. The Higgs boson structure functions as signposts of new physics

    E-Print Network [OSTI]

    Gounaris, G J

    2015-01-01

    We show that the Higgs boson structure functions observable in the inclusive process $e^-e^+ \\to H + {\\rm "anything"}$ may reveal the presence of anomalous contributions corresponding to several types of new physics partners, Higgs boson compositeness or invisible (dark) matter. This could be done without making a difficult or even an impossible experimental analysis of the contents of the "anything". We give illustrations showing how the shapes of the various structure functions containing such typical new contributions may differ from the standard prediction and allow their identification.

  19. The Discovery of the Higgs Boson: America's Role

    SciTech Connect (OSTI)

    2013-10-08

    The discovery of the Higgs boson was an international endeavor, involving thousands of physicists from across the world. While the accelerator at which the experimental work was done is located on Europe, the US supplied more physicists than any other single country. America had a very large role in the discovery of the Higgs particle and continues to have a leading role in the ongoing studies of the boson's properties. This video describes some of the contributions of U.S. universities and laboratories.

  20. Higgs boson production with one bottom quark including higher-order soft-gluon corrections

    E-Print Network [OSTI]

    B. Field; C. B. Jackson; L. Reina

    2007-07-12

    A Higgs boson produced in association with one or more bottom quarks is of great theoretical and experimental interest to the high-energy community. A precise prediction of its total and differential cross-section can have a great impact on the discovery of a Higgs boson with large bottom-quark Yukawa coupling, like the scalar (h^0 and H^0) and pseudoscalar (A^0) Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) in the region of large \\tan\\beta. In this paper we apply the threshold resummation formalism to determine both differential and total cross-sections for b g \\to b\\Phi (where \\Phi = h^0, H^0), including up to next-to-next-to-next-to-leading order (NNNLO) soft plus virtual QCD corrections at next-to-leading logarithmic (NLL) accuracy. We present results for both the Fermilab Tevatron and the CERN Large Hadron Collider (LHC).

  1. Measuring the Higgs boson mass using event-by-event uncertainties

    E-Print Network [OSTI]

    Castelli, Angelantonio; van Vulpen, Ivo; Kluit, Peter

    The thesis presents a measurement of the properties of the Higgs particle, performed by using the data collected by the ATLAS experiment in 2011 and 2012. The measurement is performed by using a three-dimensional model based on analytic functions to describe the signal produced by the Higgs boson decays into four leptons. The model includes the information provided by the uncertainty measured event-by-event on the four-lepton invariant mass. A maximum likelihood fit is used to obtain an unbiased estimate of the mass, the signal strength and the decay amplitude of the Higgs particle. The best estimation of the Higgs boson mass results to be: $124.52^{+0.48}_{-0.49}(\\text{stat.})\\pm0.08(\\text{syst.})\\text{GeV}$

  2. Upper Higgs boson mass bounds from a chirally invariant lattice Higgs-Yukawa model

    E-Print Network [OSTI]

    P. Gerhold; K. Jansen

    2010-02-23

    We establish the cutoff-dependent upper Higgs boson mass bound by means of direct lattice computations in the framework of a chirally invariant lattice Higgs-Yukawa model emulating the same chiral Yukawa coupling structure as in the Higgs-fermion sector of the Standard Model. As expected from the triviality picture of the Higgs sector, we observe the upper mass bound to decrease with rising cutoff parameter $\\Lambda$. Moreover, the strength of the fermionic contribution to the upper mass bound is explored by comparing to the corresponding analysis in the pure $\\Phi^4$-theory.

  3. Search for the Higgs boson in the diphoton decay channel with the ATLAS detector

    E-Print Network [OSTI]

    Tackmann, K; The ATLAS collaboration

    2015-01-01

    A search for the Standard Model Higgs boson in the diphoton decay channel in proton-proton collisions using recent data collected with the ATLAS detector at the LHC, over the diphoton mass range 110-150 GeV is reported. Upper limits on the cross-section times branching ratio are derived. Additionaly, the results of the search for the fermiophobic Higgs boson are presented, based on the 4.9 fb-1 of data collected in 2011 at a centre-of-mass energy of 7 TeV.

  4. Higgs-boson production at the Photon Collider at TESLA

    E-Print Network [OSTI]

    Piotr Niezurawski

    2005-03-31

    In this thesis feasibility of the precise measurement of the Higgs-boson production cross section gamma+gamma->higgs->b+bbar at the Photon Collider at TESLA is studied in detail. The study is based on the realistic luminosity spectra simulation. The heavy quark background is estimated using the dedicated code based on NLO QCD calculations. Other background processes, which were neglected in the earlier analyses, are also studied. Also the contribution from the overlaying events, gamma+gamma->hadrons, is taken into account. The non-zero beam crossing angle and the finite size of colliding bunches are included in the event generation. The analysis is based on the full detector simulation with realistic b-tagging, and the criteria of event selection are optimized separately for each considered Higgs-boson mass. For the Standard-Model Higgs boson with mass of 120 to 160 GeV the partial width \\Gamma(h->gamma+gamma)BR(h->b+bbar) can be measured with a statistical accuracy of 2.1-7.7% after one year of the Photon Collider running. The systematic uncertainties of the measurement are estimated to be of the order of 2%. For MSSM Higgs bosons A and H, for M_A=200-350 GeV and tan(beta)=7, the statistical precision of the cross-section measurement is estimated to be 8--34%, for four considered MSSM parameters sets. As heavy neutral Higgs bosons in this scenario may not be discovered at LHC or at the first stage of the e+e- collider, an opportunity of being a discovery machine is also studied for the Photon Collider.

  5. Search for the standard model Higgs boson produced in association with W and Z bosons in pp collisions at sqrt(s) = 7 TeV

    E-Print Network [OSTI]

    CMS Collaboration

    2013-01-29

    A search for the Higgs boson produced in association with a W or Z boson in proton-proton collisions at a center-of-mass energy of 7 TeV is performed with the CMS detector at the LHC using the full 2011 data sample, from an integrated luminosity of 5 inverse femtobarns. Higgs boson decay modes to tau tau and WW are explored by selecting events with three or four leptons in the final state. No excess above background expectations is observed, resulting in exclusion limits on the product of Higgs associated production cross section and decay branching fraction for Higgs boson masses between 110 and 200 GeV in these channels. Combining these results with other CMS associated production searches using the same dataset in the H to gamma gamma and H to b b-bar decay modes, the cross section for associated Higgs boson production 3.3 times the standard model expectation or larger is ruled out at the 95% confidence level for a Higgs boson mass of 125 GeV.

  6. Search for the Higgs boson decaying to b quark pairs in the W/Z associated production channels with ATLAS

    E-Print Network [OSTI]

    Pedro, Rute; The ATLAS collaboration

    2015-01-01

    In 2012, the ATLAS and CMS experiments at CERN discovered a Higgs-like boson in LHC pp collisions at $\\sqrt(s)$ = 7 and 8 TeV an approximate mass of 125 GeV. More recent experimental results, exploring the complete Run1 dataset, indicate that the observed boson is consistent with the Standard Model Higgs Boson within uncertainties. The results include spin and parity properties and couplings to the other SM particles and are mostly based in bosonic channels. Despite the increasing experimental knowledge about the Higgs boson, its couplings to down-type quarks have still to be proven. The SM 125 GeV Higgs boson decays to b quark pairs with a branching ratio of 58% but the bb production cross-section in $\\sqrt(s)$ = 8 TeV pp collisions is 7 orders of magnitude greater than the Higgs production cross section, making this decay one of the most challenging to search for at the LHC. In the associated production in which the Higgs is produced with a W/Z boson, one can use the leptonic decay of the W/Z to trigger the...

  7. Search for the Standard Model Higgs boson produced in association with a vector boson and decaying to a b-quark pair with the ATLAS detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    This Letter presents the results of a direct search with the ATLAS detector at the LHC for a Standard Model Higgs boson of mass 110?m[subscript H]?130 GeV produced in association with a W or Z boson and decaying to b[bar ...

  8. Probing Charged Higgs Boson Couplings at the FCC-hh Collider

    E-Print Network [OSTI]

    I. T. Cakir; S. Kuday; H. Saygin; A. Senol; O. Cakir

    2015-04-22

    Many of the new physics models predicts a light Higgs boson similar to the Higgs boson of the Standard Model (SM) and also extra scalar bosons. Beyond the search channels for a SM Higgs boson, the future collider experiments will explore additional channels that are specific to extended Higgs sectors. We study the charged Higgs boson production within the framework of two Higgs doublet models (THDM) in the proton-proton collisions at the FCC-hh collider. With an integrated luminosity of 500 fb$^{-1}$ at very high energy frontier, we obtain a significant coverage of the parameter space and distinguish the charged Higgs-top-bottom interaction within the THDM or other new physics models with charged Higgs boson mass up to 1 TeV.

  9. Searches for invisible decays of the Higgs boson with ATLAS and CMS

    E-Print Network [OSTI]

    Calfayan, Philippe; The ATLAS collaboration

    2015-01-01

    This talk will summarize the latest results of searches for the decay of the observed Higgs boson into invisible and quasi-invisible states. The talk should cover the results of the ATLAS and the CMS experiment based on the full dataset of LHC run-1.

  10. Searching for a Heavy Higgs boson in a Higgs-portal B-L Model

    E-Print Network [OSTI]

    Shankha Banerjee; Manimala Mitra; Michael Spannowsky

    2015-09-15

    We study the discovery prospects of a heavy neutral scalar arising from a $U(1)_{B-L}$ extension of the Standard Model (SM) during the Large Hadron Collider's high luminosity runs (HL-LHC). This heavy neutral scalar mixes with the SM Higgs boson through a Higgs portal and interacts with the SM particles with an interaction strength proportional to the sine of the mixing angle. The mixing between the two Higgs bosons is constrained by direct and indirect measurements. We choose an experimentally viable mixing angle and explore in detail the $ZZ$ and $WW$ decay modes of the heavy Higgs boson. For the $ZZ$ case, we focus on the cleanest $4\\ell$ and $2\\ell 2j$ final states and find that a heavy Higgs boson of mass smaller than 500 GeV can be discovered at the HL-LHC. For the $WW$ decay mode, we analyze the $\\ell jj \\slashed{E}_T$ signature. We implement novel background reduction techniques in order to tackle the huge background by performing both cut-based and multivariate analyses. However, large backgrounds render this channel challenging. We briefly discuss the discovery prospects of the heavy $Z'$-boson arising in this model.

  11. Asymptotic safety of gravity and the Higgs boson mass

    E-Print Network [OSTI]

    Mikhail Shaposhnikov; Christof Wetterich

    2010-01-12

    There are indications that gravity is asymptotically safe. The Standard Model (SM) plus gravity could be valid up to arbitrarily high energies. Supposing that this is indeed the case and assuming that there are no intermediate energy scales between the Fermi and Planck scales we address the question of whether the mass of the Higgs boson $m_H$ can be predicted. For a positive gravity induced anomalous dimension $A_\\lambda>0$ the running of the quartic scalar self interaction $\\lambda$ at scales beyond the Planck mass is determined by a fixed point at zero. This results in $m_H=m_{\\rm min}=126$ GeV, with only a few GeV uncertainty. This prediction is independent of the details of the short distance running and holds for a wide class of extensions of the SM as well. For $A_\\lambda 0$ is favored by explicit computations existing in the literature.

  12. Search for the Standard Model Higgs boson at LEP

    E-Print Network [OSTI]

    Wilson, Graham Wallace; ALEPH Collaboration; DELPHI Collaboration; L3 Collaboration; OPAL Collaboration; The LEP Working Group for Higgs Boson Searches

    2003-07-17

    The four LEP Collaborations, ALEPH, DELPHI, L3 and OPAL, have collected a total of 2461 pb^(?1) of e^+e^? collision data at centre-of-mass energies between 189 and 209 GeV. The data are used to search for the Standard Model Higgs boson. The search...

  13. A Search for Neutral Supersymmetric Higgs Bosons at D0

    SciTech Connect (OSTI)

    Osman, Nicolas Ahmed; /Imperial Coll., London

    2010-09-01

    A search for Higgs bosons in multijet data from the D0 detector is reported in this thesis. The Higgs boson is the only remaining undiscovered particle in the Standard Model of particle physics, and plays an integral role in this model. It is known that this model is not a complete description of fundamental physics (it does not describe gravity, for example), and so searches for physics beyond the Standard Model are an important part of particle physics. One extension of the Standard Model, the Minimal Supersymmetric Standard Model (MSSM), predicts the existence of five Higgs bosons, two of which can show an enhanced coupling to bottom quarks. For this reason, a search in the bbb (multijet) channel is a sensitive test of Higgs boson physics. The analysis described in this thesis was conducted over 6.6 fb{sup -1} of data. At the time of writing, the best limits on tan {beta} (a key parameter of the MSSM) in the multijet channel were set by D0. The new analysis described in this thesis included more data than the previous analysis in the channel, and made use of a new trigger and event-based analysis method. An improved Multivariate Analysis technique was used to separate signal and background events and produce a final discriminant for the limit setting process. These changes increased the expected sensitivity of this measurement by roughly 50% more than would be expected from the increase in the size of data sample alone.

  14. Higgs Boson: How do you search for it?

    SciTech Connect (OSTI)

    Lincoln, Don

    2011-12-12

    Updated: http://youtu.be/ktEpSvzPROc Fermilab scientist Don Lincoln describes the concept of how the search for the Higgs boson is accomplished. Several large experimental groups are hot on the trail of this elusive subatomic particle which is thought to explain the origins of particle mass.

  15. Exceptional Lie Groups, E-infinity Theory and Higgs Boson

    E-Print Network [OSTI]

    Ayman A. El-Okaby

    2007-12-30

    In this paper, we study the correlation between the exceptional lie groups and El-Naschie's transfinite E-infinity spacetime theory. Subsequently this is used to calculate the number of elementary particles in the standard model, mass of the Higgs boson and some coupling constants.

  16. Unobservable Higgs Boson and Spontaneous Violation of Lorentz Invariance

    E-Print Network [OSTI]

    Noboru Nakanishi

    2007-08-13

    The standard theory of elementary particle physics is modified in such a way that the Higgs boson becomes unobservable and Lorentz invariance is slightly violated at the level of the S-matrix. The basic technique of realizing these properties without violating the unitarity of the physical S-matrix is the use of the complex-ghost quantum field theory.

  17. Higgs Boson: How do you search for it?

    ScienceCinema (OSTI)

    Lincoln, Don

    2014-08-12

    Updated: http://youtu.be/ktEpSvzPROc Fermilab scientist Don Lincoln describes the concept of how the search for the Higgs boson is accomplished. Several large experimental groups are hot on the trail of this elusive subatomic particle which is thought to explain the origins of particle mass.

  18. Higgs Production by Gluon initiated Weak Boson Fusion

    E-Print Network [OSTI]

    M. M. Weber

    2007-09-17

    The gluon-gluon induced terms for Higgs production through weak-boson fusion are calculated. They form a finite and gauge-invariant subset of the NNLO corrections in the strong coupling constant. This is also the lowest order with sizeable t-channel colour exchange contributions, leading to additional hadronic activity between the outgoing jets.

  19. Present status and future prospects for a Higgs boson discovery at the Tevatron and LHC

    E-Print Network [OSTI]

    Howard E. Haber

    2010-11-04

    Discovering the Higgs boson is one of the primary goals of both the Tevatron and the Large Hadron Collider (LHC). The present status of the Higgs search is reviewed and future prospects for discovery at the Tevatron and LHC are considered. This talk focuses primarily on the Higgs boson of the Standard Model and its minimal supersymmetric extension. Theoretical expectations for the Higgs boson and its phenomenological consequences are reviewed.

  20. Search for Invisible Decays of a Higgs Boson Produced in Association with a Z Boson in ATLAS

    E-Print Network [OSTI]

    Taylor, Frank E.

    A search for evidence of invisible-particle decay modes of a Higgs boson produced in association with a Z boson at the Large Hadron Collider is presented. No deviation from the standard model expectation is observed in ...

  1. Higgs Boson Production from Black Holes at the LHC

    E-Print Network [OSTI]

    Gouranga C. Nayak; J. Smith

    2006-06-09

    If the fundamental Planck scale is near a TeV, then TeV scale black holes should be produced in proton-proton collisions at the LHC where \\sqrt{s} = 14 TeV. As the temperature of the black holes can be ~ 1 TeV we also expect production of Higgs bosons from them via Hawking radiation. This is a different production mode for the Higgs boson, which would normally be produced via direct pQCD parton fusion processes. In this paper we compare total cross sections and transverse momentum distributions d\\sigma/dp_T for Higgs production from black holes at the LHC with those from direct parton fusion processes at next-to-next-to-leading order and next-to-leading order respectively. We find that the Higgs production from black holes can be larger or smaller than the direct pQCD production depending upon the Planck mass and black hole mass. We also find that d\\sigma/dp_T of Higgs production from black holes increases as a function of p_T which is in sharp contrast with the pQCD predictions where d\\sigma/dp_T decreases so we suggest that the measurement of an increase in d\\sigma/dp_T as p_T increases for Higgs (or any other heavy particle) production can be a useful signature for black holes at the LHC.

  2. Higgs-Boson Production at Small Transverse Momentum

    E-Print Network [OSTI]

    Thomas Becher; Matthias Neubert; Daniel Wilhelm

    2013-10-22

    Using methods from effective field theory, we have recently developed a novel, systematic framework for the calculation of the cross sections for electroweak gauge-boson production at small and very small transverse momentum q_T, in which large logarithms of the scale ratio m_V/q_T are resummed to all orders. This formalism is applied to the production of Higgs bosons in gluon fusion at the LHC. The production cross section receives logarithmically enhanced corrections from two sources: the running of the hard matching coefficient and the collinear factorization anomaly. The anomaly leads to the dynamical generation of a non-perturbative scale q_* ~ m_H e^{-const/\\alpha_s(m_H)} ~ 8 GeV, which protects the process from receiving large long-distance hadronic contributions. We present detailed numerical predictions for the transverse-momentum spectrum of the Higgs boson, finding that it is quite insensitive to hadronic effects.

  3. Search for a light charged Higgs boson decaying into $c\\bar{s}$ at CMS

    E-Print Network [OSTI]

    Gouranga Kole

    2014-11-30

    We present results on the search for a light charged Higgs boson that can be produced in the decay of a top quark and later decays into a charm and an antistrange quark. The analysis is performed using $19.7\\invfb$ pp collison data recorded with the CMS detector at LHC.

  4. Searches Exploiting the Higgs Boson as a ?Dark/Hidden Sector Portal at the LHC

    E-Print Network [OSTI]

    Beacham, James Baker; The ATLAS collaboration

    2015-01-01

    Results are presented from LHC Run 1 ATLAS and CMS searches that use the SM Higgs boson as a portal to dark or hidden sectors, and Run 2 prospects for the same are discussed. The talk will be presented at WIN2015, the 25th International Workshop on Weak Interactions and Neutrinos, 8-13 June 2015 in Heidelberg, Germany.

  5. QCD and Electroweak Interference in Higgs production by Gauge Boson Fusion

    E-Print Network [OSTI]

    Jeppe R. Andersen; Jennifer M. Smillie

    2007-05-01

    We explicitly calculate the contribution to Higgs production at the LHC from the interference between gluon-gluon and Weak Vector Boson fusion, and compare it to the pure QCD and pure Electro-weak result. While the effect is small at tree level, we speculate it will be significantly enhanced by loop effects.

  6. Bounce Inflation Cosmology with Standard Model Higgs Boson

    E-Print Network [OSTI]

    Youping Wan; Taotao Qiu; Fa Peng Huang; Yi-Fu Cai; Hong Li; Xinmin Zhang

    2015-10-06

    It is of great interest to connect cosmology in the early universe to the Standard Model of particle physics. In this paper, we try to construct a bounce inflation model with the standard model Higgs boson, where the one loop correction is taken into account in the effective potential of Higgs field. In this model, a Galileon term has been introduced to eliminate the ghost mode when bounce happens. Moreover, due to the fact that the Fermion loop correction can make part of the Higgs potential negative, one naturally obtains a large equation of state(EoS) parameter in the contracting phase, which can eliminate the anisotropy problem. After the bounce, the model can drive the universe into the standard higgs inflation phase, which can generate nearly scale-invariant power spectrum.

  7. Bounce Inflation Cosmology with Standard Model Higgs Boson

    E-Print Network [OSTI]

    Wan, Youping; Huang, Fa Peng; Cai, Yi-Fu; Li, Hong; Zhang, Xinmin

    2015-01-01

    It is of great interest to connect cosmology in the early universe to the Standard Model of particle physics. In this paper, we try to construct a bounce inflation model with the standard model Higgs boson, where the one loop correction is taken into account in the effective potential of Higgs field. In this model, a Galileon term has been introduced to eliminate the ghost mode when bounce happens. Moreover, due to the fact that the Fermion loop correction can make part of the Higgs potential negative, one naturally obtains a large equation of state(EoS) parameter in the contracting phase, which can eliminate the anisotropy problem. After the bounce, the model can drive the universe into the standard higgs inflation phase, which can generate nearly scale-invariant power spectrum.

  8. Bounce Inflation Cosmology with Standard Model Higgs Boson

    E-Print Network [OSTI]

    Youping Wan; Taotao Qiu; Fa Peng Huang; Yi-Fu Cai; Hong Li; Xinmin Zhang

    2015-09-28

    It is of great interest to connect cosmology in the early universe to the Standard Model of particle physics. In this paper, we try to construct a bounce inflation model with the standard model Higgs boson, where the one loop correction is taken into account in the effective potential of Higgs field. In this model, a Galileon term has been introduced to eliminate the ghost mode when bounce happens. Moreover, due to the fact that the Fermion loop correction can make part of the Higgs potential negative, one naturally obtains a large equation of state(EoS) parameter in the contracting phase, which can eliminate the anisotropy problem. After the bounce, the model can drive the universe into the standard higgs inflation phase, which can generate nearly scale-invariant power spectrum.

  9. Searching for a Heavy Higgs boson in a Higgs-portal B-L Model

    E-Print Network [OSTI]

    Banerjee, Shankha; Spannowsky, Michael

    2015-01-01

    We study the discovery prospects of a heavy neutral scalar arising from a $U(1)_{B-L}$ extension of the Standard Model (SM) during the Large Hadron Collider's high luminosity runs (HL-LHC). This heavy neutral scalar mixes with the SM Higgs boson through a Higgs portal and interacts with the SM particles with an interaction strength proportional to the sine of the mixing angle. The mixing between the two Higgs bosons is constrained by direct and indirect measurements. We choose an experimentally viable mixing angle and explore in detail the $ZZ$ and $WW$ decay modes of the heavy Higgs boson. For the $ZZ$ case, we focus on the cleanest $4\\ell$ and $2\\ell 2j$ final states and find that a heavy Higgs boson of mass smaller than 500 GeV can be discovered at the HL-LHC. For the $WW$ decay mode, we analyze the $\\ell jj \\slashed{E}_T$ signature. We implement novel background reduction techniques in order to tackle the huge background by performing both cut-based and multivariate analyses. However, large backgrounds re...

  10. Higgs gravitational interaction, weak boson scattering, and Higgs inflation in Jordan and Einstein frames

    SciTech Connect (OSTI)

    Ren, Jing; Xianyu, Zhong-Zhi; He, Hong-Jian E-mail: xianyuzhongzhi@gmail.com

    2014-06-01

    We study gravitational interaction of Higgs boson through the unique dimension-4 operator ?H{sup †}HR, with H  the Higgs doublet and R  the Ricci scalar curvature. We analyze the effect of this dimensionless nonminimal coupling ?  on weak gauge boson scattering in both Jordan and Einstein frames. We explicitly establish the longitudinal-Goldstone equivalence theorem with nonzero ? coupling in both frames, and analyze the unitarity constraints. We study the ?-induced weak boson scattering cross sections at O(1?30) TeV scales, and propose to probe the Higgs-gravity coupling via weak boson scattering experiments at the LHC (14 TeV) and the next generation pp colliders (50-100 TeV). We further extend our study to Higgs inflation, and quantitatively derive the perturbative unitarity bounds via coupled channel analysis, under large field background at the inflation scale. We analyze the unitarity constraints on the parameter space in both the conventional Higgs inflation and the improved models in light of the recent BICEP2 data.

  11. Search for the standard model Higgs boson produced through vector boson fusion and decaying to b bbar

    E-Print Network [OSTI]

    CMS Collaboration

    2015-06-03

    A first search is reported for a standard model Higgs boson (H) that is produced through vector boson fusion and decays to a bottom-quark pair. Two data samples, corresponding to integrated luminosities of 19.8 inverse femtobarns and 18.3 inverse femtobarns of proton-proton collisions at sqrt(s)=8 TeV were selected for this channel at the CERN LHC. The observed significance in these data samples for a H to b bbar signal at a mass of 125 GeV is 2.2 standard deviations, whilst the expected significance is 0.8 standard deviations. The fitted signal strength mu=sigma/sigma[SM]=2.8 + 1.6 - 1.4. The combination of this result with other CMS searches for the Higgs boson decaying to a b-quark pair, yields a signal strength of 1.0 +/- 0.4, corresponding to a signal significance of 2.6 standard deviations for a Higgs boson mass of 125 GeV.

  12. Search for the standard model Higgs boson produced through vector boson fusion and decaying to b bbar

    E-Print Network [OSTI]

    CMS Collaboration

    2015-09-04

    A first search is reported for a standard model Higgs boson (H) that is produced through vector boson fusion and decays to a bottom-quark pair. Two data samples, corresponding to integrated luminosities of 19.8 inverse femtobarns and 18.3 inverse femtobarns of proton-proton collisions at sqrt(s) = 8 TeV were selected for this channel at the CERN LHC. The observed significance in these data samples for a H to b bbar signal at a mass of 125 GeV is 2.2 standard deviations, while the expected significance is 0.8 standard deviations. The fitted signal strength mu = sigma/sigma[SM] = 2.8 + 1.6 - 1.4. The combination of this result with other CMS searches for the Higgs boson decaying to a b-quark pair, yields a signal strength of 1.0 +/- 0.4, corresponding to a signal significance of 2.6 standard deviations for a Higgs boson mass of 125 GeV.

  13. A Search for the Standard Model Higgs Boson Produced in Association with a $W$ Boson

    SciTech Connect (OSTI)

    Frank, Martin Johannes; /Baylor U.

    2011-05-01

    We present a search for a standard model Higgs boson produced in association with a W boson using data collected with the CDF II detector from p{bar p} collisions at {radical}s = 1.96 TeV. The search is performed in the WH {yields} {ell}{nu}b{bar b} channel. The two quarks usually fragment into two jets, but sometimes a third jet can be produced via gluon radiation, so we have increased the standard two-jet sample by including events that contain three jets. We reconstruct the Higgs boson using two or three jets depending on the kinematics of the event. We find an improvement in our search sensitivity using the larger sample together with this multijet reconstruction technique. Our data show no evidence of a Higgs boson, so we set 95% confidence level upper limits on the WH production rate. We set limits between 3.36 and 28.7 times the standard model prediction for Higgs boson masses ranging from 100 to 150 GeV/c{sup 2}.

  14. Associated production of the Higgs boson with a W boson in proton-proton collisions: an explorative analysis of the three-leptons final state with the ATLAS experiment

    E-Print Network [OSTI]

    AUTHOR|(SzGeCERN)720937

    This work concern the study of the properties of the recently discovered Higgs boson in proton-proton collisions at the Large Hadron Collider (LHC). The Higgs boson is the particle that, according to the Standard Model (SM) theory, is responsible for the mass of all the known elementary particles (fermions and bosons). Its existence was postulated during the '60s in the so-called Brout- Englert-Higgs mechanism (BEH), but to have the experimental evidence of this particle scientists had to wait for the first results of the ATLAS and CMS Collaborations at the LHC (2012). Studying the Higgs boson production and decay modes at LHC is one of the purposes of the ATLAS Collaboration. This thesis, in particular, focuses on the study of the Higgs boson production in association with a W boson in proton-proton collision at a centre-of-mass energy of 8 TeV. The channel studied, with the Higgs boson further decaying in two W bosons, allows to direct probe the Higgs boson coupling exclusively with W bosons. The analysis h...

  15. Lightest Higgs boson production at photon colliders in the two Higgs doublet model type III

    SciTech Connect (OSTI)

    Martinez, R.; Rodriguez, J.-Alexis; Milanes, D.A.

    2005-08-01

    The branching ratios of the lightest CP-even Higgs boson h{sup 0} are calculated in the framework of the general two higgs doublet model. Different scenarios are presented taking into account constraints on the flavor changing neutral currents factors obtained in previous works. Plausible scenarios where appear flavor changing processes at tree level like bs and tc are analyzed for relevant parameters. The loop-induced Higgs couplings to photon pairs can be tested with a photon collider. The number of events of h{sup 0} as a resonance in photon colliders are calculated taking into account its corresponding background signal at TESLA, CLIC, and NLC.

  16. Dynamics of a global string with large Higgs boson mass

    E-Print Network [OSTI]

    C. Charmousis; B. Boisseau; B. Linet

    1998-01-12

    We consider a self-gravitating string generated by a global vortex solution in general relativity. We investigate the Einstein and field equations of a global vortex in the region of its central line and at a distance from the centre of the order of the inverse of its Higgs boson mass. By combining the two we establish by a limiting process of large Higgs mass the dynamics of a self-gravitating global string. Under our assumptions the presence of gravitation restricts the world sheet of the global string to be totally geodesic.

  17. Higgs bosons searches at CDF (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article)lasers (Journal Article) |different|(Journal Article)Higgs bosonsHiggs

  18. Search for the neutral MSSM Higgs bosons in the ditau decay channels at CDF Run II

    SciTech Connect (OSTI)

    Cuenca Almenar, Cristobal; /Valencia U., IFIC

    2008-04-01

    This thesis presents the results on a search for the neutral MSSM Higgs bosons decaying to tau pairs, with least one of these taus decays leptonically. The search was performed with a sample of 1.8 fb{sup -1} of proton-antiproton collisions at {radical}s = 1.96 TeV provided by the Tevatron and collected by CDF Run II. No significant excess over the Standard Model prediction was found and a 95% confidence level exclusion limit have been set on the cross section times branching ratio as a function of the Higgs boson mass. This limit has been translated into the MSSM Higgs sector parameter plane, tan{beta} vs. M{sub A}, for the four different benchmark scenarios.

  19. CDF note 10798 Seach for the SM Higgs boson in the ET +b-jets signature with relaxed

    E-Print Network [OSTI]

    Fermilab

    CDF note 10798 Seach for the SM Higgs boson in the ET +b-jets signature with relaxed kinematic cuts) We present a search for the Higgs boson produced in association with a Z or W boson in the ET +b the Higgs boson signal from the remaining background. We check the goodness of our background modeling

  20. NNLO Benchmarks for Gauge and Higgs Boson Production at TeV Hadron Colliders

    E-Print Network [OSTI]

    S. Alekhin; J. Blümlein; P. Jimenez-Delgado; S. Moch; E. Reya

    2010-11-29

    The inclusive production cross sections for $W^+, W^-$ and $Z^0$-bosons form important benchmarks for the physics at hadron colliders. We perform a detailed comparison of the predictions for these standard candles based on recent next-to-next-to-leading order (NNLO) parton parameterizations and new analyses including the combined HERA data, compare to all available experimental results, and discuss the predictions for present and upcoming RHIC, SPS, Tevatron and LHC energies. The rates for gauge boson production at the LHC can be rather confidently predicted with an accuracy of better than about 10% at NNLO. We also present detailed NNLO predictions for the Higgs boson production cross sections for Tevatron and LHC energies (1.96, 7, 8, 14 TeV), and propose a possible method to monitor the gluon distribution experimentally in the kinematic region close to the mass range expected for the Higgs boson. The production cross sections of the Higgs boson at the LHC are presently predicted with an accuracy of about 10--17%. The inclusion of the NNLO contributions is mandatory for achieving such accuracies since the total uncertainties are substantially larger at NLO.

  1. STUDY OF HIGGS BOSON PRODUCTION IN BOSONIC DECAY CHANNELS AT THE LHC (INCLUDING OFF-SHELL PRODUCTION)

    E-Print Network [OSTI]

    Oda, Susumu; The ATLAS collaboration

    2015-01-01

    Experimental studies of the Higgs boson production in bosonic decay channels by the ATLAS and CMS experiments at the LHC are described in this paper. The Higgs boson was the last undiscovered particle in the Standard Model (SM) of particle physics. The bosonic decay channels include $\\gamma\\gamma$, $Z\\gamma$, $ZZ^*$, $WW^*$. In the $\\gamma\\gamma$, $Z\\gamma$ and $ZZ^*$ decay channels, the whole event topology can be reconstructed. The $Z\\gamma$ decay channel can be sensitive to exotic Higgs decay beyond the SM. Because of its large branching fraction, the $WW^*$ decay channel is adequate to study bosonic production. Off-shell production is considered to be sensitive to the total Higgs decay width. The bosonic decay channels are a key to probe the SM and beyond.

  2. Fiducial cross sections for Higgs boson production in association with a jet at next-to-next-to-leading order in QCD

    E-Print Network [OSTI]

    Caola, Fabrizio; Schulze, Markus

    2015-01-01

    We extend the recent computation of Higgs boson production in association with a jet through next-to-next-to-leading order in perturbative QCD by including decays of the Higgs boson to electroweak vector bosons. This allows us to compute fiducial cross sections and kinematic distributions including realistic selection criteria for the Higgs boson decay products. As an illustration, we present results for $pp \\to H + j \\to \\gamma \\gamma + j$ closely following the ATLAS 8 TeV analysis and for $pp \\to H+ j \\to W W + j \\to e^+ \\mu^- \

  3. Search for lepton-flavour-violating decays of the Higgs boson...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Search for lepton-flavour-violating decays of the Higgs boson Citation Details In-Document Search Title: Search for lepton-flavour-violating decays of the Higgs...

  4. Combined CDF and D0 Searches for the Standard Model Higgs Boson Decaying to Two Photons with up to 8.2 fb^-1

    E-Print Network [OSTI]

    The CDF Collaboration; the D0 Collaboration; the Tevatron New Physics; Higgs Working Group

    2011-07-25

    We combine results from CDF and D0's direct searches for the standard model (SM) Higgs boson (H) produced in ppbar collisions at the Fermilab Tevatron at sqrt{s}=1.96 TeV, focusing on the decay H\\rightarrow\\gamma\\gamma. We compute upper limits on the Higgs boson production cross section times the decay branching fraction in the range 100Higgs boson. With datasets corresponding to 7.0 fb-1 (CDF) and 8.2 fb-1 (D0), the 95% C.L. upper limits on Higgs boson production is a factor of 10.5 times the SM cross section for a Higgs boson mass of 115 GeV/c^2.

  5. Tevatron Constraints on Models of the Higgs Boson with Exotic Spin and Parity Using Decays to Bottom-Antibottom Quark Pairs

    E-Print Network [OSTI]

    The CDF; D0 Collaborations

    2015-03-24

    Combined constraints from the CDF and D0 Collaborations on models of the Higgs boson with exotic spin $J$ and parity $P$ are presented and compared with results obtained assuming the standard model value $J^P=0^+$. Both collaborations analyzed approximately 10~fb$^{-1}$ of proton-antiproton collisions with a center-of-mass energy of 1.96 TeV collected at the Fermilab Tevatron. Two models predicting exotic Higgs bosons with $J^P=0^-$ and $J^P=2^+$ are tested. The kinematic properties of exotic Higgs boson production in association with a vector boson differ from those predicted for the standard model Higgs boson. Upper limits at the 95% credibility level on the production rates of the exotic Higgs bosons, expressed as fractions of the standard model Higgs boson production rate, are set at 0.36 for both the $J^P=0^-$ hypothesis and the $J^P=2^+$ hypothesis. If the production rate times the branching ratio to a bottom-antibottom pair is the same as that predicted for the standard model Higgs boson, then the exotic bosons are excluded with significances of 5.0 standard deviations and 4.9 standard deviations for the $J^P=0^-$ and $J^P=2^+$ hypotheses, respectively.

  6. Upper and lower Higgs boson mass bounds from a chirally invariant lattice Higgs-Yukawa model

    E-Print Network [OSTI]

    P. Gerhold

    2010-02-12

    Motivated by the advent of the Large Hadron Collider the aim of the present work is the non-perturbative determination of the cutoff-dependent upper and lower mass bounds of the Standard Model Higgs boson based on first principle calculations, in particular not relying on additional information such as the triviality property of the Higgs-Yukawa sector or indirect arguments like vacuum stability considerations. For that purpose the lattice approach is employed to allow for a non-perturbative investigation of a chirally invariant lattice Higgs-Yukawa model, serving here as a reasonable simplification of the full Standard Model, containing only those fields and interactions which are most essential for the intended Higgs boson mass determination. These are the complex Higgs doublet as well as the top and bottom quark fields and their mutual interactions. To maintain the chiral character of the Standard Model Higgs-fermion coupling also on the lattice, the latter model is constructed on the basis of the Neuberger overlap operator, obeying then an exact global lattice chiral symmetry.

  7. Search for the Standard Model Higgs Boson at the LEP2 Collider near

    E-Print Network [OSTI]

    Boyer, Edmond

    Search for the Standard Model Higgs Boson at the LEP2 Collider near ps = 183 GeV The ALEPHV. These data are used to look for possible signals from the production of the Standard Model Higgs boson on the mass of the Higgs boson: mH > 87:9 GeV=c2 at 95% con#12;dence level. The ALEPH Collaboration wish

  8. Strategy for discovering a low-mass Higgs boson at the Fermilab Tevatron Pushpalatha C. Bhat

    E-Print Network [OSTI]

    Bhat, Pushpalatha

    Strategy for discovering a low-mass Higgs boson at the Fermilab Tevatron Pushpalatha C. Bhat Fermi-mass standard model Higgs boson, during run II, via the processes pp¯WHl bb¯, pp¯ZH l l bb¯ and pp¯ZH ¯bb¯. We conventional analysis, in the integrated luminosity required to find a standard model Higgs boson in the mass

  9. arXiv:1311.5455v1 NLO QCD Corrections to Electroweak Higgs Boson

    E-Print Network [OSTI]

    Lunds Universitet,

    arXiv:1311.5455v1 [hep­ph] 21 Nov 2013 NLO QCD Corrections to Electroweak Higgs Boson Plus Three.sjodahl@thep.lu.se The implementation of the full next­to­leading order (NLO) QCD corrections to electroweak Higgs boson plus three jet Model (SM) Higgs boson [3, 4, 5, 6]. Further, reports from the ATLAS and CMS Collaborations indicate

  10. arXiv:1311.5455v1 NLO QCD Corrections to Electroweak Higgs Boson

    E-Print Network [OSTI]

    Lunds Universitet,

    arXiv:1311.5455v1 [hep­ph] 21 Nov 2013 NLO QCD Corrections to Electroweak Higgs Boson Plus Three.sjodahl@thep.lu.se The implementation of the full next­to­leading order (NLO) QCD corrections to electroweak Higgs boson plus three jet Model (SM) Higgs boson [3, 4, 5, 6]. Further, reports from the ATLAS and CMS Collaborations indicate

  11. D Note 6229-CONF Combined Upper Limits on Standard Model Higgs Boson Production

    E-Print Network [OSTI]

    Quigg, Chris

    D� Note 6229-CONF Combined Upper Limits on Standard Model Higgs Boson Production from the D�) Searches for standard model Higgs boson production in p¯p collisions at s = 1.96 TeV are carried out for Higgs boson masses (mH) in the range 100 mH 200 GeV/c2 . The contributing production processes include

  12. Search for the Standard Model Higgs Boson in the $WH \\to \\ell \

    SciTech Connect (OSTI)

    Nagai, Yoshikazu; /Tsukuba U.

    2010-02-01

    We have searched for the Standard Model Higgs boson in the WH {yields} lvbb channel in 1.96 TeV pp collisions at CDF. This search is based on the data collected by March 2009, corresponding to an integrated luminosity of 4.3 fb-1. The W H channel is one of the most promising channels for the Higgs boson search at Tevatron in the low Higgs boson mass region.

  13. Phase structure and Higgs boson mass in a Higgs-Yukawa model with a dimension-6 operator

    E-Print Network [OSTI]

    David Y. -J. Chu; Karl Jansen; Bastian Knippschild; C. -J. David Lin; Kei-Ichi Nagai; Attila Nagy

    2015-01-01

    We investigate the impact of a $\\lambda_6 \\varphi^6$ term included in a chirally invariant lattice Higgs-Yukawa model. Such a term could emerge from BSM physics at some larger energy scale. We map out the phase structure of the Higgs-Yukawa model with positive $\\lambda_6$ and negative quartic self coupling of the scalar fields. To this end, we evaluate the constraint effective potential in lattice perturbation theory and also determine the magnetization of the model via numerical simulations which allow us to reach also non-perturbative values of the couplings. As a result, we find a complex phase structure with first and second order phase transitions identified through the magnetization. Further we analyze the effect of such a $\\varphi^6$ term on the lower Higgs boson mass bound to see, whether the standard model lower mass bound can be altered.

  14. Ultra-weak sector, Higgs boson mass, and the dilaton

    SciTech Connect (OSTI)

    Allison, Kyle; Hill, Christopher T.; Ross, Graham G.

    2014-09-26

    The Higgs boson mass may arise from a portal coupling to a singlet field $\\sigma$ which has a very large VEV $f \\gg m_\\text{Higgs}$. This requires a sector of "ultra-weak" couplings $\\zeta_i$, where $\\zeta_i \\lesssim m_\\text{Higgs}^2 / f^2$. Ultra-weak couplings are technically naturally small due to a custodial shift symmetry of $\\sigma$ in the $\\zeta_i \\rightarrow 0$ limit. The singlet field $\\sigma$ has properties similar to a pseudo-dilaton. We engineer explicit breaking of scale invariance in the ultra-weak sector via a Coleman-Weinberg potential, which requires hierarchies amongst the ultra-weak couplings.

  15. Inflation scenario via the Standard Model Higgs boson and LHC

    E-Print Network [OSTI]

    A. O. Barvinsky; A. Yu. Kamenshchik; A. A. Starobinsky

    2008-09-11

    We consider a quantum corrected inflation scenario driven by a generic GUT or Standard Model type particle model whose scalar field playing the role of an inflaton has a strong non-minimal coupling to gravity. We show that currently widely accepted bounds on the Higgs mass falsify the suggestion of the paper arXiv:0710.3755 (where the role of radiative corrections was underestimated) that the Standard Model Higgs boson can serve as the inflaton. However, if the Higgs mass could be raised to $\\sim 230$ GeV, then the Standard Model could generate an inflationary scenario with the spectral index of the primordial perturbation spectrum $n_s\\simeq 0.935$ (barely matching present observational data) and the very low tensor-to-scalar perturbation ratio $r\\simeq 0.0006$.

  16. Ultra-weak sector, Higgs boson mass, and the dilaton

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Allison, Kyle; Hill, Christopher T.; Ross, Graham G.

    2014-11-01

    The Higgs boson mass may arise from a portal coupling to a singlet field $\\sigma$ which has a very large VEV $f \\gg m_\\text{Higgs}$. This requires a sector of "ultra-weak" couplings $\\zeta_i$, where $\\zeta_i \\lesssim m_\\text{Higgs}^2 / f^2$. Ultra-weak couplings are technically naturally small due to a custodial shift symmetry of $\\sigma$ in the $\\zeta_i \\rightarrow 0$ limit. The singlet field $\\sigma$ has properties similar to a pseudo-dilaton. We engineer explicit breaking of scale invariance in the ultra-weak sector via a Coleman-Weinberg potential, which requires hierarchies amongst the ultra-weak couplings.

  17. Search for a Higgs Boson Decaying to Two W Bosons at CDF

    SciTech Connect (OSTI)

    Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, Michael G.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E.; Anastassov, A.; Annovi, Alberto; Antos, J.; Apollinari, G.; /Fermilab /Purdue U.

    2008-09-01

    We present a search for a Higgs boson decaying to two W bosons in p{bar p} collisions at {radical}s = 1.96 TeV center-of-mass energy. The data sample corresponds to an integrated luminosity of 3.0 fb{sup -1} collected with the CDF II detector. We find no evidence for production of a Higgs boson with mass between 110 and 200 GeV/c{sup 2}, and determine upper limits on the production cross section. For the mass of 160 GeV/c{sup 2}, where the analysis is most sensitive, the observed (expected) limit is 0.7 pb (0.9 pb) at 95% Bayesian credibility level which is 1.7 (2.2) times the standard model cross section.

  18. tan\\beta\\ determination from the Higgs boson decay at the International Linear Collider

    E-Print Network [OSTI]

    Yokoya, Hiroshi

    2014-01-01

    We study the methods and their accuracies for determining tan\\beta\\ in two Higgs doublet models at future lepton colliders. In addition to the previously proposed methods using direct production of additional Higgs bosons, we propose a method using the precision measurement of the decay branching ratio of the standard-model (SM)-like Higgs boson. The method is available if there is a deviation from the SM in the coupling constants of the Higgs boson with the weak gauge bosons. We find that, depending on the type of Yukawa interactions, this method can give the best sensitivity in a wide range of tan\\beta.

  19. 125 Gev Higgs-Boson as Scalar partner of 91 Gev $Z^{0}$-Weak-boson in Composite subquark model

    E-Print Network [OSTI]

    Takeo Matsushima

    2012-07-10

    The composite subquark model previously proposed by us shows that the intermediate $Z^{0}$-weak-boson is realized as the composite particle and that its scalar partner has the mass value larger than $Z^{0}$-weak-boson mass. It is suggested that 125 Gev Higgs-boson found at LHC is a scalar partner of 91 Gev $Z^{0}$-weak-boson. We predict the existence of charged Higgs-bosons with the mass value around 100 to 120 Gev as the scalar partners of $W^{\\pm}$. We also discuss about Dark energy and Dark matter.

  20. Natural SUSY and the Higgs boson

    SciTech Connect (OSTI)

    Huang, Peisi

    2014-01-01

    Supersymmetry (SUSY) solves the hierarchy problem by introducing a super partner to each Standard Model(SM) particle. SUSY must be broken in nature, which means the fine-tuning is reintroduced to some level. Natural SUSY models enjoy low fine-tuning by featuring a small super potential parameter ? ~ 125 GeV, while the third generation squarks have mass less than 1.5 TeV. First and second generation sfermions can be at the multi-TeV level which yields a decoupling solution to the SUSY flavor and CP problem. However, models of Natural SUSY have difficulties in predicting a m{sub h} at 125 GeV, because the third generation is too light to give large radiative correction to the Higgs mass. The models of Radiative Natural SUSY (RNS) address this problem by allowing for high scale soft SUSY breaking Higgs mass m{sub Hu} > m{sub 0}, which leads to automatic cancellation by the Renormalization Group (RG) running effect. Coupled with the large mixing in the stop sector, RNS allows low fine-tuning at 3-10 % level and a 125 GeV SM-like Higgs. RNS can be reached at the LHC, and a linear collider. If the strong CP problem is solved by the Peccei-Quinn mechanism, then RNS accommodates mixed axion-Higgsino cold dark matter, where the Higgsino-like WIMPs, which in this case make up only a fraction of the relic abundance, can be detectable at future WIMP detectors.

  1. Search for invisible decays of Higgs bosons in the vector boson fusion and associated ZH production modes

    E-Print Network [OSTI]

    Apyan, Aram

    A search for invisible decays of Higgs bosons is performed using the vector boson fusion and associated ZH production modes. In the ZH mode, the Z boson is required to decay to a pair of charged leptons or a b[bar over b] ...

  2. Search for invisible decays of a Higgs boson using vector-boson fusion in $pp$ collisions at $\\sqrt{s}=8$ TeV with the ATLAS detector

    E-Print Network [OSTI]

    Aad, Georges; ATLAS Collaboration; Abdallah, Jalal; Abdinov, Ovsat; Aben, Rosemarie; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agricola, Johannes; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; ?lvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baak, Max; Baas, Alessandra; Baca, Matthew John; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Balunas, William Keaton; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansil, Hardeep Singh; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James Baker; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Kathrin; Becker, Maurice; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Janna Katharina; Belanger-Champagne, Camille; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernard, Nathan Rogers; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, Carolyn; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bevan, Adrian John; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Biedermann, Dustin; Bieniek, Stephen Paul; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina

    2015-01-01

    A search for a Higgs boson produced via vector-boson fusion and decaying into invisible particles is presented, using 20.3 fb$^{-1}$ of proton--proton collision data at a centre-of-mass energy of 8 TeV recorded by the ATLAS detector at the LHC. For a Higgs boson with a mass of 125 GeV, assuming the Standard Model production cross section, an upper bound of 0.28 is set on the branching fraction of $H\\to$ invisible at 95% confidence level, where the expected upper limit is 0.31. The results are interpreted in models of Higgs-portal dark matter where the branching fraction limit is converted into upper bounds on the dark-matter--nucleon scattering cross section as a function of the dark-matter particle mass, and compared to results from the direct dark-matter detection experiments.

  3. Search for invisible decays of a Higgs boson using vector-boson fusion in $pp$ collisions at $\\sqrt{s}=8$ TeV with the ATLAS detector

    E-Print Network [OSTI]

    ATLAS Collaboration

    2015-08-31

    A search for a Higgs boson produced via vector-boson fusion and decaying into invisible particles is presented, using 20.3 fb$^{-1}$ of proton--proton collision data at a centre-of-mass energy of 8 TeV recorded by the ATLAS detector at the LHC. For a Higgs boson with a mass of 125 GeV, assuming the Standard Model production cross section, an upper bound of 0.28 is set on the branching fraction of $H\\to$ invisible at 95% confidence level, where the expected upper limit is 0.31. The results are interpreted in models of Higgs-portal dark matter where the branching fraction limit is converted into upper bounds on the dark-matter--nucleon scattering cross section as a function of the dark-matter particle mass, and compared to results from the direct dark-matter detection experiments.

  4. Constraints on the mass spectrum of fourth generation fermions and Higgs bosons

    SciTech Connect (OSTI)

    Hashimoto, Michio [Theory Center, Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2010-04-01

    We reanalyze constraints on the mass spectrum of the chiral fourth generation fermions and the Higgs bosons for the standard model (SM4) and the two Higgs doublet model. We find that the Higgs mass in the SM4 should be larger than roughly the fourth generation up-type quark mass, while the light CP even Higgs mass in the two Higgs doublet model can be smaller. Various mass spectra of the fourth generation fermions and the Higgs bosons are allowed. The phenomenology of the fourth generation models is still rich.

  5. Search for associated production of a Higgs boson with a single top quark

    E-Print Network [OSTI]

    Kenneth Bloom

    2015-10-04

    We present a search for the production of a Higgs boson in association with a single top quark ($tHq$), using data samples collected by the CMS detector in $pp$ collisions at center-of-mass energy of 8 TeV corresponding to integrated luminosity of 19.7 fb$^{-1}$. The search exploits a variety of top quark and Higgs boson decay modes resulting in final states with photons, bottom quarks, or multileptons, and employs a variety of machine learning techniques to maximize the sensitivity to the signal. The present analysis is optimized for a scenario where the Yukawa coupling has sign opposite to the standard model prediction, which would result in a large enhancement of the signal cross section. Results for individual final states and the combined results will be presented.

  6. Search for associated production of a Higgs boson with a single top quark

    E-Print Network [OSTI]

    Bloom, Kenneth

    2015-01-01

    We present a search for the production of a Higgs boson in association with a single top quark ($tHq$), using data samples collected by the CMS detector in $pp$ collisions at center-of-mass energy of 8 TeV corresponding to integrated luminosity of 19.7 fb$^{-1}$. The search exploits a variety of top quark and Higgs boson decay modes resulting in final states with photons, bottom quarks, or multileptons, and employs a variety of machine learning techniques to maximize the sensitivity to the signal. The present analysis is optimized for a scenario where the Yukawa coupling has sign opposite to the standard model prediction, which would result in a large enhancement of the signal cross section. Results for individual final states and the combined results will be presented.

  7. Experimental constraints on the coupling of the Higgs boson to electrons

    E-Print Network [OSTI]

    Wolfgang Altmannshofer; Joachim Brod; Martin Schmaltz

    2015-03-16

    In the standard model (SM), the coupling of the Higgs boson to electrons is real and very small, proportional to the electron mass. New physics could significantly modify both real and imaginary parts of this coupling. We discuss experiments which are sensitive to the Higgs-electron coupling and derive the current bounds on new physics contributing to this coupling. The strongest constraint follows from the ACME bound on the electron electric dipole moment (EDM). We calculate the full analytic two-loop result for the electron EDM and show that it bounds the imaginary part of the Higgs-electron coupling to be less than 1.7 x 10^-2 times the SM electron Yukawa coupling. Deviations of the real part are much less constrained. We discuss bounds from Higgs decays, resonant Higgs production at electron colliders, Higgs mediated B -> e^+ e^- decays, and the anomalous magnetic moment of the electron. Currently, the strongest constraint comes from h -> e^+ e^- at the LHC, bounding the coupling to be less than ~600 times the SM Yukawa coupling. Important improvements can be expected from future EDM measurements as well as from resonant Higgs production at a next-generation high-luminosity e^+ e^- collider.

  8. Search for invisible decays of Higgs bosons in the vector boson fusion and associated ZH production modes

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et. al,

    2014-08-01

    A search for invisible decays of Higgs bosons is performed using the vector boson fusion and associated ZH production modes. In the ZH mode, the Z boson is required to decay to a pair of charged leptons or a b b-bar quark pair. The searches use the 8 TeV pp collision dataset collected by the CMS detector at the LHC, corresponding to an integrated luminosity of up to 19.7 inverse femtobarns. Certain channels include data from 7 TeV collisions corresponding to an integrated luminosity of 4.9 inverse femtobarns. The searches are sensitive to non-standard-model invisible decays of the recently observed Higgs boson, as well as additional Higgs bosons with similar production modes and large invisible branching fractions. In all channels, the observed data are consistent with the expected standard model backgrounds. Limits are set on the production cross section times invisible branching fraction, as a function of the Higgs boson mass, for the vector boson fusion and ZH production modes. By combining all channels, and assuming standard model Higgs boson cross sections and acceptances, the observed (expected) upper limit on the invisible branching fraction at m[H] = 125 GeV is found to be 0.58 (0.44) at 95% confidence level. We interpret this limit in terms of a Higgs-portal model of dark matter interactions.

  9. Study of the Higgs boson decay H ? ZZ(?) ? 4? and inner detector performance studies with the ATLAS experiment 

    E-Print Network [OSTI]

    Selbach, Karoline Elfriede

    2014-06-28

    The Higgs mechanism is the last piece of the SM to be discovered which is responsible for giving mass to the electroweak W± and Z bosons. Experimental evidence for the Higgs boson is therefore important and is currently ...

  10. NATURE PHYSICS | VOL 7 | DECEMBER 2011 | www.nature.com/naturephysics 919 The Higgs boson, as part of the standard

    E-Print Network [OSTI]

    Loss, Daniel

    NATURE PHYSICS | VOL 7 | DECEMBER 2011 | www.nature.com/naturephysics 919 editorial The Higgs boson. The Higgs boson is running out of places to hide. End of the line? Europe is embroiled in a major crisis

  11. Search for the standard model Higgs boson in tau lepton pair final states

    E-Print Network [OSTI]

    D0 Collaboration

    2012-05-16

    We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with zero, one, or two or more jets using data corresponding to an integrated luminosity of up to 7.3 fb^{-1} collected with the D0 detector at the Fermilab Tevatron collider. The analysis is sensitive to Higgs boson production via gluon gluon fusion, associated vector boson production, and vector boson fusion, and to Higgs boson decays to tau lepton pairs or W boson pairs. Observed (expected) limits are set on the ratio of 95% C.L. upper limits on the cross section times branching ratio, relative to those predicted by the Standard Model, of 14 (22) at a Higgs boson mass of 115 GeV and 7.7 (6.8) at 165 GeV.

  12. Search for the Higgs boson in lepton, tau and jets final states

    E-Print Network [OSTI]

    D0 Collaboration

    2013-01-28

    We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with two or more jets using 9.7 fb^{-1} of Run II Fermilab Tevatron Collider data collected with the D0 detector. The analysis is sensitive to Higgs boson production via gluon fusion, associated vector boson production, and vector boson fusion, followed by the Higgs boson decay to tau lepton pairs or to W boson pairs. The ratios of 95% C.L. upper limits on the cross section times branching ratio to those predicted by the standard model are obtained for orthogonal subsamples that are enriched in either H -> tau tau decays or H -> WW decays, and for the combination of these subsample limits. The observed and expected limit ratios for the combined subsamples at a Higgs boson mass of 125 GeV are 11.3 and 9.0 respectively.

  13. Search for the Higgs boson in lepton, tau, and jets final states

    SciTech Connect (OSTI)

    Abazov, V. M.; et al.

    2013-09-01

    We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with two or more jets using 9.7 fb?1 of Run II Fermilab Tevatron Collider data collected with the D0 detector. The analysis is sensitive to Higgs boson production via gluon fusion, associated vector boson production, and vector boson fusion, followed by the Higgs boson decay to tau lepton pairs or to W boson pairs. The ratios of 95% C.L. upper limits on the cross section times branching ratio to those predicted by the standard model are obtained for orthogonal subsamples that are enriched in either H ? ? ? decays or H ? WW decays, and for the combination of these subsample limits. The observed and expected limit ratios for the combined subsamples at a Higgs boson mass of 125 GeV are 11.3 and 9.0 respectively.

  14. Search for the standard model Higgs boson in tau lepton final states

    SciTech Connect (OSTI)

    Abazov, Victor Mukhamedovich; et al.

    2012-08-01

    We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with zero, one, or two or more jets using data corresponding to an integrated luminosity of up to 7.3 fb{sup -1} collected with the D0 detector at the Fermilab Tevatron collider. The analysis is sensitive to Higgs boson production via gluon gluon fusion, associated vector boson production, and vector boson fusion, and to Higgs boson decays to tau lepton pairs or W boson pairs. Observed (expected) limits are set on the ratio of 95% C.L. upper limits on the cross section times branching ratio, relative to those predicted by the Standard Model, of 14 (22) at a Higgs boson mass of 115 GeV and 7.7 (6.8) at 165 GeV.

  15. Search for invisible decays of the Higgs boson produced in association with a hadronically decaying vector boson in pp collisions at ?s = 8 with the ATLAS detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aad, G.; Barklow, T.

    2015-07-18

    A search for Higgs boson decays to invisible particles is performed using 20.3 fb?¹ of pp collision data at a centre-of-mass energy of 8 TeV recorded by the ATLAS detector at the Large Hadron Collider. The process considered is Higgs boson production in association with a vector boson (V = W or Z) that decays hadronically, resulting in events with two or more jets and large missing transverse momentum. No excess of candidates is observed in the data over the background expectation. The results are used to constrain V H production followed by H decaying to invisible particles for themore »Higgs boson mass range 115 H VH × BR(H ? inv.) varies from 1.6 pb at 115 GeV to 0.13 pb at 300 GeV. Assuming Standard Model production and including the gg ? H contribution as signal, the results also lead to an observed upper limit of 78% at 95% confidence level on the branching ratio of Higgs bosons decays to invisible particles at a mass of 125 GeV.« less

  16. A combined search for the standard model Higgs boson at sqrt{s}=1.96 TeV

    E-Print Network [OSTI]

    D0 Collaboration; V. M. Abazov

    2007-12-04

    We present new results of the search for WH to lepton neutrino b b production in ppbar collisions at a center of mass energy of sqrt{s}=1.96 TeV, based on a dataset with integrated luminosity of 0.44 fb-1. We combine these new results with previously published searches by the D0 collaboration, for WH and ZH production analyzed in the MET b b final state, for ZH (to l+l- b b) production, for WH (to WWW) production, and for H (to WW) direct production. No signal-like excess is observed either in the WH analysis or in the combination of all D0 Higgs boson analyses. We set 95% C.L. (expected) upper limits on to 1.9 (3.3) pb for Higgs boson masses between 105 and 145 GeV, to be compared to the theoretical prediction of 0.13 pb for a standard model (SM) Higgs boson with mass m_H=115 GeV. After combination with the other D0 Higgs boson searches, we obtain for m_H=115 GeV an observed (expected) limit 8.5 (12.1) times higher than the SM predicted Higgs boson production cross section. For m_H=160 GeV, the corresponding observed (expected) ratio is 10.2 (9.0).

  17. The Fourth Standard Model Family and the Competition in Standart Model Higgs Boson Search at Tevatron and LHC

    E-Print Network [OSTI]

    N. Becerici Schmidt; S. A. Cetin; S. Istin; S. Sultansoy

    2009-08-23

    The impact of the fourth Standard Model family on Higgs boson search at Tevatron and LHC is reviewed.

  18. Search for the Standard Model Higgs Boson in the Lepton + Missing Transverse Energy + Jets Final State in ATLAS

    E-Print Network [OSTI]

    Mark S. Neubauer; for the ATLAS Collaboration

    2011-10-11

    A search for the Standard Model Higgs boson has been performed in the H \\rightarrow WW \\rightarrow l{\

  19. Higgs Boson Mass predicted by the Four Color Theorem

    E-Print Network [OSTI]

    Ashay Dharwadker; Vladimir Khachatryan

    2009-12-28

    We show that the mathematical proof of the four color theorem yields a perfect interpretation of the Standard Model of particle physics. The steps of the proof enable us to construct the t-Riemann surface and particle frame which forms the gauge. We specify well-defined rules to match the Standard Model in a one-to-one correspondence with the topological and algebraic structure of the particle frame. This correspondence is exact - it only allows the particles and force fields to have the observable properties of the Standard Model, giving us a Grand Unified Theory. In this paper, we concentrate on explicitly specifying the quarks, gauge vector bosons, the Standard Model scalar Higgs $H^{0}$ boson and the weak force field. Using all the specifications of our mathematical model, we show how to calculate the values of the Weinberg and Cabibbo angles on the particle frame. Finally, we present our prediction of the Higgs $H^{0}$ boson mass $M_{H^{0}} = 125.992 \\simeq 126 GeV$, as a direct consequence of the proof of the four color theorem.

  20. Search for the Standard Model Higgs boson in the decay mode H-> WW-> lnulnu

    SciTech Connect (OSTI)

    Penning, B.; /Freiburg U.

    2009-09-01

    The question of the nature and principles of the universe and our place in it is the driving force of science since Mesopotamian astronomers glanced for the first time at the starry sky and Greek atomism has been formulated. During the last hundred years modern science was able to extend its knowledge tremendously, answering many questions, opening entirely new fields but as well raising many new questions. Particularly Astronomy, Astroparticle Physics and Particle Physics lead the race to answer these fundamental and ancient questions experimentally. Today it is known that matter consists of fermions, the quarks and leptons. Four fundamental forces are acting between these particles, the electromagnetic, the strong, the weak and the gravitational force. These forces are mediated by particles called bosons. Our confirmed knowledge of particle physics is based on these particles and the theory describing their dynamics, the Standard Model of Particles. Many experimental measurements show an excellent agreement between observation and theory but the origin of the particle masses and therefore the electroweak symmetry breaking remains unexplained. The mechanism proposed to solve this issue involves the introduction of a complex doublet of scalar fields which generates the masses of elementary particles via their mutual interactions. This Higgs mechanism also gives rise to a single neutral scalar boson with an unpredicted mass, the Higgs boson. During the last twenty years several experiments have searched for the Higgs boson but so far it escaped direct observation. Nevertheless these studies allow to further constrain its mass range. The last experimental limits on the Higgs mass have been set in 2001 at the LEP collider, an electron positron machine close to Geneva, Switzerland. The lower limit set on the Higgs boson mass is m{sub H} > 114.4 GeV/c{sup 2} and remained for many years the last experimental constraint on the Standard Model Higgs Boson due to the shutdown of the LEP collider and the experimental challenges at hadron machines as the Tevatron. This thesis was performed using data from the D0 detector located at the Fermi National Accelerator Laboratory in Batavia, IL. Final states containing two electrons or a muon and a tau in combination with missing transverse energy were studied to search for the Standard Model Higgs boson, utilizing up to 4.2 fb{sup -1} of integrated luminosity. In 2008 the CDF and D0 experiments in a combined effort were able to reach for the first time at a hadron collider the sensitivity to further constrain the possible Standard Model Higgs boson mass range. The research conducted for this thesis played a pivotal role in this effort. Improved methods for lepton identification, background separation, assessment of systematic uncertainties and new decay channels have been studied, developed and utilized. Along with similar efforts at the CDF experiment these improvements led finally the important result of excluding the presence of a Standard Model Higgs boson in a mass range of m{sub H} = 160-170 GeV/c{sup 2} at 95% Confidence Level. Many of the challenges and methods found in the present analysis will probably in a similar way be ingredients of a Higgs boson evidence or discovery in the near future, either at the Tevatron or more likely at the soon starting Large Hadron Collider (LHC). Continuing to pursue the Higgs boson we are looking forward to many exciting results at the Tevatron and soon at the LHC. In Chapter 2 an introduction to the Standard Model of particle physics and the Higgs mechanism is given, followed by a brief outline of existing theoretical and experimental constraints on the Higgs boson mass before summarizing the Higgs boson production modes. Chapter 3 gives an overview of the experimental setup. This is followed by a description of the reconstruction of the objects produced in proton-antiproton collisions in Chapter 4 and the necessary calorimeter calibrations in Chapter 5. Chapter 6 follows with an explanation of the phenomenology of the proton-antiproton colli

  1. Bounds on the Nonminimal Coupling of the Higgs Boson to Gravity

    E-Print Network [OSTI]

    Michael Atkins; Xavier Calmet

    2013-02-01

    We derive the first bound on the value of the Higgs boson non-minimal coupling to the Ricci scalar. We show that the recent discovery of the Higgs boson at the Large Hadron Collider at CERN implies that the non-minimal coupling is smaller than $2.6\\times 10^{15}$.

  2. Two heavy fermions bound via Higgs boson exchange

    E-Print Network [OSTI]

    Victor Flambaum; Michael Kuchiev

    2011-12-11

    A system of two heavy fermions, leptons or quarks of the fourth generation, which are bound together via the Higgs boson exchange is studied. The conventional Yukawa-type interaction produced by this exchange is accompanied by several important corrections. We derived the Hamiltonian, which describes the correction arising from the retardation (compare the Breit correction in QED); we also calculated the relativistic and radiative corrections. The Higgs-induced bound state appears for the fermion mass m>m_{cr} \\approx 500 GeV. When the long-range Coulomb interaction or the gluon exchange are included, the bound states exist for any mass, but the Higgs exchange drastically increases the binding energy of these states when m is approaching m_{cr}. In the region m>m_{cr} the gluon exchange gives a sizable correction to the Higgs induced binding energy. This correction greatly exceeds typical binding energies in the states produced via the gluon exchange only. The possibility of detection of the considered bound states at LHC is discussed.

  3. Left-right supersymmetry after the Higgs boson discovery

    E-Print Network [OSTI]

    Mariana Frank; Dilip Kumar Ghosh; Katri Huitu; Santosh Kumar Rai; Ipsita Saha; Harri Waltari

    2014-12-31

    We perform a thorough analysis of the parameter space of the minimal left-right supersymmetric model in agreement with the LHC data. The model contains left- and right-handed fermionic doublets, two Higgs bidoublets, two Higgs triplet representations, and one singlet, insuring a charge-conserving vacuum. We impose the condition that the model complies with the experimental constraints on supersymmetric particles masses and on the doubly-charged Higgs bosons, and require that the parameter space of the model satisfy the LHC data on neutral Higgs signal strengths at $2\\sigma$. We choose benchmark scenarios by fixing some basic parameters and scanning over the rest. The LSP in our scenarios is always the lightest neutralino. We find that the signals for $H\\to \\gamma \\gamma$ and $H \\to VV^\\star$ are correlated, while $H \\to b \\bar b$ is anti-correlated with all the other decay modes, and also that the contribution from singly-charged scalars dominate that of the doubly-charged scalars in $H\\to \\gamma \\gamma$ and $H \\to Z\\gamma$ loops, contrary to Type-II seesaw models. We also illustrate the range for mass spectrum of the LRSUSY model in light of planned measurements of the branching ratio of $H\\to \\gamma \\gamma$ to 10% level.

  4. A Measurement of the Recently Discovered Higgs Boson in the Decay into Two Photons with Associated Jets, Using

    E-Print Network [OSTI]

    Sheldon, Nathan D.

    A Measurement of the Recently Discovered Higgs Boson in the Decay into Two Photons with Associated or not this is the Higgs boson as predicted by the Standard Model of Particle Physics (SM). Experimentally measuring of the Higgs boson via its decay into two photons, which was one of the key discovery channels. Part

  5. CDF note 10582 Search for SM Higgs boson production in association with tt using no lepton final state

    E-Print Network [OSTI]

    Fermilab

    CDF note 10582 Search for SM Higgs boson production in association with t¯t using no lepton final is that t¯t decay all hadronic mode (all t decay into bqq ). In both cases we consider that the Higgs boson discriminant variable from different neural network to discriminate the Higgs boson signal from remained

  6. The search for Higgs boson production in the fourjet channel at 192 < # s < 202 GeV with the

    E-Print Network [OSTI]

    Glasgow, University of

    The search for Higgs boson production in the four­jet channel at 192 for neutral Higgs boson production in e + e - collisions using data collected by the ALEPH detector at the LEP with four hadronic jets. No evidence of Higgs boson production is found. In the context of the Standard

  7. ATLAS DISCOVERY POTENTIAL FOR A HEAVY CHARGED HIGGS BOSON.

    SciTech Connect (OSTI)

    ASSAMAGAN,K.A.; COADOU,Y.; DEANDREA,A.

    2002-02-01

    The sensitivity of the ATLAS detector to the discovery of a heavy charged Higgs boson is presented. Assuming a heavy SUSY spectrum, the most promising channels above the top quark mass are H{sup {+-}} {yields} tb and h{sup {+-}} {yields} {tau}{sup {+-}}{nu}{sub {tau}} which provide coverage in the low and high tan {beta} regions up to {approx} 600 GeV. The achievable precisions on the charged Higgs mass and tan {beta} determination are also discussed. The H{sup {+-}} {yields} W{sup {+-}}h{sup 0} channel, though restricted to a small MSSM parameter space, shows a viable signal in NMSSM where the parameter space is less constrained. The observation of the channel H{sup -} {yields} {tau}{sub L}{sup -} {nu}{sub {tau}} + c.c. may constitute a distinctive evidence for models with singlet neutrinos in large extra dimensions.

  8. LHC searches for heavy neutral Higgs bosons with a top jet substructure analysis

    E-Print Network [OSTI]

    Ning Chen; Jinmian Li; Yandong Liu

    2015-09-13

    We study the LHC searches for the heavy $CP$-odd Higgs boson $A$ and $CP$-even Higgs boson $H$ in the context of general two-Higgs-doublet model. Specifically, we consider the decay mode of $A/H\\to t \\bar t $ through the $b \\bar b$ or $t \\bar t $ associated production channels. In the so-called "alignment limit" of the two-Higgs-doublet model, this decay mode can be the most dominant one. By employing the HEPTopTagger and the multi-variable-analysis method, we present the search sensitivities for both $CP$-odd Higgs boson $A$ and $CP$-even Higgs boson $H$ via these channels at the high-luminosity LHC runs.

  9. Charged Higgs boson in the $W^\\pm$ Higgs channel at the Large Hadron Collider

    E-Print Network [OSTI]

    Rikard Enberg; William Klemm; Stefano Moretti; Shoaib Munir; Glenn Wouda

    2015-02-14

    In light of the recent discovery of a neutral Higgs boson, $H_{\\rm obs}$, with a mass near 125 GeV, we reassess the LHC discovery potential of a charged Higgs boson, $H^\\pm$, in the $W^\\pm H_{\\rm obs}$ decay channel. This decay channel can be particularly important for a $H^\\pm$ heavier than the top quark, when it is produced through the $pp \\rightarrow tH^\\pm$ process. The knowledge of the mass of $H_{\\rm obs}$ provides an additional handle in the kinematic selection when reconstructing a Breit-Wigner resonance in the $H_{\\rm obs} \\rightarrow b\\bar{b}$ decay channel. We consider some extensions of the Standard Model Higgs sector, with and without supersymmetry, and perform a dedicated signal-to-background analysis to test the scope of this channel for the LHC running at the design energy (14 TeV), for 300/fb (standard) and 3000/fb (high) integrated luminosities. We find that, while this channel does not show much promise for a supersymmetric $H^\\pm$ state, significant portions of the parameter spaces of several two-Higgs doublet models are testable.

  10. Radiative corrections in fermion bags bound by Higgs boson exchange

    E-Print Network [OSTI]

    M. Yu. Kuchiev; V. V. Flambaum

    2011-01-16

    Radiative corrections for several heavy fermions bound together via the Higgs boson exchange are studied. The fermion bags considered include 12, or fewer, fermions occupying the lowest S_{1/2} shell. It is shown that for `moderately heavy' fermions with masses 0.4< m c^2< 1 TeV the radiative corrections are small, 10^{-2}, and have an attractive nature. Therefore they do not put existence of the fermion bag in doubt. This proves that these fermion bags can exist in nature.

  11. On the global solutions of the Higgs boson equation

    E-Print Network [OSTI]

    Karen Yagdjian

    2010-10-03

    In this article we study global in time (not necessarily small) solutions of the equation for the Higgs boson in the Minkowski and in the de Sitter spacetimes. We reveal some qualitative behavior of the global solutions. In particular, we formulate sufficient conditions for the existence of the zeros of global solutions in the interior of their supports, and, consequently, for the creation of the so-called bubbles, which have been studied in particle physics and inflationary cosmology. We also give some sufficient conditions for the global solution to be an oscillatory in time solution.

  12. Higgs bosons searches at CDF (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article)lasers (Journal Article) |different|(Journal Article)Higgs bosons

  13. Dark matter and Higgs boson collider implications of fermions in an abelian-gauged hidden sector

    E-Print Network [OSTI]

    Shrihari Gopalakrishna; Seung J. Lee; James D. Wells

    2009-04-13

    We add fermions to an abelian-gauged hidden sector. We show that the lightest can be the dark matter with the right thermal relic abundance, and discovery is within reach of upcoming dark matter detectors. We also show that these fermions change Higgs boson phenomenology at the Large Hadron Collider (LHC), and in particular could induce a large invisible width to the lightest Higgs boson state. Such an invisibly decaying Higgs boson can be discovered with good significance in the vector boson fusion channel at the LHC.

  14. Associated Production of Higgs Boson and $t\\bar t$ at LHC

    E-Print Network [OSTI]

    Li, Hong-Lei; Si, Zong-Guo; Wang, Ying

    2015-01-01

    One of the future goals of the LHC is to precisely measure the properties of Higgs boson. The associated production of Higgs boson and the top quark pair is a promising process to investigate the related Yukawa interaction and the properties of Higgs. Compared with the pure scalar sector in the Standard Model, the Higgs sector contains both scalar and pseudoscalar in many new physics models, which makes the $t\\bar t H$ interaction more complex and provides a variety of phenomena. To investigate the $t\\bar t H$ interaction and the properties of Higgs, we study the top quark spin correlation observables at the LHC.

  15. Search for H to $ \\mathrm{b\\bar{b}}$ in association with single top quarks as a test of Higgs boson couplings

    E-Print Network [OSTI]

    Simon Fink

    2015-03-18

    The production of a Higgs boson in association with a single top quark is one of a few channels which are sensitive for not yet excluded anomalous couplings of the Higgs boson to fermions. Multivariate analysis tools are used for the reconstruction and classification of signal events, where the Higgs boson decays into bottom quarks and the single top quark decays leptonically. In this conference report the most recent results at time of the conference using the full dataset recorded by the CMS detector at 8 TeV are presented.

  16. Search for Standard Model Higgs Boson in H to WW Channel at CDF

    E-Print Network [OSTI]

    J. Pursley; for the CDF Collaboration

    2009-10-08

    We present a search for standard model Higgs boson to WW(*) production in dilepton plus missing transverse energy final states in data collected by the CDF II detector corresponding to 4.8/fb of integrated luminosity. To maximize sensitivity, the multivariate discriminants used to separate signal from background in the opposite-sign dilepton event sample are independently optimized for final states with zero, one, or two or more identified jets. All significant Higgs boson production modes (gluon fusion, associated production with either a W or Z boson, and vector boson fusion) are considered in determining potential signal contributions. We also incorporate a separate analysis of the same-sign dilepton event sample which potentially contains additional signal events originating from associated Higgs boson production mechanisms. Cross section limits relative to the combined SM predictions are presented for a range of Higgs boson mass hypotheses between 110 and 200 GeV/c^2.

  17. Search for MSSM Higgs Bosons in Tau Final States with the D0 Detector

    SciTech Connect (OSTI)

    Yang, Wan-Ching; /Manchester U.

    2010-09-01

    The cross-section times branching ratio of the Higgs boson decaying to {tau}{sup +}{tau}{sup -} final state in the Standard Model (SM) is too small to play any role in the SM Higgs boson searches. This, however, is different in the Minimal Supersymmetric Standard Model (MSSM), which predicts two Higgs doublets leading to five Higgs bosons: a pair of charged Higgs boson (H{sup {+-}}); two neutral CP-even Higgs bosons (h,H) and a CP-odd Higgs boson (A). A search for the production of neutral Higgs bosons decaying into {tau}{sup +}{tau}{sup -} final states in p{bar p} collisions at a centre-of-mass energy of {radical}s = 1.96 TeV is presented in this thesis. One of the two {tau} leptons is required to decay into a muon while the other decays hadronically. The integrated luminosity is L = 1.0-5.36 fb{sup -1}, collected by the D0 experiment at the Fermilab Tevatron Collider from 2002 to 2009 in the Run II.

  18. Tevatron Constraints on Models of the Higgs Boson with Exotic Spin and Parity Using Decays to Bottom-Antibottom Quark Pairs

    E-Print Network [OSTI]

    Aaltonen, T.

    Combined constraints from the CDF and D0 Collaborations on models of the Higgs boson with exotic spin J and parity P are presented and compared with results obtained assuming the standard model value J[superscript P] = ...

  19. Effective Yukawa couplings and flavor-changing Higgs boson decays at linear colliders

    SciTech Connect (OSTI)

    Gabrielli, E.; Mele, B.

    2011-04-01

    We analyze the advantages of a linear-collider program for testing a recent theoretical proposal where the Higgs boson Yukawa couplings are radiatively generated, keeping unchanged the standard-model mechanism for electroweak-gauge-symmetry breaking. Fermion masses arise at a large energy scale through an unknown mechanism, and the standard model at the electroweak scale is regarded as an effective field theory. In this scenario, Higgs boson decays into photons and electroweak gauge-boson pairs are considerably enhanced for a light Higgs boson, which makes a signal observation at the LHC straightforward. On the other hand, the clean environment of a linear collider is required to directly probe the radiative fermionic sector of the Higgs boson couplings. Also, we show that the flavor-changing Higgs boson decays are dramatically enhanced with respect to the standard model. In particular, we find a measurable branching ratio in the range (10{sup -4}-10{sup -3}) for the decay H{yields}bs for a Higgs boson lighter than 140 GeV, depending on the high-energy scale where Yukawa couplings vanish. We present a detailed analysis of the Higgs boson production cross sections at linear colliders for interesting decay signatures, as well as branching-ratio correlations for different flavor-conserving/nonconserving fermionic decays.

  20. MSSM Higgs Boson Searches at the LHC: Benchmark Scenarios after the Discovery of a Higgs-like Particle

    SciTech Connect (OSTI)

    Carena, M.; Heinemeyer, S.; Stål, O.; Wagner, C.E.M.; Weiglein, G.

    2013-09-01

    A Higgs-like particle with a mass of about 125.5 GeV has been discovered at the LHC. Within the current experimental uncertainties, this new state is compatible with both the predictions for the Standard Model (SM) Higgs boson and with the Higgs sector in the Minimal Supersymmetric Standard Model (MSSM). We propose new low-energy MSSM benchmark scenarios that, over a wide parameter range, are compatible with the mass and production rates of the observed signal. These scenarios also exhibit interesting phenomenology for the MSSM Higgs sector. We propose a slightly updated version of the well-known mh-max scenario, and a modified scenario (mh-mod), where the light CP-even Higgs boson can be interpreted as the LHC signal in large parts of the MA-tan \\beta\\ plane. Furthermore, we define a light stop scenario that leads to a suppression of the lightest CP-even Higgs gluon fusion rate, and a light stau scenario with an enhanced decay rate of h to \\gamma\\gamma\\ at large tan \\beta. We also suggest a \\tau-phobic Higgs scenario in which the lightest Higgs can have suppressed couplings to down-type fermions. We propose to supplement the specified value of the \\mu\\ parameter in some of these scenarios with additional values of both signs. This has a significant impact on the interpretation of searches for the non SM-like MSSM Higgs bosons. We also discuss the sensitivity of the searches to heavy Higgs decays into light charginos and neutralinos, and to decays of the form H to hh. Finally, in addition to all the other scenarios where the lightest CP-even Higgs is interpreted as the LHC signal, we propose a low-MH scenario, where instead the heavy CP-even Higgs boson corresponds to the new state around 125.5 GeV.

  1. Higgs boson production in association with b jets in the POWHEG BOX

    E-Print Network [OSTI]

    Jager, Barbara; Wackeroth, Doreen

    2015-01-01

    The hadronic production of a Higgs boson (H) in association with b jets will play an important role in investigating the Higgs-boson couplings to Standard Model particles during Run II of the CERN Large Hadron Collider, and could in particular reveal the presence of anomalies in the assumed hierarchy of Yukawa couplings to the third-generation quarks. A very high degree of accuracy in the theoretical description of this process is crucial to implement the rich physics program that could lead to either direct or indirect evidence of new physics from Higgs-boson measurements. Aiming for accuracy in the theoretical modeling of H+b-jet production, we have interfaced the analytic Next-to-Leading-Order QCD calculation of H-bottom-antibottom production with parton-shower Monte Carlo event generators in the POWHEG BOX framework. In this paper we describe the most relevant aspects of the implementation and present results for the production of H+1 b jet, H+2 b jets, and $H$ with no tagged b jets, in the form of kinema...

  2. Combined CDF and D0 Upper Limits on Standard Model Higgs Boson Production with up to 8.2 fb-1 of Data

    E-Print Network [OSTI]

    The CDF; D0 Collaborations; the TEVNPHWG Working Group

    2011-08-16

    We combine results from CDF and D0's direct searches for the standard model (SM) Higgs boson (H) produced in p-pbar collisions at the Fermilab Tevatron at sqrt(s)=1.96 TeV. The results presented here include those channels which are most sensitive to Higgs bosons with mass between 130 and 200 GeV/c^2, namely searches targeted at Higgs boson decays to W+W-, although acceptance for decays into tau+tau- and gamma gamma is included. Compared to the previous Tevatron Higgs search combination, more data have been added and the analyses have been improved to gain sensitivity. We use the MSTW08 parton distribution functions and the latest gg to H theoretical cross section predictions when testing for the presence of a SM Higgs boson. With up to 7.1 fb-1 of data analyzed at CDF, and up to 8.2 fb-1 at D0, the 95% C.L. upper limits on Higgs boson production is a factor of 0.54 times the SM cross section for a Higgs boson mass of 165 GeV/c^2. We exclude at the 95% C.L. the region 158

  3. Discovery and Characterization of a Higgs boson using four-lepton events from the CMS experiment

    E-Print Network [OSTI]

    AUTHOR|(SzGeCERN)678846

    2015-01-01

    A new particle decaying to a pair of vector bosons was discovered in 2012 by the ATLAS and CMS experiments at the Large Hadron Collider. In the wake of this discovery a rush of measurements was made to characterize this particle. The four-lepton final state has been instrumental in both the discovery and characterization of this new particle. With only about 20 events seen in the resonance peak at 125GeV the CMS experiment has been able to make considerable progress in characterizing the Higgs-like boson using the wealth of information in this final state in concert with other decay modes. In addition to the search for this new boson we present three recent results in the study of the Higgs-like boson properties: studies of the production mode, total width, and spin-parity quantum numbers. First we present the search for this new resonance using the H to ZZ to 4l decay channel. Then we discuss the production mode measurement using this final state. Next, we present two results that provided breakthroughs in t...

  4. Search for standard model Higgs boson production in association with a W boson using a neural network discriminant at CDF

    E-Print Network [OSTI]

    Xie, Si

    We present a search for standard model Higgs boson production in association with a W boson in proton-antiproton collisions (pp??W[superscript ±]H???bb?) at a center of mass energy of 1.96 TeV. The search employs data ...

  5. Search for neutral Higgs bosons decaying to tau pairs produced in association with b quarks in pp? collisions at ?s=1.96 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D; Alkhazov, Georgiy D; Alton, Andrew K; Alverson, George O; Alves, Gilvan Augusto; et al

    2011-09-12

    We report results from a search for neutral Higgs bosons produced in association with b quarks using data recorded by the D0 experiment at the Fermilab Tevatron Collider and corresponding to an integrated luminosity of 7.3 fb-1. This production mode can be enhanced in several extensions of the standard model (SM) such as in its minimal supersymmetric extension (MSSM) at high tanß. We search for Higgs bosons decaying to tau pairs with one tau decaying to a muon and neutrinos and the other to hadrons. The data are found to be consistent with SM expectations, and we set upper limitsmore »on the cross section times branching ratio in the Higgs boson mass range from 90 to 320 GeV/c2. We interpret our result in the MSSM parameter space, excluding tanß values down to 25 for Higgs boson masses below 170 GeV/c2.« less

  6. Search for neutral Higgs bosons decaying to tau pairs produced in association with b quarks in pp? collisions at ?s=1.96 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazov, Victor Mukhamedovich [Dubna, JINR; Abbott, Braden Keim [Oklahoma U.; Acharya, Bannanje Sripath [Tata Inst.; Adams, Mark Raymond [Illinois U., Chicago; Adams, Todd [Florida State U.; Alexeev, Guennadi D [Dubna, JINR; Alkhazov, Georgiy D [St. Petersburg, INP; Alton, Andrew K [Michigan U.; Augustana Coll., Sioux Falls; Alverson, George O [Northeastern U.; Alves, Gilvan Augusto [Rio de Janeiro, CBPF; Aoki, Masato [Fermilab; Louisiana Tech. U.

    2011-09-12

    We report results from a search for neutral Higgs bosons produced in association with b quarks using data recorded by the D0 experiment at the Fermilab Tevatron Collider and corresponding to an integrated luminosity of 7.3 fb-1. This production mode can be enhanced in several extensions of the standard model (SM) such as in its minimal supersymmetric extension (MSSM) at high tanß. We search for Higgs bosons decaying to tau pairs with one tau decaying to a muon and neutrinos and the other to hadrons. The data are found to be consistent with SM expectations, and we set upper limits on the cross section times branching ratio in the Higgs boson mass range from 90 to 320 GeV/c2. We interpret our result in the MSSM parameter space, excluding tanß values down to 25 for Higgs boson masses below 170 GeV/c2.

  7. Search for non Standard Model Higgs boson decays in events with displaced muon-jets

    E-Print Network [OSTI]

    Dildick, Sven; Krutelyov, Slava; Pakhotin, Yuriy; Rose, Anthony; Safonov, Alexei; Tararinov, Aysen; Bouhali, Othmane; Hernandez, Alfredo Martin Castaneda

    2015-01-01

    New light bosons that couple weakly to the standard model (SM) particles are predicted in various extensions of the standard model (BSM). Examples include supersymmetric (SUSY) theories with extended Higgs sectors or with a hidden valleys (dark SUSY). In these models the light bosons can be produced directly in the decay of a Higgs boson, or as part of the decay chain of SUSY particles. Depending on the branching fraction, the exotic decays of the SM-Higgs can be undetected in standard analysis techniques or due to its modified production cross section of the Higgs bosons at the LHC. Therefore, direct searches for non-SM decays of the Higgs boson are the fastest way to understand the nature of the Higgs boson. Either it will confirm its SM character, or it will rule out a whole array of BSM scenarios. We present status of the search at CMS for non-SM Higgs boson decays in events with displaced muon-jets.

  8. Evidence for a Particle Produced in Association with Weak Bosons and Decaying to a Bottom-Antibottom Quark Pair in Higgs Boson Searches at the Tevatron

    E-Print Network [OSTI]

    Gomez-Ceballos, Guillelmo

    We combine searches by the CDF and D0 Collaborations for the associated production of a Higgs boson with a W or Z boson and subsequent decay of the Higgs boson to a bottom-antibottom quark pair. The data, originating from ...

  9. Looking for a light Higgs boson in the Z??ll?? channel

    SciTech Connect (OSTI)

    Gainer, James S.; Keung, Wai-Yee; Low, Ian; Schwaller, Pedro

    2012-08-01

    The final state obtained when a Higgs boson decays to a photon and a Z boson has been mostly overlooked in current searches for a light Higgs boson. However, when the Z boson decays leptonically, all final state particles in this channel can be measured, allowing for accurate reconstructions of the Higgs mass and angular correlations. We determine the sensitivity of the Large Hadron Collider (LHC) running at center of mass energies of 8 and 14 TeV to Standard Model (SM) Higgs bosons with masses in the 120–130 GeV range. For the 8 TeV LHC, sensitivity to several times the SM cross section times branching ratio may be obtained with 20 inverse femtobarns of integrated luminosity, while for the 14 TeV LHC, the SM rate is probed with about 100 inverse femtobarns of integrated luminosity.

  10. Looking for a light Higgs boson in the Z??ll?? channel

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gainer, James S.; Keung, Wai-Yee; Low, Ian; Schwaller, Pedro

    2012-08-01

    The final state obtained when a Higgs boson decays to a photon and a Z boson has been mostly overlooked in current searches for a light Higgs boson. However, when the Z boson decays leptonically, all final state particles in this channel can be measured, allowing for accurate reconstructions of the Higgs mass and angular correlations. We determine the sensitivity of the Large Hadron Collider (LHC) running at center of mass energies of 8 and 14 TeV to Standard Model (SM) Higgs bosons with masses in the 120–130 GeV range. For the 8 TeV LHC, sensitivity to several times themore »SM cross section times branching ratio may be obtained with 20 inverse femtobarns of integrated luminosity, while for the 14 TeV LHC, the SM rate is probed with about 100 inverse femtobarns of integrated luminosity.« less

  11. A search for the Higgs Boson in H -> ZZ -> 4l mode

    E-Print Network [OSTI]

    Mario Pelliccioni for the CMS Collaboration

    2011-09-30

    A search for a Higgs boson in the decay channel ${\\rm H} \\rightarrow {\\rm ZZ}^{(*)}$ with each Z boson decaying to an electron or muon pair is presented using pp collisions from the LHC at $\\sqrt s$ = 7 TeV. The data analyzed correspond to an integrated luminosity of $1.13 \\pm 0.07$ fb$^{-1}$ recorded by the CMS detector in 2010 and 2011. The search covers Higgs boson mass ($m_{\\rm H}$) hypotheses of $110 Higgs boson with standard model-like decays exclude cross sections from about one to two times the expected standard model cross section for masses in the range $180 Higgs boson with a mass in the range 138 -162 $\\GeVcc$ and 178-502 $\\GeVcc$ is excluded at 95% CL.

  12. Search for Standard Model Higgs Boson Production in Association with a W Boson at CDF

    SciTech Connect (OSTI)

    Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, M.G.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; /Fermilab

    2008-03-01

    We present a search for standard model Higgs boson production in association with a W boson in proton-antiproton collisions (p{bar p} {yields} W{sup {+-}}H {yields} {ell}{nu}b{bar b}) at a center of mass energy of 1.96 TeV. The search employs data collected with the CDF II detector which correspond to an integrated luminosity of approximately 1 fb{sup -1}. We select events consistent with a signature of a single lepton (e{sup {+-}}/{mu}{sup {+-}}), missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with a secondary vertex tagging method and a neural network filter technique. The observed number of events and the dijet mass distributions are consistent with the standard model background expectations, and we set 95% confidence level upper limits on the production cross section times branching ratio ranging from 3.9 to 1.3 pb for Higgs boson masses from 110 to 150 GeV/c{sup 2}, respectively.

  13. Implications of Direct Dark Matter Constraints for Minimal Supersymmetric Standard Model Higgs Boson Searches at the Tevatron

    E-Print Network [OSTI]

    Marcela Carena; Dan Hooper; Peter Skands

    2006-08-22

    Searches for the Minimal Supersymmetric Standard Model (MSSM) Higgs bosons are among the most promising channels for exploring new physics at the Tevatron. In particular, interesting regions of large $\\tan \\beta$ and small $m_A$ are probed by searches for heavy neutral Higgs bosons, A and H, when they decay to $\\tau^+ \\tau^-$ and $b\\bar{b}$. At the same time, direct searches for dark matter, such as CDMS, attempt to observe neutralino dark matter particles scattering elastically off nuclei. This can occur through t-channel Higgs exchange, which has a large cross section in the case of large $\\tan \\beta$ and small $m_A$. As a result, there is a natural interplay between the heavy, neutral Higgs searches at the Tevatron and the region of parameter space explored by CDMS. We show that if the lightest neutralino makes up the dark matter of our universe, current limits from CDMS strongly constrain the prospects of heavy, neutral MSSM Higgs discovery at the Tevatron (at 3 sigma with 4 fb^-1 per experiment) unless $|\\mu| \\gsim$ 400 GeV. The limits of CDMS projected for 2007 will increase this constraint to $|\\mu| \\gsim$ 800 GeV. On the other hand, if CDMS does observe neutralino dark matter in the near future, it will make the discovery of heavy, neutral MSSM Higgs bosons far more likely at the Tevatron.

  14. The Higgs boson in the Standard Model theoretical constraints and a direct search in the wh channel at the Tevatron

    SciTech Connect (OSTI)

    Huske, Nils Kristian; /Paris U., VI-VII

    2010-09-01

    We have presented results in two different yet strongly linked aspects of Higgs boson physics. We have learned about the importance of the Higgs boson for the fate of the Standard Model, being either only a theory limited to explaining phenomena at the electroweak scale or, if the Higgs boson lies within a mass range of 130 < m{sub H} < 160 GeV the SM would remain a self consistent theory up to highest energy scales O(m{sub Pl}). This could have direct implications on theories of cosmological inflation using the Higgs boson as the particle giving rise to inflation in the very early Universe, if it couples non-minimally to gravity, an effect that would only become significant at very high energies. After understanding the immense meaning of proving whether the Higgs boson exists and if so, at which mass, we have presented a direct search for a Higgs boson in associated production with a W boson in a mass range 100 < m{sub H} < 150 GeV. A light Higgs boson is favored regarding constraints from electroweak precision measurements. As a single analysis is not yet sensitive for an observation of the Higgs boson using 5.3 fb{sup -1} of Tevatron data, we set limits on the production cross section times branching ratio. At the Tevatron, however, we are able to combine the sensitivity of our analyses not only across channels or analyses at a single experiment but also across both experiments, namely CDF and D0. This yields to the so-called Tevatron Higgs combination which, in total, combines 129 analyses from both experiments with luminosities of up to 6.7 fb{sup -1}. The results of a previous Tevatron combination led to the first exclusion of possible Higgs boson masses since the LEP exclusion in 2001. The latest Tevatron combination from July 2010 can be seen in Fig. 111 and limits compared to the Standard Model expectation are listed in Table 23. It excludes a SM Higgs boson in the regions of 100 < m{sub H} < 109 GeV as well as 158 < m{sub H} < 175 GeV based on the observed final limits at 95% C.L. In the most interesting low mass region between 115 and 135 GeV, even the full Tevatron combination is not yet sensitive enough to exclude a Higgs boson, or to even prove its existence with a meaningful significance. Fig. 112 shows a projection plot for sensitivity to the SM Higgs boson at the Tevatron as a measure of increasing luminosity. The 10 fb{sup -1} projection is a rather conservative outlook for the coming year of data taking as the Tevatron runs smoothly and the run till the end of 2011 is assured. By now, already 9 fb{sup -1} have been recorded by the two experiments. As the extrapolation plot shows, this amount of luminosity will allow to exclude the Higgs boson over a wide mass range at a 95% C.L. With the LHC at CERN now running and successfully collecting first data, it is worth looking at projections of Higgs boson sensitivity at the current center of mass energy of 7 TeV of the LHC accelerator. Fig. 113 shows a projection of a possible SM Higgs boson exclusion using 1 fb{sup -1} of LHC data collected by the ATLAS experiment. An exclusion is expected between 135 and 188 GeV at 95% C.L., combining the three decay channels H {yields} WW, H {yields} ZZ and H {yields} {gamma}{gamma}. A combination between LHC experiments would possibly yield an even broader range of excluded Higgs boson mass points. Therefore, whether at the Tevatron or the LHC, exciting times in the exclusion or possible discovery of the SM Higgs boson lie ahead.

  15. Multi-Higgs portal dark matter under the CDMS II results

    E-Print Network [OSTI]

    Mayumi Aoki; Shinya Kanemura; Osamu Seto

    2010-02-08

    In a scenario of Higgs portal dark matter, Higgs exchange processes are essential for both dark matter annihilation in the early Universe and direct search experiments. The CDMS II collaboration has recently released their final results on direct dark matter searches. We study a scalar dark matter model with multi-Higgs doublets under the constraint from the CDMS II results and also from the WMAP data. We find that the possible maximal value for the branching ratio of the invisible decay of the Higgs boson can be significantly greater than that in the Higgs portal model with one Higgs doublet, in particular, for the case of the so-called Type-X Yukawa interaction. Therefore, the search for the invisible decay of the Higgs boson at the CERN Large Hadron Collider and future collider experiments would provide useful information not only for the nature of dark matter but also for the structure of the Higgs sector even without directly detecting any extra scalar boson.

  16. Search for the standard model and a fermiophobic Higgs boson in diphoton final states

    E-Print Network [OSTI]

    D0 Collaboration

    2011-07-22

    We present a search for the standard model Higgs boson and a fermiophobic Higgs boson in the diphoton final states based on 8.2 fb-1 of ppbar collisions collected with the D0 detector at the Fermilab Tevatron Collider. No excess of data above background predictions is observed and upper limits at the 95% C.L. on the cross section multiplied by the branching fraction are set which are the most restrictive to date. A fermiophobic Higgs boson with a mass below 112.9 GeV is excluded at the 95% C.L.

  17. Triple Higgs boson production at a 100 TeV proton-proton collider

    E-Print Network [OSTI]

    Papaefstathiou, Andreas

    2015-01-01

    We consider triple Higgs boson production at a future 100 TeV proton-proton collider. We perform a survey of viable final states and compare and contrast triple production to Higgs boson pair production. Focussing on the $hhh \\rightarrow (b\\bar{b}) (b\\bar{b}) (\\gamma \\gamma)$ final state, we construct a baseline analysis for the Standard Model scenario and simple deformations, demonstrating that the process merits investigation in the high-luminosity phase of the future collider as a new probe of the self-coupling sector of the Higgs boson.

  18. Triple Higgs boson production at a 100 TeV proton-proton collider

    E-Print Network [OSTI]

    Andreas Papaefstathiou; Kazuki Sakurai

    2015-08-26

    We consider triple Higgs boson production at a future 100 TeV proton-proton collider. We perform a survey of viable final states and compare and contrast triple production to Higgs boson pair production. Focussing on the $hhh \\rightarrow (b\\bar{b}) (b\\bar{b}) (\\gamma \\gamma)$ final state, we construct a baseline analysis for the Standard Model scenario and simple deformations, demonstrating that the process merits investigation in the high-luminosity phase of the future collider as a new probe of the self-coupling sector of the Higgs boson.

  19. A Search for Higgs Boson in $H\\rightarrow W^+W^-$

    E-Print Network [OSTI]

    Kevin Sung; for the CMS Collaboration

    2011-09-12

    A search for the Higgs boson decaying to $W^+W^-$ has been performed on $1.1\\:$fb$^{-1}$ of pp collision data at $\\sqrt{s}=7\\:$TeV collected with the Compact Muon Solenoid (CMS) detector in 2011. No significant excess above Standard Model background expectation is observed, and upper limits on Higgs boson cross section production are derived, excluding the presence of a Higgs boson with mass in the range of $[150, 193]\\:$GeV$/c^{2}$ at 95% confidence level.

  20. Higgs Boson Search at e+e- and Photon Linear Colliders

    E-Print Network [OSTI]

    M. M. Muhlleitner

    2005-12-19

    The various search modes for the Higgs bosons of the Standard Model (SM) and its Minimal Supersymmetric Extension (MSSM) at the International Linear Collider (ILC) will be summarized briefly. In particular, as a unique discovery mode the production of heavy neutral MSSM Higgs bosons for medium values of $\\tan\\beta$ in photon collisions will be presented. Furthermore, $\\tau^+\\tau^-$ fusion into MSSM Higgs bosons in the photon mode will be shown to give access to the mixing parameter $\\tan\\beta$ with a precision of better than 10% for large values of this parameter.

  1. Combined Search for the Standard Model Higgs Boson Decaying to a bb? Pair Using the Full CDF Data Set

    E-Print Network [OSTI]

    Gomez-Ceballos, Guillelmo

    We combine the results of searches for the standard model (SM) Higgs boson based on the full CDF Run II data set obtained from ?s=1.96??TeV pp? collisions at the Fermilab Tevatron corresponding to an integrated luminosity ...

  2. Combined upper limit on Standard Model Higgs boson production at CDF

    SciTech Connect (OSTI)

    Adrian, Buzatu; /McGill U.

    2012-02-01

    The Higgs boson is the only elementary particle predicted by the Standard Model (SM) that has neither been confirmed nor refuted. The CDF collaboration has performed SM Higgs searches in many channels using p{bar p} collisions at a centre-of-mass energy {radical}s = 1.96 TeV. We present the latest combined Higgs boson search at CDF. Since the previous year's combination, the sensitivity is increased through the addition of new channels, the improvement of existing channels and the addition of new data samples. We also use the latest parton distribution functions and gg {yields} H theoretical cross sections when modelling the signal event yields. Using integrated luminosities of up to 8.2 fb{sup -1}, we observe a good agreement between data and the background prediction. Since we do not see a Higgs boson excess, we set 95% CL upper limits on the Higgs boson cross section in the range between 100 and 200 GeV/c{sup 2}, with 5 GeV/c{sup 2} increments. The observed (expected) limits for a 115 and a 165 GeV/c{sup 2} Higgs boson are 1.55 (1.49) and 0.75 (0.79) x SM, respectively. Since last year, the Higgs boson excluded range by CDF is extended to 156.5 - 173.7 and 100 - 104.5 GeV/c{sup 2}.

  3. Combined upper limit on Standard Model Higgs boson production at CDF

    E-Print Network [OSTI]

    Buzatu Adrian

    2012-02-09

    The Higgs boson is the only elementary particle predicted by the Standard Model (SM) that has neither been confirmed nor refuted. The CDF collaboration has performed SM Higgs searches in many channels using $p\\pbar$ collisions at a centre-of-mass energy $\\sqrt{s}=1.96\\tev$. We present the latest combined Higgs boson search at CDF. Since the previous year's combination, the sensitivity is increased through the addition of new channels, the improvement of existing channels and the addition of new data samples. We also use the latest parton distribution functions and $gg \\rightarrow H$ theoretical cross sections when modelling the signal event yields. Using integrated luminosities of up to 8.2 $\\invfb$, we observe a good agreement between data and the background prediction. Since we do not see a Higgs boson excess, we set 95% CL upper limits on the Higgs boson cross section in the range between 100 and 200 $\\gevcc$, with 5 $\\gevcc$ increments. The observed (expected) limits for a 115 and a 165 $\\gevcc$ Higgs boson are 1.55 (1.49) and 0.75 (0.79) $\\times$ SM, respectively. Since last year, the Higgs boson excluded range by CDF is extended to 156.5 - 173.7 and 100 - 104.5 $\\gevcc$.

  4. Complementarity in direct searches for additional Higgs bosons at the LHC and the International Linear Collider

    E-Print Network [OSTI]

    Shinya Kanemura; Hiroshi Yokoya; Ya-Juan Zheng

    2014-07-28

    We discuss complementarity of discovery reaches of heavier neutral Higgs bosons and charged Higgs bosons at the LHC and the International Linear Collider (ILC) in two Higgs doublet models (2HDMs). We perform a comprehensive analysis on their production and decay processes for all types of Yukawa interaction under the softly-broken discrete symmetry which is introduced to avoid flavour changing neutral currents, and we investigate parameter spaces of discovering additional Higgs bosons at the ILC beyond the LHC reach. We find that the 500 GeV run of the ILC with the integrated luminosity of 500 fb^{-1} shows an advantage for discovering the additional Higgs bosons in the region where the LHC cannot discover them with the integrated luminosity of 300 fb^{-1}. For the 1 TeV run of the ILC with the integrated luminosity of 1 ab^{-1}, production processes of an additional Higgs boson associated with the top quark can be useful as discovery channels in some parameter spaces where the LHC with the integrated luminosity of 3000 fb^{-1} cannot reach. It is emphasized that the complementary study at the LHC and the ILC is useful not only to survey additional Higgs bosons at the TeV scale, but also to discriminate types of Yukawa interaction in the 2HDM.

  5. Study of (W/Z)H production and Higgs boson couplings using H? W W * decays with the ATLAS detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aad, G.; et al.

    2015-08-27

    A search for Higgs boson production in association with a W or Z boson, in the H? W W * decay channel, is performed with a data sample collected with the ATLAS detector at the LHC in proton-proton collisions at centre-of-mass energies \\( \\sqrt{s}=7 \\) TeV and 8 TeV, corresponding to integrated luminosities of 4.5 fb-1 and 20.3 fb-1, respectively. The WH production mode is studied in two-lepton and three-lepton final states, while two- lepton and four-lepton final states are used to search for the ZH production mode. The observed significance, for the combined W H and ZH production, ismore »2.5 standard deviations while a significance of 0.9 standard deviations is expected in the Standard Model Higgs boson hypothesis. The ratio of the combined W H and ZH signal yield to the Standard Model expectation, ?V H , is found to be ? V H = 3.0-1.1+1.3 (stat.)-0.7 +1.0 (sys.) for the Higgs boson mass of 125.36 GeV. The W H and ZH production modes are also combined with the gluon fusion and vector boson fusion production modes studied in the H ? W W * ? ???? decay channel, resulting in an overall observed significance of 6.5 standard deviations and ?ggF + VBF + VH = 1.16-0.15+0.16 (stat.) -0.15+0.18 (sys.). The results are interpreted in terms of scaling factors of the Higgs boson couplings to vector bosons (?V ) and fermions (?F ); the combined results are: |? V | = 1.06-0.10+0.10, |? F| = 0.85-0.20+0.26.« less

  6. Limits on the Higgs boson lifetime and width from its decay to four charged leptons

    E-Print Network [OSTI]

    CMS Collaboration

    2015-07-23

    Constraints on the lifetime and width of the Higgs boson are obtained from H to ZZ to 4 lepton events using data recorded by the CMS experiment during the LHC run 1 with an integrated luminosity of 5.1 and 19.7 inverse femtobarns at a center-of-mass energy of 7 and 8 TeV, respectively. The measurement of the Higgs boson lifetime is derived from its flight distance in the CMS detector with an upper bound of tau[H] 3.5E-9 MeV. The measurement of the width is obtained from an off-shell production technique, generalized to include anomalous couplings of the Higgs boson to two electroweak bosons. From this measurement, a joint constraint is set on the Higgs boson width and a parameter f[LQ] that expresses an anomalous coupling contribution as an on-shell cross-section fraction. The limit on the Higgs boson width is Gamma[H] Higgs boson width.

  7. Constraints on the Higgs boson width from off-shell production and decay to Z-boson pairs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, Vardan; et al.,

    2014-09-01

    Constraints are presented on the total width of the recently discovered Higgs boson, Gamma[H], using its relative on-shell and off-shell production and decay rates to a pair of Z bosons, where one Z boson decays to an electron or muon pair, and the other to an electron, muon, or neutrino pair. The analysis is based on the data collected by the CMS experiment at the LHC in 2011 and 2012, corresponding to integrated luminosities of 5.1 inverse femtobarns at a centre-of-mass energy sqrt(s) = 7 TeV and 19.7 inverse femtobarns at sqrt(s) = 8 TeV. A simultaneous maximum likelihood fitmore »to the measured kinematic distributions near the resonance peak and above the Z-boson pair production threshold leads to an upper limit on the Higgs boson width of Gamma[H] « less

  8. Dark photons in the decay of Higgs-like boson

    E-Print Network [OSTI]

    Kozlov, G A

    2015-01-01

    We study the dark matter particle, the dark photon (DP), in the decay of the Higgs-like boson. The nature of dark matter is maintained through the hidden sector including the effects of breaking of the scale invariance. The model is based on the additional $U^{\\prime}(1)$ gauge group associated with light DP. The interaction between DP and quarks is mediated by the derivative of the scalar - the dilaton. The latter appears in the conformal sector which triggers the electroweak symmetry breaking. Upper limits are set on the DP mass, the mixing strength between the standard photon and DP. The model does allow to estimate the DP mass with the value of 4.5 MeV. The maximal value of the scale invariance breaking constant is also reported.

  9. Higgs boson decay into b-quarks at NNLO accuracy

    E-Print Network [OSTI]

    Vittorio Del Duca; Claude Duhr; Gabor Somogyi; Francesco Tramontano; Zoltan Trocsanyi

    2015-02-05

    We compute the fully differential decay rate of the Standard Model Higgs boson into b-quarks at next-to-next-to-leading order (NNLO) accuracy in alpha_S. We employ a general subtraction scheme developed for the calculation of higher order perturbative corrections to QCD jet cross sections, which is based on the universal infrared factorization properties of QCD squared matrix elements. We show that the subtractions render the various contributions to the NNLO correction finite. In particular, we demonstrate analytically that the sum of integrated subtraction terms correctly reproduces the infrared poles of the two-loop double virtual contribution to this process. We present illustrative differential distributions obtained by implementing the method in a parton level Monte Carlo program. The basic ingredients of our subtraction scheme, used here for the first time to compute a physical observable, are universal and can be employed for the computation of more involved processes.

  10. Evaluation of measurement accuracies of the Higgs boson branching fractions in the International Linear Collider

    E-Print Network [OSTI]

    H. Ono; A. Miyamoto

    2013-03-19

    Precise measurement of Higgs boson couplings is an important task for International Linear Collider (ILC) experiments and will facilitate the understanding of the particle mass generation mechanism. In this study, the measurement accuracies of the Higgs boson branching fractions to the $b$ and $c$ quarks and gluons, $\\Delta Br(H\\to b\\bar{b},\\sim c\\bar{c},\\sim gg)/Br$, were evaluated with the full International Large Detector model (\\texttt{ILD\\_00}) for the Higgs mass of 120 GeV at the center-of-mass (CM) energies of 250 and 350 GeV using neutrino, hadronic and leptonic channels and assuming an integrated luminosity of $250 {\\rm fb^{-1}}$, and an electron (positron) beam polarization of -80% (+30%). We obtained the following measurement accuracies of the Higgs cross section times branching fraction ($\\Delta (\\sigma \\cdot Br)/\\sigma \\cdot Br$) for decay of the Higgs into $b\\bar{b}$, $c\\bar{c}$, and $gg$; as 1.0%, 6.9%, and 8.5% at a CM energy of 250 GeV and 1.0%, 6.2%, and 7.3% at 350 GeV, respectively. After the measurement accuracy of the cross section ($\\Delta\\sigma/\\sigma$) was corrected using the results of studies at 250 GeV and their extrapolation to 350 GeV, the derived measurement accuracies of the branching fractions ($\\Delta Br/Br$) to $b\\bar{b}$, $c\\bar{c}$, and gg were 2.7%, 7.3%, and 8.9% at a CM energy of 250 GeV and 3.6%, 7.2%, and 8.1% at 350 GeV, respectively.

  11. Search for narrow high-mass resonances in proton–proton collisions at ?s = 8 TeV decaying to a Z and a Higgs boson

    E-Print Network [OSTI]

    Apyan, Aram

    A search for a narrow, high-mass resonance decaying into Z and Higgs (H) bosons is presented. The final state studied consists of a merged jet pair and a ? pair resulting from the decays of Z and H bosons, respectively. ...

  12. Observation of the diphoton decay of the Higgs boson and measurement of its properties

    E-Print Network [OSTI]

    Apyan, Aram

    Observation of the diphoton decay mode of the recently discovered Higgs boson and measurement of some of its properties are reported. The analysis uses the entire dataset collected by the CMS experiment in proton-proton ...

  13. Search for neutral Higgs bosons in events with multiple bottom quarks at the Tevatron

    E-Print Network [OSTI]

    Gomez-Ceballos, Guillelmo

    The combination of searches performed by the CDF and D0 collaborations at the Fermilab Tevatron Collider for neutral Higgs bosons produced in association with b quarks is reported. The data, corresponding to 2.6??fb[superscript ...

  14. Search for the Higgs boson in its decay into tau leptons at CMS

    E-Print Network [OSTI]

    Chan, Matthew Hans

    2013-01-01

    A search for the Standard Model Higgs boson in the H --> rr channel is presented. The search is performed on proton collision data collected by the Compact Muon Solenoid at the Large Hadron Collider. The data corresponds ...

  15. Search for the associated production of a Higgs boson with a...

    Office of Scientific and Technical Information (OSTI)

    associated production of a Higgs boson with a single top quark in proton-proton collisions at sqrt(s) 8 TeV Citation Details In-Document Search Title: Search for the associated...

  16. Search for the associated production of a Higgs boson with a...

    Office of Scientific and Technical Information (OSTI)

    associated production of a Higgs boson with a single top quark in proton-proton collisions at sqrt(s) 8 TeV Khachatryan, Vardan; et al. Abstract Not Provided Fermi National...

  17. Heavy standard model-like Higgs boson and a light stop fromYukawa...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Heavy standard model-like Higgs boson and a light stop from Yukawa-deflected gauge mediation Citation Details In-Document Search Title: Heavy standard model-like...

  18. Higgs boson and beyond: the quest for new laws of physics discussed...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    "A new particle was discovered last summer at the Large Hadron Collider at CERN in Switzerland. The Higgs boson gives mass to quarks and the electron but we don't know yet if...

  19. Phenomenological analysis of Higgs boson production through gluon fusion in association with jets

    E-Print Network [OSTI]

    Nicolas Greiner; Stefan Hoeche; Gionata Luisoni; Marek Schonherr; Jan-Christopher Winter; Valery Yundin

    2015-06-02

    We present a detailed phenomenological analysis of the production of a Standard Model Higgs boson in association with up to three jets. We consider the gluon fusion channel using an effective theory in the large top-quark mass limit. Higgs boson production in gluon fusion constitutes an irreducible background to the vector boson fusion (VBF) process; hence the precise knowledge of its characteristics is a prerequisite for any measurement in the VBF channel. The calculation is carried out at next-to-leading order (NLO) in QCD in a fully automated way by combining the two programs GoSam and Sherpa. We present numerical results for a large variety of observables for both standard cuts and VBF selection cuts. We find that for all jet multiplicities the NLO corrections are sizeable. This is particularly true in the presence of kinematic selections enhancing the VBF topology, which are based on vetoing additional jet activity. In this case, precise predictions for the background can be made using our calculation by taking the difference between the inclusive H+2 jets and the inclusive H+3 jets result.

  20. Searching for the Higgs Bosons of Minimal Supersymmetry with Muon Pairs and Bottom Quarks

    E-Print Network [OSTI]

    Sally Dawson; Duane Dicus; Chung Kao

    2002-08-07

    The prospects for the discovery of neutral Higgs bosons (phi^0 = H^0, h^0, A^0) produced with bottom quarks via Higgs decays into muon pairs (pp --> b b-bar phi^0 --> b b-bar mu mu-bar +X) at the CERN LHC are investigated in the minimal supersymmetric model. The complete physics background from the production of b b-bar mu mu-bar, b b-bar W^+ W^- (including t t-bar) and jj mu mu-bar, j = g, u, d, s, c in the Standard Model is calculated with realistic acceptance cuts. This discovery mode has a simple production mechanism from gg --> b b-bar phi^0 with its cross section proportional to 1/cos^2(beta) and could provide an opportunity to measure tan(beta) and the b b-bar phi^0 couplings. In addition, we compare the associated discovery mode above with the inclusive discovery channel pp --> phi^0 --> mu mu-bar +X. Promising results are found for the CP-odd pseudoscalar (A^0) and the heavier CP-even scalar (H^0) Higgs bosons for tan(beta) equivalent to v_2/v_1 >~ 14 and m_A,m_H <~ 325 GeV.

  1. Higgs boson gluon-fusion production beyond threshold in N³LO QCD

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Anastasiou, Charalampos; Duhr, Claude; Dulat, Falko; Furlan, Elisabetta; Gehrmann, Thomas; Herzog, Franz; Mistlberger, Bernhard

    2015-03-01

    In this article, we compute the gluon fusion Higgs boson cross-section at N³LO through the second term in the threshold expansion. This calculation constitutes a major milestone towards the full N³LO cross section. Our result has the best formal accuracy in the threshold expansion currently available, and includes contributions from collinear regions besides subleading corrections from soft and hard regions, as well as certain logarithmically enhanced contributions for general kinematics. We use our results to perform a critical appraisal of the validity of the threshold approximation at N³LO in perturbative QCD.

  2. Heavy neutral MSSM Higgs Bosons at the PLC - a comparison of two analyses

    E-Print Network [OSTI]

    M. Spira; P. Niezurawski; M. Krawczyk; A. F. Zarnecki

    2006-12-29

    Measurement of the heavy neutral MSSM Higgs bosons H and A production in the process gamma gamma --> A, H --> b anti-b at the Photon Linear Collider has been considered in two independent analyses for the parameter range corresponding to the so-called "LHC wedge". Significantly different conclusions were obtained; signal to background ratio 36 vs 2. Here assumptions and results of these two analyses are compared. We have found that differences in the final results are mainly due to different assumptions on gamma-gamma-luminosity spectra, jet definitions and selection cuts.

  3. Higgs boson gluon-fusion production beyond threshold in N3LO QCD

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Anastasiou, Charalampos; Duhr, Claude; Dulat, Falko; Furlan, Elisabetta; Gehrmann, Thomas; Herzog, Franz; Mistlberger, Bernhard

    2015-03-01

    In this article, we compute the gluon fusion Higgs boson cross-section at N3LO through the second term in the threshold expansion. This calculation constitutes a major milestone towards the full N3LO cross section. Our result has the best formal accuracy in the threshold expansion currently available, and includes contributions from collinear regions besides subleading corrections from soft and hard regions, as well as certain logarithmically enhanced contributions for general kinematics. We use our results to perform a critical appraisal of the validity of the threshold approximation at N3LO in perturbative QCD.

  4. Evidence for a Particle Produced in Association with Weak Bosons and Decaying to a Bottom-Antibottom Quark Pair in Higgs Boson Searches at the Tevatron

    E-Print Network [OSTI]

    Baringer, Philip S.; Bean, Alice; Chen, G.; Clutter, Justace Randall; Sekaric, Jadranka; Wilson, Graham Wallace; Aaltonen, T.; Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.

    2012-08-14

    Evidence for a Particle Produced in Association with Weak Bosons and Decaying to a Bottom-Antibottom Quark Pair in Higgs Boson Searches at the Tevatron T. Aaltonen,12,* V.M. Abazov,48,† B. Abbott,112,† B. S. Acharya,31,† M. Adams,78,† T. Adams,74...; published 14 August 2012) We combine searches by the CDF and D0 Collaborations for the associated production of a Higgs boson with a W or Z boson and subsequent decay of the Higgs boson to a bottom-antibottom quark pair. The data, originating from Fermilab...

  5. hep-ph/0206194, UCLA/02/TEP/8, SLAC{PUB{9198, DAMTP-2002-41, MSUHEP{20522 Isolating a light Higgs boson

    E-Print Network [OSTI]

    Schmidt, Carl

    in the channel. PACS numbers: 12.38.Bx, 14.70.Bh, 14.80.Bn Keywords: Higgs boson search, perturbative QCD I are all gen- erated by the Higgs mechanism. This mechanism leaves as its residue the Higgs boson, the one considerable light on electroweak symmetry break- ing, in particular by searching for these Higgs bosons

  6. Next-to-leading order QCD corrections to light Higgs Pair production via vector boson fusion

    E-Print Network [OSTI]

    Terrance Figy

    2008-06-15

    We present the NLO QCD corrections for light Higgs pair production via vector boson fusion at the LHC within the CP conserving type II two higgs doublet model in the form of a fully flexible parton--level Monte Carlo program. Scale dependences on integrated cross sections and distributions are reduced with QCD K-factors of order unity.

  7. The role of MSSM heavy Higgs production in the self coupling measurement of the 125 GeV Higgs boson at the LHC

    E-Print Network [OSTI]

    Biplob Bhattacherjee; Arghya Choudhury

    2015-03-19

    Measurement of the self coupling of 125 GeV Higgs boson is one of the most crucial tasks for high luminosity run of the LHC and it can only be measured in the di-Higgs final state. In the minimal supersymmetric standard model, heavy CP even Higgs ($H$) can decay into lighter 125 GeV Higgs boson ($h$) and therefore influence the di-Higgs production. We investigate the role of single $H$ production in the measurement of self coupling of $h$. We find that $H \\rightarrow hh$ decay can nontrivially affect the $h$ self coupling measurement in low tan$\\beta$ regime when the mass of the heavy Higgs boson lies between 250 - 600 GeV and depending on the parameter space it may be seen as an enhancement of the self coupling of 125 GeV Higgs boson.

  8. Search for Higgs boson like high mass resonances in the bosonic decay channels with ATLAS and CMS

    E-Print Network [OSTI]

    Lo Sterzo, Francesco; The ATLAS collaboration

    2015-01-01

    Searches for an additional heavy Higgs-like boson have been performed by both ATLAS and CMS with data collected in the Run 1 of the LHC. This document reports searches in the diboson decay channels ($\\gamma\\gamma$, $WW$, $ZZ$). Exclusion limits have been set for different hypotheses: model independent narrow-resonance, Standard Model-like Higgs, Electroweak Singlet and 2HDM. No excesses are found over the Standard Model background-only expectation.

  9. Higgs boson plus photon production at the LHC: a clean probe of the b-quark parton densities

    E-Print Network [OSTI]

    Emidio Gabrielli; Barbara Mele; Johan Rathsman

    2007-12-04

    Higgs boson production in association with a high pT photon at the CERN Large Hadron Collider is analyzed, in the framework of the MSSM model, for the heavier neutral Higgs bosons. The request of an additional photon in the exclusive Higgs boson final state selects b-quark pairs among the possible initial partonic states, since gluon-gluon initial states are not allowed by C-parity conservation. Hence, the measurement of cross sections for neutral Higgs boson plus photon production can provide a clean probe of the b-quark density in the proton as well as of the b-quark Yukawa coupling. The suppression of the production rates by the b-quark electromagnetic coupling can be compensated by the enhanced Higgs boson Yukawa coupling to b's in the large tan(beta) regime. The Higgs boson decay into a tau-lepton pair is considered, and irreducible backgrounds with corresponding signal significances are evaluated.

  10. Global Electroweak Fits and the Higgs Boson Mass

    E-Print Network [OSTI]

    Peter Renton

    2008-09-26

    The current electroweak data and the constraints on the Higgs mass are discussed. Within the context of the Standard Model the data prefer a relatively light Higgs mass.

  11. Dirac Type Gauge Theories and the Mass of the Higgs Boson

    E-Print Network [OSTI]

    Juergen Tolksdorf; Torsten Thumstaedter

    2007-06-03

    We discuss the mass of the (physical component of the) Higgs boson in one-loop and top-quark mass approximation. For this the minimal Standard Model is regarded as a specific (parameterized) gauge theory of Dirac type. It is shown that the latter formulation, in contrast to the usual description of the Standard Model, gives a definite value for the Higgs mass. The predicted value for the Higgs mass depends on the value addressed to the top mass m_T. We obtain m_H= 186 \\pm 8 GeV for m_T = 174 \\pm 3 GeV (direct observation of top events), resp. m_H = 184 \\pm 22 GeV for m_T = 172 \\pm 10 GeV (Standard Model electroweak fit). Although the Higgs mass is predicted to be near the upper bound, m_H is in full accordance with the range 114 \\leq m_H < 193 GeV that is allowed by the Standard Model. We show that the inclusion of (Dirac) massive neutrinos does not alter the results presented. We also briefly discuss how the derived mass values are related to those obtained within the frame of non-commutative geometry.

  12. Search for invisible decays of a Higgs boson produced in association with a Z boson in ATLAS

    E-Print Network [OSTI]

    Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Aefsky, Scott; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahmad, Ashfaq; Ahmadov, Faig; Aielli, Giulio; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angelidakis, Stylianos; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Astbury, Alan; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Azuelos, Georges; Azuma, Yuya; Baak, Max; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Sarah; Balek, Petr; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Bartsch, Valeria; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Katharina; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernard, Clare; Bernat, Pauline; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia, Olga; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Bittner, Bernhard; Black, Curtis; Black, James; Black, Kevin

    2014-01-01

    A search for evidence of invisible-particle decay modes of a Higgs boson produced in association with a Z boson at the Large Hadron Collider is presented. No deviation from the Standard Model expectation is observed in 4.5 fb$^{?1}$ (20.3 fb$^{?1}$) of 7 (8) TeV pp collision data collected by the ATLAS experiment. Assuming the Standard Model rate for ZH production, an upper limit of 75%, at the 95% confidence level is set on the branching ratio to invisible-particle decay modes of the Higgs boson at a mass of 125.5 GeV. The limit on the branching ratio is also interpreted in terms of an upper limit on the allowed dark matter–nucleon scattering cross section within a Higgs-portal dark matter scenario. Limits are also set on an additional neutral Higgs boson, in the mass range 110 < $m_H$ < 400 GeV, produced in association with a Z boson and decaying to invisible particles.

  13. Search for a multi-Higgs-boson cascade in W[superscript +]W[superscript ?]b[¯ over b] events with the ATLAS detector in pp collisions at ?s = 8 TeV

    E-Print Network [OSTI]

    Taylor, Frank E.

    A search is presented for new particles in an extension to the Standard Model that includes a heavy Higgs boson (H[superscript 0]), an intermediate charged Higgs-boson pair (H[superscript ±]), and a light Higgs boson ...

  14. Search for WH production with a light Higgs boson decaying to prompt electron-jets in proton–proton collisions at root s= 7 TeV with the ATLAS detector

    E-Print Network [OSTI]

    2013-01-01

    of the Standard Model (SM) Higgs boson [3–5] at this mass.and the branching ratio of a Higgs boson decaying to promptas a function of a Higgs boson mass in the range from 100 to

  15. Search for the Higgs boson in the ZH->nunubb channel: Development of a b-tagging method based on soft muons

    SciTech Connect (OSTI)

    Jamin, David; ,

    2010-10-01

    In the Standard Model of particle physics, the Higgs boson generates elementary particle masses. Current theoretical and experimental constraints lead to a Higgs boson mass between 114.4 and 158 GeV with 95% confidence level. Moreover, Tevatron has recently excluded the mass ranges between 100 and 109 GeV, 158 and 175 GeV with 95% confidence level. These results gives a clear indication to search for a Higgs boson at low mass. The D0 detector is located near Chicago, at the Tevatron, a proton-antiproton collider with an energy in the center of mass of 1.96 TeV. The topic of this thesis is the search for a Higgs boson in association with a Z boson. This channel is sensitive to low mass Higgs boson (<135 GeV) which has a branching ratio H {yields} bb varies between 50% and 90% in this mass range. The decay channel ZH {yields} {nu}{bar {nu}}b{bar b} studied has in the final state 2 heavy-flavor jets and some missing transverse energy due to escaping neutrinos. The heavy-flavor jets identification ('b-tagging') is done with a new algorithm (SLTNN) developped specifically for semi-leptonic decay of b quarks. The Higgs boson search analysis was performed with 3 fb{sup -1} of data. The use of SLTNN increases by 10% the Higgs boson signal efficiency. The global analysis sensitivity improvement, however, is rather low (<1%) after taking into account the backgrounds and systematic uncertainties.

  16. Loop induced interference effects in Higgs Boson plus two jet production at the LHC.

    E-Print Network [OSTI]

    Andersen, Jeppe R.; Binoth, T.; Heinrich, G.; Smillie, Jennifer M.

    We calculate the order O(?2?3 s) interference effect between the gluon fusion and weak boson fusion processes allowed at the one-loop level in Higgs boson plus 2 jet production at the LHC. The corresponding one-loop amplitudes, which have...

  17. Measurement of Higgs boson production and properties in the WW decay channel with leptonic final states

    E-Print Network [OSTI]

    Apyan, Aram

    A search for the standard model Higgs boson decaying to a W-boson pair at the LHC is reported. The event sample corresponds to an integrated luminosity of 4.9 fb[superscript ?1] and 19.4 fb[superscript ?1] collected with ...

  18. Determination of spin and CP of the Higgs boson from WBF.

    E-Print Network [OSTI]

    Buszello, C. P.; Marquard, P.

    We explore the possibilities to determine the spin/CP properties of the Higgs boson at the LHC. To cover the mass region below the ZZ threshold we make use of the properties of the production in Weak Boson Fusion (WBF) and the decay chain H ? W...

  19. Searches at the Tevatron for a Low Mass Standard Model Higgs Boson

    E-Print Network [OSTI]

    Bernd Stelzer

    2008-10-14

    We report on searches for the standard model Higgs boson with the CDF and D0 detectors using up to 2.7 fb$^{-1}$ of $\\sqrt s=$ 1.96 TeV proton anti-proton collisions at Fermilab's Tevatron. We focus on analyses that are sensitive to low mass Higgs production with $m_HHiggs boson production, and set upper limits on cross section times branching ratio. Several analyses improvements have increased the sensitivity to a Higgs signal faster than what is expected from increasing datasets alone.

  20. Search for a pseudoscalar boson decaying into a Z boson and the 125 GeV Higgs boson in ?[superscript +]?[superscript ?]b[bar over b] final states

    E-Print Network [OSTI]

    Apyan, Aram

    Results are reported on a search for decays of a pseudoscalar A boson into a Z boson and a light scalar h boson, where the Z boson decays into a pair of oppositely-charged electrons or muons, and the h boson decays into ...

  1. Living Without Supersymmetry -- the Conformal Alternative and a Dynamical Higgs Boson

    E-Print Network [OSTI]

    Philip D. Mannheim

    2015-06-01

    We show that key results of supersymmetry can be achieved via conformal symmetry. We propose that the Higgs boson be a dynamical bound state rather than a fundamental scalar, so that there is no quadratic divergence self-energy problem for it and no need to invoke supersymmetry to resolve it. We study a conformal invariant theory of interacting fermions and gauge bosons, in which there is scaling with anomalous dimensions and dynamical symmetry breaking, with the dynamical dimension of $\\bar{\\psi}\\psi$ being reduced from 3 to 2. With this reduction we augment the theory with a then renormalizable 4-fermion interaction with dynamical dimension equal to 4. We reinterpret the theory as a renormalizable version of the Nambu-Jona-Lasinio (NJL) model, with the gauge theory sector with its now massive fermion being the mean field and the 4-fermion interaction being the residual interaction. It is this residual interaction that generates dynamical Goldstone and Higgs states, states that, as noted by Baker and Johnson, the gauge theory sector itself does not possess. The Higgs boson is found to be a narrow resonance just above threshold. We couple the theory to conformal gravity, with the interplay between conformal gravity and the 4-fermion interaction taking care of the vacuum energy problem. With conformal gravity being a consistent quantum gravity theory there is no need for string theory with its supersymmetric underpinnings. With conformal gravity fits to galactic rotation curves and the accelerating universe not needing dark matter, there is no need to introduce supersymmetry for either the vacuum energy problem or to provide a potential dark matter candidate. We propose that it is conformal symmetry rather than supersymmetry that is fundamental, with the theory of nature being a locally conformal, locally gauge invariant, non-Abelian NJL theory.

  2. Living Without Supersymmetry -- the Conformal Alternative and a Dynamical Higgs Boson

    E-Print Network [OSTI]

    Philip D. Mannheim

    2015-08-06

    We show that key results of supersymmetry can be achieved via conformal symmetry. We propose that the Higgs boson be a dynamical bound state rather than a fundamental scalar, so that there is no quadratic divergence self-energy problem for it and no need to invoke supersymmetry to resolve it. We study a conformal invariant theory of interacting fermions and gauge bosons, in which there is scaling with anomalous dimensions and dynamical symmetry breaking, with the dynamical dimension of $\\bar{\\psi}\\psi$ being reduced from 3 to 2. With this reduction we augment the theory with a then renormalizable 4-fermion interaction with dynamical dimension equal to 4. We reinterpret the theory as a renormalizable version of the Nambu-Jona-Lasinio (NJL) model, with the gauge theory sector with its now massive fermion being the mean field and the 4-fermion interaction being the residual interaction. It is this residual interaction that generates dynamical Goldstone and Higgs states, states that, as noted by Baker and Johnson, the gauge theory sector itself does not possess. The Higgs boson is found to be a narrow resonance just above threshold. We couple the theory to conformal gravity, with the interplay between conformal gravity and the 4-fermion interaction taking care of the vacuum energy problem. With conformal gravity being a consistent quantum gravity theory there is no need for string theory with its supersymmetric underpinnings. With conformal gravity fits to galactic rotation curves and the accelerating universe not needing dark matter, there is no need to introduce supersymmetry for either the vacuum energy problem or to provide a potential dark matter candidate. We propose that it is conformal symmetry rather than supersymmetry that is fundamental, with the theory of nature being a locally conformal, locally gauge invariant, non-Abelian NJL theory.

  3. Search for a new resonance decaying to a W or Z boson and a Higgs boson in the ??/??/?? + bb¯ final states with the ATLAS detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aad, G.

    2015-06-16

    A search for a new resonance decaying to a W or Z boson and a Higgs boson in the ??/??/??+bb¯ final states is performed using 20.3 fb-1 of pp collision data recorded at ?s = 8 TeV with the ATLAS detector at the Large Hadron Collider. The search is conducted by examining the WH / ZH invariant mass distribution for a localized excess. Thus, no significant deviation from the Standard Model background prediction is observed. The results are interpreted in terms of constraints on the Minimal Walking Technicolor model and on a simplified approach based on a phenomenological Lagrangian ofmore »Heavy Vector Triplets.« less

  4. Study of the spin and parity of the Higgs boson in diboson decays with the ATLAS detector

    E-Print Network [OSTI]

    Aad, Georges; Abdallah, Jalal; Abdinov, Ovsat; Aben, Rosemarie; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agricola, Johannes; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; ?lvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baak, Max; Baas, Alessandra; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansil, Hardeep Singh; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James Baker; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Kathrin; Becker, Maurice; Becker, Sebastian; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Janna Katharina; Belanger-Champagne, Camille; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernard, Nathan Rogers; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, Carolyn; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bevan, Adrian John; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Biedermann, Dustin; Bieniek, Stephen Paul; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien

    2015-01-01

    Studies of the spin, parity and tensor couplings of the Higgs boson in the $H\\rightarrow ZZ^*\\rightarrow 4\\ell$ , $H\\rightarrow WW^* \\rightarrow e\

  5. Complementarity in direct searches for additional Higgs bosons at the LHC and the International Linear Collider

    E-Print Network [OSTI]

    Kanemura, Shinya; Zheng, Ya-Juan

    2014-01-01

    We discuss complementarity of discovery reaches of heavier neutral Higgs bosons and charged Higgs bosons at the LHC and the International Linear Collider (ILC) in two Higgs doublet models (2HDMs). We perform a comprehensive analysis on their production and decay processes for all types of Yukawa interaction under the softly-broken discrete symmetry which is introduced to avoid flavour changing neutral currents, and we investigate parameter spaces of discovering additional Higgs bosons at the ILC beyond the LHC reach. We find that the 500 GeV run of the ILC with the integrated luminosity of 500 fb^{-1} shows an advantage for discovering the additional Higgs bosons in the region where the LHC cannot discover them with the integrated luminosity of 300 fb^{-1}. For the 1 TeV run of the ILC with the integrated luminosity of 1 ab^{-1}, production processes of an additional Higgs boson associated with the top quark can be useful as discovery channels in some parameter spaces where the LHC with the integrated luminos...

  6. Multi-Higgs boson production in the standard model and beyond

    SciTech Connect (OSTI)

    Binoth, T.; Karg, S.; Kauer, N.; Rueckl, R.

    2006-12-01

    We present a calculation of the loop-induced processes gg{yields}HH and gg{yields}HHH, and investigate the observability of multi-Higgs boson production at the CERN Large Hadron Collider (LHC) in the Standard Model (SM) and beyond. While the SM cross sections are too small to allow observation at the LHC, we demonstrate that physics beyond the SM can lead to amplified, observable cross sections. Furthermore, the applicability of the heavy top quark approximation in two- and three-Higgs boson production is investigated. We conclude that multi-Higgs boson production at the SuperLHC is an interesting probe of Higgs sectors beyond the SM and warrants further study.

  7. One-loop Higgs boson production at the Linear Collider within the general two-Higgs-doublet model: e+e- versus gamma-gamma

    E-Print Network [OSTI]

    Joan Sola; David Lopez-Val

    2011-07-07

    We present an updated overview on the phenomenology of one-loop Higgs boson production at Linear Colliders within the general Two-Higgs-Doublet Model (2HDM). First we report on the Higgs boson pair production, and associated Higgs-Z boson production, at O(alpha^3_{ew}) from e+e- collisions. These channels furnish cross-sections in the range of 10-100 fb for Ecm=0.5 TeV and exhibit potentially large radiative corrections (of order 50%), whose origin can be traced back to the genuine enhancement capabilities of the triple Higgs boson self-interactions. Next we consider the loop-induced production of a single Higgs boson from direct gamma-gamma scattering. We single out sizable departures from the corresponding rates in the Standard Model, which are again correlated to trademark dynamical features of the 2HDM -- namely the balance of the non-standard Higgs/gauge, Higgs/fermion and Higgs self-interactions leading to sizable (destructive) interference effects. This pattern of quantum effects is unmatched in the MSSM, and could hence provide distinctive footprints of non-supersymmetric Higgs boson physics. Both calculations are revisited within a common, brought-to-date framework and include, in particular, the most stringent bounds from unitarity and flavor physics.

  8. Search for exotic decays of a Higgs boson into undetectable particles and photons

    E-Print Network [OSTI]

    Khachatryan, Vardan; CMS Collaboration; Tumasyan, Armen; Adam, Wolfgang; A??lar, Ece; Bergauer, Thomas; Brandstetter, Johannes; Brondolin, Erica; Dragicevic, Marko; Erö, Janos; Flechl, Martin; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Knünz, Valentin; König, Axel; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Matsushita, Takashi; Mikulec, Ivan; Rabady, Dinyar; Rahbaran, Babak; Rohringer, Herbert; Schieck, Jochen; Schöfbeck, Robert; Strauss, Josef; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Knutsson, Albert; Lauwers, Jasper; Luyckx, Sten; Ochesanu, Silvia; Rougny, Romain; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Abu Zeid, Shimaa; Blekman, Freya; D'Hondt, Jorgen; Daci, Nadir; De Bruyn, Isabelle; Deroover, Kevin; Heracleous, Natalie; Keaveney, James; Lowette, Steven; Moreels, Lieselotte; Olbrechts, Annik; Python, Quentin; Strom, Derek; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Van Parijs, Isis; Barria, Patrizia; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Delannoy, Hugo; Fasanella, Giuseppe; Favart, Laurent; Gay, Arnaud; Grebenyuk, Anastasia; Lenzi, Thomas; Léonard, Alexandre; Maerschalk, Thierry; Marinov, Andrey; Perniè, Luca; Randle-conde, Aidan; Reis, Thomas; Seva, Tomislav; Vander Velde, Catherine; Vanlaer, Pascal; Yonamine, Ryo; Zenoni, Florian; Zhang, Fengwangdong; Beernaert, Kelly; Benucci, Leonardo; Cimmino, Anna; Crucy, Shannon; Dobur, Didar; Fagot, Alexis; Garcia, Guillaume; Gul, Muhammad; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Poyraz, Deniz; Ryckbosch, Dirk; Salva Diblen, Sinem; Sigamani, Michael; Strobbe, Nadja; Tytgat, Michael; Van Driessche, Ward; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Beluffi, Camille; Bondu, Olivier; Brochet, Sébastien; Bruno, Giacomo; Castello, Roberto; Caudron, Adrien; Ceard, Ludivine; Da Silveira, Gustavo Gil; Delaere, Christophe; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Jafari, Abideh; Jez, Pavel; Komm, Matthias; Lemaitre, Vincent; Mertens, Alexandre; Nuttens, Claude; Perrini, Lucia; Pin, Arnaud; Piotrzkowski, Krzysztof; Popov, Andrey; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Beliy, Nikita; Hammad, Gregory Habib; Aldá Júnior, Walter Luiz; Alves, Gilvan; Brito, Lucas; Correa Martins Junior, Marcos; Hensel, Carsten; Mora Herrera, Clemencia; Moraes, Arthur; Pol, Maria Elena; Rebello Teles, Patricia; Belchior Batista Das Chagas, Ewerton; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Da Costa, Eliza Melo; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Huertas Guativa, Lina Milena; Malbouisson, Helena; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Ahuja, Sudha; Bernardes, Cesar Augusto; De Souza Santos, Angelo; Dogra, Sunil; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Moon, Chang-Seong; Novaes, Sergio F; Padula, Sandra; Romero Abad, David; Ruiz Vargas, José Cupertino; Aleksandrov, Aleksandar; Genchev, Vladimir; Hadjiiska, Roumyana; Iaydjiev, Plamen; Piperov, Stefan; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Ahmad, Muhammad; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Cheng, Tongguang; Du, Ran; Jiang, Chun-Hua; Plestina, Roko; Romeo, Francesco; Shaheen, Sarmad Masood; Tao, Junquan; Wang, Chunjie; Wang, Zheng; Zhang, Huaqiao; Asawatangtrakuldee, Chayanit; Ban, Yong; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Xu, Zijun; Zou, Wei; Avila, Carlos; Cabrera, Andrés; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Polic, Dunja; Puljak, Ivica; Ribeiro Cipriano, Pedro M; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Kadija, Kreso; Luetic, Jelena; Micanovic, Sasa; Sudic, Lucija; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Rykaczewski, Hans; Bodlak, Martin; Finger, Miroslav; Finger Jr, Michael

    2015-01-01

    A search is presented for exotic decays of a Higgs boson into undetectable particles and one or two isolated photons in pp collisions at a center-of-mass energy of 8 TeV. The data correspond to an integrated luminosity of up to 19.4 fb$^{-1}$ collected with the CMS detector at the LHC. Higgs bosons produced in gluon-gluon fusion and in association with a Z boson are investigated, using models in which the Higgs boson decays into a gravitino and a neutralino or a pair of neutralinos, followed by the decay of the neutralino to a gravitino and a photon. The selected events are consistent with the background-only hypothesis, and limits are placed on the product of cross sections and branching fractions. Assuming a standard model Higgs boson production cross-section, a 95% confidence level upper limit is set on the branching fraction of a 125 GeV Higgs boson decaying into undetectable particles and one or two isolated photons as a function of the neutralino mass. For neutralino masses from 1 to 120 GeV an upper li...

  9. Limits on the Higgs boson lifetime and width from its decay to four charged leptons

    E-Print Network [OSTI]

    Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; A??lar, Ece; Bergauer, Thomas; Brandstetter, Johannes; Brondolin, Erica; Dragicevic, Marko; Erö, Janos; Flechl, Martin; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Knünz, Valentin; König, Axel; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Matsushita, Takashi; Mikulec, Ivan; Rabady, Dinyar; Rahbaran, Babak; Rohringer, Herbert; Schieck, Jochen; Schöfbeck, Robert; Strauss, Josef; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Knutsson, Albert; Lauwers, Jasper; Luyckx, Sten; Ochesanu, Silvia; Rougny, Romain; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Abu Zeid, Shimaa; Blekman, Freya; D'Hondt, Jorgen; Daci, Nadir; De Bruyn, Isabelle; Deroover, Kevin; Heracleous, Natalie; Keaveney, James; Lowette, Steven; Moreels, Lieselotte; Olbrechts, Annik; Python, Quentin; Strom, Derek; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Van Parijs, Isis; Barria, Patrizia; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Delannoy, Hugo; Fasanella, Giuseppe; Favart, Laurent; Gay, Arnaud; Grebenyuk, Anastasia; Lenzi, Thomas; Léonard, Alexandre; Maerschalk, Thierry; Marinov, Andrey; Perniè, Luca; Randle-conde, Aidan; Reis, Thomas; Seva, Tomislav; Vander Velde, Catherine; Vanlaer, Pascal; Yonamine, Ryo; Zenoni, Florian; Zhang, Fengwangdong; Beernaert, Kelly; Benucci, Leonardo; Cimmino, Anna; Crucy, Shannon; Dobur, Didar; Fagot, Alexis; Garcia, Guillaume; Gul, Muhammad; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Poyraz, Deniz; Ryckbosch, Dirk; Salva Diblen, Sinem; Sigamani, Michael; Strobbe, Nadja; Tytgat, Michael; Van Driessche, Ward; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Beluffi, Camille; Bondu, Olivier; Brochet, Sébastien; Bruno, Giacomo; Castello, Roberto; Caudron, Adrien; Ceard, Ludivine; Da Silveira, Gustavo Gil; Delaere, Christophe; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Jafari, Abideh; Jez, Pavel; Komm, Matthias; Lemaitre, Vincent; Mertens, Alexandre; Nuttens, Claude; Perrini, Lucia; Pin, Arnaud; Piotrzkowski, Krzysztof; Popov, Andrey; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Beliy, Nikita; Hammad, Gregory Habib; Aldá Júnior, Walter Luiz; Alves, Gilvan; Brito, Lucas; Correa Martins Junior, Marcos; Hamer, Matthias; Hensel, Carsten; Mora Herrera, Clemencia; Moraes, Arthur; Pol, Maria Elena; Rebello Teles, Patricia; Belchior Batista Das Chagas, Ewerton; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Da Costa, Eliza Melo; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Huertas Guativa, Lina Milena; Malbouisson, Helena; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Ahuja, Sudha; Bernardes, Cesar Augusto; De Souza Santos, Angelo; Dogra, Sunil; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Moon, Chang-Seong; Novaes, Sergio F; Padula, Sandra; Romero Abad, David; Ruiz Vargas, José Cupertino; Aleksandrov, Aleksandar; Genchev, Vladimir; Hadjiiska, Roumyana; Iaydjiev, Plamen; Piperov, Stefan; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Ahmad, Muhammad; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Cheng, Tongguang; Du, Ran; Jiang, Chun-Hua; Plestina, Roko; Romeo, Francesco; Shaheen, Sarmad Masood; Tao, Junquan; Wang, Chunjie; Wang, Zheng; Zhang, Huaqiao; Asawatangtrakuldee, Chayanit; Ban, Yong; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Xu, Zijun; Zou, Wei; Avila, Carlos; Cabrera, Andrés; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Polic, Dunja; Puljak, Ivica; Ribeiro Cipriano, Pedro M; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Kadija, Kreso; Luetic, Jelena; Micanovic, Sasa; Sudic, Lucija; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Rykaczewski, Hans; Bodlak, Martin; Finger, Miroslav; Finger Jr, Michael

    2015-01-01

    Constraints on the lifetime and width of the Higgs boson are obtained from $\\mathrm{H} \\to \\mathrm{ZZ} \\to 4\\ell$ events using data recorded by the CMS experiment during the LHC run 1 with an integrated luminosity of 5.1 and 19.7 fb$^{-1}$ at a center-of-mass energy of 7 and 8 TeV, respectively. The measurement of the Higgs boson lifetime is derived from its flight distance in the CMS detector with an upper bound of $\\tau_{\\mathrm{H}} $ lower than $ 1.9 \\times 10^{-13}$ s at the 95% confidence level (CL), corresponding to a lower bound on the width of $\\Gamma_{\\mathrm{H}} $ larger than $ 3.5 \\times 10^{-9} $ MeV. The measurement of the width is obtained from an off-shell production technique, generalized to include anomalous couplings of the Higgs boson to two electroweak bosons. From this measurement, a joint constraint is set on the Higgs boson width and a parameter $f_{\\Lambda Q}$ that expresses an anomalous coupling contribution as an on-shell cross-section fraction. The limit on the Higgs boson width is ...

  10. Search for a Higgs boson in the decay channel $H$ to ZZ(*) to $q$ qbar $\\ell^-$ l+ in $pp$ collisions at $\\sqrt{s}=7$ TeV

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et al.

    2012-04-01

    A search for the standard model Higgs boson decaying into two Z bosons with subsequent decay into a final state containing two quark jets and two leptons, H to ZZ(*) to q q-bar l-l+ is presented. Results are based on data corresponding to an integrated luminosity of 4.6 inverse femtobarns of proton-proton collisions at sqrt(s)=7 TeV, collected with the CMS detector at the LHC. In order to discriminate between signal and background events, kinematic and topological quantities, including the angular spin correlations of the decay products, are employed. Events are further classified according to the probability of the jets to originate from quarks of light or heavy flavor or from gluons. No evidence for the Higgs boson is found, and upper limits on its production cross section are determined for a Higgs boson of mass between 130 and 600 GeV.

  11. Hiding a Heavy Higgs Boson at the 7 TeV LHC

    SciTech Connect (OSTI)

    Bai, Yang; Fan, JiJi; Hewett, JoAnne L.

    2012-03-20

    A heavy Standard Model Higgs boson is not only disfavored by electroweak precision observables but is also excluded by direct searches at the 7 TeV LHC for a wide range of masses. Here, we examine scenarios where a heavy Higgs boson can be made consistent with both the indirect constraints and the direct null searches by adding only one new particle beyond the Standard Model. This new particle should be a weak multiplet in order to have additional contributions to the oblique parameters. If it is a color singlet, we find that a heavy Higgs with an intermediate mass of 200-300 GeV can decay into the new states, suppressing the branching ratios for the standard model modes, and thus hiding a heavy Higgs at the LHC. If the new particle is also charged under QCD, the Higgs production cross section from gluon fusion can be reduced significantly due to the new colored particle one-loop contribution. Current collider constraints on the new particles allow for viable parameter space to exist in order to hide a heavy Higgs boson. We categorize the general signatures of these new particles, identify favored regions of their parameter space and point out that discovering or excluding them at the LHC can provide important indirect information for a heavy Higgs. Finally, for a very heavy Higgs boson, beyond the search limit at the 7 TeV LHC, we discuss three additional scenarios where models would be consistent with electroweak precision tests: including an additional vector-like fermion mixing with the top quark, adding another U(1) gauge boson and modifying triple-gauge boson couplings.

  12. MSSM Higgs boson searches at the Tevatron and the LHC: Impact of different benchmark scenarios

    SciTech Connect (OSTI)

    Carena, Marcela S. [FNAL; Heinemeyer, S. [CERN; Wagner, C. E.M. [Argonne /Chicago U., EFI; Weiglein, G. [Durham U., IPPP

    2006-01-24

    The Higgs boson search has shifted from LEP2 to the Tevatron and will subsequently move to the LHC. The current limits from the Tevatron and the prospective sensitivities at the LHC are often interpreted in specific MSSM scenarios. For heavy Higgs boson production and subsequent decay into b{bar b} or {tau}{sup +}{tau}{sup -}, the present Tevatron data allow to set limits in the M{sub A}-tan {beta} plane for small M{sub A} and large tan {beta} values. Similar channels have been explored for the LHC, where the discovery reach extends to higher values of M{sub A} and smaller tan {beta}. Searches for MSSM charged Higgs bosons, produced in top decays or in association with top quarks, have also been investigated at the Tevatron and the LHC. We analyze the current Tevatron limits and prospective LHC sensitivities. We discuss how robust they are with respect to variations of the other MSSM parameters and possible improvements of the theoretical predictions for Higgs boson production and decay. It is shown that the inclusion of supersymmetric radiative corrections to the production cross sections and decay widths leads to important modifications of the present limits on the MSSM parameter space. The impact on the region where only the lightest MSSM Higgs boson can be detected at the LHC is also analyzed. We propose to extend the existing benchmark scenarios by including additional values of the higgsino mass parameter {mu}. This affects only slightly the search channels for a SM-like Higgs boson, while having a major impact on the searches for non-standard MSSM Higgs bosons.

  13. Search for MSSM Higgs Boson Production in Proton Anti-Proton Collisions, with a Higgs Decaying into Taus

    SciTech Connect (OSTI)

    Svoisky, Peter V.; /Notre Dame U.

    2008-04-01

    We present a search for the production of neutral Higgs bosons in association with bottom quarks in p{bar p} collisions at {radical}s = 1.96 TeV. The cross section for this process is enhanced in many extensions of the Standard Model (SM), such as in its Minimal Supersymmetric extension (MSSM) at large tan {beta}. The data, corresponding to a recorded integrated luminosity of 1 fb{sup -1}, were collected with the D0 detector at the Fermilab Tevatron Collider. In the absence of a signal a 95% C.L. limit is set on the production cross section times branching ratio, and the results are also interpreted in the MSSM.

  14. Search for a Higgs Boson Produced in Association with a W Boson in pbar-p Collisions at sqrt{s} = 1.96 TeV

    E-Print Network [OSTI]

    CDF Collaboration; T. Aaltonen

    2009-06-30

    We present a search for a standard model Higgs boson produced in association with a W boson using 2.7 1/fb of integrated luminosity of pbar-p collision data taken at sqrt{s} = 1.96 TeV. Limits on the Higgs boson production rate are obtained for masses between 100 GeV and 150 GeV. Through the use of multivariate techniques, the analysis achieves an observed (expected) 95% confidence level upper limit of 5.6 (4.8) times the theoretically expected production cross section for a standard model Higgs boson with a mass of 115 GeV.

  15. Decoupling of Higgs boson from the inflationary stage of Universe evolution

    E-Print Network [OSTI]

    V. V. Kiselev; S. A. Timofeev

    2010-05-07

    The constraint on the mass of Higgs field in the Standard Model at the minimal interaction with the gravity is derived in the form of lower bound $m_H> 150$ GeV by the strict requirement of decoupling the Higgs boson from the inflation of early Universe: the inflation produced by the Higgs scalar could crucially destroy visible properties of large scale structure of Universe, while the large mass makes the Higgs particle not able to produce the inflation and shifts its cosmological role into the region of quantum gravity.

  16. Review of Higgs physics

    E-Print Network [OSTI]

    Ocariz, Jose; The ATLAS collaboration

    2015-01-01

    The eperimental status on Higgs boson physics is reviewed. Results from both ATLAS and CMS, using data collected in LHC run 1, are presented. Prospects for Higgs physics with Run 2 and beyond are discussed.

  17. Constraints on Models of the Higgs Boson with Exotic Spin and Parity using Decays to Bottom-Antibottom Quarks in the Full CDF Data Set

    E-Print Network [OSTI]

    Aaltonen, T.

    A search for particles with the same mass and couplings as those of the standard model Higgs boson but different spin and parity quantum numbers is presented. We test two specific alternative Higgs boson hypotheses: a ...

  18. Measurements of the Higgs Boson in the $H\\rightarrow\\tau\\tau$ Decay Channel

    E-Print Network [OSTI]

    Howard, Jacob

    The generation of vector boson mass via the Higgs mechanism in the Standard Model has been confirmed by the 2012 discovery of a candidate Higgs boson in the $H\\rightarrow{WW}$, $H\\rightarrow{ZZ}$, and $H\\rightarrow\\gamma\\gamma$ decay channels. In contrast, the Yukawa couplings hypothesized to provide the mass of fermions in the Standard Model have yet to be observed. The $H\\rightarrow\\tau\\tau$ decay channel currently provides the best opportunity for observing these couplings. This thesis describes two separate but related searches for Higgs boson decays in the $H\\rightarrow\\tau\\tau$ decay channel using proton-proton collisions recorded by the ATLAS detector. The first analysis is a general search for all Higgs boson production mechanisms leading to a $H\\rightarrow\\tau\\tau$ decay using 4.5 fb$^{-1}$ of 7 TeV and 20.3 fb$^{-1}$ of 8 TeV proton-proton collision data. A deviation from the background-only hypothesis is observed with a significance of $4.5\\sigma$ for a hypothetical Higgs boson mass of ${m_{H} ...

  19. Search for a light Higgs boson in the radiative decays of J/psi

    E-Print Network [OSTI]

    Ablikim, M

    2015-01-01

    We search for a light Higgs boson $A^0$ in the fully reconstructed decay chain of $J/\\psi \\rightarrow \\gamma A^0$, $A^0 \\rightarrow \\mu^+\\mu^-$ using $(225.0\\pm2.8)\\times10^6$ $J/\\psi$ events collected by the BESIII experiment. The $A^0$ is a hypothetical CP-odd light Higgs boson predicted by many extensions of the Standard Model including the Next-to-Minimal Supersymmetric Standard Model. We find no evidence for $A^0$ production and set $90\\%$ confidence-level upper limits on the product branching fraction $\\mathcal{B}(J/\\psi \\rightarrow \\gamma A^0) \\times \\mathcal{B}(A^0 \\rightarrow \\mu^+\\mu^-)$ in the range of $(2.8-471.4)\\times 10^{-8}$ for $0.212 \\le m_{A^0} \\le 3.0$ GeV/$c^2$. The new limits are an order of magnitude below our previous results and can exclude a large portion of the parameter space of the new physics models.

  20. Combined CDF and D0 Searches for the Standard Model Higgs Boson Decaying to Two Photons with up to 8.2 fb^-1

    SciTech Connect (OSTI)

    Not Available

    2011-07-01

    We combine results from CDF and D0's direct searches for the standard model (SM) Higgs boson (H) produced in p{bar p} collisions at the Fermilab Tevatron at {radical}s = 1.96 TeV, focusing on the decay H {yields} {gamma}{gamma}. We compute upper limits on the Higgs boson production cross section times the decay branching fraction in the range 100 < m{sub H} < 150 GeV/c{sup 2}, and we interpret the results in the context of the standard model. We use the MSTW08 parton distribution functions and the latest theoretical cross section predictions when testing for the presence of a SM Higgs boson. With datasets corresponding to 7.0 fb{sup -1} (CDF) and 8.2 fb{sup -1} (D0), the 95% C.L. upper limits on Higgs boson production is a factor of 10.5 times the SM cross section for a Higgs boson mass of 115 GeV/c{sup 2}.

  1. Hidden-Sector Higgs Bosons at High-Energy Electron-Positron Colliders

    E-Print Network [OSTI]

    Jack H. Collins; James D. Wells

    2012-09-30

    The possibility of a scalar messenger that can couple the Standard Model (SM) to a hidden sector has been discussed in a variety of contexts in the literature in recent years. We consider the case that a new scalar singlet charged under an exotic spontaneously broken Abelian gauge symmetry mixes weakly with the SM Higgs resulting in two scalar mass states, one of which has heavily suppressed couplings to the SM particles. Previous phenomenological studies have focussed on potential signatures for such a model at the Large Hadron Collider (LHC). However, there are interesting regions of the parameter space in which the heavier Higgs state would be out of reach for LHC searches if its mass is greater than 1 TeV. We therefore investigate the discovery potential for such a particle at a 3 TeV electron-positron collider, which is motivated by the recent developments of the Compact Linear Collider (CLIC). We find that such an experiment could substantially extend our discovery reach for a heavy, weakly coupled Higgs boson, and we discuss three possible search channels.

  2. Search for the Associated Production of the Standard-Model Higgs Boson in the All-Hadronic Channel

    E-Print Network [OSTI]

    Makhoul, K.

    We report on a search for the standard-model Higgs boson in pp? collisions at ?s=1.96??TeV using an integrated luminosity of 2.0??fb[superscript -1]. We look for production of the Higgs boson decaying to a pair of bottom ...

  3. 2014 8 22 4:00PM-5:00PM Title: "Exploration of the Higgs boson and the Physics case for the Large Hadron Electron

    E-Print Network [OSTI]

    Wang, Yayu

    2014 8 22 4:00PM-5:00PM Title: "Exploration of the Higgs boson and the Physics case for the Large Hadron Electron Collider" Abstract: With the discovery of a Higgs boson at the Large Hadron) Prof. Mellado is an expert on the Higgs boson ­ a sub-atomic particle that is thought to give matter

  4. 86The Higgs Boson and the Mystery of Mass Why is it that some elementary particles such as the photon and gluon do not carry

    E-Print Network [OSTI]

    86The Higgs Boson and the Mystery of Mass Why is it that some elementary particles to add a new particle called the Higgs Boson to the known collection of fundamental particles. Depending on how strongly a particle such as electrons or neutrinos interacted with the Higgs Boson, it would 'pick

  5. Search for a Two-Higgs-Boson Doublet Using a Simplified Model in pp[over ¯] Collisions at sqrt[s]=1.96??TeV

    E-Print Network [OSTI]

    Goncharov, Maxim

    We present a search for new particles in an extension to the standard model that includes a heavy Higgs boson (H[superscript 0]), a lighter charged Higgs boson (H[superscript ±]), and an even lighter Higgs boson h[superscript ...

  6. Discovery Potential of the Standard Model Higgs Boson Through H -> WW Decay Mode with the ATLAS Detector at LHC

    E-Print Network [OSTI]

    Hai-Jun Yang; for the ATLAS Collaboration

    2009-10-01

    We report results of a study of the Standard Model Higgs boson discovery potential through the W-pair leptonic decay modes with the ATLAS detector at LHC at 14 TeV center-of-mass energy. We used MC samples with full detector simulation and reconstruction of the ATLAS experiment to estimate the ATLAS detection sensitivity for the reaction of pp -> H -> WW -> e\

  7. Constraints on models of the Higgs boson with exotic spin and parity using the full CDF data set

    E-Print Network [OSTI]

    T. Aaltonen; CDF Collaboration

    2015-01-23

    A search for particles with the same mass and couplings as those of the standard model Higgs boson but different spin and parity quantum numbers is presented. We test two specific non-standard Higgs boson hypotheses: a pseudoscalar Higgs boson with spin-parity $J^P$ = $0^-$ and a graviton-like Higgs boson with $J^P$ = $2^+$, assuming for both a mass of 125 GeV/$c^2$. We search for these exotic states produced in association with a vector boson and decaying into a bottom-antibottom quark pair. The vector boson is reconstructed through its decay into an electron or muon pair, or an electron or muon and a neutrino, or it is inferred from an imbalance in total transverse momentum. We use expected kinematic differences between events containing exotic Higgs bosons and those containing standard model Higgs bosons. The data were collected by the CDF experiment at the Tevatron proton-antiproton collider, operating at a center-of-mass energy of $\\sqrt{s}=1.96$ TeV, and correspond to an integrated luminosity of 9.45 fb$^{-1}$. We observe no significant deviations from the predictions of the standard model with a Higgs boson of mass 125 GeV/$c^2$, and set bounds on the possible rate of production of each exotic state.

  8. Measurements of the total and differential cross sections of Higgs boson production

    E-Print Network [OSTI]

    ATLAS Collaboration; The ATLAS collaboration

    2015-01-01

    We present measurements of the total and differential cross sections of Higgs boson production that were performed using 20.3 fb$^{-1}$ of $pp$ collisions produced by the Large Hadron Collider at a center-of-mass energy of $\\sqrt{s} = 8$ TeV and recorded by the ATLAS detector. Cross sections are obtained from measured $H \\to \\gamma\\gamma$ and $H \\to ZZ \\to 4 \\ell$ event yields, which are combined accounting for detector efficiencies, fiducial acceptances and branching fractions. Differential cross sections are reported as a function of Higgs boson transverse momentum, Higgs boson rapidity, number of jets in the event, and transverse momentum of the leading jet. The total production cross section is determined to be: $\\sigma_{pp \\to H} = 33.0 \\pm 5.3 \\, (\\text{stat}) \\pm 1.6 \\, (\\text{sys})$ pb. The measurements are then compared to state-of-the-art predictions.

  9. $Z'$ resonance and associated $Zh$ production at future Higgs boson factory: ILC and CLIC

    E-Print Network [OSTI]

    Gutierrez-Rodriguez, A

    2015-01-01

    We study the prospects of the B-L model with an additional $Z'$ boson to be a Higgs boson factory at high-energy and high-luminosity linear electron positron colliders, such as the ILC and CLIC, through the Higgs-strahlung process $e^{+}e^{-}\\rightarrow (Z, Z') \\to Zh$, including both the resonant and non-resonant effects. We evaluate the total cross section of $Zh$ and we calculate the total number of events for integrated luminosities of 500-2000\\hspace{0.8mm}$fb^{-1}$ and center of mass energies between 500 and 3000\\hspace{0.8mm}$GeV$. We find that the total number of expected $Zh$ events can reach $10^6$, which is a very optimistic scenario and it would be possible to perform precision measurements for both the $Z'$ and Higgs boson in future high-energy $e^+e^-$ colliders experiments.

  10. Associated production of A^0 and Z^0 bosons and Rare Pseudoscalar Higgs Decays

    E-Print Network [OSTI]

    B. Field

    2005-02-22

    We study the production of a pseudoscalar Higgs boson A^0 in association with a Z^0 boson at a future international linear collider (ILC). We consider the contributions to this process at the one loop level in the Minimal Supersymmetric Standard Model (MSSM) from top and bottom quarks as well as stop and sbottom squarks. We also study the squark contributions to the decay widths of the pseudoscalar Higgs boson for the decays A^0 --> \\gamma Z^0$ and A^0 --> Z^0 Z^0. The contribution from the supersymmetric loops are found to be directly proportional to the squark mixing and potentially large due to the massive pseudoscalar Higgs coupling to squarks.

  11. Prospects to Measure the Higgs Boson Mass and Cross Section in ee-->ZH Using the Recoil Mass Spectrum

    E-Print Network [OSTI]

    W. Lohmann; M. Ohlerich; A. Raspereza; A. Schälicke

    2007-10-13

    The process ee-->ZH allows to measure the Higgs boson in the recoil mass spectrum against the Z boson without any assumptions on the Higgs boson decay. We performed a full simulation and reconstruction of ee-->ZH using the MOKKA and MARLIN packages describing the LDC detector. The Z is reconstructed from its decays into electrons and muons. The mass of the Higgs boson is set to 120 GeV. Assuming a centre-of-mass energy of 250 GeV and an integrated luminosity of 50/fb the Higgs boson mass and the Higgs-strahlung cross section can be measured with a precision of 120 MeV and 9%, respectively.

  12. Search for New Heavy Higgs Boson in B-L model at the LHC using Monte Carlo Simulation

    E-Print Network [OSTI]

    Hesham Mansour; Nady Bakhet

    2013-04-24

    The aim of this work is to search for a new heavy Higgs boson in the B-L extension of the Standard Model at LHC using the data produced from simulated collisions between two protons at different center of mass energies by Monte Carlo event generator programs to find new Higgs boson signatures at the LHC. Also we study the production and decay channels for Higgs boson in this model and its interactions with the other new particles of this model namely the new neutral gauge massive boson and the new fermionic right-handed heavy neutrinos .

  13. Higgs boson mass and sparticle spectroscopy in Yukawa unified SUSY SO(10)

    SciTech Connect (OSTI)

    Shafi, Qaisar

    2012-07-27

    We employ third family Yukawa unification, predicted by simple supersymmetric SO(10) models, to estimate the lightest MSSM Higgs boson mass. For {mu} > 0 (or {mu} < 0) and m{sub t} = 173.1GeV, the Higgs mass is estimated to lie close to 123-124 GeV. The theoretical uncertainty in this estimate is {+-}3 GeV. We highlight some LHC testable benchmark points which also display the presence of neutralino-stau coannihilation channel.

  14. The symmetry and simplicity of the laws of physics and the Higgs boson

    E-Print Network [OSTI]

    Juan Maldacena

    2015-07-07

    We describe the theoretical ideas, developed between the 1950s-1970s, which led to the prediction of the Higgs boson, the particle that was discovered in 2012. The forces of nature are based on symmetry principles. We explain the nature of these symmetries through an economic analogy. We also discuss the Higgs mechanism, which is necessary to avoid some of the naive consequences of these symmetries, and to explain various features of elementary particles.

  15. The symmetry and simplicity of the laws of physics and the Higgs boson

    E-Print Network [OSTI]

    Juan Maldacena

    2014-10-24

    We describe the theoretical ideas, developed between the 1950s-1970s, which led to the prediction of the Higgs boson, the particle that was discovered in 2012. The forces of nature are based on symmetry principles. We explain the nature of these symmetries through an economic analogy. We also discuss the Higgs mechanism, which is necessary to avoid some of the naive consequences of these symmetries, and to explain various features of elementary particles.

  16. Supersymmetric QCD corrections to the top quark decay of a heavy charged higgs boson

    E-Print Network [OSTI]

    Ricardo A. Jimenez; Joan Sola

    1996-10-24

    The supersymmetric QCD corrections to the hadronic width of a heavy charged Higgs boson, basically dominated by the top-quark decay mode $H^{+}\\rightarrow t \\bar{b}$, are evaluated at ${\\cal O}(\\alpha_s)$ within the MSSM and compared with the standard QCD corrections. The study of such quantum effects, which turn out to be rather large, is essential to understand the hypothetical supersymmetric nature of a heavy charged Higgs boson potentially produced in the near future at the Tevatron and/or at the LHC.

  17. Particle Physics after the Higgs-Boson Discovery: Opportunities for the Large Hadron Collider

    SciTech Connect (OSTI)

    Quigg, Chris

    2015-08-24

    The first run of the Large Hadron Collider at CERN brought the discovery of the Higgs boson, an apparently elementary scalar particle with a mass of 125 GeV, the avatar of the mechanism that hides the electroweak symmetry. Then, a new round of experimentation is beginning, with the energy of the proton–proton colliding beams raised to 6.5 TeV per beam, from 4 TeV at the end of the first run. I summarize what we have learned about the Higgs boson, and calls attention to some issues that will be among our central concerns in the near future.

  18. Determination of spin and CP of the Higgs boson from WBF.

    E-Print Network [OSTI]

    Buszello, C P; Marquard, P

    114.4 GeV < mH < 246 GeV (95% C.L.) [1]. When the Higgs mass is above the Z pair threshold, it decays with a large branching fraction into Z bosons, that can be discovered in the “golden” ?+?+???? decay mode. As long as mH & 130 GeV the decay into four... qq ? qqH ? qqWW ? qq ?? ?? [4, 5, 6] have the largest discovery potential. In recent papers [8, 3] we discussed the possible determination of the spin/CP properties of the Higgs boson. To analyse these properties we introduced hypothetical couplings...

  19. Collider Detector at Fermilab (CDF): Data from Standard Model and Supersymmetric Higgs Bosons Research of the Higgs Group

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The Collider Detector at Fermilab (CDF) is a Tevatron experiment at Fermilab. The Tevatron, a powerful particle accelerator, accelerates protons and antiprotons close to the speed of light, and then makes them collide head-on inside the CDF detector. The CDF detector is used to study the products of such collisions. The CDF Physics Group at Fermilab is organized into six working groups, each with a specific focus. The Higgs group searches for Standard Model and Supersymmetric Higgs bosons. Their public web page makes data and numerous figures available from both CDF Runs I and II.

  20. Higgs funnel region of SUSY dark matter for small $\\tan?$ and renormalization group effects on pseudoscalar Higgs boson with scalar mass non-universality

    E-Print Network [OSTI]

    Utpal Chattopadhyay; Debottam Das

    2009-02-05

    A non-universal scalar mass supergravity type of model is explored where the first two generation of scalars and the third generation of sleptons may be very massive. Lighter or vanishing third generation of squarks as well as Higgs scalars at the unification scale cause the radiative electroweak symmetry breaking constraint to be less prohibitive. Thus, both FCNC/CP-violation problems as well as the naturalness problem are within control. We identify a large slepton mass effect in the RGE of $m_{H_D}^2$ (for the down type of Higgs) that may turn the later negative at the electroweak scale even for a small $\\tan\\beta$. A hyperbolic branch/focus point like effect is found for $m_A^2$ that may result in very light Higgs spectra. The lightest stable particle is dominantly a bino that pair annihilates via Higgs exchange, giving rise to a WMAP satisfied relic density region for all $\\tan\\beta$. Detection prospects of such LSPs in the upcoming dark matter experiments both of direct and indirect types (photon flux) are interesting. The Higgs bosons and the third generation of squarks are light in this scenario and these may be easily probed besides charginos and neutralinos in the early runs of LHC.

  1. Measurement of the MSSM Higgs-bosons production in gamma gamma -> A,H -> b bbar at the Photon Collider at TESLA

    E-Print Network [OSTI]

    P. Niezurawski; A. F. Zarnecki; M. Krawczyk

    2003-07-14

    Results from a realistic simulation of the heavy MSSM Higgs-bosons A and H production, gamma gamma -> A,H -> b bbar, at the Photon Collider at TESLA are reported. In the scenario where a light SM-like Higgs boson h exists, we study (following M. Muehlleitner et al.) Higgs bosons A and H for masses M_A=200,250,300,350 GeV and tan(beta)=7. This scenario corresponds to parameters region not accessible at LHC or at the first stage of the e^+ e^- collider. NLO estimation of background, analysis of overlaying events, realistic b-tagging and corrections for escaping neutrinos were performed. The statistical precision of the cross-section measurement is estimated to be 8-20%.

  2. Constraints on the Higgs boson width from off-shell production and decay to Z-boson pairs

    SciTech Connect (OSTI)

    Khachatryan, Vardan [Yerevan Physics Institute (Armenia); et al.,

    2014-09-01

    Constraints are presented on the total width of the recently discovered Higgs boson, Gamma[H], using its relative on-shell and off-shell production and decay rates to a pair of Z bosons, where one Z boson decays to an electron or muon pair, and the other to an electron, muon, or neutrino pair. The analysis is based on the data collected by the CMS experiment at the LHC in 2011 and 2012, corresponding to integrated luminosities of 5.1 inverse femtobarns at a centre-of-mass energy sqrt(s) = 7 TeV and 19.7 inverse femtobarns at sqrt(s) = 8 TeV. A simultaneous maximum likelihood fit to the measured kinematic distributions near the resonance peak and above the Z-boson pair production threshold leads to an upper limit on the Higgs boson width of Gamma[H] < 22 MeV at a 95% confidence level, which is 5.4 times the expected value in the standard model at the measured mass.

  3. Search for the Standard Model Higgs Boson associated with a W Boson using Matrix Element Technique in the CDF detector at the Tevatron

    SciTech Connect (OSTI)

    Alvarez Gonzalez, Barbara; /Oviedo U.

    2010-05-01

    In this thesis a direct search for the Standard Model Higgs boson production in association with a W boson at the CDF detector in the Tevatron is presented. This search contributes predominantly in the region of low mass Higgs region, when the mass of Higgs boson is less than about 135 GeV. The search is performed in a final state where the Higgs boson decays into two b quarks, and the W boson decays leptonically, to a charged lepton (it can be an electron or a muon) and a neutrino. This work is organized as follows. Chapter 2 gives an overview of the Standard Model theory of particle physics and presents the SM Higgs boson search results at LEP, and the Tevatron colliders, as well as the prospects for the SM Higgs boson searches at the LHC. The dataset used in this analysis corresponds to 4.8 fb{sup -1} of integrated luminosity of p{bar p} collisions at a center of mass energy of 1.96 TeV. That is the luminosity acquired between the beginning of the CDF Run II experiment, February 2002, and May 2009. The relevant aspects, for this analysis, of the Tevatron accelerator and the CDF detector are shown in Chapter 3. In Chapter 4 the particles and observables that make up the WH final state, electrons, muons, E{sub T}, and jets are presented. The CDF standard b-tagging algorithms to identify b jets, and the neural network flavor separator to distinguish them from other flavor jets are also described in Chapter 4. The main background contributions are those coming from heavy flavor production processes, such as those coming from Wbb, Wcc or Wc and tt. The signal and background signatures are discussed in Chapter 5 together with the Monte CArlo generators that have been used to simulate almost all the events used in this thesis. WH candidate events have a high-p{sub T} lepton (electron or muon), high missing transverse energy, and two or more than two jets in the final state. Chapter 6 describes the event selection applied in this analysis and the method used to estimate the background contribution. The Matrix Element method, that was successfully used in the single t0p discovery analysis and many other analyses within the CDF collaboration, is the multivariate technique used in this thesis to discriminate signal from background events. With this technique is possible to calculate a probability for an event to be classified as signal or background. These probabilities are then combined into a discriminant function called the Event Probability Discriminant, EPD, which increases the sensitivity of the WH process. This method is described in detail in Chapter 7. As no evidence for the signal has been found, the results obtained with this work are presented in Chapter 8 in terms of exclusion regions as a function of the mass of the Higgs boso, taking into account the full systematics. The conclusions of this work to obtain the PhD are presnted in Chapter 9.

  4. Measurement of WZ production and searches for anomalous top quark decays and Higgs boson production using tri-lepton final states in ppbar collisions at ?s = 1.96 TeV

    E-Print Network [OSTI]

    McGivern, Carrie Lynne

    2012-05-31

    We present the results of three analyses; a WZ production cross section measurement, a search for new physics in anomalous top quark decays, and the search for the standard model Higgs boson, all with final states of three ...

  5. Search for WH production with a light Higgs boson decaying to prompt electron-jets in proton–proton collisions at ?s=7 TeV with the ATLAS detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    A search is performed for WH production with a light Higgs boson decaying to hidden-sector particles resulting in clusters of collimated electrons, known as electron-jets. The search is performed with 2.04 fb[superscript ...

  6. Study of (W/Z)H production and Higgs boson couplings using H? W W * decays with the ATLAS detector

    SciTech Connect (OSTI)

    Aad, G.

    2015-08-27

    A search for Higgs boson production in association with a W or Z boson, in the H? W W * decay channel, is performed with a data sample collected with the ATLAS detector at the LHC in proton-proton collisions at centre-of-mass energies \\( \\sqrt{s}=7 \\) TeV and 8 TeV, corresponding to integrated luminosities of 4.5 fb-1 and 20.3 fb-1, respectively. The WH production mode is studied in two-lepton and three-lepton final states, while two- lepton and four-lepton final states are used to search for the ZH production mode. The observed significance, for the combined W H and ZH production, is 2.5 standard deviations while a significance of 0.9 standard deviations is expected in the Standard Model Higgs boson hypothesis. The ratio of the combined W H and ZH signal yield to the Standard Model expectation, ?V H , is found to be ? V H = 3.0-1.1+1.3 (stat.)-0.7 +1.0 (sys.) for the Higgs boson mass of 125.36 GeV. The W H and ZH production modes are also combined with the gluon fusion and vector boson fusion production modes studied in the H ? W W * ? ???? decay channel, resulting in an overall observed significance of 6.5 standard deviations and ?ggF + VBF + VH = 1.16-0.15+0.16 (stat.) -0.15+0.18 (sys.). The results are interpreted in terms of scaling factors of the Higgs boson couplings to vector bosons (?V ) and fermions (?F ); the combined results are: |? V | = 1.06-0.10+0.10, |? F| = 0.85-0.20+0.26.

  7. Higgs boson pair production: top quark mass effects at NLO and NNLO

    E-Print Network [OSTI]

    Grigo, Jonathan; Steinhauser, Matthias

    2015-01-01

    We compute next-to-next-to-leading order QCD corrections to the gluon-induced production cross section of Higgs boson pairs in the large top quark mass limit using the soft-virtual approximation. In the limit of infinitely-heavy top quark we confirm the results in the literature. We add two more expansion terms in the inverse top quark mass to the $M_t\\to\\infty$ result. Since the $1/M_t$ expansion converges poorly, we try to improve on it by factorizing the exact leading order cross section. We discuss two ways of doing that and conclude that the finite top quark mass effects shift the cross section at most by about 10\\% at next-to-leading order and by about 5\\% at next-to-next-to-leading order.

  8. Search for a Fermiophobic Higgs Boson Decaying into Diphotons in p p-bar Collisions at sqrt{s} = 1.96 TeV

    SciTech Connect (OSTI)

    Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, Jahred A.; /Chicago U., EFI; Akimoto, T.; /Tsukuba U.; Alvarez Gonzalez, B.; /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, Dante E.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, Alberto; /Frascati; Antos, Jaroslav; /Comenius U.; Apollinari, G.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U.

    2009-05-01

    A search for a narrow diphoton mass resonance is presented based on data from 3.0 fb{sup -1} of integrated luminosity from p{bar p} collisions at {radical}s = 1.96 TeV collected by the CDF experiment. No evidence of a resonance in the diphoton mass spectrum is observed, and upper limits are set on the cross section times branching fraction of the resonant state as a function of Higgs boson mass. The resulting limits exclude Higgs bosons with masses below 106 GeV/c{sup 2} at a 95% Bayesian credibility level (C.L.) for one fermiophobic benchmark model.

  9. Search for neutral Higgs bosons decaying to tau pairs produced in association with b-quarks at s**(1/2)=1.96 TeV

    SciTech Connect (OSTI)

    Herner, Kenneth Richard; /SUNY, Stony Brook

    2008-12-01

    We report results from a search for neutral Higgs bosons decaying to tau pairs produced in association with a b-quark in 1.6 fb{sup -1} of data taken from June 2006 to March 2008 with the D0 detector at Fermi National Accelerator Laboratory. The final state includes a muon, hadronically decaying tau, and jet identified as coming from a b-quark. We set cross section times branching ratio limits on production of such neutral Higgs bosons {phi} in the mass range from 90 GeV to 160 GeV. Exclusion limits are set at the 95% Confidence Level for several supersymmetric scenarios.

  10. Searches for Higgs boson like high mass resonances in the bosonic decay channels with ATLAS and CMS

    E-Print Network [OSTI]

    Lo Sterzo, Francesco; The ATLAS collaboration

    2015-01-01

    In this talk the searches of the ATLAS and CMS experiment for additional Higgs boson like resonances in the WW, ZZ and $\\gamma\\gamma$ final state, for high masses beyond 125 GeV are summarized. The searches are based on the full LHC run-1 dataset of each experiment. Upper limits are presented in the context of an electro-weak singlet extension of the standard model.

  11. Combined CDF and D0 Upper Limits on Standard Model Higgs Boson Production with up to 8.6 fb-1 of Data

    E-Print Network [OSTI]

    The CDF; D0 Collaborations; the Tevatron New Phenomena; Higgs Working Group

    2011-09-20

    We combine results from CDF and D0 on direct searches for the standard model (SM) Higgs boson (H) in ppbar collisions at the Fermilab Tevatron at sqrt{s}=1.96 TeV. Compared to the previous Tevatron Higgs boson search combination more data have been added, additional channels have been incorporated, and some previously used channels have been reanalyzed to gain sensitivity. We use the MSTW08 parton distribution functions and the latest theoretical cross sections when comparing our limits to the SM predictions. With up to 8.2 fb-1 of data analyzed at CDF and up to 8.6 fb-1 at D0, the 95% C.L. our upper limits on Higgs boson production are factors of 1.17, 1.71, and 0.48 times the values of the SM cross section for Higgs bosons of mass m_H=115 GeV/c^2, 140 GeV/c^2, and 165 GeV/c^2, respectively. The corresponding median upper limits expected in the absence of Higgs boson production are 1.16, 1.16, and 0.57. There is a small (approx. 1 sigma) excess of data events with respect to the background estimation in searches for the Higgs boson in the mass range 125

  12. Combined CDF and D0 Upper Limits on Standard Model Higgs Boson Production with up to 8.6 fb-1 of Data

    SciTech Connect (OSTI)

    CDF, The; Collaborations, D0; Phenomena, the Tevatron New; Group, Higgs Working

    2011-07-01

    We combine results from CDF and D0 on direct searches for the standard model (SM) Higgs boson (H) in p{bar p} collisions at the Fermilab Tevatron at {radical}s = 1.96 TeV. Compared to the previous Tevatron Higgs boson search combination more data have been added, additional channels have been incorporated, and some previously used channels have been reanalyzed to gain sensitivity. We use the MSTW08 parton distribution functions and the latest theoretical cross sections when comparing our limits to the SM predictions. With up to 8.2 fb{sup -1} of data analyzed at CDF and up to 8.6 fb{sup -1} at D0, the 95% C.L. our upper limits on Higgs boson production are factors of 1.17, 1.71, and 0.48 times the values of the SM cross section for Higgs bosons of mass m{sub H} = 115 GeV/c{sup 2}, 140 GeV/c{sup 2}, and 165 GeV/c{sup 2}, respectively. The corresponding median upper limits expected in the absence of Higgs boson production are 1.16, 1.16, and 0.57. There is a small ({approx} 1{sigma}) excess of data events with respect to the background estimation in searches for the Higgs boson in the mass range 125 < m{sub H} < 155 GeV/c{sup 2}. We exclude, at the 95% C.L., a new and larger region at high mass between 156 < m{sub H} < 177 GeV/c{sup 2}, with an expected exclusion region of 148 < m{sub H} < 180 GeV/c{sup 2}.

  13. Triple vector boson production through Higgs-Strahlung with NLO multijet merging

    SciTech Connect (OSTI)

    Hoeche, Stefan; Kraus, Frank; Pozzorini, Stephano; Schoenherr, Marek; Thompson, Jennifer M.; Zapp, Korinna C.

    2014-07-25

    Triple gauge boson hadroproduction, in particular the production of three W-bosons at the LHC, is considered at next-to leading order accuracy in QCD. The NLO matrix elements are combined with parton showers. Multijet merging is invoked such that NLO matrix elements with one additional jet are also included. The studies here incorporate both the signal and all relevant backgrounds for V H production with the subsequent decay of the Higgs boson into W– or ?–- pairs. They have been performed using SHERPA+OPENLOOPS in combination with COLLIER.

  14. Associated production of a top pair and a Higgs boson beyond NLO

    E-Print Network [OSTI]

    Broggio, Alessandro; Pecjak, Ben D; Signer, Adrian; Yang, Li Lin

    2015-01-01

    We consider soft gluon emission corrections to the production of a top-antitop pair in association with a Higgs boson at hadron colliders. In particular, we present a soft-gluon resummation formula for this production process and gather all elements needed to evaluate it at next-to-next-to-leading logarithmic order. We employ these results to obtain approximate next-to-next-to-leading order (NNLO) formulas, and implement them in a bespoke parton-level Monte Carlo program which can be used to calculate the total cross section along with arbitrary differential distributions. We use this tool to study the phenomenological impact of the approximate NNLO corrections, finding that they increase the total cross section and the differential distributions which we evaluated in this work.

  15. Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aad, G.

    2015-04-21

    Results of a search for H ? ?? decays are presented, based on the full set of proton-proton collision data recorded by the ATLAS experiment at the LHC during 2011 and 2012. The data correspond to integrated luminosities of 4.5 fb–1 and 20.3 fb–1 at centre-of-mass energies of ?s=7 TeV and ?s=8 TeV respectively. All combinations of leptonic (? ? ???¯ with ? = e, ?) and hadronic (? ? hadrons ?) tau decays are considered. An excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.5 (3.4) standardmore »deviations. This excess provides evidence for the direct coupling of the recently discovered Higgs boson to fermions. The measured signal strength, normalized to the Standard Model expectation, of ? = 1.43–0.37+0.43 is consistent with the predicted Yukawa coupling strength in the Standard Model.« less

  16. Radiative Mixing of the One Higgs Boson and Emergent Self-Interacting Dark Matter

    E-Print Network [OSTI]

    Ma, Ernest

    2015-01-01

    In all scalar extensions of the standard model of particle interactions, the one Higgs boson responsible for electroweak symmetry breaking always mixes with other neutral scalars at tree level unless a symmetry prevents it. An unexplored important option is that the mixing may be radiative, and thus guaranteed to be small. Two first such examples are discussed. One is based on the soft breaking of the discrete symmetry $Z_3$. The other starts with the non-Abelian discrete symmetry $A_4$ which is then softly broken to $Z_3$, and results in the emergence of an interesting dark-matter candidate together with a light mediator for the dark matter to have its own long-range interaction.

  17. Search for neutral Higgs bosons decaying to tau pairs produced in association with b quarks in $p\\bar{p}$ collisions at $\\sqrt{s} = 1.96$ TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazov, Victor Mukhamedovich

    2011-09-12

    We report results from a search for neutral Higgs bosons produced in association with b quarks using data recorded by the D0 experiment at the Fermilab Tevatron Collider and corresponding to an integrated luminosity of 7.3 fb-1. This production mode can be enhanced in several extensions of the standard model (SM) such as in its minimal supersymmetric extension (MSSM) at high tanß. We search for Higgs bosons decaying to tau pairs with one tau decaying to a muon and neutrinos and the other to hadrons. The data are found to be consistent with SM expectations, and we set upper limitsmore »on the cross section times branching ratio in the Higgs boson mass range from 90 to 320 GeV/c2. We interpret our result in the MSSM parameter space, excluding tanß values down to 25 for Higgs boson masses below 170 GeV/c2.« less

  18. Search for Higgs Boson Production in Association with the W boson in 1.96-TeV Proton-Antiproton Collisions

    SciTech Connect (OSTI)

    Ishizawa, Yoshio; /Tsukuba U.

    2005-09-01

    A search for the Standard Model Higgs boson was carried out in WH {yields} {ell}{nu}b{bar b} process in p{bar p} collisions at a center of mass energy of 1.96 TeV, where W, H, {ell}, {nu}, b and p denote either a W{sup +} or W{sup -} boson, Higgs boson, lepton (electron or muon), neutrino, bottom quark and proton, respectively. The data were collected with the Collider Detector at Fermilab from February 2002 to August 2004. The corresponding integrated luminosity is 319 pb{sup -1}. We select events containing a single high-p{sub T} electron or muon, a large imbalance of the total transverse energy from a neutrino and two b quark jets. The main backgrounds are the W + light flavor/gluon jets and W + heavy flavor jets processes. Requiring the secondary vertex b-tagging enables us to reject the W + light flavor/gluon jets events effectively. After all event selections, they observe 187 events which is in agreement with the Standard Model background expectation of 175.2 {+-} 26.3 events, and there is no significant excess originating from the Higgs boson in the reconstructed dijet invariant mass distribution. They thus set a 95% confidence level upper limit on the production cross section times branching ratio decaying into bb, {sigma}(p{bar p} {yields} W H) x Br(H {yields} b{bar b}). The detection efficiency for the W H events, which is necessary for calculating the upper limit, is determined by the Monte Carlo except for the lepton identification efficiency, the lepton trigger efficiency and the b-tagging efficiency which are estimated from the CDF real data. The resultant 95% confidence level upper limits are 10.0 pb to 2.8 pb using at least one b-tagging method and 9.7 pb to 6.6 pb using double b-tagging method for the Higgs boson mass region 110 GeV/c{sup 2} to 150 GeV/c{sup 2}, where the Standard Model prediction is approximately one or two order of magnitude lower than the results.

  19. Search for neutral Higgs bosons decaying to tau pairs in pp collisions at sqrt(s) = 7 TeV

    E-Print Network [OSTI]

    CMS Collaboration

    2014-11-12

    A search for neutral Higgs bosons decaying to tau pairs at a center-of-mass energy of 7 TeV is performed using a dataset corresponding to an integrated luminosity of 4.6 inverse femtobarns recorded by the CMS experiment at the LHC. The search is sensitive to both the standard model Higgs boson and to the neutral Higgs bosons predicted by the minimal supersymmetric extension of the standard model (MSSM). No excess of events is observed in the tau-pair invariant-mass spectrum. For a standard model Higgs boson in the mass range of 110-145 GeV upper limits at 95% confidence level (CL) on the production cross section are determined. We exclude a Higgs boson with m(H) = 115 GeV with a production cross section 3.2 times of that predicted by the standard model. In the MSSM, upper limits on the neutral Higgs boson production cross section times branching fraction to tau pairs, as a function of the pseudoscalar Higgs boson mass, m(A), sets stringent new bounds in the parameter space, excluding at 95% CL values of tan(beta) as low as 7.1 at m(A) = 160 GeV in the m[h](max) benchmark scenario.

  20. Evidence for a Higgs boson in tau decays with the CMS detector

    E-Print Network [OSTI]

    Dutta, Valentina

    2014-01-01

    In this thesis, I describe the search for a Higgs boson through its decay to a pair of tan leptons with the tau-pair subsequently decaying to ail electron, a muon, and neutrinos. The search is performed using data collected ...