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Title: Search for excited leptons in proton-proton collisions at √(s) = 8 TeV

Abstract

Our search for compositeness of electrons and muons is presented using a data sample of proton-proton collisions at a center-of-mass energy of √(s) = 8 TeV collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 19.7 fb-1. Excited leptons (ℓ*) produced via contact interactions in conjunction with a standard model lepton are considered, and a search is made for their gauge decay modes. The decays considered are ℓ* →ℓγ and ℓ* → ℓZ, which give final states of two leptons and a photon or, depending on the Z-boson decay mode, four leptons or two leptons and two jets. The number of events observed in data is consistent with the standard model prediction. Exclusion limits are set on the excited lepton mass, and the compositeness scale L. For the case Mℓ* = L the existence of excited electrons (muons) is excluded up to masses of 2.45 (2.47) TeV at 95% confidence level. The neutral current decays of excited leptons are considered for the first time, and limits are extended to include the possibility that the weight factors f and f ', which determine the couplings between standard model leptons and excited leptons via gauge mediatedmore » interactions, have opposite sign.« less

Authors:
 [1]
  1. Yerevan Physics Inst. (YerPhI) (Armenia). et al.
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP)
Contributing Org.:
CMS Collaboration
OSTI Identifier:
1230027
Report Number(s):
FERMILAB-PUB-15-516-CMS
Journal ID: ISSN 1029-8479; arXiv eprint number arXiv:1511.01407; TRN: US1601628
Grant/Contract Number:  
AC02-07CH11359
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of High Energy Physics (Online)
Additional Journal Information:
Journal Volume: 2016; Journal Issue: 125; Journal ID: ISSN 1029-8479
Publisher:
Springer Berlin
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Khachatryan, Vardan. Search for excited leptons in proton-proton collisions at √(s) = 8 TeV. United States: N. p., 2016. Web. doi:10.1007/JHEP03(2016)125.
Khachatryan, Vardan. Search for excited leptons in proton-proton collisions at √(s) = 8 TeV. United States. https://doi.org/10.1007/JHEP03(2016)125
Khachatryan, Vardan. 2016. "Search for excited leptons in proton-proton collisions at √(s) = 8 TeV". United States. https://doi.org/10.1007/JHEP03(2016)125. https://www.osti.gov/servlets/purl/1230027.
@article{osti_1230027,
title = {Search for excited leptons in proton-proton collisions at √(s) = 8 TeV},
author = {Khachatryan, Vardan},
abstractNote = {Our search for compositeness of electrons and muons is presented using a data sample of proton-proton collisions at a center-of-mass energy of √(s) = 8 TeV collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 19.7 fb-1. Excited leptons (ℓ*) produced via contact interactions in conjunction with a standard model lepton are considered, and a search is made for their gauge decay modes. The decays considered are ℓ* →ℓγ and ℓ* → ℓZ, which give final states of two leptons and a photon or, depending on the Z-boson decay mode, four leptons or two leptons and two jets. The number of events observed in data is consistent with the standard model prediction. Exclusion limits are set on the excited lepton mass, and the compositeness scale L. For the case Mℓ* = L the existence of excited electrons (muons) is excluded up to masses of 2.45 (2.47) TeV at 95% confidence level. The neutral current decays of excited leptons are considered for the first time, and limits are extended to include the possibility that the weight factors f and f ', which determine the couplings between standard model leptons and excited leptons via gauge mediated interactions, have opposite sign.},
doi = {10.1007/JHEP03(2016)125},
url = {https://www.osti.gov/biblio/1230027}, journal = {Journal of High Energy Physics (Online)},
issn = {1029-8479},
number = 125,
volume = 2016,
place = {United States},
year = {Thu Mar 17 00:00:00 EDT 2016},
month = {Thu Mar 17 00:00:00 EDT 2016}
}

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Cited by: 18 works
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Works referenced in this record:

Vector boson pair production at the LHC
journal, July 2011


New Generation of Parton Distributions with Uncertainties from Global QCD Analysis
journal, July 2002


Observable effects of the possible sub-structure of leptons and quarks
journal, May 1982


A quantum structuredynamic model of quarks, leptons, weak vector bosons and Higgs mesons
journal, February 1981


Cuba—a library for multidimensional numerical integration
journal, June 2005


Maximizing boosted top identification by minimizing N-subjettiness
journal, February 2012


Search for composite and exotic fermions at LEP 2
journal, March 1999


Composite models for quarks and leptons
journal, February 1984


A brief introduction to PYTHIA 8.1
journal, June 2008


Search for excited leptons at 130–140 GeV
journal, September 1996


Are quarks composite?
journal, November 1975


Search for Excited and Exotic Muons in the μ γ Decay Channel in p p ¯ Collisions at s = 1.96 TeV
journal, November 2006


A New Method for Combining NLO QCD with Shower Monte Carlo Algorithms
journal, November 2004


A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX
journal, June 2010


Search for excited leptons in pp collisions at <mml:math altimg="si1.gif" overflow="scroll" xmlns:xocs="http://www.elsevier.com/xml/xocs/dtd" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.elsevier.com/xml/ja/dtd" xmlns:ja="http://www.elsevier.com/xml/ja/dtd" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:tb="http://www.elsevier.com/xml/common/table/dtd" xmlns:sb="http://www.elsevier.com/xml/common/struct-bib/dtd" xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:cals="http://www.elsevier.com/xml/common/cals/dtd"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>7</mml:mn><mml:mtext> TeV</mml:mtext></mml:math>
journal, March 2013


Longitudinally-invariant k⊥-clustering algorithms for hadron-hadron collisions
journal, September 1993


Search for excited electrons in p p ¯ collisions at s = 1.96 TeV
journal, May 2008


W+W−, WZ and ZZ production in the POWHEG BOX
journal, November 2011


PYTHIA 6.4 physics and manual
journal, May 2006


FastJet user manual: (for version 3.0.2)
journal, March 2012


Search for heavy narrow dilepton resonances in pp collisions at <mml:math altimg="si1.gif" overflow="scroll" xmlns:xocs="http://www.elsevier.com/xml/xocs/dtd" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.elsevier.com/xml/ja/dtd" xmlns:ja="http://www.elsevier.com/xml/ja/dtd" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:tb="http://www.elsevier.com/xml/common/table/dtd" xmlns:sb="http://www.elsevier.com/xml/common/struct-bib/dtd" xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:cals="http://www.elsevier.com/xml/common/cals/dtd"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>7</mml:mn><mml:mtext> TeV</mml:mtext></mml:math> and <mml:math altimg="si2.gif" overflow="scroll" xmlns:xocs="http://www.elsevier.com/xml/xocs/dtd" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.elsevier.com/xml/ja/dtd" xmlns:ja="http://www.elsevier.com/xml/ja/dtd" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:tb="http://www.elsevier.com/xml/common/table/dtd" xmlns:sb="http://www.elsevier.com/xml/common/struct-bib/dtd" xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:cals="http://www.elsevier.com/xml/common/cals/dtd"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>8</mml:mn><mml:mtext> TeV</mml:mtext></mml:math>
journal, March 2013


Identifying boosted objects with N-subjettiness
journal, March 2011


Search for heavy resonances in the W/Z-tagged dijet mass spectrum in pp collisions at 7 TeV
journal, June 2013


Event generation with SHERPA 1.1
journal, February 2009


N Jettiness: An Inclusive Event Shape to Veto Jets
journal, August 2010


Search for excited electrons in ep collisions at HERA
journal, August 2008


Geant4—a simulation toolkit
journal, July 2003

  • Agostinelli, S.; Allison, J.; Amako, K.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 506, Issue 3
  • https://doi.org/10.1016/S0168-9002(03)01368-8

Search for excited muons in p p ¯ collisions at s = 1.96 TeV
journal, June 2006


Search for Excited and Exotic Electrons in the e γ Decay Channel in p p ¯ Collisions at s = 1.96 TeV
journal, March 2005


Search for excited leptons at LEP
journal, August 2003


Matching NLO QCD computations with parton shower simulations: the POWHEG method
journal, November 2007


New Tests for Quark and Lepton Substructure
journal, March 1983


Search for unstable heavy and excited leptons at LEP2
journal, May 2000


Performance of CMS muon reconstruction in pp collision events at √s = 7 TeV
journal, October 2012


Determination of jet energy calibration and transverse momentum resolution in CMS
journal, November 2011


Cuba—a library for multidimensional numerical integration
journal, June 2007


A quantum structuredynamic model of quarks, leptons, weak vector bosons, and Higgs mesons
conference, January 1981


Performance of Electron Reconstruction and Selection with the CMS Detector in Proton-Proton Collisions at √s = 8 TeV
text, January 2015


Event generation with SHERPA 1.1
text, January 2009


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Hunting for heavy composite Majorana neutrinos at the LHC
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