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Title: Search for Techniparticles in e+jets Events at D0

Abstract

We search for the technicolor process pp{yields}{rho}{sub T}/{omega}{sub T}{yields}W{pi}{sub T} in events containing one electron and two jets, in data corresponding to an integrated luminosity of 390 pb{sup -1}, recorded by the D0 experiment at the Fermilab Tevatron. Technicolor predicts that technipions {pi}{sub T} decay dominantly into bb, bc, or bc, depending on their charge. In these events b and c quarks are identified by their secondary decay vertices within jets. Two analysis methods based on topological variables are presented. Since no excess above the standard model prediction was found, the result is presented as an exclusion in the {pi}{sub T} vs {rho}{sub T} mass plane for a given set of model parameters.

Authors:
; ; ; ; ; ; ; ;  [1]; ; ; ; ; ; ; ; ;  [2]; ;  [3]
  1. Joint Institute for Nuclear Research, Dubna (Russian Federation)
  2. University of Oklahoma, Norman, Oklahoma 73019 (United States)
  3. Michigan State University, East Lansing, Michigan 48824 (United States) (and others)
Publication Date:
OSTI Identifier:
20951441
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 98; Journal Issue: 22; Other Information: DOI: 10.1103/PhysRevLett.98.221801; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; B QUARKS; BEAM LUMINOSITY; C QUARKS; ELECTRONS; FERMILAB TEVATRON; PARTICLE DECAY; STANDARD MODEL; TOPOLOGY

Citation Formats

Abazov, V. M., Alexeev, G. D., Kalinin, A. M., Kharzheev, Y. M., Malyshev, V. L., Tokmenin, V. V., Eijk, B. van, Vertogradov, L. S., Yatsunenko, Y. A., Abbott, B., Gutierrez, P., Hall, I., Jain, S., Kopal, M., Pompos, A., Severini, H., Skubic, P., Strauss, M., Abolins, M., and Benitez, J. A. Search for Techniparticles in e+jets Events at D0. United States: N. p., 2007. Web. doi:10.1103/PHYSREVLETT.98.221801.
Abazov, V. M., Alexeev, G. D., Kalinin, A. M., Kharzheev, Y. M., Malyshev, V. L., Tokmenin, V. V., Eijk, B. van, Vertogradov, L. S., Yatsunenko, Y. A., Abbott, B., Gutierrez, P., Hall, I., Jain, S., Kopal, M., Pompos, A., Severini, H., Skubic, P., Strauss, M., Abolins, M., & Benitez, J. A. Search for Techniparticles in e+jets Events at D0. United States. doi:10.1103/PHYSREVLETT.98.221801.
Abazov, V. M., Alexeev, G. D., Kalinin, A. M., Kharzheev, Y. M., Malyshev, V. L., Tokmenin, V. V., Eijk, B. van, Vertogradov, L. S., Yatsunenko, Y. A., Abbott, B., Gutierrez, P., Hall, I., Jain, S., Kopal, M., Pompos, A., Severini, H., Skubic, P., Strauss, M., Abolins, M., and Benitez, J. A. Fri . "Search for Techniparticles in e+jets Events at D0". United States. doi:10.1103/PHYSREVLETT.98.221801.
@article{osti_20951441,
title = {Search for Techniparticles in e+jets Events at D0},
author = {Abazov, V. M. and Alexeev, G. D. and Kalinin, A. M. and Kharzheev, Y. M. and Malyshev, V. L. and Tokmenin, V. V. and Eijk, B. van and Vertogradov, L. S. and Yatsunenko, Y. A. and Abbott, B. and Gutierrez, P. and Hall, I. and Jain, S. and Kopal, M. and Pompos, A. and Severini, H. and Skubic, P. and Strauss, M. and Abolins, M. and Benitez, J. A.},
abstractNote = {We search for the technicolor process pp{yields}{rho}{sub T}/{omega}{sub T}{yields}W{pi}{sub T} in events containing one electron and two jets, in data corresponding to an integrated luminosity of 390 pb{sup -1}, recorded by the D0 experiment at the Fermilab Tevatron. Technicolor predicts that technipions {pi}{sub T} decay dominantly into bb, bc, or bc, depending on their charge. In these events b and c quarks are identified by their secondary decay vertices within jets. Two analysis methods based on topological variables are presented. Since no excess above the standard model prediction was found, the result is presented as an exclusion in the {pi}{sub T} vs {rho}{sub T} mass plane for a given set of model parameters.},
doi = {10.1103/PHYSREVLETT.98.221801},
journal = {Physical Review Letters},
number = 22,
volume = 98,
place = {United States},
year = {Fri Jun 01 00:00:00 EDT 2007},
month = {Fri Jun 01 00:00:00 EDT 2007}
}
  • The authors search for the technicolor process ppbar -> rho{sub T}/omega{sub T} ->W+pi{sub T} in events containing one electron and two jets, in data corresponding to an integrated luminosity of 390 pb-1, recorded by the D0 experiment at the Fermilab Tevatron. Technicolor predicts that technipions, pi{sub T}, decay dominantly into b-bbar, b-cbar, or bbar-c, depending on their charge. In these events b and c quarks are identified by their secondary decay vertices within jets. Two analysis methods based on topological variables are presented. Since no excess above the standard model prediction was found, the result is presented as an exclusionmore » in the pi{sub T} vs. rho{sub T} mass plane for a given set of model parameters.« less
  • In this study, a search is performed for heavy Majorana neutrinos (N) decaying into a W boson and a lepton using the CMS detector at the Large Hadron Collider. A signature of two jets and either two same sign electrons or a same sign electron-muon pair is searched for using 19.7 inverse femtobarns of data collected during 2012 in proton-proton collisions at a centre-of-mass energy of 8 TeV. The data are found to be consistent with the expected standard model (SM) background and, in the context of a Type-1 seesaw mechanism, upper limits are set on the cross section timesmore » branching fraction for production of heavy Majorana neutrinos in the mass range between 40 and 500 GeV. The results are additionally interpreted as limits on the mixing between the heavy Majorana neutrinos and the SM neutrinos. In the mass range considered, the upper limits range between 0.00015 - 0.72 for |V eN| 2 and 6.6x10 -5 - 0.47 for |V eN V* μN| 2 / ( |V eN| 2 + |V μN| 2), where V lN is the mixing element describing the mixing of the heavy neutrino with the SM neutrino of flavour l. These limits are the most restrictive direct limits for heavy Majorana neutrino masses above 200 GeV.« less
  • A search is performed for heavy Majorana neutrinos (N) using an event signature defined by two same-sign charged leptons of the same flavour and two jets. The data correspond to an integrated luminosity of 4.98 inverse femtobarns of pp collisions at a centre-of-mass energy of 7 TeV collected with the CMS detector at the Large Hadron Collider. No excess of events is observed beyond the expected standard model background and therefore upper limits are set on the square of the mixing parameter, abs(V[ell N]) squared, for ell = e, mu, as a function of heavy Majorana-neutrino mass. These are themore » first direct upper limits on the heavy Majorana-neutrino mixing for m[N] > 90 GeV.« less
  • The authors construct probability density functions for signal and background events in multi-dimensional space, using Monte Carlo samples. A variant of the Bayes` discriminant function is then applied to classify signal and background events. The effect of some kinematic quantities on the performance of the discriminant has been studied and the results of applying the PDE method to search for the top quark in D0 data (p{bar p} collisions at {radical}s = 1.8 TeV) will be presented.
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