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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) (SC-25)
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:
Accepted Manuscript
Journal Name:
Journal of High Energy Physics (Online)
Additional Journal Information:
Journal Name: Journal of High Energy Physics (Online); 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. doi:10.1007/JHEP03(2016)125.
Khachatryan, Vardan. Thu . "Search for excited leptons in proton-proton collisions at √(s) = 8 TeV". United States. doi: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},
journal = {Journal of High Energy Physics (Online)},
number = 125,
volume = 2016,
place = {United States},
year = {2016},
month = {3}
}

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