Search for physics beyond the standard model in multilepton final states in proton-proton collisions at s$$ \sqrt{s} $$ = 13 TeV

Abstract A search for physics beyond the standard model in events with at least three charged leptons (electrons or muons) is presented. The data sample corresponds to an integrated luminosity of 137 fb−1 of proton-proton collisions at s$$ \sqrt{s} $$ = 13 TeV, collected with the CM...

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Main Authors: Sirunyan, A. M, Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Dragicevic, M., Erö, J., Escalante Del Valle, A., Flechl, M., Frühwirth, R., Jeitler, M., Krammer, N., Krätschmer, I., Liko, D., Madlener, T., Mikulec, I., Rad, N., Schieck, J.
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:English
Published: Springer Berlin Heidelberg 2021
Online Access:https://hdl.handle.net/1721.1/131717
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author Sirunyan, A. M
Tumasyan, A.
Adam, W.
Ambrogi, F.
Bergauer, T.
Dragicevic, M.
Erö, J.
Escalante Del Valle, A.
Flechl, M.
Frühwirth, R.
Jeitler, M.
Krammer, N.
Krätschmer, I.
Liko, D.
Madlener, T.
Mikulec, I.
Rad, N.
Schieck, J.
author2 Massachusetts Institute of Technology. Department of Physics
author_facet Massachusetts Institute of Technology. Department of Physics
Sirunyan, A. M
Tumasyan, A.
Adam, W.
Ambrogi, F.
Bergauer, T.
Dragicevic, M.
Erö, J.
Escalante Del Valle, A.
Flechl, M.
Frühwirth, R.
Jeitler, M.
Krammer, N.
Krätschmer, I.
Liko, D.
Madlener, T.
Mikulec, I.
Rad, N.
Schieck, J.
author_sort Sirunyan, A. M
collection MIT
description Abstract A search for physics beyond the standard model in events with at least three charged leptons (electrons or muons) is presented. The data sample corresponds to an integrated luminosity of 137 fb−1 of proton-proton collisions at s$$ \sqrt{s} $$ = 13 TeV, collected with the CMS detector at the LHC in 2016–2018. The two targeted signal processes are pair production of type-III seesaw heavy fermions and production of a light scalar or pseudoscalar boson in association with a pair of top quarks. The heavy fermions may be manifested as an excess of events with large values of leptonic transverse momenta or missing transverse momentum. The light scalars or pseudoscalars may create a localized excess in the dilepton mass spectra. The results exclude heavy fermions of the type-III seesaw model for masses below 880 GeV at 95% confidence level in the scenario of equal branching fractions to each lepton flavor. This is the most restrictive limit on the flavor-democratic scenario of the type-III seesaw model to date. Assuming a Yukawa coupling of unit strength to top quarks, branching fractions of new scalar (pseudoscalar) bosons to dielectrons or dimuons above 0.004 (0.03) and 0.04 (0.03) are excluded at 95% confidence level for masses in the range 15–75 and 108–340 GeV, respectively. These are the first limits in these channels on an extension of the standard model with scalar or pseudoscalar particles.
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spelling mit-1721.1/1317172023-12-22T18:51:14Z Search for physics beyond the standard model in multilepton final states in proton-proton collisions at s$$ \sqrt{s} $$ = 13 TeV Sirunyan, A. M Tumasyan, A. Adam, W. Ambrogi, F. Bergauer, T. Dragicevic, M. Erö, J. Escalante Del Valle, A. Flechl, M. Frühwirth, R. Jeitler, M. Krammer, N. Krätschmer, I. Liko, D. Madlener, T. Mikulec, I. Rad, N. Schieck, J. Massachusetts Institute of Technology. Department of Physics Abstract A search for physics beyond the standard model in events with at least three charged leptons (electrons or muons) is presented. The data sample corresponds to an integrated luminosity of 137 fb−1 of proton-proton collisions at s$$ \sqrt{s} $$ = 13 TeV, collected with the CMS detector at the LHC in 2016–2018. The two targeted signal processes are pair production of type-III seesaw heavy fermions and production of a light scalar or pseudoscalar boson in association with a pair of top quarks. The heavy fermions may be manifested as an excess of events with large values of leptonic transverse momenta or missing transverse momentum. The light scalars or pseudoscalars may create a localized excess in the dilepton mass spectra. The results exclude heavy fermions of the type-III seesaw model for masses below 880 GeV at 95% confidence level in the scenario of equal branching fractions to each lepton flavor. This is the most restrictive limit on the flavor-democratic scenario of the type-III seesaw model to date. Assuming a Yukawa coupling of unit strength to top quarks, branching fractions of new scalar (pseudoscalar) bosons to dielectrons or dimuons above 0.004 (0.03) and 0.04 (0.03) are excluded at 95% confidence level for masses in the range 15–75 and 108–340 GeV, respectively. These are the first limits in these channels on an extension of the standard model with scalar or pseudoscalar particles. 2021-09-20T17:29:53Z 2021-09-20T17:29:53Z 2020-03-10 2020-06-26T13:19:15Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/131717 Journal of High Energy Physics. 2020 Mar 10;2020(3):51 PUBLISHER_CC en https://doi.org/10.1007/JHEP03(2020)051 Creative Commons Attribution https://creativecommons.org/licenses/by/4.0/ The Author(s) application/pdf Springer Berlin Heidelberg Springer Berlin Heidelberg
spellingShingle Sirunyan, A. M
Tumasyan, A.
Adam, W.
Ambrogi, F.
Bergauer, T.
Dragicevic, M.
Erö, J.
Escalante Del Valle, A.
Flechl, M.
Frühwirth, R.
Jeitler, M.
Krammer, N.
Krätschmer, I.
Liko, D.
Madlener, T.
Mikulec, I.
Rad, N.
Schieck, J.
Search for physics beyond the standard model in multilepton final states in proton-proton collisions at s$$ \sqrt{s} $$ = 13 TeV
title Search for physics beyond the standard model in multilepton final states in proton-proton collisions at s$$ \sqrt{s} $$ = 13 TeV
title_full Search for physics beyond the standard model in multilepton final states in proton-proton collisions at s$$ \sqrt{s} $$ = 13 TeV
title_fullStr Search for physics beyond the standard model in multilepton final states in proton-proton collisions at s$$ \sqrt{s} $$ = 13 TeV
title_full_unstemmed Search for physics beyond the standard model in multilepton final states in proton-proton collisions at s$$ \sqrt{s} $$ = 13 TeV
title_short Search for physics beyond the standard model in multilepton final states in proton-proton collisions at s$$ \sqrt{s} $$ = 13 TeV
title_sort search for physics beyond the standard model in multilepton final states in proton proton collisions at s sqrt s 13 tev
url https://hdl.handle.net/1721.1/131717
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