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

CMS Collaboration

Research output: Contribution to journalArticle

161 Citations (Scopus)

Abstract

The first direct search for lepton-flavour-violating decays of the recently discovered Higgs boson (H) is described. The search is performed in the H→μτe and H→μτh channels, where τe and τh are tau leptons reconstructed in the electronic and hadronic decay channels, respectively. The data sample used in this search was collected in pp collisions at a centre-of-mass energy of s=8 TeV with the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 19.7 fb−1. The sensitivity of the search is an order of magnitude better than the existing indirect limits. A slight excess of signal events with a significance of 2.4 standard deviations is observed. The p-value of this excess at MH=125 GeV is 0.010. The best fit branching fraction is B(H→μτ)=(0.84−0.37 +0.39)%. A constraint on the branching fraction, B(H→μτ)<1.51% at 95% confidence level is set. This limit is subsequently used to constrain the μ–τ Yukawa couplings to be less than 3.6×10−3.

Original languageEnglish
Pages (from-to)337-362
Number of pages26
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume749
DOIs
Publication statusPublished - 7 Oct 2015

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Higgs bosons
leptons
decay
center of mass
confidence
standard deviation
luminosity
collisions
sensitivity
electronics
energy

Keywords

  • CMS
  • Higgs
  • Lepton-flavour-violation
  • Muons
  • Physics
  • Taus

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Cite this

Search for lepton-flavour-violating decays of the Higgs boson. / CMS Collaboration.

In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, Vol. 749, 07.10.2015, p. 337-362.

Research output: Contribution to journalArticle

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abstract = "The first direct search for lepton-flavour-violating decays of the recently discovered Higgs boson (H) is described. The search is performed in the H→μτe and H→μτh channels, where τe and τh are tau leptons reconstructed in the electronic and hadronic decay channels, respectively. The data sample used in this search was collected in pp collisions at a centre-of-mass energy of s=8 TeV with the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 19.7 fb−1. The sensitivity of the search is an order of magnitude better than the existing indirect limits. A slight excess of signal events with a significance of 2.4 standard deviations is observed. The p-value of this excess at MH=125 GeV is 0.010. The best fit branching fraction is B(H→μτ)=(0.84−0.37 +0.39){\%}. A constraint on the branching fraction, B(H→μτ)<1.51{\%} at 95{\%} confidence level is set. This limit is subsequently used to constrain the μ–τ Yukawa couplings to be less than 3.6×10−3.",
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AU - Adam, W.

AU - Bergauer, T.

AU - Dragicevic, M.

AU - Erö, J.

AU - Friedl, M.

AU - Frühwirth, R.

AU - Ghete, V. M.

AU - Hartl, C.

AU - Hörmann, N.

AU - Hrubec, J.

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AU - Krätschmer, I.

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AU - Rabady, D.

AU - Rahbaran, B.

AU - Rohringer, H.

AU - Schöfbeck, R.

AU - Strauss, J.

AU - Treberer-Treberspurg, W.

AU - Waltenberger, W.

AU - Wulz, C. E.

AU - Mossolov, V.

AU - Shumeiko, N.

AU - Suarez Gonzalez, J.

AU - Alderweireldt, S.

AU - Bansal, S.

AU - Cornelis, T.

AU - De Wolf, E. A.

AU - Janssen, X.

AU - Knutsson, A.

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AU - Ochesanu, S.

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AU - Van De Klundert, M.

AU - Van Haevermaet, H.

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N2 - The first direct search for lepton-flavour-violating decays of the recently discovered Higgs boson (H) is described. The search is performed in the H→μτe and H→μτh channels, where τe and τh are tau leptons reconstructed in the electronic and hadronic decay channels, respectively. The data sample used in this search was collected in pp collisions at a centre-of-mass energy of s=8 TeV with the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 19.7 fb−1. The sensitivity of the search is an order of magnitude better than the existing indirect limits. A slight excess of signal events with a significance of 2.4 standard deviations is observed. The p-value of this excess at MH=125 GeV is 0.010. The best fit branching fraction is B(H→μτ)=(0.84−0.37 +0.39)%. A constraint on the branching fraction, B(H→μτ)<1.51% at 95% confidence level is set. This limit is subsequently used to constrain the μ–τ Yukawa couplings to be less than 3.6×10−3.

AB - The first direct search for lepton-flavour-violating decays of the recently discovered Higgs boson (H) is described. The search is performed in the H→μτe and H→μτh channels, where τe and τh are tau leptons reconstructed in the electronic and hadronic decay channels, respectively. The data sample used in this search was collected in pp collisions at a centre-of-mass energy of s=8 TeV with the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 19.7 fb−1. The sensitivity of the search is an order of magnitude better than the existing indirect limits. A slight excess of signal events with a significance of 2.4 standard deviations is observed. The p-value of this excess at MH=125 GeV is 0.010. The best fit branching fraction is B(H→μτ)=(0.84−0.37 +0.39)%. A constraint on the branching fraction, B(H→μτ)<1.51% at 95% confidence level is set. This limit is subsequently used to constrain the μ–τ Yukawa couplings to be less than 3.6×10−3.

KW - CMS

KW - Higgs

KW - Lepton-flavour-violation

KW - Muons

KW - Physics

KW - Taus

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EP - 362

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

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