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.

Khachatryan, V., Sirunyan, A., Tumasyan, A., Adam, W., Bergauer, T., Dragicevic, M., et al. (2015). Search for lepton-flavour-violating decays of the Higgs boson. PHYSICS LETTERS. SECTION B, 749, 337-362 [10.1016/j.physletb.2015.07.053].

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

DINARDO, MAURO EMANUELE
Membro del Collaboration Group
;
FIORENDI, SARA
Membro del Collaboration Group
;
GENNAI, STEFANO
Membro del Collaboration Group
;
GEROSA, RAFFAELE ANGELO
Membro del Collaboration Group
;
GHEZZI, ALESSIO
Membro del Collaboration Group
;
GOVONI, PIETRO
Membro del Collaboration Group
;
LUCCHINI, MARCO TOLIMAN
Membro del Collaboration Group
;
MANZONI, RICCARDO ANDREA
Membro del Collaboration Group
;
MARTELLI, ARABELLA
Membro del Collaboration Group
;
MARZOCCHI, BADDER
Membro del Collaboration Group
;
MORONI, LUIGI
Membro del Collaboration Group
;
PAGANONI, MARCO
Membro del Collaboration Group
;
RAGAZZI, STEFANO
Membro del Collaboration Group
;
TABARELLI DE FATIS, TOMMASO
Membro del Collaboration Group
;
Branca, A;De Guio, F
Membro del Collaboration Group
;
2015

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.
Articolo in rivista - Articolo scientifico
CMS; Higgs; Lepton-flavour-violation; Muons; Physics; Taus; Nuclear and High Energy Physics
English
2015
749
337
362
reserved
Khachatryan, V., Sirunyan, A., Tumasyan, A., Adam, W., Bergauer, T., Dragicevic, M., et al. (2015). Search for lepton-flavour-violating decays of the Higgs boson. PHYSICS LETTERS. SECTION B, 749, 337-362 [10.1016/j.physletb.2015.07.053].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/153367
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