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 -> mu tau(e) and H -> mu tau(h) channels, where tau(e) and tau(h) 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 root 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 M-H = 125 GeV is 0.010. The best fit branching fraction is beta(H -> mu tau) = (0.84(-0.37)(+0.39))%. A constraint on the branching fraction, beta(H -> mu tau) < 1.51% at 95% confidence level is set. This limit is subsequently used to constrain the mu-tau Yukawa couplings to be less than 3.6 x 10(-3). (C) 2015 CERN for the benefit of the CMS Collaboration. Published by Elsevier B.V.

Khachatryan, V., Sirunyan, A.M., 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

CIOCCI, MARIA AGNESE;MESSINEO, ALBERTO MARIA;
2015-01-01

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 -> mu tau(e) and H -> mu tau(h) channels, where tau(e) and tau(h) 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 root 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 M-H = 125 GeV is 0.010. The best fit branching fraction is beta(H -> mu tau) = (0.84(-0.37)(+0.39))%. A constraint on the branching fraction, beta(H -> mu tau) < 1.51% at 95% confidence level is set. This limit is subsequently used to constrain the mu-tau Yukawa couplings to be less than 3.6 x 10(-3). (C) 2015 CERN for the benefit of the CMS Collaboration. Published by Elsevier B.V.
2015
Khachatryan, V., Sirunyan, A.M., 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].
File in questo prodotto:
File Dimensione Formato  
Search for lepton flavour violating decays.pdf

accesso aperto

Tipologia: PDF editoriale
Licenza: Creative commons
Dimensione 1.43 MB
Formato Adobe PDF
1.43 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/1327833