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).
Search for lepton-flavour-violating decays of the Higgs boson
PAGANO, Davide;
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).File | Dimensione | Formato | |
---|---|---|---|
2-s2.0-84940403742.pdf
accesso aperto
Tipologia:
Full Text
Licenza:
DRM non definito
Dimensione
2.12 MB
Formato
Adobe PDF
|
2.12 MB | Adobe PDF | Visualizza/Apri |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.