The result of a search for flavor changing neutral currents (FCNC) through single top quark production in association with a photon is presented. The study is based on proton-proton collisions at a center-of-mass energy of 8 TeV using data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.8 fb−1. The search for tγ events where t → Wb and W → μν is conducted in final states with a muon, a photon, at least one hadronic jet with at most one being consistent with originating from a bottom quark, and missing transverse momentum. No evidence of single top quark production in association with a photon through a FCNC is observed. Upper limits at the 95% confidence level are set on the tuγ and tcγ anomalous couplings and translated into upper limits on the branching fraction of the FCNC top quark decays: ℬ(t → uγ) < 1.3 × 10− 4 and ℬ(t → cγ) < 1.7 × 10− 3. Upper limits are also set on the cross section of associated tγ production in a restricted phase-space region. These are the most stringent limits currently available.

Search for anomalous single top quark production in association with a photon in pp collisions at √s = 8 TeV

Cappello, G.
Membro del Collaboration Group
;
Costa, S.
Membro del Collaboration Group
;
Giordano, F.
Membro del Collaboration Group
;
Potenza, R.
Membro del Collaboration Group
;
Tricomi, A.
Membro del Collaboration Group
;
Tuve, C.
Membro del Collaboration Group
;
2016-01-01

Abstract

The result of a search for flavor changing neutral currents (FCNC) through single top quark production in association with a photon is presented. The study is based on proton-proton collisions at a center-of-mass energy of 8 TeV using data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.8 fb−1. The search for tγ events where t → Wb and W → μν is conducted in final states with a muon, a photon, at least one hadronic jet with at most one being consistent with originating from a bottom quark, and missing transverse momentum. No evidence of single top quark production in association with a photon through a FCNC is observed. Upper limits at the 95% confidence level are set on the tuγ and tcγ anomalous couplings and translated into upper limits on the branching fraction of the FCNC top quark decays: ℬ(t → uγ) < 1.3 × 10− 4 and ℬ(t → cγ) < 1.7 × 10− 3. Upper limits are also set on the cross section of associated tγ production in a restricted phase-space region. These are the most stringent limits currently available.
2016
Flavour Changing Neutral Currents; Hadron-Hadron scattering (experiments); Top physics; Nuclear and High Energy Physics
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11769/309944
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