Search for top quark flavor changing neutral currents in same-sign top quark production

• Published in: Physical review. D, Particles, fields, gravitation, and cosmology Vol. 91; no. 1
• Main Author: Goldouzian, Reza
• Format: Journal Article
• Language: English
• Published: 21-01-2015
• Subjects: Channels; Collisions; Confidence intervals; Cosmology; Decay; Flavor (particle physics); Higgs bosons; Quarks; Searching
• ISSN: 1550-7998; 1550-2368
• DOI: 10.1103/PhysRevD.91.014022

The presence of the anomalous top-quark flavor-changing neutral-current (FCNC) interactions leads to the production of same-sign top quarks in proton-proton collisions. The results of a search for events with same-sign dileptons and b jets conducted by the CMS Collaboration with 10.5 fb super(-1) of data collected in pp collisions at [radical]s = 8 TeV are used to obtain the constraints on the strength of top-quark FCNC interactions. The 95% confidence level upper limits on the branching ratios of top-quark decays to a light quark q = u, c and a gauge or a Higgs boson are set to be BR(t arrow right u gamma ) < 1.27%, BR(t arrow right uZ) < 0.8%, BR(t arrow right ug) < 1.02%, and BR(t arrow right uH) < 4.21%. The sensitivity of future searches in the same-sign top-quark channel is also presented.