Search for anomalous Wtb couplings and flavour-changing neutral currents in t-channel single top quark production in pp collisions at √s=7 and 8 TeV

Khachatryan, V. and Sirunyan, A. M. and Tumasyan, A. R. and Adam, Wolfgang and Asilar, Ece and Md. Ali, Mohd. Adli (2017) Search for anomalous Wtb couplings and flavour-changing neutral currents in t-channel single top quark production in pp collisions at √s=7 and 8 TeV. Journal of High Energy Physics, 2017 (2). pp. 1-44. ISSN 1029-8479

	PDF (The CMS Collaboration) - Published Version Restricted to Repository staff only Download (1MB) | Request a copy
	PDF (scopus) - Supplemental Material Restricted to Repository staff only Download (517kB) | Request a copy

Abstract

Single top quark events produced in the t channel are used to set limits on anomalous Wtb couplings and to search for top quark flavour-changing neutral current (FCNC) interactions. The data taken with the CMS detector at the LHC in proton-proton collisions at √ s = 7 and 8 TeV correspond to integrated luminosities of 5.0 and 19.7 fb−1 , respectively. The analysis is performed using events with one muon and two or three jets. A Bayesian neural network technique is used to discriminate between the signal and backgrounds, which are observed to be consistent with the standard model prediction. The 95% confidence level (CL) exclusion limits on anomalous right-handed vector, and left- and righthanded tensor Wtb couplings are measured to be |f R V | < 0.16, |f L T | < 0.057, and −0.049 < f R T < 0.048, respectively. For the FCNC couplings κtug and κtcg, the 95% CL upper limits on coupling strengths are |κtug|/Λ < 4.1 × 10−3 TeV−1 and |κtcg|/Λ < 1.8 × 10−2 TeV−1 , where Λ is the scale for new physics, and correspond to upper limits on the branching fractions of 2.0 × 10−5 and 4.1 × 10−4 for the decays t → ug and t → cg, respectively.

Item Type:	Article (Journal)
Additional Information:	7861/63059
Uncontrolled Keywords:	Flavour changing neutral currents, Hadron-hadron scattering (experiments),top physics
Subjects:	Q Science > Q Science (General) Q Science > QC Physics
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Science Kulliyyah of Science > Department of Physics
Depositing User:	Dr Mohd Adli MD Ali
Date Deposited:	05 Nov 2018 12:21
Last Modified:	03 Jan 2019 12:57
URI:	http://irep.iium.edu.my/id/eprint/63059

Actions (login required)

View Item