10-1007-JHEP04-2016-023.pdf (1013.45 kB)
Search for anomalous couplings in the W tb vertex from the measurement of double differential angular decay rates of single top quarks produced in the t-channel with the ATLAS detector
journal contribution
posted on 2023-06-09, 05:12 authored by Benedict AllbrookeBenedict Allbrooke, Lily AsquithLily Asquith, Alessandro CerriAlessandro Cerri, C A Chavez Barajas, Antonella De SantoAntonella De Santo, Fabrizio SalvatoreFabrizio Salvatore, I Santoyo Castillo, K Suruliz, Mark SuttonMark Sutton, Iacopo Vivarelli, The ATLAS CollaborationThe electroweak production and subsequent decay of single top quarks is determined by the properties of the Wtb vertex. This vertex can be described by the complex parameters of an effective Lagrangian. An analysis of angular distributions of the decay products of single top quarks produced in the t -channel constrains these parameters simultaneously. The analysis described in this paper uses 4.6 fb-1 of proton-proton collision data at sv = 7 TeV collected with the ATLAS detector at the LHC. Two parameters are measured simultaneously in this analysis. The fraction f1 of decays containing transversely polarised W bosons is measured to be 0.37 ± 0.07 (stat.?syst.). The phase d- between amplitudes for transversely and longitudinally polarised W bosons recoiling against left-handed b-quarks is measured to be -0.014p ± 0.036p (stat.?syst.). The correlation in the measurement of these parameters is 0.15. These values result in two-dimensional limits at the 95% confidence level on the ratio of the complex coupling parameters gR and VL, yielding Re[gR/VL] ? [-0.36, 0.10] and Im[gR/VL] ? [-0.17, 0.23] with a correlation of 0.11. The results are in good agreement with the predictions of the Standard Model.
Funding
STFC Consolidated Grant Supplement; G1316; STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCIL; ST/M000753/1
History
Publication status
- Published
File Version
- Published version
Journal
Journal of High Energy PhysicsISSN
1029-8479Publisher
Springer VerlagExternal DOI
Issue
4Page range
23Department affiliated with
- Physics and Astronomy Publications
Research groups affiliated with
- Experimental Particle Physics Research Group Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2017-02-15First Open Access (FOA) Date
2017-02-15First Compliant Deposit (FCD) Date
2017-02-15Usage metrics
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