Search for anomalous couplings in the $Wtb$ vertex from the measurement of double differential angular decay rates of single top quarks produced in the $t$-channel with the ATLAS detector

G. Aad 1 S. Albrand 2 J. Collot 2 S. Crépé-Renaudin 2 P.A. Delsart 2 C. Gabaldon 2 M.H. Genest 2 J.Y. Hostachy 2 F. Ledroit-Guillon 2 A. Lleres 2 A. Lucotte 2 F. Malek 2 C. Monini 2 J. Stark 2 B. Trocmé 2 M. Wu 2 G. Rahal 3 M.K. Ayoub 4 A. Bassalat 4 C. Bécot 4 S. Binet 4 C. Bourdarios 4 D. Delgove 4 J-B. de Vivie De Regie 4 L. Duflot 4 M. Escalier 4 L. Fayard 4 D. Fournier 4 E.L. Gkougkousis 4 J-F. Grivaz 4 T. Guillemin 4 F. Hariri 4 S. Henrot-Versille 4 J. Hrivnac 4 L. Iconomidou-Fayard 4 M. Kado 4 A. Lounis 4 N. Makovec 4 N. Morange 4 C. Nellist 4 P. Petroff 4 L. Poggioli 4 P. Puzo 4 A. Renaud 4 D. Rousseau 4 G. Rybkin 4 A.C. Schaffer 4 E. Scifo 4 L. Serin 4 S. Simion 4 R. Tanaka 4 D. Zerwas 4 Zhongkai Zhang 4 Y. Zhao 4 Z. Barnovska 5 N. Berger 5 M. Delmastro 5 L. Di Ciaccio 5 S. Elles 5 C. Goy 5 T. Hryn’ova 5 S. Jézéquel 5 I. Koletsou 5 R. Lafaye 5 J. Levêque 5 N. Massol 5 P. Mastrandea 5 G. Sauvage 5 E. Sauvan 5 O. Simard 5 T. Todorov 5 I. Wingerter-Seez 5 E. Yatsenko 5 D. Boumediene 6 E. Busato 6 D. Calvet 6 S. Calvet 6 J. Donini 6 E. Dubreuil 6 G. Gilles 6 Ph. Gris 6 H. Liao 6 R. Madar 6 D. Pallin 6 S.M. Romano Saez 6 C. Santoni 6 D. Simon 6 T. Theveneaux-Pelzer 6 F. Vazeille 6 L. Alio 1 M. Barbero 1 Y. Coadou 1 C. Diaconu 1 S. Diglio 1 F. Djama 1 O. Duccu 1 L. Feligioni 1 J. Gao 1 G.D. Hallewell 1 F. Hubaut 1 S.J. Kahn 1 E. B. F. G. Knoops 1 E. Le Guirriec 1 J. Liu 1 K. Liu 1 D. Madaffari 1 K. Mochizuki 1 E. Monnier 1 S. Muanza 1 Y. Nagai 1 E. Nagy 1 P. Pralavorio 1 A. Rozanov 1 T. Serre 1 M. Talby 1 R.E. Ticse Torres 1 E. Tiouchichine 1 S. Tisserant 1 J. Toth 1 F. Touchard 1 L. Vacavant 1
Abstract : The 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 $\sqrt{s}$ = 7 TeV collected with the ATLAS detector at the LHC.Two parameters are measured simultaneously in this analysis. The fraction $f_1$ of decays containing transversely polarised $W$ bosons is measured to be $0.37 \pm 0.07$ (stat.$\oplus$syst.). The phase $\delta_{-}$ between amplitudes for transversely and longitudinally polarised $W$ bosons recoiling against left-handed $b$-quarks is measured to be $-0.14\pi \pm 0.036\pi$ (stat.$\oplus$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 $g_\mathrm{R}$ and $V_\mathrm{L}$, yielding Re [$g_\mathrm{R}/V_\mathrm{L}$] $\in [-0.36,0.10]$ and Im [$g_\mathrm{R}/V_\mathrm{L}$] $\in [-0.17,0.23]$ with a correlation of 0.11. The results are in good agreement with the predictions of the Standard Model.
Type de document :
Article dans une revue
Journal of High Energy Physics, Springer Verlag (Germany), 2016, 04, pp.023. 〈10.1007/JHEP04(2016)023〉
Liste complète des métadonnées

http://hal.in2p3.fr/in2p3-01215348
Contributeur : Emmanuelle Vernay <>
Soumis le : mercredi 14 octobre 2015 - 07:50:28
Dernière modification le : mardi 13 février 2018 - 13:28:06

Lien texte intégral

Identifiants

Citation

G. Aad, S. Albrand, J. Collot, S. Crépé-Renaudin, P.A. Delsart, et al.. Search for anomalous couplings in the $Wtb$ vertex from the measurement of double differential angular decay rates of single top quarks produced in the $t$-channel with the ATLAS detector. Journal of High Energy Physics, Springer Verlag (Germany), 2016, 04, pp.023. 〈10.1007/JHEP04(2016)023〉. 〈in2p3-01215348〉

Partager

Métriques

Consultations de la notice

263