Flavour tagged time-dependent angular analysis of the $B_s \rightarrow J/\psi \phi$ decay and extraction of $\Delta\Gamma$ and the weak phase $\phi_s$ in ATLAS

G. Aad (1) , S. Abdel Khalek (2) , A. Bassalat (2) , C. Becot (2) , S. Binet (2) , C. Bourdarios (2) , D. Charfeddine (2) , J.B. de Vivie de Regie (2) , L. Duflot (2) , M. Escalier (2) , L. Fayard (2) , D. Fournier (2) , J.-F. Grivaz (2) , T. Guillemin (2) , S. Henrot-Versillé (2) , J. Hrivnac (2) , L. Iconomidou-Fayard (2) , M. Kado (2) , A. Lounis (2) , N. Makovec (2) , P. Matricon (2) , L. Poggioli (2) , P. Puzo (2) , A. Renaud (2) , D. Rousseau (2) , G. Rybkin (2) , A.C. Schaffer (2) , E. Scifo (2) , L. Serin (2) , S. Simion (2) , R. Tanaka (2) , H.L. Tran (2) , D. Zerwas (2) , Z. Zhang (2) , G. Rahal (3) , D. Boumediene (4) , Emmanuel Busato (4) , D. Calvet (4) , S. Calvet (4) , J. Donini (4) , E. Dubreuil (4) , N. Ghodbane (4) , Ph. Gris (4) , C. Guicheney (4) , H. Liao (4) , D. Pallin (4) , Daniela Paredes Hernández (4) , F. Podlyski (4) , C. Santoni (4) , Timothée Theveneaux-Pelzer (4) , Loïc Valery (4) , F. Vazeille (4) , S. Albrand (5) , J. Brown (5) , B. Clement (5) , J. Collot (5) , S. Crépé-Renaudin (5) , B. Dechenaux (5) , P.A. Delsart (5) , C. Gabaldon (5) , M.H. Genest (5) , J.Y. Hostachy (5) , B.T. Le (5) , F. Ledroit-Guillon (5) , A. Lleres (5) , A. Lucotte (5) , F. Malek (5) , C. Monini (5) , J. Stark (5) , B. Trocmé (5) , Z. Barnovska (6) , N. Berger (6) , M. Delmastro (6) , L. Di Ciaccio (6) , T.K.O. Doan (6) , S. Elles (6) , C. Goy (6) , T. Hryn'Ova (6) , S. Jézéquel (6) , H. Keoshkerian (6) , I. Koletsou (6) , R. Lafaye (6) , J. Leveque (6) , V.P. Lombardo (6) , N. Massol (6) , H. Przysiezniak (6) , G. Sauvage (6) , E. Sauvan (6) , M. Schwoerer (6) , O. Simard (6) , T. Todorov (6) , I. Wingerter-Seez (6) , L. Alio (1) , M. Barbero (1) , C. Bertella (1) , J. C. Clémens (1) , Y. Coadou (1) , F. Djama (1) , L. Feligioni (1) , D. Hoffmann (1) , F. Hubaut (1) , E. B. F. G. Knoops (1) , E. Le Guirriec (1) , B. Li (1) , D. Madaffari (1) , K. Mochizuki (1) , E. Monnier (1) , S. Muanza (1) , Y. Nagai (1) , P. Pralavorio (1) , A. Rozanov (1) , T. Serre (1) , M. Talby (1) , N. Tannoury (1) , E. Tiouchichine (1) , S. Tisserant (1) , J. Toth (1) , F. Touchard (1) , M. Ughetto (1) , L. Vacavant (1)

1 CPPM - Centre de Physique des Particules de Marseille
2 LAL - Laboratoire de l'Accélérateur Linéaire
3 CC-IN2P3 - Centre de Calcul de l'IN2P3
4 LPC - Laboratoire de Physique Corpusculaire - Clermont-Ferrand
5 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
6 LAPP - Laboratoire d'Annecy de Physique des Particules

A measurement of the $B_s \rightarrow J/\psi \phi$ decay parameters, updated to include flavour tagging is reported using $4.9 fb^{-1}$ of integrated luminosity collected by the ATLAS detector from $\sqrt{s}= 7$TeV $pp$ collisions recorded in 2011 at the LHC. The values measured for the physical parameters are: \begin{eqnarray*} \phi_s & = & 0.12 \pm 0.25(stat.)\pm 0.05(syst.)rad \\ \Delta\Gamma & = & 0.053 \pm 0.021(stat.) 0.010(syst.)ps^{-1} \\ \Gamma_s & = & 0.677 \pm 0.007 (stat.)\pm 0.004 (syst.)ps^{-1}\\ |A_{\parallel}(0)|^2 & = & 0.220 \pm 0.008 (stat.)\pm 0.009(syst.)\\ |A_{0}(0)|^2 & = & 0.529 \pm 0.006 (stat.)\pm 0.012(syst.)\\ \delta_\perp & = & 3.89 \pm 0.47(stat.) \pm 0.11(syst.)rad \end{eqnarray*} where the parameter $\Delta\Gamma$ is constrained to be positive. The $S$-wave contribution was measured and found to be compatible with zero. Results for $\phi_s$ and $\Delta\Gamma$ are also presented as $68\%$ and $95\%$ likelihood contours, which show agreement with the Standard Model expectations.

Domaines: Physique des Hautes Energies - Expérience [hep-ex]

G. Aad, S. Abdel Khalek, A. Bassalat, C. Becot, S. Binet, et al.. Flavour tagged time-dependent angular analysis of the $B_s \rightarrow J/\psi \phi$ decay and extraction of $\Delta\Gamma$ and the weak phase $\phi_s$ in ATLAS. Physical Review D, 2014, 90, pp.052007. ⟨10.1103/PhysRevD.90.052007⟩. ⟨in2p3-01022705⟩