Measurement of the parity-violating asymmetry parameter ab and the helicity amplitudes for the decay Lambda(0)(b) -> J/psi Lambda(0) with the ATLAS detector

作者：Aad G^*; Abajyan T; Abbott B; Abdallah J; Khalek S Abdel; Abdinov O; Aben R; Abi B; Abolins M; AbouZeid O S; Abramowicz H; Abreu H; Abulaiti Y; Acharya B S; Adamczyk L; Adams D L; Adelman J; Adomeit S; Adye T; Agatonovic Jovin T; Aguilar Saavedra J A; Agustoni M; Ahlen S P; Ahmad A; Ahmadov F; Aielli G; Akesson T P A; Akimoto G; Akimov A V; Albert J; Albrand S; Alconada Verzini M J; Aleksa M; Aleksandrov I N; Alexa C

来源：Physical Review D - Particles, Fields, Gravitation and Cosmology, 2014, 89(9): 092009.

DOI：10.1103/PhysRevD.89.092009

A measurement of the parity-violating decay asymmetry parameter, ab, and the helicity amplitudes for the decay.Lambda(0)(b) -> J/psi(mu(+) mu(-)) Lambda(0)(p pi(-)) is reported. The analysis is based on 1400 Lambda(0)(b)and (Lambda) over bar (0)(b) baryons selected in 4.6 fb(-1) of proton-proton collision data with a center-of-mass energy of 7 TeV recorded by the ATLAS experiment at the LHC. By combining the.0 b and. _ 0 b samples under the assumption of CP conservation, the value of ab is measured to be 0.30 +/- 0.16(stat) +/- 0.06(syst). This measurement provides a test of theoretical models based on perturbative QCD or heavy-quark effective theory.

• 单位
  McGill; 山东大学; 香港理工大学; 中山大学; 上海交通大学; 中国科学院; 中国科学技术大学; 中国地震局; 南京大学