在 B_{s}^{0}→ϕγ 衰变中测量 CP 破坏和混合诱导可观测量。

Measurement of CP-Violating and Mixing-Induced Observables in B_{s}^{0}→ϕγ Decays.

机构信息

Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands.

Physik-Institut, Universität Zürich, Zürich, Switzerland.

出版信息

Phys Rev Lett. 2019 Aug 23;123(8):081802. doi: 10.1103/PhysRevLett.123.081802.

DOI:10.1103/PhysRevLett.123.081802

PMID:31491228

Abstract

A time-dependent analysis of the B_{s}^{0}→ϕγ decay rate is performed to determine the CP -violating observables S_{ϕγ} and C_{ϕγ} and the mixing-induced observable A_{ϕγ}^{Δ}. The measurement is based on a sample of pp collision data recorded with the LHCb detector, corresponding to an integrated luminosity of 3 fb^{-1} at center-of-mass energies of 7 and 8 TeV. The measured values are S_{ϕγ}=0.43±0.30±0.11, C_{ϕγ}=0.11±0.29±0.11, and A_{ϕγ}^{Δ}=-0.67_{-0.41}^{+0.37}±0.17, where the first uncertainty is statistical and the second systematic. This is the first measurement of the observables S and C in radiative B_{s}^{0} decays. The results are consistent with the standard model predictions.

摘要

对 B_{s}^{0}→ϕγ 衰变率进行了时变分析，以确定 CP 破坏可观测量 S_{ϕγ}和 C_{ϕγ}以及混合诱导可观测量 A_{ϕγ}^{Δ}。该测量基于 LHCb 探测器记录的 pp 碰撞数据样本，在质心能量为 7 和 8 TeV 时对应的积分亮度为 3 fb^{-1}。测量值为 S_{ϕγ}=0.43±0.30±0.11，C_{ϕγ}=0.11±0.29±0.11，A_{ϕγ}^{Δ}=-0.67_{-0.41}^{+0.37}±0.17，其中第一个不确定性是统计不确定性，第二个是系统不确定性。这是首次在辐射 B_{s}^{0}衰变中测量可观测量 S 和 C。结果与标准模型预测一致。