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arXiv 1208.0572hep-ex
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用ATLAS对衰变Bs -> J/psi phi的含时角分析和Delta Gamma_s和CP破坏弱相位phi_s的提取

Time-dependent angular analysis of the decay Bs -> J/psi phi and extraction of Delta Gamma_s and the CP-violating weak phase phi_s by ATLAS

ATLAS Collaboration

摘要:

利用ATLAS探测器2011年在质心能量sqrt(s)= 7 TeV的LHC pp碰撞中收集的4.9 fb-1的积分亮度,测量了Bs J/psi phi衰变参数,包括CP破坏弱相位phi_s和衰变宽度差Δ Gamma_s。平均衰变宽度Gamma_s和横向振幅|A0(0)|^2和|A||(0)|#21042;也被测量。这些参数的报告值为:phi_s = 0.22 \pm 0.41(统计)\pm 0.10(系统)rad Delta Gamma_s = 0.053 \pm 0.021(统计)\pm 0.010(系统)ps-1 Gamma_s = 0.677 \pm 0.007(统计)\pm 0.004(系统)PS-1| A0(0)|^2 = 0.528 \pm 0.006(统计)\pm 0.009(系统)|A||(0)|^2 = 0.220 \pm 0.008(统计)\pm 0.007(系统)其中引用的phi_s和Delta Gamma_s的值对应于与外部测量兼容的解,其中强相位delta垂直于该解被约束,并且其中Delta Gamma_s被约束为正。还测量了S波KK或f0通过衰变Bs -> J/psi K+K-(f0)的污染分数,发现与零一致。phi_s和Delta Gamma_s的结果也显示为68%、90%和95%的似然等高线,这表明与标准模型预期一致。

英文摘要:

A measurement of Bs J/psi phi decay parameters, including the CP-violating weak phase phi_s and the decay width difference Delta Gamma_s is reported, using 4.9 fb-1 of integrated luminosity collected in 2011 by the ATLAS detector from LHC pp collisions at a centre- of-mass energy sqrt(s) = 7 TeV. The mean decay width Gamma_s and the transversity amplitudes |A0(0)|^2 and |A||(0)|^2 are also measured. The values reported for these parameters are: phi_s = 0.22 \pm 0.41 (stat.) \pm 0.10 (syst.) rad Delta Gamma_s = 0.053 \pm 0.021 (stat.) \pm 0.010 (syst.) ps-1 Gamma_s = 0.677 \pm 0.007 (stat.) \pm 0.004 (syst.) ps-1 |A0(0)|^2 = 0.528 \pm 0.006 (stat.) \pm 0.009 (syst.) |A||(0)|^2 = 0.220 \pm 0.008 (stat.) \pm 0.007 (syst.) where the values quoted for phi_s and Delta Gamma_s correspond to the solution compatible with the external measurements to which the strong phase delta perpendicular is constrained and where Delta Gamma_s is constrained to be positive. The fraction of S-wave KK or f0 contamination through the decays Bs -> J/psi K+K-(f0) is measured as well and is found to be consistent with zero. Results for phi_s and Delta Gamma_s are also presented as 68%, 90% and 95% likelihood contours, which show agreement with Standard Model expectations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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