Measurement of CP--violating asymmetries in D0 -->pi+ pi- and D0 -->K+K- decays at CDF
Measurement of CP--violating asymmetries in D0 -->pi+ pi- and D0 -->K+K- decays at CDF
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CP 的测量 - D0 -->pi pi- 和 D0 -->K K- 中违反不对称性在 CDF 处衰减
DOI：
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发表时间：
2011
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通讯作者：
E. al.
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作者：
C. C. T. Aaltonen;E. al.
本文报道了在Fermilab升级对撞机探测器收集的5.9 fb-1积分光度数据样本中重建的cabibbo抑制的D0—>pi+ pi-和D0—>K+K-衰变中cp违反不对称性（Acp）的测量。我们使用强衰变D*+—>D0 pi+来识别产生时的迷人介子的味道，并利用p-pbar碰撞中cp守恒的强c-cbar对的产生。cabibbo青睐的D0 ->K- p+衰变的高统计样本有或没有D*标签用于校正仪器效应并显着降低系统不确定性。我们测量了Acp(D0—>pi+ pi-) = (+0.22 +- 0.24 (stat) +- 0.11 (syst))%和Acp(D0—>K+ K-) = (-0.24 +- 0.22 (stat) +- 0.09 (syst))%，与CP守恒一致。这是迄今为止单次实验得出的最精确的结论。在D0—> π + π -和D0—>K+K-衰变中可以忽略直接CP违背的假设下，结果提供了D0混合中CP违背不对称性的上限，在90%的置信水平下，|Acp^{ind}(D0)|<0.13%。
We report on a measurement of CP-violating asymmetries (Acp) in the Cabibbo-suppressed D0 -->pi+ pi- and D0 -->K+K- decays reconstructed in a data sample corresponding to 5.9 fb-1 of integrated luminosity collected by the upgraded Collider Detector at Fermilab. We use the strong decay D*+ -->D0 pi+ to identify the flavor of the charmed meson at production and exploit CP-conserving strong c-cbar pair-production in p-pbar collisions. High-statistics samples of Cabibbo-favored D0 -->K- p+ decays with and without a D* tag are used to correct for instrumental effects and significantly reduce systematic uncertainties. We measure Acp(D0 -->pi+ pi-) = (+0.22 +- 0.24 (stat) +- 0.11 (syst))% and Acp(D 0 -->K+ K-) = (-0.24 +- 0.22 (stat) +- 0.09 (syst))%, in agreement with CP conservation. These are the most precise determinations from a single experiment to date. Under the assumption of negligible direct CP violation in D0 -->pi+ pi- and D0 -->K+K- decays, the results provide an upper limit to the CP-violating asymmetry in D0 mixing, |Acp^{ind}(D0)|<0.13% at the 90% confidence level.