b - →k - η的pqcd计算：lo - 交叉学科理论研究中心.pptVIP

* * * * * * * * * * * * * * * * * * ◆ phep-ph/1111.6264 ◆ pQCD predictions ◆ pQCD predictions ◆ three reasons: DA’s of the kaon meson used by Li are very different from those used in this paper; some new Gegenbauer moments are used in this paper. (c) The constructive interference between three parts also play an important role! ◆ Why 2 pQCD predictions so different ? ◆ DA’s used in this our paper ◆ DA’s used in Phys.Rev. D 63,014003(2001) ◆ Contributions from twist-2 and -3 parts ◆ For Bs^0 \to \pi^+ \pi^- decay, our pQCD predictions are confirmed by both CDF and LHCb experiments! ◆ For B^0 \to K^+ K^- decay, our new pQCD predictions agree well with the measured values from CDF and LHCb experiments! ◆ For the pure annihilation B_c decays, we have calculated about 200 chanels: B_c → PP, PV, VV, SP, SV, AV, VA ◆ Xin Liu, Z.J. Xiao and C.D. Lv, [1] Phys.Rev. D81, 014022 (2010); [2] Phys.Rev. D81, 074017 (2010); [3] Phys.Rev. D82, 054029 (2010); [4] J. Phys. G38, 035009 (2011); [5] Phys.Rev. D84, 074033 (2011); ◆ pQCD predictions to be tested at LHC ◆ 过去的20年, B物理实验和理论研究已经取得了巨大的成功! 导致两位日本物理学家获得2008年诺贝尔物理奖! ◆ 目前看到一些puzzle, 但仍然没有发现solid的新物理存在的 evidence。 ◆ 强子矩阵元的计算仍存在较大的误差，因子化方法有待改进，计算困难，需要更多的研究！ ◆ pQCD因子化方法下，NLO贡献的计算只完成了一部分，需要继续努力。 5、Summary Expectations ◆ LHC实验有可能直接发现带电Higgs等新物理粒子！ ◆ LHCb, Super-B等相关实验将提供大量的 b 物理数据，实现对CKM相角，典型衰变道分支比和CP破坏的精确测量。与LHC的直接发现互补！ ◆ 在B介子衰变过程中,通过圈图效应,发现新物理存在的证据是可能的！ ◆ 国内已经有很好的实验研究和理论研究团队,已经做了大量的工作！可以并应当做出更多的贡献! 预祝 FPCP 2012 圆满成功！ SCET SCET is an effective theory by integrating out high energy modes. Define effective fields (like collinear quarks, collinear gluons, soft quarks,…). Express an amplitude in terms of expansion of nonlocal operators of these effective fields. The coefficients of these operators are the hard kernels. The matrix element of the operators are DAs. Compute hard kernels, and show their IR finiteness order by order. * * * * * * * * * *