我们观察到B 0到ppbar K*0的衰变，其分支分数为（1.18^{+0.29}-0.25}（stat.）\pm 0.11（系统））\times 10^{-6}.对于低ppbar质量区域中的信号，统计显著性为7.2 σ。我们研究了B 0到ppbar K*0的衰变动力学，并与B+到ppbar K*+的衰变动力学进行了比较。发现K*0介子几乎是100%极化的（在螺旋度为零的状态下，极化率为（101 \pm 13 \pm 3）%），而K*+介子在螺旋度为零的状态下极化率为（32 \pm 17 \pm 9）%。B 0到p pbar K*0和B+到p pbar K*+的直接CP不对称性分别测量为-0.08 \pm 0.20 \pm 0.02和-0.01 \pm 0.19 \pm 0.02。我们还研究了低质量ppbar增强的阈值附近的特性和相关的角分布。此外，我们还报道了分支分数BF（B+ to p pbar K*+）=（3.38^{+0.73}_{-0.60} \pm 0.39）\times 10^{-6}和BF（B 0 to p pbar K 0）=（2.51^{+0.35}_{-0.29} \pm 0.21）\times 10^{-6}的改进测量，这取代了我们以前的测量。这些结果是从KEKB非对称能量e^+ e^-对撞机上Belle探测器在Upplane（4S）共振附近收集的492 fb^{-1}数据样本中获得的。
英文摘要：
We observe the decay B0 to p pbar K*0 with a branching fraction of (1.18^{+0.29}_{-0.25} (stat.) \pm 0.11 (syst.)) \times 10^{-6}. The statistical significance is 7.2 sigma for the signal in the low ppbar mass region. We study the decay dynamics of B0 to p pbar K*0 and compare it with B+ to p pbar K*+. The K*0 meson is found to be almost 100% polarized (with a fraction of (101 \pm 13 \pm 3)% in the helicity zero state), while the K*+ meson has a (32 \pm 17 \pm 9)% fraction in the helicity zero state. The direct CP asymmetries for B0 to p pbar K*0 and B+ to p pbar K*+ are measured to be -0.08\pm 0.20\pm 0.02 and -0.01\pm 0.19\pm 0.02, respectively. We also study the characteristics of the low mass ppbar enhancements near threshold and the associated angular distributions. In addition, we report improved measurements of the branching fractions BF(B+ to p pbar K*+) = (3.38^{+0.73}_{-0.60} \pm 0.39) \times 10^{-6} and BF(B0 to p pbar K0) = (2.51^{+0.35}_{-0.29} \pm 0.21) \times 10^{-6}, which supersede our previous measurements. These results are obtained from a 492 fb^{-1} data sample collected near the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+ e^- collider.
Observation of B+ -> p pbar pi+, B0 -> p pbar K0, and B+ -> p pbar K*+
We report the first observation of a b -> u type charmless baryonic B decay, B+ -> p pbar pi+, as well as b -> s type B0 -> p pbar K0 and B+ -> p pbar K*+ decays. The analysis is based on a 78fb^{-1} data sample recorded on the Upsilon(4S) resonance with the Belle detector at KEKB. We find BF(B+ -> p pbar pi+) = (3.06^{+0.73}_{-0.62} \pm 0.37)*10^{-6}, BF(B0 -> p pbar K0) =(1.88^{+0.77}_{-0.60} \pm 0.23)*10^{-6}, and BF(B+ -> p pbar K*+) = (10.3^{+3.6 + 1.3}_{-2.8 -1.7})*10^{-6}. We also update BF(B+ -> p pbar K+) = (5.66^{+0.67}_{-0.57} \pm 0.62)* 10^{-6}, and present an upper limit on BF(B0 …
Observation and study of the baryonic B-meson decays B to D(*) p pbar (pi) (pi)
我们利用SLAC PEP-II非对称能量e+ e对撞机上BaBar探测器记录的455 x 10^6个BBbar对，给出了涉及粲介子、质子和π介子的B介子衰变模式的结果。测量以下十个衰变的支化分数：B0 bar至D0 p pbar、B0 bar至D*0 p pbar、B0 bar至D+ p pbar pi-、B0 bar至D*+ p pbar pi-、B-至D0 p pbar pi-、B-至D*0 p pbar pi-、B0 bar至D0 p pbar pi- pi+、B0 bar至D*0 p pbar pi- pi+、B-至D+ p pbar pi- pi-，和B-到D*+ pbar π-π-，首次观察到四个B-和两个五体B 0 bar模。四体模式比三体和五体模式更强。在三体模式中，M（p pbar）和M（D（*）0 p）不变质量分布在阈值附近显示增强。在B 0 bar到D+ p pbar pi-的四体模式中，M（p pi-）分布在1.5 GeV/c^2附近显示出一个来源不明的狭窄结构。与其他模式相比，五体模式的分布与均匀相空间预测的预期相似。
Observation of Bs->K+K- and Measurements of Branching Fractions of Charmless Two-body Decays of B0 and Bs Mesons in p-pbar Collisions at sqrt(s)=1.96 TeV
