基於Belle偵測器所收集到253/fb的資料,我們量測了B介子至不含魅夸克的強子之稀有二體衰變,其中包含了K與π介子兩種強子。在這些衰變模式中,測量了它們衰變分支比以及直接電荷宇稱的不對稱性。基於3.9個標準差,我們得到了B介子衰變至K介子與π介子的直接電荷宇稱對稱破壞之證據。同時,以5.8個標準差的信心水準,我們觀測到了B介子衰變至兩個中性π介子的衰變模式。
With integrated luminosity 253/fb data acquired at Belle, we have studied two body charmless hadronic B-> h h decay modes, where h stands for charged or neutral K/pi mesons. Among these modes, we have measured the branching fractions and charge asymmetries. The evidence of charge asymmetry for B^0 -> K^+pi^- is found with 3.9 sigma and the branching fraction of B^0 -> pi^0 pi^0 is observed with 5.8 sigma standard deviation from zero.