B介子的衰变  

B MESON DECAYS

作　　者：孔令宜[1] 

机构地区：[1]河北师范大学物理学系

出　　处：《山东师范大学学报（自然科学版）》2001年第1期22-25,共4页Journal of Shandong Normal University(Natural Science)

摘　　要：一般认为非相对论性夸克模型只在动量反冲较小的区域适用 ,而对动量反冲极大的B介子稀有衰变B→K γ(q2 =0 )不适用 .工作于无限动量参照系的BSW模型却恰好适用于q2 =0区域 ,可证明在该模型中用于联系B→K γ稀有衰变和B→ρe ν半轻子衰变q2 =0谱的一个比在SU(3)味对称下与具体波函数无关 ,还可证明该性质在相对论性光前夸克模型中 ,当b夸克质量无穷大时也成立 ,事实上相对论性光前夸克模型在b夸克质量趋于无穷大时退化成BSW模型 .The exclusive rare decay B→k*γ takes place in a region of maximum recoil,q2=0,posing a problem for nonrelativistic quark models which are usually thought to be most reliable at zero recoil.The BSW model,formulated in the IMF formalism,is designed to work at q2=0.We show that this feature is also true in relativistic quark models formulated in the IMF,if the b quark is infinitely heavy.In fact,these relativistic models,which have a different spin structure from the BSW case, reduce to the BSW model in the heavy b—quark limit.A direct measurement of the q2—spectrum of the semileptonic decay can therefore provide accurate information for the exclusive rare decay.

关 键 词：稀有衰变 半轻子衰变 相对论性光前夸克模型 

分 类 号：O572.33[理学—粒子物理与原子核物理]