Braaten Eric, Kusunoki Masaoki, Nussinov Shmuel
Physics Department, The Ohio State University, Columbus, Ohio 43210, USA.
Phys Rev Lett. 2004 Oct 15;93(16):162001. doi: 10.1103/PhysRevLett.93.162001. Epub 2004 Oct 12.
If the recently discovered charmonium state X( 3872) is a loosely bound S-wave molecule of the charm mesons D0 D(*0) or D(0) D0, it can be produced in B-meson decay by the coalescence of charm mesons. If this coalescence mechanism dominates, the ratio of the differential rate for B+ -->D(0) D( 0)K+ near the D0 D(*0) threshold and the rate for B+ -->XK+ is a function of the D0 D(*0) invariant mass and hadron masses only. The identification of the X( 3872) as a D0 D(*0)/D(*0)D0 molecule can be confirmed by observing an enhancement in the D0 D(*0) invariant mass distribution near the threshold. An estimate of the branching fraction for B+ -->XK+ is consistent with observations if X has quantum numbers J(PC)=1(++ ) and if J/psi pi(+) pi(-) is one of its major decay modes.
如果最近发现的粲偶素态X(3872)是粲介子D0D*(0)或D*(0)D0的一个松散束缚的S波分子，那么它可以在B介子衰变中通过粲介子的合并产生。如果这种合并机制占主导，那么在D0D*(0)阈值附近B+→D(0)D*(0)K+的微分速率与B+→XK+的速率之比仅是D0D*(0)不变质量和强子质量的函数。通过观察阈值附近D0D*(0)不变质量分布中的增强，可以确认将X(3872)鉴定为D0D*(0)/D*(0)D0分子。如果X具有量子数J(PC)=1(++)且如果J/ψπ(+)π(-)是其主要衰变模式之一，那么对B+→XK+分支比的估计与观测结果一致。
