科研之友
微信
新浪微博
Facebook
分享链接
摘要
We propose to use hard exclusive production of an exotic hadron for finding its internal quark-gluon configuration by the constituent-counting rule in perturbative QCD. In particular, the cross section for the exclusive process pi(-) + p -> K-0 + Lambda(1405) is estimated at the scattering angle theta = 90 degrees in the center-of-mass frame by using current experimental data. In comparison, the cross section for the ground-state Lambda production pi(-) + p -> K-0 + Lambda is also shown. We suggest that the internal quark configuration of Lambda(1405) should be determined by the asymptotic scaling behavior of the cross section. If it is an ordinary three-quark baryon, the scaling of the cross section is s(8)d sigma/dt constant, whereas it is s(10)d sigma/dt constant if Lambda(1405) is a five-quark hadron, where s and t are Mandelstam variables. Such a measurement will be possible, for example, by using the high-momentum beam line at Japan Proton Accelerator Research Complex. In addition, another exclusive process gamma + p -> K+ + (1405) could be investigated at laser electron photon beam line at SPring-8 and JLab for finding the nature of Lambda(1405). We indicate that the constituent-counting rule could be used as a valuable quantity in determining internal structure of exotic hadrons by high-energy exclusive processes, where quark-gluon degrees of freedom explicitly appear. Furthermore, it is interesting to investigate the transition from hadron degrees of freedom to quark-gluon ones for exclusive exotic-hadron production processes.
- 出版日期2013-8-7
