Some predictions of diquark model for hidden charm pentaquark discovered at the LHCb

• Published in: The journal of high energy physics Vol. 2015; no. 12; pp. 1 - 17
• Main Authors: Li, Guan-Nan, He, Xiao-Gang, He, Min
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2015
• Subjects: Channels; Classical and Quantum Gravitation; Decay; Decay rate; Elementary Particles; Flavours; Mathematical models; Mesons; Octets; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum numbers; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; String Theory; Rare Decays; Heavy Quark Physics
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP12(2015)128

A bstract The LHCb has discovered two new states with preferred J P quantum numbers 3/2 − and 5/2 + from Λ b decays. These new states can be interpreted as hidden charm pentaquarks. It has been argued that the main features of these pentaquarks can be described by diquark model. The diquark model predicts that the 3/2 − and 5/2 + are in two separate octet multiplets of flavor SU(3) and there is also an additional decuplet pentaquark multiplet. Finding the states in these multiplets can provide crucial evidence for this model. The weak decays of b-baryon to a light meson and a pentaquark can have Cabibbo allowed and suppressed decay channels. We find that in the SU(3) limit, for U -spin related decay modes the ratio of the decay rates of Cabibbo suppressed to Cabibbo allowed decay channels is given by | V cd | 2 /| V cs | 2 . There are also other testable relations for b-baryon weak decays into a pentaquark and a light pseudoscalar. These relations can be used as tests for the diquark model for pentaquark.