Study on the structure of exotic states?c1(3872) via beauty-hadron decays in pp collisions at A. s=8 TeV ffi

摘要

A dynamically constrained phase-space coalescence (DCPC) model was introduced to study the exotic state & chi;c1(3872) yield for three possible structures: tetraquark state, nuclearlike state, and molecular state respectively, where the hadronic final states generated by the parton and hadron cascade model (PACIAE). The & chi;c1(3872)=& psi; (2S) cross-section ratio from beauty-hadron decays (nonprompt) based on the & chi;c1(3872) or & psi;(2S) & RARR; J=& psi;& pi;+ & pi;- bound state in the decay chains as a function of charged-particle multiplicity and ffiffi transverse momentum in pp collisions at A. s = 8 TeV are calculated. A tetraquark state scenario from PACIAE+DCPC model shows better agreement with the LHCb and ATLAS measurements for the nonprompt & chi;c1(3872)=& psi; (2S) cross-section ratio distributions, indicating that the & chi;c1(3872) is more likely to be a compact tetraquark state.

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