The Study Of Mixed Hadron States

QCD sum rule(QCDSR)is an important non-perturbative method in Quantum ChromoDynamic(QCD).It is successful in describing the structures of various hadrons.In the scenario of QCDSR,we introduce a method by which we can estimate the mixing strength of hadrons.We could find a possible mixed state via this method.We construct a mixing current from two currents which represent different states respectively,and then select out the cross terms which involve two parts of corresponding states.We insert the complete set of particles in correlation function of cross term,and we could find the mixing state which is both strongly coupled with each state.This is the mixing state that possibly mixed with these two states.We could estimate the mixing strength of the mixing state by comparing the coupling constant of each pure corresponding current,and estimate the proportions of each part of mixing state.In this paper,we estimate the mixing effects in hybrid state,glueball,and X,Y state.We have obtained the mass predictions of the mixing state which is mixed with hybrid state and 1--quark-antiquark states and the mixing state which is mixed with glueball and 0++ quarkantiquark states,and we estimate the mixing strength of these mixing states.We suggest that these mixing states are both weakly mixed with relative states.In hybrid scenario,we suggest that p meson state which has quantum number 1--,is preferred to be the quark-antiquark state,while in glueball scenario,we suggest that σ(500),which has quantum number 0++,is preferred to be the quark-antiquark state,and f(1710)which has same quantum number is preferred to be glueball state.Besides,we have obtained the mass predictions of the molecular mixing states which are mixed with two different kinds of molecular states QQqq and QqqQ in the assumptions of X,Y molecular states.We find that the 1++mixing state which is corresponding to X state has relatively large mixing strength and the 1--mixing state which is corresponding to Y state is weakly mixed with two kinds of molecular states.We suggest that X molecular states are mixed with QQqq and QqqQ states while Y molecular states are preferred to be one of QQqq and QqqQ states.Besides,we have computed the molecular states which have quantum number 1-+,and these molecular states can not match the observed particles.On the aspect of QCD calculations,we have involved the radiative corrections in the calculations towards light quarks to make QCDSR calculations more reliable.We have introduced various methods when we need to involve heavy quark mass in QCD calculations,and we introduce the train of thoughts for dealing with radiative corrections which include heavy quark mass.