Study Of The Strong Decays Of ?_c Baryons

For the properties of strong interaction of the ?c,some low-energy states(S-wave and P-wave)?c have been well understood in theory,and their quantum numbers have been basically established in past dacedes.In recent years,more and more highly ex-cited ?c have been found in experiments,which makes people have strong interest in identification of the quantum numbers of these highly excited states.Due to the limita-tion of experimence,the quantum numbers of these highly excited states have not been measured.For theoretical physicists,the establishment of their quantum numbers not only provides theoretical explanation,but also help us to understand the structure and dynamics of ?c.As a phenomenological model,3P0 model has made a lot of success in calculating hadron decays.In chapter ? of this article,we introduce 3P0 model in detail,such as calculation of some matrix elements and integrals.We discussed also the uncertainties of the final numerical results from the uncertainties of parameters.So far,in the review of particle physics,?c+?c(2595)+?c(2625)+?c(2765)+or?c(2765)+,?c(2860)+,?c(2880)+and ?c(2940)+have been listed.For low-lying ?c+,Ac(2286)+is believed the ground 1S-wave charmed baryon with JP=1/2+with confi-dence.?c(2595)+ and ?c(2625)+ are popularly believed the 1P-wave charmed baryonwith JP=1/2-and JP=3/2-,respectively.However,the JP assignments are different for highly excited ?c(2765)+(?c(2765)),?c(2860)+?c(2880)+and ?c(2940)+ in differen-t literature.The ?c baryons have not been systematically analyzed in the 3P0 model,either.Therefore,calculation of the strong decay of the excited state ?c baryons,deter-mination of their JP quantum number is an important topic.In this work,all the observed?c except for the lowest located ?c(2286)+ are systematically examined as the 1 P-wave,1D-wave or 2S-wave Ac baryons from their strong decay properties in the 3P0 model in chapter ?.Based on our calculation and analyses,we obtain some conclusions as follows:?c(2595)+and ?c(2625)+re possibly the 1 P-wave charmed baryons with JP quan-turn numbers 1/2-and 3/2,respectively;For ?c(2765)+(or ?c(2765)).this paper only calculates decay of Ac charmed baryon,it seems possibly the 2S-wave or 1D-wave charmed baryon.So far,few experimental information of ?c(2765)+ is obtained,and we have no sufficient information to learn ?c(2765)+(?c(2765)+;?c(2860)+eems the 1P-wave charmed baryon,it also could be the 1D-wave charmed baryon.In this paper,the predicted branching ratio R=?(?c(2520)++,0?/?c(2455)++,0?)=2.8.The measurement of the R will be very important for the identification of?c(2860)+;?c(2880)+may be a 1D-wave charmed baryon.The branching ratio R=?(?c(2520)++,0?/?c(2455)++,?r)=0.35 is similar to experiment;?c(2940)+is possibly the 1P-wave charmed baryon,it is also possibly the 1D-wave charmed baryon.The branching ratios R=?(?c(2520)++,0?/?c(2455)++,0?)are largely different in these assignments,which could be employed to distinguish them by experiment in the future.