2010年4月

In recent years, with the rapid development of experimental technology, the emer-gence of high-energy accelerators or colliders and their successful operation have greatly promoted the development of particle physics. The major collaborations in the world also discovered many new hadrons one after the after, such as mesons DSJ,X(3872),X(1835),X(1576),Y(4260),Y(2175) and baryonsΛc+(2940),Ωc*(2772),Σc(2800),Ξc(2645),Ξc(2790),Ξc(2815),Ξc(2930),Ξc(2980),Ξc(3055),Ξc(3080),Ξc(3123),Λc(2880),Σb,Σb* and bizarreΘ(1540) "pentquarks".These particles have aroused many scientists'enthusiasm about them and they have done a lot of work for them, but so far great controversy still exists as to their structures and properties. It's is very meaningful for the calculation of the excited state of these heavy flavor baryons, which will promote the experimental and theoretical studies. The na-ture and study results of heavy flavor baryons system will help better understand the quantum chromodynamics, test the flavour invariance of confinement potential and the validity of one gluon exchange potential. It can help us study the interaction between quarks between the system lighter quark and heavy quark system. Additionally, It is also a good place to test the prediction according to different theoretical methods. The research on resonances has real theoretical significance for the understanding of the strong interaction, dynamically generated mechanism of the baryon resonances and the structure of hadrons.There is strong interaction between hadrons. According to QCD theory, the strong interaction is made by exchanging the colored gluons. the coupling constant of strong interaction is in inverse proportion to energy, when the energy reduces to about 1GeV, that is, when the energy is in the range of interaction between nuclear molecular, the energy range of strong coupling constant is about O(1), thus the perturbation theory used in the calculation of quantum field theory will not be applicable any more.The Chiral Unitary Approach of the Chiral Effective Theory has achieved great success in explaining the interaction between hadrons.In this paper,the coupled-channel BS equation of Chiral unitary approach is applied to study the sector pseudoscalar meson-baryon scattering when isospin as I=1／2,strangeness as S=-1,and charm asC=+1. Based on the Lagrangian quantity that meets the chiral symmetry,this study calculates the Born amplitude of the meson-baryon scattering coupling channel under the isospin system,and thus we get the full amplitude of scattering T.And the algebraic BS conpling channel equa-tion is used to get some resonances in the S=-1,C=+lsector and compute the coupling constant |gi|.During the compution,the results by using dimensional reg-ularization method and three-momentum cut-off method respectively turn out to be quite similar,which indicated that using different renormalization method could get the same result.Under different renormalization paramters,the pole has a slight offset, but not very obvious,which indicates the results is not very sensitive to the renormal-ization parameter value.In the pseudoscalar meson-baryon S wave scattering when I=1／2,S=-1,C=+1 dynamics created three JP:1／2-resonances states in-cludingΞc(S1)(M=2778.13MeV,Γ:43.44MeV),Ξc(S2)(M=2929.48MeV,Γ= 105.87MeV),Ξc(S3)(M=3014.2MeV,Γ=22.97MeV)；In P wave scattering,dy-namics created three JP=1／2+,3／2+Ξc resonances states includingΞc(P1)(M= 2863.82MeV,Γ=150.8MeV),Ξc(P2)(M=2964.82MeV,Γ=39.72MeV).Ξc(P3)(M=2983.14MeV,Γ:59.22MeV)；In D wave scattering,dynamics created one JP=3／2-,5／2-Ξc.resonances state asΞc(D1)(M=2875.05MeV,Γ=114MeV).Of them,bothΞc(S2)(3014)andΞc(P2)(2965)have a excellent agreement with the data listed in particle table.Thus It's concluded thatΞc(S3)(3014)andΞc(P2)(2965)the resonances state ofΞc(3055)andΞc(2980),respectively and the fact thatΞc(S1)(2778)is consid-ered asΞc(2790).And so far,there is no counterpart of resonances stateΞc(S2)(2929).Ξc(P1)(2864).Ξc(P3)(2983)andΞc(D1)(2875).Thus,the decay modes of four newΞc res-onances states are predicted as follows:K∑c as the main decay modes ofΞc(S2)(2929)K∑c andπΞc as the main main decay modes ofΞc(P1)(2864),ηΞc and K∑c as the main decay modes ofΞc(P3)(2983),πΞc,KΛc and K∑c as the main decay modes ofΞc(D1)(2875).