Studies The Production Of Hadron With Photon,Pion And Kaonic Beam

It is very important to help us to reveal the internal structure of the hadron,and to understand the QCD theory by studying the generation of hadrons.Combining the constituent quark model and the effective Lagrangian method,We study the product of hadrons with photon,π,and K beam.First,we use photon interaction with Neutron to study the cascade generation of nucleon resonance states.Although the classic constituent quark model has many problems,for the baryon decay,the model is still the starting point of work.In quark models,the internal dynamics is described by two oscillators,usually denoted as ρ and λ.In the simplest approximation,both oscillators are harmonic;in more realistic cases,mixing of quark model states occurs.Theρ oscillator is in the ground state and the diquark and the third quark rotate around the center of mass,and λ oscillator is the two quarks of the diquark carry the angular momentum.The starting point of our work is λ oscillator and ρoscillator can decay between them.We studied the mutual excitation between oscillator and oscillator in the reaction process.We believe that there are the ρoscillator and λ oscillator of excited state in the vicinity of 2.0Ge V,can directly decay to the quality of 1.7 Ge V near the excited state,the low-quality excited state may also be λ oscillator and ρ oscillator of quark combination.The pion and radiative decay amplitudes of nucleon resonances are studied within the constituent quark model,which is used to calculate the couplings constants,especially for the decay of a nucleon resonance near 2.1 Ge V to another nucleon resonance near 1.7 Ge V.The three-pion photoproduction off the neutron target,γn→R′（2000）→R⁺（1700）π^-→π^-π^-?⁺⁺,is investigated based on the ef-fective Lagrangian method with the coupling constant obtained form the decay amplitudes.Experiments found that some low-quality particles,in addition to meet the two quark model,the molecular state of interpretation can also be very good compared with experimental data.More representative of the two tensor mesons f₂（1270）and f′₂（1525）,which aroused the broad interest of theoretical physicists.how they are produced is of great importance in understanding their internal structure.We investigate the productiong of f₂（1270）and f′₂（1525）mesons in the K^-_p→Λ f₂（1270）,K^-_p→Λ f′₂（1525）and K^-_p→K^-K⁺Λ reactionswithin an effective Lagrangian approach.For K^-_p→f₂Λ reaction,by consid-ering thecontributions from the t-channel K+exchange and u-channel nucleon pole,we get a fairly good description of the experimental measurements about the total and differential cross sections.We investigate the production of charmed baryon Λ_C（2940）in the K^-_p→Λ^*_cD^-_s reaction within an effective Lagrangian approach.It is found that the contributions from only the t channel D^*0 exchange by assuming that the Λ^*_c is a pD^*0 molecular state with spin-parity J^p = 1/2^±.The results show that the size of the two sections are about μ,but there is a big difference between the two.The background contribution from the Λ_c（2286）+seriously affecting the detection of Λ_C（2940）with Jp= 1/2⁺.In addition,we present the Dalitz plot and invariant mass distribution of the Λ*Cproduction in the beam energy P_K^-=16 Ge V.It is found that the theoretical numerical results of the Dalitz plot,and invariant mass distribution of the two assignments are sizably different.This conclusion can be easily distinguished but need more information to confirm the Jp.Finally,we study the high energy π meson interaction with proton and nucleus production of Z_c（3900）within the effective Lagrangian method.Empirically,the S-channel and u-channel contributions are much smaller than tchannel contribution especially at high energies.We take the J/ψ as the exchanged meson in the t channel,Since the J/ψN N vertex is OZI suppressed,the Primakoff effect will be introduced here.As is well known in the photoninduced Primakoff effect,the high energy pion beam will interact with the nucleon or nuclei through exchanging a virtual photon.Combined with the vector meson dominance（VMD）mechanism,the Z_c（3900）can be produced.Here,we only consider Γ = 29 Me V,because the cross sections with two choices of the decay width are on the same order of magnitude but different.At energies higher than about 30 Ge V,the cross sections with nuclei are on the order of magnitude of 1000 nb or more with cutoff Λin a range of 1～2 Ge V,with which the crosssection with the proton target is on the order of magnitude of 1 nb.After replacing the proton with the nuclei,the total cross section of the Z_c（3900）production enhances obviously to an order of magnitude of 100 nb with an assumption of the branch ratio as 0.1 for the Z_c（3900）in the J/ψπ channel.However,we have roughly calculated the produce cross-section of Z_c（3900）with the light nucleus12 C and the heavy nuclear208 Pb target,even if only a small fraction of decay,is also easier to experimentally than proton targets,especially in high energy conditions.