Research On Vector Meson Production In Color Dipole Model

The main content of this thesis is application of the color dipole model in the vector meson production in electron-proton scatterings and nucleus-nucleus ultraperipheral collisions.The color dipole model is a model to describe the electron-proton scattering in the high energy limit.In the color dipole model,the process of the electronproton scatterings can be viewed as three steps.In the first step,the photon splits into a quark and an antiquark.In the second step,the quark and antiquark interact with the proton through gluons emitted from the proton.In the third step,the quark and antiquark recombine into a final particle.The quark and antiquark is called color dipole which is color singlet.The color dipole model can be only employed when the Bjorken variable x<0.01.In the Deep Inelastic Scattering(DIS),the color dipole model can describe the experimental data well.In electron-proton scattering,the virtual photon interacts with the proton.If the final particle is the real photon or vector mesons.This process is diffractive process.The color dipole model can be used in the vector meson production in diffractive process.In nucleus-nucleus collisions,when the impact parameter is larger than the sum of radius of the two nuclei,the direct strong interaction in nuclei can be neglected.This process is nucleus-nucleus ultraperipheral collisions.In nucleusnucleus ultraperipheral collisions,the real photon interacts with the nuclei and vector meson can be produced in nucleus-nucleus ultraperipheral collisions.The color dipole model is also can be applied in the vector meson production in nuclear ultraperipheral collisions.In diffractive and nucleus-nucleus ultraperipheral collisions,the main interaction is the photon-proton interaction.In diffractive process,the photon is virtual photon.In nucleus-nucleus ultraperipheral collisions,the photon is real photon.In the calculation of cross section of electron-proton scattering using color dipole model,the follow three parts are included.They are the light-cone function of the photon,the dipole-proton amplitude and the light-cone wave function of the vector meson.The light-cone function of the photon can be computed perturbatively in Quantum Electrodynamics(QED).The dipole-proton amplitude is dependent on the models.The light-cone wave function of the vector meson is also dependent on models.Dipole-proton amplitude is important in the dipole model and it reflects the interaction between the color dipole and the gluons.The dipole-proton amplitude is the solution of the Balitsky-Kovchegov(BK)evolution equation.There are various phenomenological model for the dipole-proton amplitude in practice.The light-cone wave function of the photon can be computed in Quantum Electrodynamics.But the light-cone wave function of the vector meson can not be computed analytically.There are various models for the vector mesons in lightcone system.Many of them are independent on Hamiltonian.The AdS/QCD holographic wave function in basis of light-cone quantization is dependent on the Hamiltonian,and it is the solution to the schr?dinger differential equation.In this thesis,the AdS/QCD wave function of J/? in BLFQ is employed in calculation of J/? production in diffractive process.In this thesis,the color dipole is implemented in the vector meson production in nucleus-nucleus ultraperipheral collisions.The numerical results of vector meson production in nucleus-nucleus ultraperipheral collisions are compared with the experimental data in this thesis.The theoretical predictions in this thesis give a good agreement with the experimental data at the LHC.Some light vector mesons rapidity distributions are also calculated in color dipole model in nucleus-nucleus ultraperipheral collisions for the future experiments.