Nuclear Modification In Deeply Inelastic Scattering

The cold nuclear matter,as a good testground to test and learn about Quantum Chromodynamics(QCD),is the focus of future Electron-Ion Collider experiment and also of our study.Deep Inelastic scattering(DIS),as an important process which gives birth to the parton model,also serves as a excellent process which can provide us the information about proton and nucleus.This thesis is devoted to investigate the nuclear modification to deeply inelastic scattering in a large nucleus.We investigate the nuclear modification to DIS process from two aspects,the medium induced radiation spectrum and large angle dijet production.We revisit radiative parton energy loss in deeply inelastic scattering(DIS)off a large nucleus within the perturbative QCD approach.We calculate the gluon radiation spectra induced by double parton scattering in DIS without collinear expansion in the transverse momentum of initial gluons as in the original high-twist approach.One can name our approach as generalized High-Twist approach.The final radiative gluon spectrum can be expressed in terms of the convolution of hard partonic parts and uninte-grated or transverse momentum dependent(TMD)quark-gluon correlations.The TMD quark-gluon correlation can be factorized approximately as a product of initial quark distribution and TMD gluon distribution which can be used to define the generalized or TMD jet transport coefficient.Under the static scattering center and soft radiative gluon approximation,we recover the result by Gylassy-Levai-Vitev in the first order of the opacity expansion.The difference as a result of the soft radiative gluon approximation is investigated numerically under the static scattering center approximation.On the other hand,Large angle gluon radiations induced by multiple parton scat-terings contribute to dijet production in deeply inelastic scattering(DIS)off a large nucleus.Within the generalized high-twist approach to multiple parton scattering,such contributions at the leading order in perturbative QCD can be expressed as a convolution of the multiple parton scattering amplitudes and the transverse momentum dependent(TMD)two-parton correlation matrix elements.We study this medium-induced dijet spectrum and azimuthal angle correlation under the approximation of small longitudinal momentum transfer for the secondary scattering and the factorization of quark-gluon correlation matrix elements as a product of large-x quark and small-x gluon TMD par-ton distribution function(PDF).We find that the medium induced dijet correlation is sensitive to the transverse momentum broadening in quark TMD PDF and saturation in gluon TMD PDF inside the nucleus.The dijet correlation is also found to increase with the dijet rapidity gap and have a quadratic nuclear size dependence because of the Landau-Pomercanchuk-Migdal(LPM)interference effect in induced gluon emission.In the future EIC experiment,the measurements of such unique features in the dijet correlation can shed light on the LPM interference and gluon saturation physics in large nuclei.