QCD Process in Few Nucleon Systems

Authors

Dhiraj MaheswariFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Physics

First Advisor's Name

Misak Sargsian

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Werner Boeglin

Second Advisor's Committee Title

Committee member

Third Advisor's Name

Lei Guo

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Mirroslav Yotov

Fourth Advisor's Committee Title

Committee member

Keywords

Nuclear physics, Hard QCD processes, photodisintegration, polarized deep inelastic scattering, spin structure of neutron

Date of Defense

6-20-2018

Abstract

One of the important issues of Quantum Chromodynamics (QCD) - the fundamental theory of strong interaction, is the understanding of the role of the quark-gluon interactions in the processes involving nuclear targets. One direction in such studies is to explore the onset of the quark gluon degrees of freedom in nuclear dynamics. The other direction is using the nuclear targets as a “micro-labs” in studies of the QCD processes involving protons and neutrons bound in the nucleus. In the proposed research, we work in both directions considering high energy photo- and electro-production reactions involving deuteron and 3 He nuclei.

In the first half of the research, we study the high energy break-up of the 3 He nucleus, caused by a incoming photon, into a proton-deuteron pair at the large center of mass scattering angle. The main motivation of the research is the theoretical interpretation of recent experimental data which revealed the unprecedentedly large exponent s −17 , for the energy dependence of the differential cross section. In the present research, we extend the theoretical formalism of the hard QCD rescattering model to calculate energy and angular dependences of the absolute cross section of the γ 3 He → pd reaction in high momentum transfer limit.

The second half of the research explores the deep-inelastic scattering of a polarized electron off the polarized deuteron and 3 He nuclei, to explore the quark-gluon structure of polarized neutron. The main reason of using deuteron is that it is the most simple and best understood nucleus. While the reason of using polarized 3 He as an effective polarized neutron target is that because of the Pauli-principle, the two protons in the target are in the opposite spin states and thus the neutron has all the polarization of the 3 He nucleus. However this approximation is exact only for the S-state and becomes less accurate with the increase of the internal momentum of the bound nucleons in the nucleus. There are several planned experiments which will be performed during next few years at the kinematics in which the internal momenta of the probed neutron cannot be neglected. Therefore, for the reliable interpretation of the data, all the nuclear effects, especially the effects related to the relativistic treatment of high momentum component of the nuclear wave function, should be taken into account. In this work, we developed a comprehensive theoretical framework for calculation of the all relevant nuclear effects that will allow the accurate extraction of the neutron data from deepinelastic scattering involving deuteron and 3 He targets.

Identifier

FIDC006838

Recommended Citation

Maheswari, Dhiraj, "QCD Process in Few Nucleon Systems" (2018). FIU Electronic Theses and Dissertations. 3795.
https://digitalcommons.fiu.edu/etd/3795