Study Of Phase Structure Of 2-Flavor Color Superconductor Quark Matter In Magnetic Fields

It is of great scientific significance both in basic theory and experiment to study the phases and phase transitions of strongly interacting matter at extreme temperature and density.As Nobel winner F.Wilczek put it,it involves“the condensed matter physics of QCD.”It is generally accepted that at low temperature(T?0)and high density(?_B>>?_QCD,where?_QCDis the intrinsic scale in QCD),quarks can conduct Cooper pairing through a similar-to-Bardeen-Cooper-Schrieffer(BCS)mechanism,leading to the breaking of global color symmetry and the formation of the so-called color-flavor-locking superconducting phase.On the other hand,a large number of studies have shown that magnetic field has a non-trivial effect on the quark matter phase.It is not only an important subject of basic theory to explore the vacuum structure of QCD under strong magnetic field,but also has direct practical relevance to the phenomenology of relativistic heavy ion collision.In this thesis,the phase structure of two-color superconducting quark in magnetic field is studied.Based on the NJL model of finite temperature and density coupled with external magnetic field,the thermodynamic potential is obtained by means of mean field approx-imation,and the corresponding energy gap equation is numerically solved.We find that the influence of external magnetic field on the phase structure of two-flavor superconducting quark matter is reflected in the following aspects:first,the existence of magnetic catalytic effect,that is,the magnetic field strengthens the chiral symmetry breaking;secondly,we calculate the effects of magnetic field on the energy gap of color superconductivity quark matter,by using different regularization schemes,and the phase diagram at T-e B plane is given.We also briefly discuss the effect of coupling constants on color superconducting phase.