Study On Production Of Light(Anti) Nuclei In High-Energy Pb-Pb Collisions

The puzzle of asymmetry between matter and antimatter in the present observable universe is an important advanced research project which needs to be addressed in modern particle physics,astrophysics and cosmology.With the improvement of high-energy experiments and advanced theories,a series of antiparticles(such as,positron,anti-proton and anti-hypertriton)were detected and certified;in addition,more physical properties of them were researched and measured.High-energy ion collisions create a high energy density similar to that of the Universe microseconds after the Big Bang,so they are regarded as a feasible means of studying on the evolution and production of anti-nuclei in a controlled laboratory.Furthermore,there is a new possibility that solving the asymmetry problem of matter and antimatter when the cosmos formed and evolved at the extremely initial stage.In this paper,the relative basic knowledge of high-energy ion collisions and antimatter research are briefly introduced;besides,there is a concise introduction to the two research simulated models which are used by the research project study,i.e.,the parton and hadron cascade(PACIAE)model and the dynamically constrained phase-space coalescence(DCPC)model.Then,the research of antimatter in high-energy Pb-Pb collisions and the relative experiments data from ALICE group in European Organization for Nuclear Research(CERN)are described.Finally,the production of light(anti)nuclei and their properties in mid-rapidity region for Pb-Pb collisions at the center-of-mass energy 2.76 Te V based on PACIAE+DCPC models are respectively showed.The main contents are presented as follows:(1)The transverse momentum distributions of final-state hadrons for different centrality bins are simulated by PACIAE model.It’s clear that a strong centrality dependence of their distributions exists;(2)The yield property of light(anti)nuclei for different centrality bins is discussed from two aspects,including integrated yields and cumulate yields.The truth that centrality plays a key role in this property is obtained;(3)The yield ratios between light anti-nuclei and corresponding nuclei in different centrality bins are researched.The results could be gained: their ratios remain unchanged,i.e.,the ratios are independent with selected centralities;(4)The distribution property of relative yield per participant nucleon for light(anti)nuclei in different centralities is studied.Obviously,the dependence between the relative yields of light(anti)nuclei and their mass number is presented;i.e.,the scaling property of mass exists in this progress;(5)There is also a discussion about the distribution property of coalescence parameters for light(anti)nuclei from central to peripheral collisions.We can find that the values of their coalescence parameters keep constant,and there exists an additional restricted condition for strangeness in the process of(anti)hyper-nuclei production.In addition,compared with the CERN-ALICE experimental data,the results of PACIAE + DCPC models are in agreement with those data of experiments within error ranges.