Prof. Shi Shusu Makes Impressive Progress in Experimental Research on Relativistic Heavy-Ion Collisions Collective Motion

Vice Prof. Shi Shusu from CCNU College of Physical Science and Technology and his collaborators have made great progress in the experimental research on Relativistic Heavy-Ion Collisions Collective Motion (RHICCM). Research results related were published on Physical Review Letters, an international academic journal of physics. 

  Generally speaking, the purpose of the experiment is “to explore new states and properties of the matter”. A matter can be viewed as an onion in a scientific way: if the molecule is ripped out, there comes the atom; if the atom is ripped out, then there comes proton and neutron. Is there something smaller than proton and neutron? If yes, then what’s that? And in which forms do they live in the matter? To explore these questions, we carry out the research of RHICCM.

  The result of the research shows that with our current cognition, there comes quark and gluon after proton and neutron are peeled. As distinct from proton and neutron, quark and gluon cannot exist independently, however. Neither can they be detected directly. With the temperature on the earth, they are as if imprisoned within the hadron so that we cannot see the free quark and gluon.

  So what should we do? RHIC is currently the only way to release and liberate quark and gluon in the world.

  Then, what is RHIC? For example: if we peel gold nuclei into ions, take the 97 electrons away, and accelerate the ions close to the speed of light, then it will contain enormous energy. And if we make the gold nuclei (That is “RHIC”; heavy ions here refers to the gold nuclei) collide, then it will deposit a large amount of energy which produces an early-universe-alike environment of high energy density and high temperature. Only in this kind of situation can quark and gluon be released.

  And based on a lot of calculation and experiments, the existence of quark and gluon and their collective motion were found with the energy from the center of mass.  

  Moreover, as a research on basic physics, the main purpose of the research on RHICCM is to explore the properties of the high-temperature and high-density quark and gluon. As great scientific discoveries never lack the support of high and new technology, the conditions of the experiment have to be conducted in a large heavy-ion accelerator. The particle accelerator that Prof. Shi Shusu experimented with in the Brookhaven National Laboratory, the U.S., now possesses the most advanced technology in the world. And his experimental research has greatly promoted the development of particle accelerator and detector technology.

  Science means prudence, so every step of the experiment complies with the accuracy and prudence of science, which makes scientific experiments quite time-demanding and energy-consuming. At first, the data that Prof. Shi had collected was little and low-in-accuracy. During 2010 and 2011, Prof. Shi took advantage of a large-scale computer cluster called “farm” (It meant the computer cluster was as large as a farm) in order to get a more accurate result. In 2016, an article that concluded the experimental research results was eventually published in Physical Review Letters.

  Human beings are forever stepping on the road of making progress, so is scientific research. Let’s look forward to the new progress that scientists will make in the fields of basic structures and properties of the matter!