Ziming Liu

Quark Gluon Plasma (QGP)

A quark–gluon plasma (QGP) or quark soup is a state of matter in quantum chromodynamics (QCD) which exists at extremely high temperature and/or density. This state is thought to consist of asymptotically free strong-interacting quarks and gluons, which are ordinarily confined by color confinement inside atomic nuclei or other hadrons.

This phase of QCD matter is believed to exist at the very beginning after the big bang. Experimentally, QGP can be created for a short time in Relativistic Heavy-Ion Collisions.

Our work (Highlight: Innovative work!)

We provide a data-driven machine learning method (Principal Component Analysis) to discover new flow observables, which are better indicators for initial fluctuations than traditional fourier flow harmonics.

This work has been presented by me on 4th China LHC Physics Conference (Oral). If you are interested, click me to get the slides.

The paper is in preparation and will be soon submitted.
Title: Principal Component Analysis of Collective Flow in Relativistic Heavy-Ion Collisions. Click me to get the paper.
Collaborators: HuiChao Song, Wenbin Zhao

Bag Model for hadrons

In dealing with the nature of quark confinement, one picture for hadrons is that of an elastic bag which allows the quarks to move freely around, as long as you don't try to pull them further apart. But if you try to pull a quark out, the bag stretches and resists.

Our work (Literature review)

We did literature review on the bag model of hadrons. First, we use the simplest model where quarks are treated as free non-relativistic particles in a spherical infinite potential well. Later, we introduce cases where relativistic cases dominate and a well that can change sizes. Finally, as an application of the theory, we estimate the radius of hadrons.

This work is the final essay of Seminars for Quantum Mechanics in 2018 Spring, Peking University. click me to get the paper.
Collaborators: Mingyang Duan
Instructor: Yuxin Liu.