Quark-Gluon Plasma: a study of an extreme state of matter at LHC

Few microseconds after the Big Bang, the universe was filled with an extreme state of matter called Quark-Gluon Plasma. This state of matter consists of deconfined quarks and gluons, interacting dominantly via the strong nuclear force, one of the four fundamental forces in nature. The Quark-Gluon Plasma does not exist at ordinary temperatures and energy densities, where the building blocks of matter are composite particles, baryons (made up of three quarks) and mesons (made up of one quark and one antiquark). In collisions of heavy ions at the Large Hadron Collider the Quark-Gluon Plasma can be produced. Therefore, by producing and studying the properties of Quark-Gluon Plasma in heavy-ion collisions we are essentially recreating and studying the conditions which existed in the distant past of our universe and shedding light on its evolution.

This module introduces the most important concepts of Quark-Gluon Plasma and heavy-ion physics, including also the basics of Quantum ChromoDynamics, which is the successful fundamental theory of strong nuclear force. The topics to be covered include: kinematic variables in heavy-ion collisions, determination of collision geometry (centrality), two- and multi-particle correlation techniques, collective phenomena, femtoscopy, jet suppression, di-leptons, direct photons, quarkonia, transport coefficients, confinement and asymptotic freedom, QCD phase diagram... Since currently one of the most informative physical phenomena in the exploration of Quark-Gluon Plasma properties in heavy-ion collisions is collective anisotropic flow, a special focus will be given to its explanation, both from theoretical and experimental point of view. The most important experimental findings to date on Quark-Gluon Plasma properties will be reviewed.

After successful participation in the module the students are able to

• understand the basic properties of an extreme state of matter, Quark- Gluon Plasma,
• apply and interpret various physical phenomena specific for heavy-ion collisions to constrain its fundamental properties.
• know some state-of-the-art experimental techniques, e.g. multi- particle correlation techniques and femtoscopy,
• link specific observables emerging from these techniques with the fundamental properties of Quark-Gluon Plasma.

No preconditions in addition to the requirements for the Master’s program in Physics.

The module cosists of a lecture with an integrated seminar. The content of the lecture is delivered through presentation, assuming no prior knowledge on the subject. Both theoretical and experimental aspects of the field will be addressed in equal amount. Students will be challenged to participate interactively in the course by optionally selecting one topic not covered in the main lecture, and presenting it in a form of a 20min seminar.

In total there will be 14 days of lectures, each lecture lasting 2x45min. One day is reserved for student seminars.

PowerPoint presentation projected from laptop. Blackboard for additional clarifications.

J. Bartke: Relativistic Heavy Ion Physics, World Scientific Publishing, (2008)

There will be an oral exam of 25 minutes duration. Therein the achievement of the competencies given in section learning outcome is tested exemplarily at least to the given cognition level using comprehension questions and sample calculations.

For example an assignment in the exam might be:

• Describe one experimental observable in heavy-ion collisions which can be used to constrain the properties of a Quark-Gluon Plasma.
• What are multi-particle azimuthal correlations and how can they be used in the measurement of anisotropic flow phenomenon?
• What is the femtoscopy technique in high-energy nuclear collisions?
• How can we use the Glauber model to describe the initial geometry of heavy-ion collisions?

There will be a bonus (one intermediate stepping of "0,3" to the better grade) on passed module exams (4,3 is not upgraded to 4,0). The bonus is applicable to the exam period directly following the lecture period (not to the exam repetition) and subject to the condition that the student passes the mid-term of preparing and giving a seminar talk on a topic related to the contents of the lecture.