A charming witness of the strongest magnetic field in the universe


Quantum ChromoDynamics (QCD) is the theory describing the strong interaction in the Standard Model of particle physics. Under extreme conditions of high temperature and pressure, QCD predicts the formation of a new state of matter, the so-called Quark Gluon Plasma (QGP), in which quarks and gluons are deconfined. The study of the QGP has a large impact on particle physics, astrophysics and cosmology since it has been the state of our Universe a few microseconds after the Big Bang. Heavy-ion collisions at ultra-relativistic energies at the Large Hadron Collider produce the optimal conditions to form the QGP in the laboratory. The hot QCD matter is produced within an unprecedented strong magnetic field, which properties and effects have not been yet explored.
The charm quark is the best candidate to probe the properties of this magnetic field because its formation timescale is comparable to the timescale when the magnetic field attains its maximum value and the kinetic relaxation time of charm is similar to the QGP lifetime. These factors allow the charm quark to retain the initial kick picked up from the electromagnetic field, resulting in a significantly larger signal compared to that of lighter quarks.
I will perform, within the scope of the VENI program, the first measurement of the D meson directed flow with extremely good precision, which is a superior observable to study the magnetic field generated in heavy-ion collisions. The measurement of the directed flow of D mesons will give access to early time dynamics, which are the least understood until now. This measurement will be the first significant and uncontroversial observation of an effect of the magnetic field produced in heavy-ion collisions, which will shed light on fundamental and unexplored proprieties of the QGP (e.g. conductivity and initial density) allowing to constrain theoretical models.





Dr. A.D. Dubla

Verbonden aan

Universität Heidelberg, Kirchhoff-Institut für Physik


01/09/2019 tot 30/09/2022