Quark Matter in Neutron Star Mergers

The existence and location of a first order phase transition from nuclear to deconfined quark matter are one of particle physics's most

exciting unanswered questions. With the discovery of gravitational waves from a binary neutron star merger in 2017 from the LIGO

and VIRGO detectors, entirely new ways of investigating dense matter have emerged. Future third-generation gravitational-wave

detectors like the planned Einstein Telescope (ET) in Europe will be able to not only measure the inspiral but the actual merger of the

stars. Only by improving the microscopic physics implemented in numerical simulations, we will be able to decode and constrain the

governing forces of particle physics imprinted in the merger signal and unlock ET's full potential. This includes a proper treatment of

the microscopic physics of chemical equilibration and deconfinement in quark matter. In previous works, the effects of the weak

interaction have been ignored, which dismisses important effects like bulk viscosity and phase conversion dissipation. The aim of

QUARKSTAR is to investigate, compute and provide all the necessary microscopic physics for the proper treatment of quark matter in

mergers. The main focus is to provide the results in a way that they can be used by the merger community and implemented in future simulations. This might open a completely new pathway to the discovery of quark matter in dense matter.

As an expert on microscopic physics, transport, and weak interaction processes in neutron star mergers, Dr. Alexander Haber will join

forces with the numerical general relativity group of Prof. Nils Andersson in Southampton. This ideal placement allows Dr. Haber to

receive all relevant training for his future academic career while presenting the ideal combination of knowledge from microscopic

physics to general relativity necessary to tackle the question of quark matter and deconfinement in neutron star mergers.