Formation of color superconducting quark matter in supernovae and protoneutron stars
Final Report Abstract
In this project we have tested, for the first time, the effect of the formation of quark matter on the evolution of core collapse supernovae and we have proven that this process could be a suitable mechanism for the explosion of supernovae, at least for progenitor masses up to 15M⊙. Moreover, a clear signature of the formation of quark matter is evident within the neutrino signal emitted in the early post-bounce phase. This implies that, for the next galactic supernova, the present neutrino detectors such as SuperK and IceCube will be able to test our results and therefore could finally provide the smoking gun for the deconfinement of quarks at high density. The further evolution of the protoneutron star, within a few seconds after the explosion, could also be very rich in phenomenology: we have for the first time simulated the evolution of protoneutron stars by considering the formation of a color superconducting phase. Since the deleptonization of the star drives also a progressive increase of the isospin asymmetry of matter, a phase transition between different quark phase occurs, which is likely to strongly influence the neutrino signal emitted by the star at the later stages of the evolution. Work along this line is in progress. Finally, we want summarize two more remarkable unexpected findings occurred during this project: from the theoretical point of view, the study of protoneutron stars allowed to better understand the properties of the quark hadron phase transition at finite isospin density: this fact, with the calculation of the symmetry energy of the two flavor color superconductivity, stimulates further investigations in a quite different physical system i.e. the hot and expanding fireball created in heavy ions collisions. In particular, signatures of the formation of the diquark condensate could be expected in connection with the so called isospin distillation effect which we plan to study in the near future. From the observation point of view, the discovery of a two solar masses neutron star gave us the opportunity to strongly constrain the quark matter equation of state: to reach such a large gravitational mass, hybrid or quark stars are likely to be composed by color superconducting quark matter.
Publications
- “Hadron-quark phase transistion at nonzero isospin density: The Effect of quark pairing”, Phys. Rev. D 81, 094024, (2010)
G. Pagliara, J. Schaffner-Bielich
- “Nucleation of quark matter in protoneutron star matter”, Phys. Rev. D 81, 123012, (2010)
B.W. Mintz, E.S. Fraga, G. Pagliara, J. Schaffner-Bielich
- “Core-collapse supernova explosions triggered by a quark-hadron phase transition during the early post-bounce phase”, Astrophys.J.Suppl. 194, 39, (2011)
T. Fischer, I. Sagert, G. Pagliara, M. Hempel, J. Schaffner-Bielich, T. Rauscher, F.-K. Thielemann, R. Kappeli, G. Martinez-Pinedo, M. Liebendorfer
- “Formation of quark phases in protoneutron stars: the transition from the two flavor color superconducting phase to the normal quark phase”, Phys.Rev.D 83, 125013 (2011)
G. Pagliara
