The RIKEN BNL Research Center offers a Fellow system at Brookhaven's Relativistic Heavy Ion Collider (RHIC) allowing joint appointments with universities and research laboratories throughout the world, enabling talented researchers to hold tenure track positions at their home institution as well as a Fellow position with the Center.
This system was established to increase the research potential of the Center and to disseminate its research activities and results. To date, nine RHIC Physics Fellows have received the U.S. Department of Energy Outstanding Junior Investigator Award and over 50 Fellows have received tenure at their home institutions since the inception of the program.
Institutions interested in initiating a new RHIC Physics Fellow position may obtain details on how to proceed by contacting Tammy Stein, 1-631-344-5753.
D. Kharzeev, Group Leader
This group conducts QCD related research that includes heavy ion physics, the quark gluon plasma, color glass condensate and hard QCD/spin physics.
T. Izubuchi, Group Leader
This group's mission is to solve the dynamics of QCD from first principle lattice simulations using in-house computer resources.
Y. Akiba, Group Leader
This group studies the spin structure of the proton via polarized p+p collisions at RHIC as well as the properties of quark gluon plasma.
The RIKEN BNL Research Center is part of Brookhaven's Nuclear & Particle Physics Directorate.
RIKEN Lunch Seminar
"Sterile neutrino dark matter produced after the QCD phase transition"
Presented by Louis Lello, University of Pittsburgh
12:30 pm, Building 510 Room 2-160
Thursday, December 3, 2015, 12:30 pm
Hosted by: Daniel Pitonyak
Sterile neutrinos are SU(2) singlets that mix with active neutrinos via a mass matrix, its diagonalization leads to mass eigenstates that couple via standard model vertices. We study the production of sterile neutrinos in the early universe from pion decays shortly after the QCD phase transition in the absence of a lepton asymmetry. We introduce the quantum kinetic equations that describe their production, freeze out and decay and discuss the various processes that lead to their production in a wide range of temperatures assessing their feasibility as dark matter candidates. We consider the production of heavy neutrinos in the mass range < 140MeV from pion decay shortly after the QCD crossover including finite temperature corrections to the pion form factors and mass. We consider the different decay channels that allow for the production of heavy neutrinos showing that their frozen distribution functions exhibit effects from "kinematic entanglement" and argue for their viability as mixed dark matter candidates. We discuss abundance, phase space density and stability constraints and argue that heavy neutrinos with lifetime >1/H0 freeze out of local thermal equilibrium.