Israel Joint Particle Physics Meetings

Joint seminar Technion: Schmidt-Hoberg/Bloch

by Itay Bloch (Tel Aviv University), Kai Ronald Schmidt-Hoberg (Deutsches Elektronen-Synchrotron (DE))

Asia/Jerusalem
Description

11:00 Kai Schmidt-Hoberg (DESY)

Dark Matter from Exponential Growth

I will discuss a novel mechanism for the production of dark matter (DM) from a thermal bath, based on the idea that DM particles $\chi$ can transform heat bath particles $\psi$: $\chi \psi \to \chi \chi$.For a small initial abundance of $\chi$ this leads to an exponential growth of the DM number density. We demonstrate that this mechanism complements freeze-in and freeze-out production in a generic way, opening new parameter space to explain the observed DM abundance. An interesting specific scenario is the case of sterile neutrinos with secret interactions, where the exponential growth opens up significant new parameter space where sterile neutrinos make up all of the observed dark matter consistent with bounds from X-rays, structure formation and DM self-interactions.

13:00 Itay Bloch (TAU)

Millicharged Dark Matter Propagating in Space and Earth:

The possibility of having DM (or a fraction of it) charged under a dark U(1) which mixes with the U(1)EM has been of interest for many years. Many different experiments search for such a millicharged DM (MCDM), under the assumption that its velocity would be Maxwell Boltzmann distributed. However, our galaxy and local environment have a variety of effects that make this assumption highly non trivial. In this talk, I will discuss the effects of galactic magnetic fields, collisions with Cosmic rays, acceleration from Supernovae remnants, and energy losses due collisions with particles in the interstellar medium on the velocity distribution of MCDM outside the solar system. Furthermore, to arrive at an underground detector, the MCDM would need to pass through the solar wind, not be deflected by earth's magnetic field, and pass through earth's crust to reach the underground lab. We will discuss these effects as well. I will show some preliminary results from this ongoing calculation, and discuss how the different aspects of it can be performed more accurately in the future.