Dear Astro-lunchers,
We will have Astroparticle Lunch at 11:45 am this Friday (EDT)! This week, our Lunch features Nirmal Raj (TRIUMF), who will bring us go through his recent work on identifying the dark matter subhalos by their encounters with neutrons stars, cosmic rays, and paleolithic minerals
Dark Matter Direct Detection in an Inter-Clump Void
Abstract: On sub-kiloparsec scales dark matter could cluster and form compact subhalos, in which the majority of Galactic dark matter could reside. Null results in direct detection experiments since their advent four decades ago could then be the result of extremely rare encounters between the Earth and these subhalos. I present alternative and promising means to identify subhalo dark matter interacting with Standard Model particles: (1) subhalo collisions with old neutron stars can transfer kinetic energy and brighten the latter to luminosities within the reach of imminent infrared, optical, and ultraviolet telescopes; this already sets bounds on self-interacting dark matter in subhalos from the coldest known neutron star, (2) subhalo dark matter scattering with cosmic rays results in detectable effects, (3) historic Earth-subhalo encounters can leave dark matter tracks in paleolithic minerals deep underground. These searches, which are highly complementary to microlensing surveys, could discover dark matter subhalos over vast parametric ranges, between the masses of a typical lake and a typical star, with corresponding dark matter cross sections and masses spanning tens of orders of magnitude.
Feel free to join us to learn more details and talk with Nirmal!
After Nirmal’s talk, Ivan will share a paper about a search of dark matter hot spot by the IceCubedata [2109.07885].
We will continue to hold the Lunch in the ‘Price Place + Zoom’ mode. The Zoom link and selected papers of the week are both available in our website:https://sites.google.com/site/ccappastrolunch/ccapp-astroparticle-lunch