Conveners
DM II
- Nirmal Raj (TRIUMF)
Dark matter could take the form of macroscopic objects, scattering on baryonic matter with geometric cross section. There is a wide "asteroid" mass range over which such objects are almost unconstrained. We show that when a dark asteroid travels through a star, it produces shock waves which reach the stellar surface, leading to a distinctive transient UV emission. In a dense globular cluster,...
Indirect detection experiments typically measure the flux of annihilating dark matter (DM) particles propagating freely through galactic halos. We consider a new scenario where celestial bodies "focus" DM annihilation events, increasing the efficiency of halo annihilation. In this setup, DM is first captured by celestial bodies, such as neutron stars or brown dwarfs, and then annihilates...
Weak-scale secluded sector dark matter can reproduce the observed dark matter relic density via thermal freeze-out within that sector. If supersymmetric, three portals to the visible sector — a gauge portal, a Higgs portal, and a gaugino portal — are present. We present the gamma ray spectra relevant for indirect detection in these set-ups. Since R-parity is no longer necessary to ensure...
Numerous particle models for the cosmological dark matter feature a pair-annihilation rate that scales with powers of the relative velocity between the annihilating particles. As a result, the annihilation rate in the central regions of dark matter halo can be significantly lower than at the halo's periphery for particular ambient gravitational potentials. While this might be offset by an...
The paradigm of neutral naturalness suggests the existence of highly non-minimal hidden sectors. In particular, the Mirror Twin Higgs model postulates that some of dark matter is in the form of mirror matter, featuring mirror quarks, leptons and gauge bosons whose masses are a few times heavier than their Standard Model counterparts. I will discuss the possibility that mirror matter could have...
I report on an ongoing investigation of how a hidden ‘dark’ confining gauge sector, common in Hidden Valley models such as the Mirror Twin Higgs, could lead to novel signatures in indirect detection searches for dark matter. Dark matter annihilation can then lead to dark showers of multiple and various hadrons, distinct from particle pair production. If there are no light fermions charged...
Gravitational waves provide a unique method of testing theories with extended gauge symmetries. In particular, spontaneous symmetry breaking can lead to a detectable stochastic gravitational wave background generated by cosmic strings and first order phase transitions in the early universe. I will discuss the unique gravitational wave signature of a simple model with gauged baryon and lepton...
