BSM PANDEMIC Delta Series: Peizhi Du (Stony Brook) and Jessica Howard (UC Irvine)

by Dr Peizhi Du (Stony Brook), Jessica Howard (UC Irvine)


Dear physics friends,

Please join us for this week's BSM PANDEMIC Delta Series on Tuesday, October 12th at 11 am Pacific/2 pm Eastern.  There will be two 25-minute talks with time for discussion at the end of each (no social period).


Peizhi Du (Stony Brook)

"Direct Detection of Sub-MeV Dark Matter with Doped Semiconductors"

We propose a new idea of probing sub-MeV dark matter (DM) using doped semiconductors. Dopants in semiconductors form energy levels that are tens of meV below the conduction band or above the valence band. These materials can be new DM detector targets with a threshold of tens of meV, which can probe dark matter masses down to tens of keV for DM-electron scattering and tens of meV for DM absorption. In this talk, I will take Phosphorus-doped silicon as an example of commonly used doped semiconductors, and show that these targets have rich signals such as phonon, electron ionization, and electron-hole pair creation in different energy regions. Moreover, I will demonstrate that doped semiconductors have an excellent reach over a wide range of DM masses and have the potential to probe the entire range of freeze-in benchmarks for scattering via a light dark photon.


Jessica Howard (UC Irvine)

"Dark Matter Freeze-out during SU(2)_L Confinement"

We explore the possibility that dark matter is a pair of SU(2)_L doublets and propose a novel mechanism of dark matter production that proceeds through the confinement of the weak sector of the Standard Model. This phase of confinement causes the Standard Model doublets and dark matter to confine into pion-like objects. Before the weak sector deconfines, the dark pions freezeout and generate a relic abundance of dark matter. We solve the Boltzmann equations for this scenario to determine the scale of confinement and constituent dark matter mass required to produce the observed relic density. We determine which regions of this parameter space evade direct detection and collider bounds.