Invisibles 2021 Workshop

May 31, 2021 to June 4, 2021
Online
Europe/Madrid timezone

Searches for Dark Photons at Belle II

Jun 2, 2021, 3:36 PM
6m
Online

Online

PhD forum talk + poster

Speaker

Miho Wakai (University of British Columbia)

Description

Belle II is a B-Factory experiment designed to produce precision measurements of CP violation in the weak sector as well as search for Beyond the Standard Model particle physics. The $e^{+}e^{-}$ collisions are created by the SuperKEKB accelerator which has achieved a world record of instantaneous luminosity of $2.4 \times 10^{34} {\text{cm}^{-2}}{\text{s}^{-1}}$. One of the highest priorities for the early data of the experiment is the search for dark photons that decay to dark matter. A dark photon is a mediator within the dark sector which mixes with the Standard Model (SM) photon. The experimental signature is a single energetic photon observed in the detector. A dark photon would produce an excess of events in the single photon recoil mass. A particularly challenging case is when the visible photon carries the full beam energy, which corresponds to a low-mass dark photon. There is a significant background from the SM process $e^{+}e^{-}\rightarrow \gamma\gamma$, where one of the photons is missed due to detector imperfections. This has motivated us to study the structure of the sub-detectors and compare the data and Monte Carlo response. By understanding the photon detection sensitivity of the sub-detectors, we will estimate the background for dark photon studies. This talk will discuss the ''single photon search'' and the approach to quantifying this background.

Primary author

Miho Wakai (University of British Columbia)

Presentation materials

 MihoWakai_Invisibles2021.pdf MihoWakai_Invisibles_poster.pdf