000003598 001__ 3598
000003598 005__ 20230523230552.0
000003598 037__ $$aBELLE2-MTHESIS-2023-015
000003598 041__ $$aeng
000003598 100__ $$aMiho Wakai
000003598 245__ $$aSearch for invisible decays of dark photon at Belle II
000003598 260__ $$aVancouver$$bUniversity of British Columbia$$c2021
000003598 300__ $$a91
000003598 500__ $$aPresented on 31 10 2021
000003598 502__ $$aMSc$$bVancouver, University of British Columbia$$c2021
000003598 520__ $$aThe Standard Model of particle physics displays a good description of the nature of fundamental particles. However, there are some inconsistencies between theory and experimental evidence. One of the observations made through astronomy and cosmology but is not explained by the Standard Model is dark matter. Many theories have been made to explain dark matter, which includes the dark photon particle. The dark photon is a hypothetical particle thought to exist as a mediator between the Standard Model photon and dark matter particles. The dark photons can be produced at an electron-positron collider like the Belle II experiment, located at the KEK particle physics facility. The work presented shows the first attempts of the search for dark photons with invisible decays, where studies on background were conducted for low dark photon masses. This involved understanding the different backgrounds for dark photon events, the geometry and efficiency of the main sub-detectors, and making the final background estimates. In addition, discrepancies between data and Monte Carlo events for the background control sample were found due to detector imperfections, which are also summarised here.
000003598 700__ $$aChris Hearty $$edir.
000003598 8560_ $$fmiho@phas.ubc.ca
000003598 8564_ $$uhttps://docs.belle2.org/record/3598/files/BELLE2-MTHESIS-2023-015.pdf
000003598 980__ $$aTHESIS