Studies of dark Higgs model and CMS phase-2 detector upgrade

by Jongho Lee (MS Candidate)

Wednesday Nov 13, 2019, 3:30 PM → 4:00 PM Asia/Seoul

119호 (제1과학관)

발표제목: Search for dark Higgs at sqrt{s} = 13 TeV and CMS phase-2 detector upgrade

Studies of dark Higgs model is performed using events with a large-radius jet associated with large missing transverse energy from proton-proton collisions at sqrt(s) = 13 TeV. The data sample analyzed corresponds to an integrated luminosity of 59.97 fb-1 collected by the CMS detector at the LHC in 2018. The dark Higgs boson (hs) is motivated by the necessity of generating mass for dark matter particles (χ) in the dark sector. It may relax constraints of traditional monojet-based dark matter search by introducing a new annihi- lation channel, χχ → hshs. A new software framework based on a columnar database for input data representation will be used for the physics analysis of dark Higgs boson.
Meanwhile, a track isolation algorithm for a Level-1 (L1) pixel-based electron trigger is developed for the CMS Phase-2 upgrade. The main idea of the track isolation method is to use the difference of the number of pixel tracks inside ∆R cone to the L1 e/γ object between prompt elec- trons and semi-leptonic decay of hadrons. In addition, the development of an application-specific integrated circuit (ASIC) design for the endcap tim- ing layer (ETL) in the MIP timing detector (MTD) for the CMS Phase-2 upgrade is described. The MTD is designed to reduce multiple proton-proton collisions (pileup) effect by a factor of 10 with a time resolution of 30-40 ps. Test of the prototype of ASIC consisting of preamplifier, discriminator, and charge injection circuit is presented.

Thesis Advisor: Prof. Chang-Seong Moon