HEP Seminar- Luca Mastrolorenzo-CERN-"Unveiling the Higgs Boson's Charm with the CMS Experiment"

Thu, Apr 21, 2022, 2:00 pm
303 Jadwin Hall

Probing the Yukawa couplings is paramount to understand the role played by the Higgs boson in the Standard Model. Ten years after the discovery of the Higgs boson, all the Yukawa couplings to the third generation of fermions have been measured. More recently the CMS and ATLAS collaborations claimed the evidence of the Higgs boson decay to muons, assessing for the first time the coupling of the Higgs boson to fermions of the second generation. The next goal in the characterization of the Higgs boson properties is represented by the measurement of the couplings of the Higgs boson to second-generation quarks. In this seminar, the most recent results of the direct search for the VH, H->cc process with the CMS experiment is presented. The search targets Higgs bosons produced in association with a vector boson (W, Z) exploiting the full LHC Run-2 data set. To fully exploit the topology of the H->cc decay in the different regimes of the Higgs boson transverse momentum, two strategies have been adopted aiming to reconstruct the Higgs boson candidate through two distinct “small-radius” jets or via a unique "large-jet". Remarkable improvements have been brought to the analysis techniques with respect to the previous public results: from new and more efficient algorithms to tag charm-initiated jets to dedicated jet energy and mass regression techniques, conceived exploiting advanced machine learning methods. The analysis strategy has been extensively validated by observing the VZ, Z->cc process for the first time at a hadron collider experiment. The results represent the world's most stringent limit on the VH, H->cc process and on the Higgs-charm Yukawa coupling.