Publications & Experiences
My work focuses on High Energy Physics (HEP) and Phenomenology, utilizing computational tools to simulate and analyze particle interactions.
Email me:
francis.lance.jumawan@cern.ch
Probing the Higgs b-quark coupling (yb) at the ATLAS experiment
This CERN Summer Student Program project focuses on probing the Higgs boson’s bottom Yukawa coupling (yb) through the associated production of a Higgs boson with two b-quarks (bbH). The bbH production cross section is approximately 0.5 pb at the LHC and have some destructive interference contributions from other Higgs production processes such as gluon-gluon Fusion (ggH) and Higgs Strahlung (VH). While the decay channel H→bb have the largest branching ratio, its precision is limited by the resolution. The decay channel for this search is H→γγ to avoid the resolution limitation since photon measurement in the ATLAS detector has a resolution of about 1-2%. In this feasibility study, Run 2 and Run 3 samples from the H→γγ analysis are used. The analysis utilizes kinematic selections, newly engineered discriminating variables, and boosted decision trees to enhance signal-background separation. Statistical sensitivity is assessed through binned significance and maximum-likelihood fits. The findings indicate limited sensitivity with the current samples, methods, and channel, highlighting the need for increased signal statistics, improved forward b-tagging, and advanced background separation.
Read PaperNon-resonant anomaly detection for semi-visible jets with leptonic decays
In this study, we explore the capabilities of Non-Resonant Anomaly Detection techniques, Reweight and Generate, for identifying semi-visible jets (SVJ) within the Hidden Valley (HV) dark sector model. Using simulated events generated from PYTHIA, MadGraph5, and Delphes, we trained a Boosted Decision Tree (BDT) to select optimal features for distinguishing the signal from QCD backgrounds. With an AUC value of 0.998, the features selected are HT, MET, mjj, and N-subjettiness ratios (τ21 and τ32). Our results confirm that both Reweight and Generate provide reliable background extrapolation, as validated by Wasserstein distance metrics. Additionally, the Reweight method improves the detection significance from 2.6σ to approximately 5σ, demonstrating its potential for enhancing sensitivity in non-resonant searches.
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