Speaker
Description
A direct measurement of the Higgs self coupling is very crucial to understand the nature of electroweak symmetry breaking. This requires an observation of production of Higgs boson pair, which suffers from very low event rate even at the current LHC run. In our work, we study the prospects of observing the non-resonant Higgs pair production at the high luminosity run of the 14 TeV LHC (HL-LHC). Here, we choose multiple final states based on the event rate and cleanliness, namely, $b\bar{b}\gamma \gamma$, $b\bar{b} \tau^+ \tau^-$, $b\bar{b} WW^*$, $WW^*\gamma \gamma$ and $4W$ channels and do a collider study by employing a cut-based as well as multivariate analyses using the Boosted Decision Tree (BDT) algorithm. Also, we consider various physics beyond the standard model (BSM) scenarios, for example resonant Higgs pair production, to quantify the effects of contamination when one tries to measure the SM di-Higgs signals. In a later study, we search specifically for the heavy resonant scalars ($H/A$) via their decay into two SM Higgs boson at the HL-LHC. After performing multivariate analysis using BDT algorithm in various final states, we set upper limits on the production cross-section of heavy scalar times its branching ratio into final state products for different values of heavy scalar masses. Finally, we translate these limits and put strong constraints on the $m_A-tan\beta$ parameter space (where $m_A$ and $tan\beta$ are respectively the mass of the pseudoscalar and the ratio of the vacuum expectation values of the two Higgs doublets) in the context of Minimal Supersymmetric Standard Model (MSSM).
