Phenomenology 2025 Symposium

Probing neutral Higgs Boson with all-top and same-sign top final states at LHC

19 May 2025, 17:30

15m

David Lawrence Hall 106, University of Pittsburgh

Electroweak, Higgs, and Top Quark Physics Electroweak

Speaker

Chenyu Fang

Description

A general two Higgs doublet model is adopted to study flavor changing neutral Higgs (FCNH) interactions in $pp\to t\varphi \to t(tc)$ at the Large Hadron Collider, where $\varphi$ is either the CP-even Higgs scalar ($H$) or the CP-odd Higgs pseudoscalar ($A$). We considered two final states, (i) single lepton: $ttc\to bjjcb\ell \nu$, and (ii) same sign di-lepton: $ttc\to bbc\ell \ell \nu \nu$ where $\ell =e$ or $\mu$ and $\nu =$ neutrino, and $t$ represents either a top quark or an anti-top quark. We evaluated the cross sections for the FCNH signal and for the dominant physics backgrounds. Realistic acceptance cuts are applied to investigate the discovery potential. In addition, we have applied $b$ tagging and $c$ tagging at the event level using the ATLAS and CMS tagging and mis-tagging efficiencies. Promising results have been obtained for the single lepton top quark final states to reconstruct the Higgs mass. Furthermore, we employ the Higgs mass from the single lepton analysis to develop selection criteria for the same sign di-lepton final state, which is almost background free. Since the discovered light Higgs scalar behaves like the standard model Higgs boson, we expect $H\to tc$ and $A\to tc$ to offer great promise to search for new physics beyond the Standard Model.

Presentation materials

Pheno2025.pdf