Analysis of top quark pair production signal from neutral 2HDM Higgs bosons at LHC

TL;DR

This paper investigates the detection of neutral Higgs bosons from the two Higgs doublet model type I at the LHC by analyzing top quark pair production events, focusing on boosted top jets to distinguish signal from background.

Contribution

It introduces a novel analysis method using boosted top jets to identify Higgs boson signals in top pair production at the LHC, especially in the low tan beta region.

Findings

Boosted top jets effectively discriminate signal from standard model background.

Certain low tan beta regions remain accessible for detection.

Invariant mass analysis supports potential Higgs boson discovery in this channel.

Abstract

In this paper, the top quark pair production events are analyzed as a source of neutral Higgs bosons of two Higgs doublet model type I at LHC. The production mechanism is $pp \to H/A \to t\bar{t}$ assuming a fully hadronic final state through $t \to Wb \to jjb$. In order to distinguish the signal from the main background which is the standard model $t\bar{t}$, we benefit from the fact that the top quarks in signal events acquire a large Lorentz boost due to the heavy neutral Higgs boson. This feature leads to three collinear jets (a fat jet) which is a discriminating tool for identification of the top quarks from the Higgs boson resonances. Events with two identified top jets are selected and the invariant mass of the top pair is calculated for both signal and background. It is shown that the low $\tan\beta$ region has still some parts which can be covered by this analysis and has not been excluded yet by flavor physics data.