Exotic searches by ATLAS and CMS

A Kaur

doi:10.1088/1742-6596/1690/1/012169

Abstract

ATLAS and CMS are two general-purpose detectors setting almost opposite to each other at the LHC ring. Both detectors resulted in the discovery of Higgs Boson in 2012. With successful data taking during Run-II, ATLAS and CMS recorded up to 139fb −1 of integrated luminosity and probes for rare and exotic decays and sets exclusion limits on various models searching beyond standard model physics.

Highlights

The standard model (SM) of particle physics successfully explains the structure of matter and forces acting between them but still, it fails (i) to include the fourth fundamental force i.e. gravitational force (ii) to explain matter-antimatter in the universe (iii) to explain the 95% dark energy and dark matter forming the universe and so on.There are several models evolved with time to explain the physics beyond the standard model and are known as ”Beyond Standard Model (BSM)”
With successful data taking during Run-II, ATLAS and CMS recorded up to 139f b−1 of integrated luminosity and probes for rare and exotic decays and sets exclusion limits on various models searching beyond standard model physics
Another pioneering search [12] is performed by ATLAS for dark matter particles produced in association with a Dark Higgs boson decaying to VV where V= W ±, Z

Summary

Introduction

The standard model (SM) of particle physics successfully explains the structure of matter and forces acting between them but still, it fails (i) to include the fourth fundamental force i.e. gravitational force (ii) to explain matter-antimatter in the universe (iii) to explain the 95% dark energy and dark matter forming the universe and so on. No significant excess above the Standard Model expectation is observed and 95% CL upper limits are set on the production cross section as a function of the LQ mass, under different assumptions for the branching fractions into tτ and bν as shown in figure 10. The observed data distributions are compatible with the expected Standard Model background and lower limits on the production cross-section are set at 1.48 TeV and 1.47 TeV for the electron and muon channels, respectively as shown in figure 11. The channel in which both the top quark and the τ lepton decay hadronically is investigated, including the case of a large LQ-t mass splitting giving rise to a boosted top quark whose decay products may not be separated on the scale of the spatial resolution of the jet Such a signature has not been previously examined in searches for physics beyond the standard model. The range of lower limits on the LQ mass, at 95% CL,is 0.98-1.73 TeV, depending on λ and the LQ spin as shown in figure 12

CMS Preliminary 2

Findings

Conclusion