Prospects for a fourth generation of leptons in a 13 TeV p-p collider

TL;DR

This paper explores the potential for discovering a hypothetical fourth generation of leptons at a 13 TeV proton-proton collider, using simulations to analyze their production, decay, and detection prospects.

Contribution

It provides the first detailed simulation-based analysis of fourth-generation leptons at the LHC, including mass constraints, kinematic studies, and discovery potential assessments.

Findings

Observed a global excess of 1.46 sigma in the signal window.

Achieved a local excess of 3.33 sigma in the 180-300 GeV mass range.

Identified that higher luminosity and energy improve detection prospects.

Abstract

In the Standard Model, three discovered generations of leptons and quarks are known to date. However, speculations about existence of next generations have a strong foothold. In this study, we sequentially extrapolate the Standard Model to include a fourth generation of leptons (l4, nu4) with a massive Dirac neutrino. We perform MC simulated event generation of pp -> l4 l4(bar) scattering processes at an LHC-like p-p collider with sqrt(s) = 13 TeV by considering l4 mass of 190 GeV and nu4 mass of 100 GeV with PYTHIA. We demonstrate mass constraints of sequential leptons from oblique parameters and study important jet and lepton kinematics in our simulation with CMS like constraints. Fourth generation neutrino is stable in this scenario making l4 -> W nu4 the only dominant channel in collider searches. With the cut-flow, we achieve global excess of (1.46 +/- 0.068(stat.)) sigma and local excess of (3.33 +/- 0.241(stat.)) sigma in the 180-300 GeV signal window. Missing Transverse Energy (MET) provides clean signature of nu4. We assess discovery potential of the BSM lepton against lepton mass, center-of-mass energy (Ecom) and luminosities. Higher luminosities and Ecom are promising to probe BSM moderate mass lepton scenarios at present and future colliders.