arXiv subjects

Soumyadip Kundu

Publications and source records attributed to Soumyadip Kundu.

3 recordsLinked to original sources

arXiv2026

Multi-Higgs production from a theory of varying Higgs quartic and top Yukawa couplings

We study the collider phenomenology of a theory in which the Higgs quartic self-coupling and the top Yukawa coupling are \textit{varying couplings}, which arise dynamically from two scalar fields, $ϕ_1$ and $ϕ_2$. Depending on the scalar masses relative to twice the top-quark mass, the heavy scalars decay mainly to Higgs boson pairs ($hh$) or to top-quark pairs ($t\bar t$), giving two distinct signatures. We find sizeable cross sections for resonant $hh$ production, and also for the background-suppressed process with three Higgs bosons ($hhh$) from associated production, $pp \to hϕ_i \to hhh$. By recasting ATLAS resonance searches, we set bounds on the effective new-physics scales $Λ_1$ and $Λ_2$ at the TeV scale. We also show that the High-Luminosity LHC (HL-LHC) will probe this parameter space further, through combined measurements of the $hh$, $t\bar t$ and multi-Higgs channels. This gives a strong, multi-channel test of whether the electroweak sector has a dynamical origin.

hep-ph↗

arXiv2026

Testing varying coupling constants through multi-Higgs production at the LHC

We propose the One Scalar Theory (1ST), a minimalist framework where a single real singlet scalar field mediates the dynamical generation of the Higgs self-coupling and the top Yukawa coupling. Unlike generic portal models, the 1ST removes parametric freedom by locking production and decay modes to a single fundamental scale $Λ_0$, rendering the framework highly predictive with unique experimental signals. We demonstrate that the collider phenomenology is partitioned by the $2m_t$ kinematic threshold into di-Higgs and di-top resonance regimes. By recasting current ATLAS data, we set lower bounds on $Λ_0$ at the TeV scale and show that the High-Luminosity LHC will probe this scale up to $4$ TeV, providing a definitive test for the dynamical origin of the electroweak sector.

hep-ph↗

arXiv2025

Vector leptoquark contributions to lepton dipole moments

Leptoquarks (LQs) can contribute to the magnetic and electric dipole moments of charged leptons, which the current experiments have measured with good accuracy. We revisit the parameter spaces of TeV-scale vector LQs that contribute to these observables and study how these models fare against the LHC bounds. We show that significant portions of the parameter space are excluded when the current LHC data is utilised effectively. We find that only $U_1$ and $V_2$ can explain the observed positive shift in $(a_μ^{\rm exp} - a_μ^{\rm SM})$ through a lepton chirality-flipping contribution with $\mathcal O(1)$ LQ-quark-lepton coupling. We also see how these two LQs can fit the electron dipole moment and atomic parity violation measurements. We find that the current electric dipole moment measurements of the muon cannot restrain the LQ-quark-lepton couplings within perturbative regions.

hep-ph↗