arXiv subjects

Sourabh Dube

Publications and source records attributed to Sourabh Dube.

4 recordsLinked to original sources

arXiv2026

Applying Self-organizing Maps to the Inverse Problem

In the inverse problem in particle physics, given an unexpected observation, one aims to identify a unique choice from amongst several competing hypotheses. We explore a novel approach of applying self-organizing maps to the inverse problem in a search for vector-like leptons in a trilepton final state. We define an approach combining the inherent clustering of these maps and elements of supervised learning. We compare the performance of this approach with a multiclassfying neural network. We find that the method using self-organizing maps competes well (despite not using any standard model processes in the training), and provides additional tools that would help characterize any observed excesses in searches.

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arXiv2025

Fatjet Signatures of Quintuplet Fermions at the LHC

This paper explores a simplified extension of the standard model featuring a neutral fermion quintuplet and a scalar quadruplet, which together generate neutrino masses through tree and loop level mechanisms. The quintuplet fermions decay into standard model gauge bosons via the scalars, producing unique collider signatures at the LHC characterized by multilepton and multijet final states. The study focuses on the pair production of quintuplet fermions in the 700-1200 GeV mass range, where their decays produce highly boosted W and Z bosons identifiable as fatjets. Emphasis is placed on the production and decay of doubly charged fermions due to their higher cross section. Advanced jet substructure and kinematic techniques are applied to enhance sensitivity by reducing standard model backgrounds. A detailed analysis of signal significance is performed in the two lepton, two fatjet and three lepton, one fatjet channels for different masses of the fermion and the scalars, optimizing selection cuts to maximize signal efficiency over standard model backgrounds. The study found that both channels exhibit excellent performance, with significance exceeding $5σ$ under realistic conditions including a 50\% background uncertainty at integrated luminosity up to 3000 fb$^{-1}$.

hep-ph↗

arXiv2017

Lepton-Jets and Low-Mass Sterile Neutrinos at Hadron Colliders

Sterile neutrinos, if they exist, are potential harbingers for physics beyond the Standard Model. They have the capacity to shed light on our flavor sector, grand unification frameworks, dark matter sector and origins of baryon anti-baryon asymmetry. There have been a few seminal studies that have broached the subject of sterile neutrinos with low, electroweak-scale masses (i.e. $Λ_{\text{\tiny{QCD}}} \ll m_{N_R} \ll m_{W^\pm}$) and investigated their reach at hadron colliders using lepton jets. These preliminary studies nevertheless assume background-free scenarios after certain selection criteria which are overly optimistic and untenable in realistic situations. These lead to incorrect projections. The unique signal topology and challenging hadronic environment also make this mass-scale regime ripe for a careful investigation. With the above motivations, we attempt to perform the first systematic study of low, electroweak-scale, right-handed neutrinos at hadron colliders, in this unique signal topology. There are currently no active searches at hadron colliders for sterile neutrino states in this mass range, and we frame the study in the context of the $13\,\rm{TeV}$ high-luminosity Large Hadron Collider and the proposed FCC-hh/SppC $100\,\rm{TeV}$ $pp$-collider.

hep-ph↗

arXiv2012

Addressing the Multi-Channel Inverse Problem at High Energy Colliders: A Model Independent Approach to the Search for New Physics with Trileptons

We describe a method for interpreting trilepton searches at high energy colliders in a model-independent fashion and apply it to the recent searches at the Tevatron. The key step is to recognize that the trilepton signature is comprised of four experimentally very different channels defined by the number of tau-leptons in the trilepton state. Contributions from these multiple channels to the overall experimental sensitivity (cross section times branching ratio) are model-independent and can be parametrized in terms of relevant new particle masses. Given the trileptonic branching ratios of a specific model, these experimentally obtained multichannel sensitivities can be combined to obtain a cross section measurement that can be used to confront the model with data. Our model-independent results are more widely applicable than the current Tevatron trilepton results which are stated exclusively in terms of mSUGRA parameters of supersymmetry. The technique presented here can be expanded beyond trilepton searches to the more general "inverse problem" of experimentally discriminating between competing models that seek to explain new physics discovered in multiple channels.

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