Subhadeep Mondal

Scopus Publications

Measurement of top-quark pair production in association with charm quarks in proton–proton collisions at s=13 TeV with the ATLAS detector
G. Aad, E. Aakvaag, B. Abbott, S. Abdelhameed, K. Abeling, N.J. Abicht, S.H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz,et al.
Elsevier BV

Combination of searches for singly and doubly charged Higgs bosons produced via vector-boson fusion in proton–proton collisions at s=13 TeV with the ATLAS detector
G. Aad, E. Aakvaag, B. Abbott, S. Abdelhameed, K. Abeling, N.J. Abicht, S.H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz,et al.
Elsevier BV

Simultaneous Unbinned Differential Cross-Section Measurement of Twenty-Four (Formula presented) Kinematic Observables with the ATLAS Detector
G. Aad, E. Aakvaag, B. Abbott, S. Abdelhameed, K. Abeling, N. J. Abicht, S. H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz,et al.
American Physical Society (APS)
Z boson events at the Large Hadron Collider can be selected with high purity and are sensitive to a diverse range of QCD phenomena. As a result, these events are often used to probe the nature of the strong force, improve Monte Carlo event generators, and search for deviations from standard model predictions. All previous measurements of Z boson production characterize the event properties using a small number of observables and present the results as differential cross sections in predetermined bins. In this analysis, a machine learning method called is used to produce a simultaneous measurement of twenty-four Z+jets observables using 139 fb−1 of proton-proton collisions at s=13 TeV collected with the ATLAS detector. Unlike any previous fiducial differential cross-section measurement, this result is presented unbinned as a dataset of particle-level events, allowing for flexible reuse in a variety of contexts and for new observables to be constructed from the twenty-four measured observables. © 2024 CERN, for the ATLAS Collaboration 2024 CERN

Disentangling Sources of Momentum Fluctuations in (Formula presented) and (Formula presented) Collisions with the ATLAS Detector
G. Aad, E. Aakvaag, B. Abbott, S. Abdelhameed, K. Abeling, N. J. Abicht, S. H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz,et al.
American Physical Society (APS)
High-energy nuclear collisions create a quark-gluon plasma, whose initial condition and subsequent expansion vary from event to event, impacting the distribution of the eventwise average transverse momentum [P([pT])]. Disentangling the contributions from fluctuations in the nuclear overlap size (geometrical component) and other sources at a fixed size (intrinsic component) remains a challenge. This problem is addressed by measuring the mean, variance, and skewness of P([pT]) in Pb208+Pb208 and Xe129+Xe129 collisions at sNN=5.02 and 5.44 TeV, respectively, using the ATLAS detector at the LHC. All observables show distinct features in ultracentral collisions, which are explained by a suppression of the geometrical component as the overlap area reaches its maximum. These results demonstrate a new technique to separate geometrical and intrinsic fluctuations, providing constraints on initial conditions and properties of the quark-gluon plasma, such as the speed of sound. © 2024 CERN, for the ATLAS Collaboration 2024 CERN

Search for heavy right-handed Majorana neutrinos in the decay of top quarks produced in proton-proton collisions at (Formula Presented) with the ATLAS detector
G. Aad, E. Aakvaag, B. Abbott, S. Abdelhameed, K. Abeling, N. J. Abicht, S. H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz,et al.
American Physical Society (APS)
A search for heavy right-handed Majorana neutrinos is performed with the ATLAS detector at the CERN Large Hadron Collider, using the 140 fb−1 of proton–proton collision data at s=13 TeV collected during Run 2. This search targets tt¯ production, in which both top quarks decay into a bottom quark and a W boson, where one of the W bosons decays hadronically and the other decays into an electron or muon and a heavy neutral lepton. The heavy neutral lepton is identified through a decay into an electron or muon and another W boson, resulting in a pair of same-charge same-flavor leptons in the final state. This paper presents the first search for heavy neutral leptons in the mass range of 15–75 GeV using tt¯ events. No significant excess is observed over the background expectation, and upper limits are placed on the signal cross sections. Assuming a benchmark scenario of the phenomenological type-I seesaw model, these cross section limits are then translated into upper limits on the mixing parameters of the heavy Majorana neutrino with Standard Model neutrinos. © 2024 CERN, for the ATLAS Collaboration 2024 CERN

Measurements of Lund subjet multiplicities in 13 TeV proton-proton collisions with the ATLAS detector
G. Aad, E. Aakvaag, B. Abbott, K. Abeling, N.J. Abicht, S.H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz, H. Abreu,et al.
Elsevier BV

Software Performance of the ATLAS Track Reconstruction for LHC Run 3
, G. Aad, B. Abbott, K. Abeling, N. J. Abicht, S. H. Abidi, A. Aboulhorma, H. Abramowicz, H. Abreu, Y. Abulaiti,et al.
Springer Science and Business Media LLC
AbstractCharged particle reconstruction in the presence of many simultaneous proton–proton ($$p {} p $$ p p ) collisions in the LHC is a challenging task for the ATLAS experiment’s reconstruction software due to the combinatorial complexity. This paper describes the major changes made to adapt the software to reconstruct high-activity collisions with an average of 50 or more simultaneous $$p {} p $$ p p interactions per bunch crossing (pile-up) promptly using the available computing resources. The performance of the key components of the track reconstruction chain and its dependence on pile-up are evaluated, and the improvement achieved compared to the previous software version is quantified. For events with an average of $$60~p {} p $$ 60 p p collisions per bunch crossing, the updated track reconstruction is twice as fast as the previous version, without significant reduction in reconstruction efficiency and while reducing the rate of combinatorial fake tracks by more than a factor two.

Deep Generative Models for Fast Photon Shower Simulation in ATLAS
, G. Aad, B. Abbott, D. C. Abbott, A. Abed Abud, K. Abeling, D. K. Abhayasinghe, S. H. Abidi, A. Aboulhorma, H. Abramowicz,et al.
Springer Science and Business Media LLC
AbstractThe need for large-scale production of highly accurate simulated event samples for the extensive physics programme of the ATLAS experiment at the Large Hadron Collider motivates the development of new simulation techniques. Building on the recent success of deep learning algorithms, variational autoencoders and generative adversarial networks are investigated for modelling the response of the central region of the ATLAS electromagnetic calorimeter to photons of various energies. The properties of synthesised showers are compared with showers from a full detector simulation using geant4. Both variational autoencoders and generative adversarial networks are capable of quickly simulating electromagnetic showers with correct total energies and stochasticity, though the modelling of some shower shape distributions requires more refinement. This feasibility study demonstrates the potential of using such algorithms for ATLAS fast calorimeter simulation in the future and shows a possible way to complement current simulation techniques.

Jet radius dependence of dijet momentum balance and suppression in Formula Presented collisions at 5.02 TeV with the ATLAS detector
Atlas Collaboration

This paper describes a measurement of the jet radius dependence of the dijet momentum balance between leading back-to-back jets in 1.72 $nb^{-1}$ of Pb+Pb collisions collected in 2018 and 255 pb$^{-1}$ of $pp$ collisions collected in 2017 by the ATLAS detector at the LHC. Both data sets were collected at $ \\sqrt{s_{\\rm NN}}=$ 5.02 TeV. Jets are reconstructed using the anti-$k_t$ algorithm with jet radius parameters $R=$ 0.2, 0.3, 0.4, 0.5 and 0.6. The dijet momentum balance distributions are constructed for leading jets with transverse momentum $p_{\\rm T}$ from 100 to 562 GeV for $R=$ 0.2, 0.3 and 0.4 jets, and from 158 to 562 GeV for $R=$ 0.5 and 0.6 jets. The absolutely normalized dijet momentum balance distributions are constructed to compare measurements of the dijet yields in Pb+Pb collisions directly to the dijet cross sections in $pp$ collisions. For all jet radii considered here, there is a suppression of more balanced dijets in Pb+Pb collisions compared to $pp$ collisions, while for more imbalanced dijets there is an enhancement. There is a jet radius dependence to the dijet yields, being stronger for more imbalanced dijets than for more balanced dijets. Additionally, jet pair nuclear modification factors are measured. The subleading jet yields are found to be more suppressed than leading jet yields in dijets. A jet radius dependence of the pair nuclear modification factors is observed, with the suppression decreasing with increasing jet radius. These measurements provide new constraints on jet quenching scenarios in the quark-gluon plasma.

Search for Formula Presented-parity violating supersymmetric decays of the top squark to a Formula Presented-jet and a lepton in Formula Presented Formula Presented collisions with the ATLAS detector
G. Aad, E. Aakvaag, B. Abbott, S. Abdelhameed, K. Abeling, N. J. Abicht, S. H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz,et al.
American Physical Society (APS)
A search is presented for direct pair production of the stop, the supersymmetric partner of the top quark, in a decay through an R-parity violating coupling to a charged lepton and a b-quark. The dataset corresponds to an integrated luminosity of 140 fb−1 of proton-proton collisions at a center-of-mass energy of s=13 TeV collected between 2015 and 2018 by the ATLAS detector at the LHC. The final state has two charged leptons (electrons or muons) and two b-jets. The results of the search are interpreted in the context of a Minimal Supersymmetric Standard Model with an additional B−L gauge symmetry that is spontaneously broken. No significant excess is observed over the Standard Model background, and exclusion limits on stop pair production are set at 95% confidence level. The corresponding lower limits on the stop mass for 100% branching ratios to a b-quark and an electron, muon, or tau-lepton are 1.9 TeV, 1.8 TeV and 800 GeV, respectively, extending the reach of previous LHC searches. © 2024 CERN, for the ATLAS Collaboration 2024 CERN

Interpretations of the ATLAS measurements of Higgs boson production and decay rates and differential cross-sections in pp collisions at s = 13 TeV
, G. Aad, B. Abbott, K. Abeling, N. J. Abicht, S. H. Abidi, A. Aboulhorma, H. Abramowicz, H. Abreu, Y. Abulaiti,et al.
Springer Science and Business Media LLC
Abstract Measurements of the Higgs boson production times decay rates and differential cross-sections have recently been performed by the ATLAS experiment in several decay channels using up to 139 fb−1 of proton-proton collision data at $$ \\sqrt{s} $$ s = 13 TeV recorded at the Large Hadron Collider. This paper presents multiple interpretations of these Higgs boson measurements. Measurements of production-mode cross-sections, simplified template cross-sections and fiducial differential cross-sections in different decay channels are reparameterised in terms of the impact of Standard Model effective field theory operators, and constraints are reported on the corresponding Wilson coefficients. Production and decay rate measurements are interpreted in UV-complete extensions of the Standard Model, namely the two-Higgs-doublet model (2HDM) near the alignment limit and the Minimal Supersymmetric Standard Model (MSSM) for various MSSM benchmark scenarios. The constraints on the 2HDM parameters (cos(β − α), tanβ) and the MSSM parameters (mA, tanβ) are complementary to those obtained from direct searches for additional Higgs bosons.

Search for a resonance decaying into a scalar particle and a Higgs boson in the final state with two bottom quarks and two photons in proton–proton collisions at s = 13 TeV with the ATLAS detector
, G. Aad, E. Aakvaag, B. Abbott, K. Abeling, N. J. Abicht, S. H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz,et al.
Springer Science and Business Media LLC
Abstract A search for the resonant production of a heavy scalar X decaying into a Higgs boson and a new lighter scalar S, through the process X → S(→$$ b\\overline{b} $$ b b ¯ )H(→γγ), where the two photons are consistent with the Higgs boson decay, is performed. The search is conducted using an integrated luminosity of 140 fb−1 of proton-proton collision data at a centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the Large Hadron Collider. The search is performed over the mass range 170 ≤ mX ≤ 1000 GeV and 15 ≤ mS ≤ 500 GeV. Parameterised neural networks are used to enhance the signal purity and to achieve continuous sensitivity in a domain of the (mX, mS) plane. No significant excess above the expected background is found and 95% CL upper limits are set on the cross section times branching ratio, ranging from 39 fb to 0.09 fb. The largest deviation from the background-only expectation occurs for (mX, mS) = (575, 200) GeV with a local (global) significance of 3.5 (2.0) standard deviations.

Search for neutral long-lived particles that decay into displaced jets in the ATLAS calorimeter in association with leptons or jets using pp collisions at s = 13 TeV
, G. Aad, E. Aakvaag, B. Abbott, S. Abdelhameed, K. Abeling, N. J. Abicht, S. H. Abidi, M. Aboelela, A. Aboulhorma,et al.
Springer Science and Business Media LLC
Abstract A search for neutral long-lived particles (LLPs) decaying in the ATLAS hadronic calorimeter using 140 fb−1 of proton-proton collisions at $$ \\sqrt{s} $$ s = 13 TeV delivered by the LHC is presented. The analysis is composed of three channels. The first targets pair-produced LLPs, where at least one LLP is produced with sufficiently low boost that its decay products can be resolved as separate jets. The second and third channels target LLPs respectively produced in association with a W or Z boson that decays leptonically. In each channel, different search regions target different kinematic regimes, to cover a broad range of LLP mass hypotheses and models. No excesses of events relative to the background predictions are observed. Higgs boson branching fractions to pairs of hadronically decaying neutral LLPs larger than 1% are excluded at 95% confidence level for proper decay lengths in the range of 30 cm to 4.5 m depending on the LLP mass, a factor of three improvement on previous searches in the hadronic calorimeter. The production of long-lived dark photons in association with a Z boson with cross-sections above 0.1 pb is excluded for dark photon mean proper decay lengths in the range of 20 cm to 50 m, improving previous ATLAS results by an order of magnitude. Finally, long-lived photo-phobic axion-like particle models are probed for the first time by ATLAS, with production cross-sections above 0.1 pb excluded in the 0.1 mm to 10 m range.

Search for pair production of boosted Higgs bosons via vector-boson fusion in the bb¯bb¯ final state using pp collisions at s=13TeV with the ATLAS detector
G. Aad, E. Aakvaag, B. Abbott, S. Abdelhameed, K. Abeling, N.J. Abicht, S.H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz,et al.
Elsevier BV

Search for Light Long-Lived Particles in pp Collisions at sqrt[s]=13 TeV Using Displaced Vertices in the ATLAS Inner Detector
G. Aad, E. Aakvaag, B. Abbott, S. Abdelhameed, K. Abeling, N. J. Abicht, S. H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz,et al.
American Physical Society (APS)
A search for long-lived particles (LLPs) using 140 fb−1 of pp collision data with s=13 TeV recorded by the ATLAS experiment at the LHC is presented. The search targets LLPs with masses between 5 and 55 GeV that decay hadronically in the ATLAS inner detector. Benchmark models with LLP pair production from exotic decays of the Higgs boson and models featuring long-lived axionlike particles (ALPs) are considered. No significant excess above the expected background is observed. Upper limits are placed on the branching ratio of the Higgs boson to pairs of LLPs, the cross section for ALPs produced in association with a vector boson, and, for the first time, on the branching ratio of the top quark to an ALP and a u/c quark. © 2024 CERN, for the ATLAS Collaboration 2024 CERN

Search for the Exclusive W Boson Hadronic Decays W^{±}→π^{±}γ, W^{±}→K^{±}γ and W^{±}→ρ^{±}γ with the ATLAS Detector
G. Aad, B. Abbott, K. Abeling, N. J. Abicht, S. H. Abidi, A. Aboulhorma, H. Abramowicz, H. Abreu, Y. Abulaiti, B. S. Acharya,et al.
American Physical Society (APS)
A search for the exclusive hadronic decays W±→π±γ, W±→K±γ, and W±→ρ±γ is performed using up to 140 fb−1 of proton-proton collisions recorded with the ATLAS detector at a center-of-mass energy of s=13 TeV. If observed, these rare processes would provide a unique test bench for the quantum chromodynamics factorization formalism used to calculate cross sections at colliders. Additionally, at future colliders, these decays could offer a new way to measure the W boson mass through fully reconstructed decay products. The search results in the most stringent upper limits to date on the branching fractions B(W±→π±γ)<1.9×10−6, B(W±→K±γ)<1.7×10−6, B(W±→ρ±γ)<5.2×10−6 at 95% confidence level. © 2024 CERN, for the ATLAS Collaboration 2024 CERN

Combination and summary of ATLAS dark matter searches interpreted in a 2HDM with a pseudo-scalar mediator using 139 fb<sup>−1</sup> of s=13 TeV pp collision data
G. Aad, B. Abbott, K. Abeling, N.J. Abicht, S.H. Abidi, A. Aboulhorma, H. Abramowicz, H. Abreu, Y. Abulaiti, A.C. Abusleme Hoffman,et al.
Elsevier BV

Determination of the Relative Sign of the Higgs Boson Couplings to W and Z Bosons Using WH Production via Vector-Boson Fusion with the ATLAS Detector
G. Aad, B. Abbott, K. Abeling, N. J. Abicht, S. H. Abidi, A. Aboulhorma, H. Abramowicz, H. Abreu, Y. Abulaiti, B. S. Acharya,et al.
American Physical Society (APS)
The associated production of Higgs and W bosons via vector-boson fusion is highly sensitive to the relative sign of the Higgs boson couplings to W and Z bosons. In this Letter, two searches for this process are presented, using 140 fb−1 of proton-proton collision data at s=13 TeV recorded by the ATLAS detector at the LHC. The first search targets scenarios with opposite-sign couplings of the W and Z bosons to the Higgs boson, while the second targets standard model-like scenarios with same-sign couplings. Both analyses consider Higgs boson decays into a pair of b quarks and W boson decays with an electron or muon. The data exclude the opposite-sign coupling hypothesis with a significance beyond 5σ, and the observed (expected) upper limit set on the cross section for vector-boson fusion WH production is 9.0 (8.7) times the standard model value at 95% confidence level. © 2024 CERN, for the ATLAS Collaboration 2024 CERN

Measurement of single top-quark production in association with a Formula Presented boson in Formula Presented collisions at Formula Presented with the ATLAS detector
G. Aad, E. Aakvaag, B. Abbott, S. Abdelhameed, K. Abeling, N. J. Abicht, S. H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz,et al.
American Physical Society (APS)
The inclusive cross section for the production of a single top quark in association with a W boson is measured using 140 fb−1 of proton-proton collision data collected with the ATLAS detector at s=13 TeV. Events containing two charged leptons and at least one jet identified as originating from a b-quark are selected. A multivariate discriminant is constructed to separate the tW signal from the tt¯ background. The cross section is extracted using a profile likelihood fit to the signal and control regions and it is measured to be σtW=75−14+15 pb, in good agreement with the Standard Model prediction. The measured cross section is used to extract a value for the left-handed form factor at the Wtb vertex times the Cabibbo-Kobayashi-Maskawa matrix element |fLVVtb| of 0.97±0.10. © 2024 CERN, for the ATLAS Collaboration 2024 CERN

Measurements of jet cross-section ratios in 13 TeV proton-proton collisions with ATLAS
G. Aad, E. Aakvaag, B. Abbott, K. Abeling, N. J. Abicht, S. H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz, H. Abreu,et al.
American Physical Society (APS)
Measurements of jet cross-section ratios between inclusive bins of jet multiplicity are performed in 140 fb−1 of proton-proton collisions with s=13 TeV center-of-mass energy, recorded with the ATLAS detector at CERN’s Large Hadron Collider. These ratios are constructed from double-differential cross-section measurements that are made in bins of jet multiplicity and other observables that are sensitive the energy scale and angular distribution of radiation due to the strong interaction in the final state. Additionally, the scalar sum of the two leading jets’ transverse momenta is measured triple differentially, in bins of the third jet’s transverse momentum and of jet multiplicity. These measurements are unfolded to account for acceptance and detector-related effects. The measured distributions are used to construct ratios of the inclusive jet-multiplicity bins, which have been shown to be sensitive to the strong coupling αS while being less sensitive than other observables to systematic uncertainties and parton distribution functions. The measured distributions are compared with state-of-the-art QCD calculations, including next-to-next-to-leading-order predictions for two- and three-jet events. These predictions are generally found to model the data well and perform best in bins with a modest requirement on the third jet’s transverse momentum. Significant differences between data and Monte Carlo predictions are observed in events with large rapidity gaps and invariant masses of the leading jet pair. Studies leading to reduced jet energy scale uncertainties significantly improve the precision of this work and are documented herein. © 2024 CERN, for the ATLAS Collaboration 2024 CERN

Precise measurements of W- and Z-boson transverse momentum spectra with the ATLAS detector using pp collisions at s=5.02 TeV and 13 TeV
, G. Aad, B. Abbott, K. Abeling, N. J. Abicht, S. H. Abidi, A. Aboulhorma, H. Abramowicz, H. Abreu, Y. Abulaiti,et al.
Springer Science and Business Media LLC
AbstractThis paper describes measurements of the transverse momentum spectra of W and Z bosons produced in proton–proton collisions at centre-of-mass energies of $$\\sqrt{s}=5.02$$ s = 5.02 TeV and $$\\sqrt{s}=13$$ s = 13 TeV with the ATLAS experiment at the Large Hadron Collider. Measurements are performed in the electron and muon channels, $$W\\rightarrow \\ell \\nu $$ W → ℓ ν and $$Z\\rightarrow \\ell \\ell $$ Z → ℓ ℓ ($$\\ell =e$$ ℓ = e or $$\\mu $$ μ ), and for W events further separated by charge. The data were collected in 2017 and 2018, in dedicated runs with reduced instantaneous luminosity, and correspond to 255 and 338 $$\\hbox {pb}^{-1}$$ pb - 1 at $$\\sqrt{s}=5.02$$ s = 5.02 TeV and 13 TeV, respectively. These conditions optimise the reconstruction of the W-boson transverse momentum. The distributions observed in the electron and muon channels are unfolded, combined, and compared to QCD calculations based on parton shower Monte Carlo event generators and analytical resummation. The description of the transverse momentum distributions by Monte Carlo event generators is imperfect and shows significant differences largely common to $$W^-$$ W - , $$W^+$$ W + and Z production. The agreement is better at $$\\sqrt{s}=5.02$$ s = 5.02 TeV, especially for predictions that were tuned to Z production data at $$\\sqrt{s}=7$$ s = 7 TeV. Higher-order, resummed predictions based on DYTurbo generally match the data best across the spectra. Distribution ratios are also presented and test the understanding of differences between the production processes.

Measurements of inclusive and differential cross-sections of tt¯γ production in pp collisions at s = 13 TeV with the ATLAS detector
, G. Aad, E. Aakvaag, B. Abbott, K. Abeling, N. J. Abicht, S. H. Abidi, M. Aboelela, A. Aboulhorma, H. Abramowicz,et al.
Springer Science and Business Media LLC
Abstract Inclusive and differential cross-sections are measured at particle level for the associated production of a top quark pair and a photon ($$ t\\overline{t}\\gamma $$ t t ¯ γ ). The analysis is performed using an integrated luminosity of 140 fb−1 of proton-proton collisions at a centre-of-mass energy of 13 TeV collected by the ATLAS detector. The measurements are performed in the single-lepton and dilepton top quark pair decay channels focusing on $$ t\\overline{t}\\gamma $$ t t ¯ γ topologies where the photon is radiated from an initial-state parton or one of the top quarks. The absolute and normalised differential cross-sections are measured for several variables characterising the photon, lepton and jet kinematics as well as the angular separation between those objects. The observables are found to be in good agreement with the Monte Carlo predictions. The photon transverse momentum differential distribution is used to set limits on effective field theory parameters related to the electroweak dipole moments of the top quark. The combined limits using the photon and the Z boson transverse momentum measured in $$ t\\overline{t} $$ t t ¯ production in associations with a Z boson are also set.

Constraints on simplified dark matter models involving an s-channel mediator with the ATLAS detector in pp collisions at s=13 TeV
, G. Aad, E. Aakvaag, B. Abbott, S. Abdelhameed, K. Abeling, N. J. Abicht, S. H. Abidi, M. Aboelela, A. Aboulhorma,et al.
Springer Science and Business Media LLC
AbstractThis paper reports a summary of searches for a fermionic dark matter candidate in the context of theoretical models characterised by a mediator particle exchange in the s-channel. The data sample considered consists of pp collisions delivered by the Large Hadron Collider during its Run 2 at a centre-of-mass energy of $$\\sqrt{s} = 13\\,\\textrm{TeV}$$ s = 13 TeV and recorded by the ATLAS detector, corresponding to up to 140 fb$$^{-1}$$ - 1 . The interpretations of the results are based on simplified models where the new mediator particles can be spin-0, with scalar or pseudo-scalar couplings to fermions, or spin-1, with vector or axial-vector couplings to fermions. Exclusion limits are obtained from various searches characterised by final states with resonant production of Standard Model particles, or production of Standard Model particles in association with large missing transverse momentum.

Subhadeep Mondal

RESEARCH INTERESTS

Scopus Publications