arXiv subjects

Pramod Sharma

Publications and source records attributed to Pramod Sharma.

15 recordsLinked to original sources

arXiv2026

Radiative Signature of New Scalar Boson Decays in the $m_{\ell \ell \gamma}$ Spectrum at the LHC

We investigate the radiative decay $S \to W^+W^-\gamma$ in the context of the multi-lepton anomalies and recent indications of a narrow scalar resonance near $m_S = 152 \pm 1~\text{GeV}$ in the $\gamma\gamma$, $Z\gamma$, and $W^+W^-$ channels at the Large Hadron Collider. These excesses arise in final states containing leptons, missing transverse momentum, and associated $b$-jets, and motivate a search for a corresponding localized excess in the invariant-mass spectrum of the dilepton--photon system, $m_{\ell\ell\gamma}$, in events with associated $b$-jets. We use recent CMS measurements of the ${t\bar{t}}\gamma$ differential cross sections~\cite{CMS:2025zbe} to study the $m_{\ell\ell\gamma}$ spectrum and perform a search for a scalar-resonance contribution. A localized excess is observed, compatible with the scalar-resonance hypothesis, with a global significance of $2.7\sigma$ at $m_S = 152~\text{GeV}$. This result provides additional support for the hypothesis of a narrow resonance. The ratio $\sigma(S \to W^+W^-\gamma)/\sigma(S \to W^+W^-) = (2.14 \pm 0.77)$\% is extracted. This value is compatible with an enhanced radiative contribution that could arise in scenarios beyond the Standard Model.

hep-ph↗

arXiv2025

Exploring the Discovery Reach for a 95 GeV Scalar in Future $e^+e^-$ Collisions

The observed indications for a new scalar resonance with a mass around 95\,GeV, initially reported by LEP and supported by CMS and ATLAS in di-photon, $\tau \tau$, and $W^+ W^-$ channels, motivate exploring its discovery potential at future electron-positron colliders. This study focuses on the production of the new scalar ($S$) via $e^+ e^- \rightarrow ZS $ with $Z \rightarrow \mu^+ \mu^- $ and $S \rightarrow b \bar{b}$ and optimizes the signal recognition using the recoil-mass method. By employing deep neural networks for signal-background discrimination, we demonstrate that a 95\,GeV scalar, mixing with the Standard Model Higgs by an angle of $\sim$0.1, can be observed with a 5$\sigma$ significance at $\sqrt{s}$ = 250\,GeV or 200\,GeV with 5~ab$^{-1}$ of integrated luminosity.

hep-ph↗

arXiv2025

Analyzing $t\bar{t}Z$-couplings at the future $e^-p$ collider

The proposed Large Hadron Electron Collider (LHeC), with center-of-mass energy of $\sqrt{s}\approx 1.3$ TeV, provides a clean and sensitive environment to probe the top quark's neutral current interactions with the $Z$ boson via the process $e^- p \to e^- t \bar{t}$. We investigate the precision with which the Standard Model (SM) $t\bar{t}Z$ couplings-the vector and axial-vector components ($\Delta C_{1V}$, $\Delta C_{1A}$)-can be measured, along with possible new physics effects parameterized by higher-dimensional operators inducing weak electric and magnetic dipole-like interactions ($C_{2V}$, $C_{2A}$). Focusing on the semileptonic decay channel, where either the top quark or anti-top decays leptonically to a positively charged lepton ($\ell^+ = e^+, \mu^+$), we utilize the azimuthal angle difference $\Delta \phi$ between the scattered electron and the charged lepton as the key observable. Using a one-parameter multi-bin $\chi^2$-analysis of this differential distribution, we find that constraints on $\Delta C_{1V}$ and $\Delta C_{1A}$ improve from order $10^{-1}$ at 50 fb$^{-1}$ to order $10^{-2}$ at 1000 fb$^{-1}$, corresponding to approximately 50% and 6% precision relative to their SM values. The anomalous tensor couplings $C_{2V}$ and $C_{2A}$ are constrained at the $10^{-1}$ level even at low luminosity and improve moderately with high luminosity. While the two-parameter analysis broadens the allowed regions due to parameter correlations, it retains competitive sensitivity, particularly for SM-like couplings. A systematic uncertainty of 5% is assumed throughout. These results highlight the LHeC's potential to provide complementary and competitive sensitivity to top-$Z$ couplings compared to current and future hadron and lepton collider capabilities.

hep-ph↗

arXiv2025

NLO QCD effects on angular observables in $e^-p \to e^-(\nu_e)Hj$ in presence of non-standard $HVV$ couplings

The single Higgs production in neutral-current (NC) and charged-current (CC) processes at an electron-proton ($ep$) collider is a useful channel to probe new physics effects in the Higgs coupling to vector boson ($HVV$). In this context, observables sensitive to non-standard couplings previously studied at leading order require improved theoretical precision through the inclusion of radiative corrections. In this work, we present a fully differential Higgs plus one jet production at next-to-leading-order (NLO) accuracy in QCD for both the NC and CC processes. For the proposed Large Hadron electron Collider (LHeC) configuration, with a 60~GeV electron beam and a 7~TeV proton beam, the total cross sections receive modest corrections with significantly reduced scale uncertainties. We find that in several kinematic distributions which are relevant to the analysis of $HVV$ couplings, the NLO K-factors are not flat. Within the Standard Model, the polar angle of the electron (for NC) and the azimuthal angular correlation (for both NC and CC processes) receive maximum corrections in the range of 8-10\% in certain bins. We also compute NLO QCD corrections in the presence of non-standard $HVV$ interactions. The corrections in the azimuthal angular correlations are similar to the standard model predictions. For the polar angle of the electron, the corrections are sensitive to the nature of the $HVV$ coupling.

hep-ph↗

arXiv2025

Role of angular observables in probing non-standard $HZZ$ couplings at an electron-proton collider

In this study, we explore various lab-frame angular observables at Large Hadron-electron Collider (LHeC) to test their sensitivity on the most general structure of the Higgs ($H$) to neutral weak boson ($Z$) coupling ($HZZ$) via the process $e^- p \rightarrow e^- H j$ at the center of mass energy $\sqrt{s}~\approx$ 1.3 TeV. The most general Lorentz structure of the $HZZ$ coupling beyond the standard model is composed of two CP-even ($\lambda_{1Z}$ and $\lambda_{2Z}$) and one CP-odd (${\tilde \lambda_Z}$) components. In a previous study, we looked at the absolute value of azimuthal correlation ($|\Delta \phi|$) between the final state electron and the jet to derive constraints on the non-standard $HZZ$ couplings. This choice of observable is motivated by its potential to discriminate between CP-odd and CP-even couplings in the $e^- p \rightarrow \nu_e H j$ process. Since the process $e^- p \rightarrow e^- H j$ has an electron in the final state, one can construct more angular observables. In addition to $|\Delta \phi|$, we identify new angular observables: the sign-sensitive azimuthal correlation ($\Delta \phi$) and the polar angle of the final state electron ($\theta$), suitable for constraining non-standard $HZZ$ coupling. Our analysis shows that these new angles improve the constraints on $\lambda_{2Z}$ and ${\tilde \lambda}_Z$ in the range of 48-67\%. We also study the potential of the asymmetry in $\Delta \phi$ to constrain the parameters corresponding to the CP-odd coupling.

hep-ph↗

arXiv2025

Comprehensive Constraints on ALP Couplings from future $e^+e^-$ Colliders, Muon $g-2$, Thermal Dark Matter and Higgs Measurements

In this article, we present projected 95\% C.L. limits on Axion-Like Particle (ALP) couplings from ALP production at a future $e^+e^-$ collider operating at $\sqrt{s} = 250~\text{GeV}$ with integrated luminosity $L = 0.5~\text{ab}^{-1}$. We constrain the effective couplings $g_{\gamma\gamma}$, $g_{Z\gamma}$, $g_{ZZ}$, and $g_{WW}$ over the ALP mass range $20~\text{GeV} \leq m_a \leq 100~\text{GeV}$, finding projected bounds at the level of $\mathcal{O}(10^{-1})~\text{TeV}^{-1}$ for $g_{\gamma\gamma}/f_a$. Given that the latest muon anomalous magnetic moment measurement ($\Delta a_\mu$) shows no statistically significant deviation from the Standard Model prediction, we reinterpret the ALP contributions to $\Delta a_\mu$ as a stringent consistency requirement. We then derive the corresponding allowed regions for $g_{\gamma\gamma}$ and the ALP--muon coupling $C_{\mu\mu}$, and apply them to a fermionic dark matter scenario in which the relic density depends on both the dark matter mass $m_\chi$ and $m_a$. The same parameter space is further constrained by Higgs signal strength measurements through $h \to \gamma\gamma$ and $h \to Z\gamma$. A comparative analysis with existing experimental and theoretical bounds highlights the complementarity of $\Delta a_\mu$, dark matter, and Higgs observables in restricting ALP couplings, demonstrating that even in the absence of a $\Delta a_\mu$ anomaly, these constraints provide essential guidance for viable ALP parameter space.

hep-ph↗

arXiv2024

Diffusion-Augmented Coreset Expansion for Scalable Dataset Distillation

With the rapid scaling of neural networks, data storage and communication demands have intensified. Dataset distillation has emerged as a promising solution, condensing information from extensive datasets into a compact set of synthetic samples by solving a bilevel optimization problem. However, current methods face challenges in computational efficiency, particularly with high-resolution data and complex architectures. Recently, knowledge-distillation-based dataset condensation approaches have made this process more computationally feasible. Yet, with the recent developments of generative foundation models, there is now an opportunity to achieve even greater compression, enhance the quality of distilled data, and introduce valuable diversity into the data representation. In this work, we propose a two-stage solution. First, we compress the dataset by selecting only the most informative patches to form a coreset. Next, we leverage a generative foundation model to dynamically expand this compressed set in real-time, enhancing the resolution of these patches and introducing controlled variability to the coreset. Our extensive experiments demonstrate the robustness and efficiency of our approach across a range of dataset distillation benchmarks. We demonstrate a significant improvement of over 10% compared to the state-of-the-art on several large-scale dataset distillation benchmarks. The code will be released soon.

cs.CV↗

arXiv2024

NLO QCD effects on angular observables in single Higgs production at electron-proton collider

Properties of the Higgs boson ($H$) at current and future particle colliders are crucial to explore new physics beyond the standard model. In particular, experimental and theoretical outlooks at future colliders drive interest in Higgs to gauge boson couplings. Single Higgs production via vector-boson fusion allows probing Higgs couplings with massive vector bosons ($V = W, Z$). We consider electron-proton (eP) collider to study these couplings due to the low background. In a recent study, we considered the most general anomalous Higgs-vector boson ($HVV$) couplings and explored the potential of eP collider in constraining the parameters of $HVV$ couplings. Our results were based on leading order predictions in perturbation theory. We include further Next to Leading Order (NLO) corrections of Quantum Chromodynamic (QCD) in Standard Model signal to make precise predictions. In this talk, I will present the effect of NLO QCD corrections on the standard model and anomalous $HVV$ couplings.

hep-ph↗

arXiv2024

Next-Token Prediction Task Assumes Optimal Data Ordering for LLM Training in Proof Generation

In the field of large language model (LLM)-based proof generation, despite extensive training on large datasets such as ArXiv, LLMs still exhibit only modest performance on proving tasks of moderate difficulty. We believe that this is partly due to the widespread presence of suboptimal ordering within the data for each proof used in training. For example, published proofs often follow a purely logical order, where each step logically proceeds from the previous steps based on the deductive rules. This order is designed to facilitate the verification of the proof's soundness, rather than to help people and models learn the discovery process of the proof. In proof generation, we argue that the optimal order for one training data sample occurs when the relevant intermediate supervision for a particular proof step in the proof is always positioned to the left of that proof step. We call such order the intuitively sequential order. We validate our claims using two tasks: intuitionistic propositional logic theorem-proving and digit multiplication. Our experiments verify the order effect and provide support for our explanations. We demonstrate that training is most effective when the proof is in the intuitively sequential order. Moreover, the order effect and the performance gap between models trained on different data orders can be substantial -- with an 11 percent improvement in proof success rate observed in the propositional logic theorem-proving task, between models trained on the optimal order compared to the worst order. Lastly, we define a common type of order issue in advanced math proofs and find that 17.3 percent of theorems with nontrivial proofs in the first two chapters of a widely used graduate-level mathematics textbook suffer from this issue. A detailed list of those proofs is provided in the appendix.

cs.CL↗

arXiv2024

Discovery Potential of Future Electron-Positron Colliders for a 95 GeV Scalar

The Large Electron Positron collider observed an indication for a new Higgs boson with a mass around $95$\,GeV-$100$\,GeV in the process $e^+e^-\to Z^*\to ZS$ with $S\to b\bar b$. The interest in this excess re-emerged with the di-photon signature at $\approx$\,95\,GeV at the Large Hadron Collider. In fact, a combined global significance of $3.4\sigma$ is obtained once $WW$ and $\tau\tau$ signals are included in addition. In this article, we perform a feasibility study for discovering such a new scalar $S$ at future electron-positron colliders using the recoil-mass method applied to $e^{+} e^{-} \to ZS$ with $Z \rightarrow \mu^{+} \mu^{-}$ and $S \to b \bar{b}$. For this, we employ a Deep Neural Network to enhance the separation between the Standard Model background and the signal, reducing the required integrated luminosity necessary for discovery by a factor of two to three. As a result, an $SU(2)_L$ singlet Higgs with a mass of $\approx$\,95\,GeV can be observed with more than 5$\sigma$ significance at a 250\,GeV centre-of-mass energy collider with $5~ {\rm ab}^{-1}$ integrated luminosity if it has a mixing angle of at least $0.1$ with the Standard Model Higgs, which means that a discovery can be achieved within the whole 95\% confidence-level region preferred by Large Electron Positron excess. Furthermore, including more decay channels such as $S\to \tau\tau$ and $Z\to e^+e^-$ further enhances the discovery potential of future $e^+e^-$ accelerators, like CEPC, CLIC, FCC-ee and ILC.

hep-ph↗

arXiv2023

Axion-Like Particles at future $e^- p$ collider

In this work, we explore the possibilities of producing Axion-Like Particles (ALPs) in a future $e^-p$ collider. Specifically, we focus on the proposed Large Hadron electron collider (LHeC), which can achieve a center-of-mass energy of $\sqrt{s} \approx 1.3$~TeV, enabling us to probe relatively high ALP masses with $m_a \lesssim 300$~GeV. The production of ALPs can occur through various channels, including $W^+W^-$, $\gamma\gamma$, $ZZ$, and $Z\gamma$-fusion within the collider environment. To investigate this, we conduct a comprehensive analysis that involves estimating the production cross section and constraining the limits on the associated couplings of ALPs, namely $g_{WW}$, $g_{\gamma\gamma}$, $g_{ZZ}$, and $g_{Z\gamma}$. To achieve this, we utilize a multiple-bin $\chi^2$ analysis on sensitive differential distributions. Through the analysis of these distributions, we determine upper bounds on the associated couplings within the mass range of 5~GeV $\leq m_a \leq$ 300~GeV. The obtained upper bounds are of the order of ${\cal O}(10^{-1})$ for $g_{\gamma\gamma}$ ($g_{WW}$, $g_{ZZ}$, $g_{Z\gamma}$) in $m_a \in$~[5, 200 (300)]~GeV considering an integrated luminosity of 1~ab$^{-1}$. Furthermore, we compare the results of our study with those obtained from other available experiments. We emphasize the limits obtained through our analysis and showcase the potential of the LHeC in probing the properties of ALPs.

hep-ph↗

arXiv2022

Probing non-standard $HVV (V=W, Z)$ couplings in single Higgs production at future electron-proton collider

The couplings of the Higgs boson ($H$) with massive gauge bosons of weak interaction ($V= W, Z$), can be probed in single Higgs boson production at the proposed future Large Hadron-Electron Collider (LHeC). In the collision of an electron with a proton, single Higgs production takes place via so-called charged-current ($e^-p \to \nu_e H j$) and neutral-current ($e^-p \to e^-H j$) processes. We explore the potential of the azimuthal angle correlation between the forward jet and scattered neutrino or electron in probing the non-standard $HVV$ couplings at the collider center-of-mass energy of $\sqrt{s} \approx 1.3$~TeV. We choose the most general modifications (of $CP$-even and $CP$-odd nature) to these couplings due to new physics effects beyond the standard model. We derive exclusion limits on new physics parameters of $HVV$ couplings as a function of integrated luminosity at $95\%$ C.L. using the azimuthal angular correlations in charged- and neutral-current processes. We find that using 1000 $fb^{-1}$ data, the standard model-like new physics parameters in $HWW$ and $HZZ$ couplings can be constrained with accuracies of $4\%$ and $15\%$, respectively. The least constrained $CP$-even parameters of $HWW$ coupling can be as large as 0.04, while those of $HZZ$ coupling can have values around 0.31. Allowed values of $CP$-odd parameters in $HWW$ and $HZZ$ couplings are found to be around 0.14 and 0.34, respectively. We also study changes in the allowed values of non-trivial new physics parameters in the presence of other parameters.

hep-ph↗

arXiv2021

Multilingual Molecular Representation Learning via Contrastive Pre-training

Molecular representation learning plays an essential role in cheminformatics. Recently, language model-based approaches have gained popularity as an alternative to traditional expert-designed features to encode molecules. However, these approaches only utilize a single molecular language for representation learning. Motivated by the fact that a given molecule can be described using different languages such as Simplified Molecular Line Entry System (SMILES), The International Union of Pure and Applied Chemistry (IUPAC), and The IUPAC International Chemical Identifier (InChI), we propose a multilingual molecular embedding generation approach called MM-Deacon (multilingual molecular domain embedding analysis via contrastive learning). MM-Deacon is pre-trained using SMILES and IUPAC as two different languages on large-scale molecules. We evaluated the robustness of our method on seven molecular property prediction tasks from MoleculeNet benchmark, zero-shot cross-lingual retrieval, and a drug-drug interaction prediction task.

cs.LG↗

arXiv2019

Effect of Hagedorn States on Isothermal Compressibility of Hadronic Matter formed in Heavy-Ion Collisions: From NICA to LHC Energies

In this work, we have studied the isothermal compressibility ($κ_T$) as a function of temperature, baryon chemical potential and centre-of-mass energy ($\sqrt{s_{NN}}$) using hadron resonance gas (HRG) and excluded-volume hadron resonance gas (EV-HRG) models. A mass cut-off dependence of isothermal compressibility has been studied for a physical resonance gas. Further, we study the effect of heavier resonances ($>$ 2 GeV) on the isothermal compressibility by considering the Hagedorn mass spectrum, $ρ(m)\sim{\exp(bm)}/{(m^2+m_0^2)^{5/4}}$. Here, the parameters, $b$ and $m_0$ are extracted after comparing the results of recent lattice QCD simulations at finite baryonic chemical potential. We find a significant difference between the results obtained in EV-HRG and HRG models at a higher temperatures and higher baryochemical potentials. The inclusion of the Hagedorn mass spectrum in the partition function for hadron gas has a large effect at a higher temperature. A higher mass cut-off in the Hagedorn mass spectrum takes the isothermal compressibility to a minimum value, which occurs near the Hagedorn temperature ($T_H$). We show explicitly that at the future low energy accelerator facilities like FAIR (CBM), Darmstadt and NICA, Dubna the created matter would be incompressible compared to the high energy facilities like RHIC and LHC.

hep-ph↗

arXiv2016

Matrix Factorization at Scale: a Comparison of Scientific Data Analytics in Spark and C+MPI Using Three Case Studies

We explore the trade-offs of performing linear algebra using Apache Spark, compared to traditional C and MPI implementations on HPC platforms. Spark is designed for data analytics on cluster computing platforms with access to local disks and is optimized for data-parallel tasks. We examine three widely-used and important matrix factorizations: NMF (for physical plausability), PCA (for its ubiquity) and CX (for data interpretability). We apply these methods to TB-sized problems in particle physics, climate modeling and bioimaging. The data matrices are tall-and-skinny which enable the algorithms to map conveniently into Spark's data-parallel model. We perform scaling experiments on up to 1600 Cray XC40 nodes, describe the sources of slowdowns, and provide tuning guidance to obtain high performance.

cs.DC↗