arXiv subjects

Apurba Tiwari

Publications and source records attributed to Apurba Tiwari.

7 recordsLinked to original sources

arXiv2026

Criticality Quenching and Microstructure of Quintessence-AdS Black Holes

In this work, we investigate the thermodynamic geometry of Reissner-Nordstrom Anti-de Sitter (RN-AdS) black holes with quintessence in the grand canonical ensemble. The analysis employs the Ruppeiner curvature scalar to elucidate the microscopic interactions and critical phenomena in the extended phase space. Divergence of the scalar curvature signal phase transitions, while its sign characterizes the nature of the underlying interactions; negative for attractive and positive for repulsive type interactions. The analysis reveals that attractive interactions dominate at low electric potentials, whereas repulsive interactions prevail at higher potentials unlike the usual charged black holes. Finally, the interaction strength is fairly constant during the phase transition, providing a greater understanding of the quintessence influenced microscopic attributes of RN-AdS black holes.

hep-th↗

arXiv2025

Probing phase transitions and microscopic interactions in quasi-topological black holes

In this paper, we examine the thermodynamic geometry of four-dimensional quasi-topological black holes by computing the Ruppeiner scalar curvature R which serves as an empirical tool to describe the nature of interactions among black hole microstructures. In four dimensions, we write novel black hole solutions within the framework of generalized quasi-topological gravity, extended through a fundamental p-form field. Temperature, entropy, and thermodynamic volume are explicitly expressed using the extended first law. The nature of the interactions between the microstructure is then revealed by computing R, where positive curvature indicates repulsion dominant interactions and negative curvature indicates the dominance of attraction. Our approach uses divergences and sign changing nature of R to identify critical points and phase transitions. Further, our analysis reveals a notably streamlined thermodynamic behavior, a single zero-crossing of curvature R, marking a second-order phase transition and offering direct insight into the underlying microstructure interactions.

gr-qc↗

arXiv2023

$t\bar{t}H$ Interactions and T-odd Correlations at Hadron Colliders

We explore $\mathcal CP$-violation effects of Higgs-top interactions in the associated production of a Higgs boson with top-pair in the dileptonic decay modes of top-quark originating from proton proton collisions $pp \to t\bar{t}H \to (l^+ ν_l b)(l^{-} \bar{ν_l} \bar{b})H$ at NLO in QCD matched to parton shower via T-odd observables using momenta of various particles involved in the process. In particular, we predict the constraints on the $\mathcal CP$-violating $t\bar{t}H$ coupling obtained through the production asymmetries associated with the T-odd observables in the dileptonic decay channel of the $t\bar{t}$ pair for the LHC with centre-of-mass energy of 13 TeV and an integrated luminosity of 139 fb$^{-1}$. We also present the corresponding limits for future hadron colliders, namely the High Luminosity LHC (HL-LHC) and the Future Circular Collider (FCC-HH). Our estimates of the $t\bar{t}H$ interaction strength reveal that the upper bound on pseudoscalar coupling $c_p$ corresponding to the largest asymmetry would be of about $1.96 \times 10^{-2}$ at 2.5$σ$ C.L. for $c_s$ = 1 at the LHC with $\sqrt{S}$ = 13 TeV for an integrated luminosity of 139 fb$^{-1}$. The respective limits for HL-LHC and FCC-hh with the projected Luminosities of 3 ab$^{-1}$ and 30 ab$^{-1}$ are found to be to $3.4\times 10^{-3}$ and $1.6\times 10^{-4}$ respectively at 2.5$σ$ C.L.

hep-ph↗

arXiv2022

New physics contributions to $Wtb$ anomalous couplings and top-quark decay

In this work, we study the new physics effects arising due the presence of anomalous $Wtb$ vertex through the semileptonic decay modes of the top-quark at the Large Hadron Collider. An estimate on the sensitivities of the aforementioned interaction at 5$σ$ CL in the context of top-quark decay-width measurements and cross-section measurements would also be discussed for the pre-existing 13 TeV LHC data and its projections for the proposed LHC runs at 14 TeV, 27 TeV and 100 TeV. We also incorporate the $\mathcal CP$-violating effects to such interactions by constructing the $\mathcal CP$-violating asymmetries.

hep-ph↗

arXiv2022

$\mathcal CP$-violating anomalous interactions at Large Hadron Collider

In this study, we explore the effects of $\mathcal CP$-violating anomalous interactions of the top-quark through the semileptonic decay modes of the top-quark arising due to pair-production of $t\bar{t}$ at the Large Hardon Collider. Predictions on the LHC sensitivities of the coupling strength to such $\mathcal CP$-violating interactions would be discussed for the 13 TeV LHC data and for the future hadron collider with 14 TeV energy.

hep-ph↗

arXiv2022

The anomalous $Wtb$ vertex and top-pair production at the LHC

We perform an exclusive study of the anomalous $Wtb$ interaction in the context of LHC. The limits on $Wtb$ anomalous couplings have been estimated via the measurements of the top-quark decay width and cross-section as well as production asymmetries in case the CP is violated. Our investigations reveal that the upper bounds on $(|C_L|, |C_R|)$ would be of about (1.82, 0.03) $\times 10^{-4}$ at $2.5 σ$ C.L., for the already collected data at the LHC with $\sqrt{S} = 13$ TeV for an integrated luminosity of 139 fb$^{-1}$. The corresponding limits for future hadron colliders, namely, High Luminosity LHC (HL-LHC), High Energy LHC (HE-LHC) and Future Circular Collider (FCC-hh) for the projected luminosities of 3 ab$^{-1}$, 12 ab$^{-1}$ and 30 ab$^{-1}$ are found to be to $(0.81, 0.006)\times 10^{-4}$, $(0.44, 0.0017)\times 10^{-4}$ and $(0.21, 0.0004)\times 10^{-4}$ respectively at 2.5$σ$ C. L..

hep-ph↗

arXiv2021

T-odd anomalous interactions of the top-quark at the Large Hadron Collider

We study the effects of T-odd interactions of top-quark via the pair production of top-quark in the semileptonic detection modes at the Large Hadron Collider by means of the T-odd observables constructed through the momenta of the observed decay products of the top (and anti-top)-quark for a wide range of CP-violating scale $Λ$. Estimates on the sensitivities of the coupling strength of such interactions for 13 TeV LHC energy with $\int \mathcal L dt$ = 36.1 fb$^{-1}$, 140 fb$^{-1}$ and for HL-LHC with 14 TeV energy with integrated luminosities of 0.3 ab$^{-1}$, 1 ab$^{-1}$, 2 ab$^{-1}$ and 3 ab$^{-1}$ are also presented for $Λ$ ranging between $M_W$ and 2 TeV.

hep-ph↗