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Subash Chandra Behera

Publications and source records attributed to Subash Chandra Behera.

8 recordsLinked to original sources

Minima of geodeics length functions for non-uniform filling

Kerckhoff proved that the geodesic length function $\ell_\Omega$ of a filling $\Omega$ on $S_g$ attains a unique minimum in Teichm\"uller space. Recent work of Ernesto Girondo et al. computed these minima for uniform fillings using the algebraic machinery of dessins d'enfants and Grothendieck-Belyi surfaces. We present an elementary optimization approach for $4$-regular topological uniform fillings, bypassing this framework. Furthermore, we analyze two special classes of non-uniform $4$-regular fillings using fat graphs and optimization techniques. We explicitly compute their minima and prove that in both classes, the minimum of these length functions is attained at a triangle surface.

math.GT

Exploring differential two-particle correlations in $\gamma p$ and low-multiplicity pp collisions using PYTHIA8

A study of two-particle differential number ($B$) and transverse momentum ($P_{2}^\mathrm{CD}$) balance functions in photon-proton ($\gamma p$) and proton-proton (pp) collisions at $\sqrt{s}=$ 5.36 TeV is presented. The analysis focuses on inclusive charged hadrons within the pseudorapidity coverage $|\eta|<2.4$ and the transverse momentum interval $0.3 < p_\mathrm{T} < 3.0$ GeV and examines their correlations in terms of relative pseudorapidity ($\Delta\eta$) and relative azimuthal angle ($\Delta\phi$). The correlation functions are evaluated for same- and opposite-sign pairs, and their combinations are used to extract charge-dependent (CD) and charge-independent (CI) components. The evolution of the near-side peak of the CD correlations is investigated in terms of $\Delta\eta$ and $\Delta\phi$ as a function of charged-particle multiplicity ($N_\mathrm{ch}$) for $\gamma p$ collisions and compared to pp collisions at a similar multiplicity range. A clear multiplicity dependence of the balance function width is obtained. The width is found systematically lower in $\gamma p$ events than in pp collisions. This study provides valuable information on particle correlations and production mechanisms in low-$N_\mathrm{ch}$ regimes for upcoming measurements in small systems.

nucl-ex

Jet-associated Balance Functions of Charged and Identified Hadrons in pp Collisions at $\sqrt{s}=13.6$ TeV using PYTHIA8

We present a study of charge balance functions inside jets in proton-proton collisions at $\sqrt{s}=13.6$ TeV using the PYTHIA8 event generator. The balance function is a differential observable of opposite-charge correlations, which is calculated in the jet frame for inclusive charged hadrons and the identified $\pi$, $K$, and $p$. The results show a clear narrowing of the balancing width with increasing jet charged multiplicity, indicating that particle production becomes more localized in momentum space in high-multiplicity jets.This trend resembles features attributed to collective expansion in heavy-ion collisions. The species dependence highlights sensitivity to the redistribution of strangeness and baryon number during string fragmentation and color reconnection. The new CR tune yields a little broader proton balance-function width in $\Delta\phi^{*}$ than CP5, hinting at enhanced baryon-production dynamics, whereas meson widths differ only mildly. These comparisons suggest that multiparton interactions and color reconnection contribute to the observed trends, potentially generating collective like features inside jets, especially in high multiplicity jets, via nontrivial color dynamics alongside standard fragmentation. Taken together, the results establish identified hadron balance functions in high multiplicity jets as a sensitive probe of hadronization and provide new constraints for models of small system collectivity.

hep-ex

System size and event shape dependence of particle-identified balance functions in proton-proton collisions at $\sqrt{s} = 13$ TeV using PYTHIA 8 and EPOS models

We investigate charge balance functions for pion, kaon, and proton pairs in proton-proton (pp) collisions at $\sqrt{s}=13$ TeV using Monte Carlo models, PYTHIA8 and EPOS-LHC, with transverse spherocity to classify event topology and charged-particle multiplicity to select system size. Simulations with PYTHIA8 and EPOS-LHC reveal that balance-function widths in rapidity and azimuthal angle depend on multiplicity and event shape. In PYTHIA8, widths decrease monotonically with multiplicity, consistent with local charge conservation in a fragmentation-dominated scenario. In contrast, the EPOS-LHC model, especially when using the core corona implementation, exhibits a more intricate response, where the combined effects of hydrodynamic radial flow and longitudinal diffusion result in narrower azimuthal correlations and broader rapidity correlations. These features are characteristic signatures of collective dynamics, similar to those observed in heavy-ion collisions. Events with low spherocity, which are jet-like in nature, exhibit significantly narrower balance function widths compared to isotropic events with high spherocity, illustrating that event-shape selection provides clear sensitivity to the underlying dynamics of particle production in pp collisions. The species dependence and event-shape sensitivity of the balance-function widths provide information about the hadronization dynamics and collectivity in small systems. These results demonstrate that multidimensional, particle species dependent balance function measurements can disentangle the underlying mechanisms of charge correlations and medium-like behavior in high-multiplicity pp collisions.

hep-ex

Two-particle number and transverse momentum balance function with event topology in pp collisions at $\sqrt{s}=13$ TeV

The first study of charge-dependent two-particle differential number ($B$) and momentum balance functions ($P_{2}^{CD}$) with respect to an event shape variable, transverse spherocity, is reported. Results are presented from PYTHIA8 and EPOS-LHC model calculations in proton-proton (pp) collisions at $\sqrt{s} = 13$ TeV. To distinguish between back-to-back jet-like topologies and isotropic events, low and high transverse spherocity values are chosen. The correlation functions are measured as a function of averaged charged-particle multiplicity ($\langle N_{ch}\rangle$) in relative pseudorapidity ($\Delta\eta$) and relative azimuthal angle ($\Delta\phi$) with $|\eta| < 2.4$ and $0.2 < p_{\rm {T}} < 2.0$ GeV. A narrowing of the balance function width is observed in $\Delta\eta$ and $\Delta\phi$ from low- to high-multiplicity collisions. Wider balance functions are found in isotropic events as compared to jet-like events. However, for the momentum correlations, a nearly flat dependence is observed with $\langle N_{ch}\rangle$. This study investigates charge conservation mechanisms and their correlations for events classified with jet-like and isotropic topologies. To isolate medium-driven effects, we compare EPOS-LHC with its hydrodynamic core enabled and disabled and observed narrowing patterns in $B$ and $P_{2}^{CD}$ as a quantitative handle on radial-flow-induced localization of charge-balancing pairs.

hep-ex

Some analogues of isoperimetric inequality

The discrete isoperimetric inequality states that among all n -gons with a fixed area, the regular n -gon has the least perimeter. We prove analogues of the discrete isoperimetric inequality (involving circumradius or inradius) for cyclic and tangential polygons in hyperbolic geometry, considering both single and multiple polygons. Furthermore, we establish two versions of the isoperimetric inequality for multiple polygons in hyperbolic geometry with some restriction on their area or perimeter.

math.GT

Angle Parametrization of Teichmüller space and hyperelliptic surfaces

Let $S_g$ be a closed orientable surface of genus $g \geq 2$, and let $\mathcal{T}_g$ be the Teichmüller space of $S_g$. Let $\mathcal{H}_g$ denotes the space of all hyperelliptic surfaces of genus $g$. For $g\geq 3$, we have proved that $\mathcal{T}_g$ can be parametrized by $6g-5$ angle parameters. We also prove that for $g\geq 2$, $\mathcal{H}_g$ can be parametrized by $4g-2$ angle parameters.

math.GT

Dynamics of Hot QCD Matter -- Current Status and Developments

The discovery and characterization of hot and dense QCD matter, known as Quark Gluon Plasma (QGP), remains the most international collaborative effort and synergy between theorists and experimentalists in modern nuclear physics to date. The experimentalists around the world not only collect an unprecedented amount of data in heavy-ion collisions, at Relativistic Heavy Ion Collider (RHIC), at Brookhaven National Laboratory (BNL) in New York, USA, and the Large Hadron Collider (LHC), at CERN in Geneva, Switzerland but also analyze these data to unravel the mystery of this new phase of matter that filled a few microseconds old universe, just after the Big Bang. In the meantime, advancements in theoretical works and computing capability extend our wisdom about the hot-dense QCD matter and its dynamics through mathematical equations. The exchange of ideas between experimentalists and theoreticians is crucial for the progress of our knowledge. The motivation of this first conference named "HOT QCD Matter 2022" is to bring the community together to have a discourse on this topic. In this article, there are 36 sections discussing various topics in the field of relativistic heavy-ion collisions and related phenomena that cover a snapshot of the current experimental observations and theoretical progress. This article begins with the theoretical overview of relativistic spin-hydrodynamics in the presence of the external magnetic field, followed by the Lattice QCD results on heavy quarks in QGP, and finally, it ends with an overview of experiment results.

nucl-th