Publications

Order by: publication date number of citations

• Open strange meson $K^\pm_1$ in hot and dense nuclear matter

  Rajesh Kumar, Arvind Kumar

  SciPost Phys. Proc. 8, 055 (2022) · published 12 July 2022 | Toggle abstract · pdf

  Using the unification of the chiral SU(3) model and QCD sum rules, we deduce the in-medium properties of $K^\pm_1$ meson. Within the chiral SU(3) model, medium modified gluon and quark condensates are evaluated through their interactions with the scalar fields ($\sigma$, $\zeta$, $\delta$, and $\chi$). These condensates are further used as input in the Borel transformed equations of QCD sum rules to evaluate the in-medium mass of strange $K^\pm_1$ meson. The in-medium property of the above meson can be used to study the restoration of chiral symmetry in nuclear matter.

  1 citation

• M5-brane prongs, string soliton bound states and wall-crossing

  Varun Gupta, K. Narayan

  SciPost Phys. Core 8, 004 (2025) · published 13 January 2025 | Toggle abstract · pdf

  We study Abelian M5-brane field configurations representing BPS bound states of self-dual string solitons whose locations correspond to the endlines of M2-branes ending on the M5-branes. The BPS equations are obtained from appropriate Bogomolny completion of the effective Abelian low energy functional with two transverse scalars, using two vectors representing the directions along which these endline strings extend. Then we impose boundary conditions on the scalars near the string soliton cores. This leads to a molecule-like equilibrium structure of two non-parallel string solitons at fixed transverse separations, with the M5-brane "prong" deformations comprising two "spikes", each shaped like a ridge. The resulting picture becomes increasingly accurate as one approaches the wall of marginal stability, on which these states decay. There are various parallels with wall-crossing phenomena for string web configurations obtained from D3-brane deformations.

  1 citation

• Measurement of Transverse Spin Dependent Azimuthal Correlations of Charged Pion(s) in $p^{\uparrow} p$ Collisions at $\sqrt s = 200$ GeV at STAR

  Babu R. Pokhrel

  SciPost Phys. Proc. 8, 047 (2022) · published 12 July 2022 | Toggle abstract · pdf

  At the leading twist, the transversity distribution function, $h^{q}_{1}(x)$, where $x$ is the longitudinal momentum fraction of the proton carried by quark $q$, encodes the transverse spin structure of the nucleon. Extraction of it is difficult because of its chiral-odd nature. In transversely polarized proton-proton collisions ($p^\uparrow p$), $h_{1}^{q}(x)$ can be coupled with another chiral-odd partner, a spin-dependent fragmentation function (FF). The resulting asymmetries in hadron(s) azimuthal correlations directly probe $h_{1}^{q}(x)$. We report the measurement of correlation asymmetries for charged pion(s) in $p^\uparrow p$, through the Collins and the Interference FF channel.

  1 citation

• Codebase release 1.0 for QDarts

  Jan A. Krzywda, Weikun Liu, Evert van Nieuwenburg, Oswin Krause

  SciPost Phys. Codebases 43-r1.0 (2025) · published 9 January 2025 | Toggle abstract · src

  We present QDarts, an efficient simulator for realistic charge stability diagrams of quantum dot array (QDA) devices in equilibrium states. It allows for pinpointing the location of concrete charge states and their transitions in a high-dimensional voltage space (via arbitrary two-dimensional cuts through it), and includes effects of finite tunnel coupling, non-constant charging energy and a simulation of noisy sensor dots. These features enable close matching of various experimental results in the literature, and the package hence provides a flexible tool for testing QDA experiments, as well as opening the avenue for developing new methods of device tuning.

  1 citation

• Generalized Gibbs ensembles in weakly interacting dissipative systems and digital quantum computers

  Iris Ulčakar, Zala Lenarčič

  SciPost Phys. 19, 068 (2025) · published 4 September 2025 | Toggle abstract · pdf

  Identifying use cases with superconducting circuits not critically affected by the inherent noise is a pertinent challenge. Here, we propose using a digital quantum computer to showcase the activation of integrable effects in weakly dissipative integrable systems. Dissipation is realized by coupling the system's qubits to ancillary ones that are periodically reset. We compare the digital reset protocol to the usual Lindblad continuous-time evolution by considering non-interacting integrable systems dynamics, which can be analyzed using scattering between the Bogoliubov quasiparticles caused by the dissipation. If not dominant, the inherent noise would cause extra scattering but would not critically change the physics. A corresponding quantum computer implementation would illuminate the possibilities of stabilizing exotic states in nearly integrable quantum materials.

  1 citation

• Algebraic structure of classical integrability for complex sine-Gordon

  Jean Avan, Luc Frappat, Eric Ragoucy

  SciPost Phys. 8, 033 (2020) · published 2 March 2020 | Toggle abstract · pdf

  The algebraic structure underlying the classical $r$-matrix formulation of the complex sine-Gordon model is fully elucidated. It is characterized by two matrices $a$ and $s$, components of the $r$ matrix as $r=a-s$. They obey a modified classical reflection/Yang--Baxter set of equations, further deformed by non-abelian dynamical shift terms along the dual Lie algebra $su(2)^*$. The sign shift pattern of this deformation has the signature of the twisted boundary dynamical algebra. Issues related to the quantization of this algebraic structure and the formulation of quantum complex sine-Gordon on those lines are introduced and discussed.

  1 citation

• Cavity-induced bifurcation in classical rate theory

  Kalle Sulo Ukko Kansanen, Tero Tapio Heikkilä

  SciPost Phys. 16, 025 (2024) · published 23 January 2024 | Toggle abstract · pdf

  We show how coupling an ensemble of bistable systems to a common cavity field affects the collective stochastic behavior of this ensemble. In particular, the cavity provides an effective interaction between the systems, and parametrically modifies the transition rates between the metastable states. We predict that the cavity induces a phase transition at a critical temperature which depends linearly on the number of systems. It shows up as a spontaneous symmetry breaking where the stationary states of the bistable system bifurcate. We observe that the transition rates slow down independently of the phase transition, but the rate modification vanishes for alternating signs of the system-cavity couplings, corresponding to a disordered ensemble of dipoles. Our results are of particular relevance in polaritonic chemistry where the presence of a cavity has been suggested to affect chemical reactions.

  1 citation

• Weak vs. strong breaking of integrability in interacting scalar quantum field theories

  Bence Fitos, Gábor Takács

  SciPost Phys. 15, 137 (2023) · published 5 October 2023 | Toggle abstract · pdf

  The recently proposed classification of integrability-breaking perturbations according to their strength is studied in the context of quantum field theories. Using random matrix methods to diagnose the resulting quantum chaotic behaviour, we investigate the $\phi^4$ and $\phi^6$ interactions of a massive scalar, by considering the crossover between Poissonian and Wigner-Dyson distributions in systems truncated to a finite-dimensional Hilbert space. We find that a naive extension of the scaling of crossover coupling with the volume observed in spin chains does not give satisfactory results for quantum field theory. Instead, we demonstrate that considering the scaling of the crossover coupling with the number of particles yields robust signatures, and is able to distinguish between the strengths of integrability breaking in the $\phi^4$ and $\phi^6$ quantum field theories.

  1 citation

• The resistance of quantum entanglement to temperature in the Kugel-Khomskii model

  Valerii E. Valiulin, Andrey V. Mikheyenkov, Nikolay M. Chtchelkatchev, Kliment I. Kugel

  SciPost Phys. Core 6, 025 (2023) · published 4 April 2023 | Toggle abstract · pdf

  The Kugel-Khomskii model with entangled spin and orbital degrees of freedom is a good testing ground for many important features in quantum information processing, such as robust gaps in the entanglement spectra. Here, we demonstrate that the entanglement can be also robust under effect of temperature within a wide range of parameters. It is shown, in particular, that the temperature dependence of entanglement often exhibits a nonmonotonic behavior. Namely, there turn out to be ranges of the model parameters, where entanglement is absent at zero temperature, but then, with an increase in temperature, it appears, passes through a maximum, and again vanishes.

  1 citation

• Two-dimensional Ising and Potts model with long-range bond disorder: A renormalization group approach

  Francesco Chippari, Marco Picco, Raoul Santachiara

  SciPost Phys. 15, 135 (2023) · published 4 October 2023 | Toggle abstract · pdf

  In this paper we provide new analytic results on two-dimensional $q$-Potts models ($q ≥ 2$) in the presence of bond disorder correlations which decay algebraically with distance with exponent $a$. In particular, our results are valid for the long-range bond disordered Ising model ($q=2$). We implement a renormalization group perturbative approach based on conformal perturbation theory. We extend to the long-range case the RG scheme used in [V. Dotsenko et al., Nucl. Phys. B 455 701-23] for the short-range disorder. Our approach is based on a $2$-loop order double expansion in the positive parameters $(2-a)$ and $(q-2)$. We will show that the Weinrib-Halperin conjecture for the long-range thermal exponent can be violated for a non-Gaussian disorder. We compute the central charges of the long-range fixed points finding a very good agreement with numerical measurements.

  1 citation