Publications

Order by: publication date number of citations

• Algebraic Bethe Ansatz for spinor R-matrices

  Vidas Regelskis

  SciPost Phys. 12, 067 (2022) · published 17 February 2022 | Toggle abstract · pdf

  We present a supermatrix realisation of $q$-deformed spinor-spinor and spinor-vector $R$-matrices. These $R$-matrices are then used to construct transfer matrices for $U_{q^2}(\mathfrak{so}_{2n+1})$- and $U_{q}(\mathfrak{so}_{2n+2})$-symmetric closed spin chains. Their eigenvectors and eigenvalues are computed.

  1 citation

• Recent progress on the study of nucleon structure from lattice QCD and future perspectives

  Constantia Alexandrou

  SciPost Phys. Proc. 3, 015 (2020) · published 25 February 2020 | Toggle abstract · pdf

  We review the progress achieved within the last five years in the simulations of lattice QCD, as well as in the analysis for selected quantities probing nucleon structure. In particular, we discuss results on the nucleon electromagnetic form factors, $\sigma$-terms, the momentum fraction carried b quark in the nucleon and the helicity and transversity. All quantities are obtained using simulations generated with quark masses fixed to their physical values. In addition, we review the on-going effort to extract parton distribution functions (PDFs) directly from lattice QCD using the quasi-PDFs approach.

  1 citation

• Efficiency of dynamical decoupling for (almost) any spin–boson model

  Alexander Hahn, Daniel Burgarth, Davide Lonigro

  SciPost Phys. 19, 035 (2025) · published 13 August 2025 | Toggle abstract · pdf

  Dynamical decoupling is a technique aimed at suppressing the interaction between a quantum system and its environment by applying frequent unitary operations on the system alone. In the present paper, we analytically study the dynamical decoupling of a two-level system coupled with a structured bosonic environment initially prepared in a thermal state. We find sufficient conditions under which dynamical decoupling works for such systems, and—most importantly—we find bounds for the convergence speed of the procedure. Our analysis is based on a new Trotter theorem for multiple Hamiltonians and involves a rigorous treatment of the evolution of mixed quantum states via unbounded Hamiltonians. A comparison with numerical experiments shows that our bounds reproduce the correct scaling in various relevant system parameters. Furthermore, our analytical treatment allows for quantifying the decoupling efficiency for boson baths with infinitely many modes, in which case a numerical treatment is unavailable.

  1 citation

• Impact of uncertainties of unbound 10Li on the ground state of two-neutron halo 11Li

  Jagjit Singh, Wataru Horiuchi

  SciPost Phys. Proc. 3, 007 (2020) · published 24 February 2020 | Toggle abstract · pdf

  Recently, the energy spectrum of 10Li was measured upto 4.6 MeV, via one-neutron transfer reaction d(9Li, p)10Li. Considering the ambiguities on the 10Li continuum spectrum with reference to new data, we report the con guration mixing in the ground state of the two-neutron halo nucleus 11Li for two different choices of the 9Li+n potential. For the present study, we employ a three-body (core+n+n) structure model developed for describing the two-neutron halo system by explicit coupling of unbound continuum states of the subsystem (core+n), and discuss the two-neutron correlations in the ground state of 11Li.

  1 citation

• Attention to the strengths of physical interactions: Transformer and graph-based event classification for particle physics experiments

  Luc Builtjes, Sascha Caron, Polina Moskvitina, Clara Nellist, Roberto Ruiz de Austri, Rob Verheyen, Zhongyi Zhang

  SciPost Phys. 19, 028 (2025) · published 28 July 2025 | Toggle abstract · pdf

  A major task in particle physics is the measurement of rare signal processes. Even modest improvements in background rejection, at a fixed signal efficiency, can significantly enhance the measurement sensitivity. Building on prior research by others that incorporated physical symmetries into neural networks, this work extends those ideas to include additional physics-motivated features. Specifically, we introduce energy-dependent particle interaction strengths, derived from leading-order SM predictions, into modern deep learning architectures, including Transformer Architectures (Particle Transformer), and Graph Neural Networks (Particle Net). These interaction strengths, represented as the SM interaction matrix, are incorporated into the attention matrix (transformers) and edges (graphs). Our results in event classification show that the integration of all physics-motivated features improves background rejection by $10\%-40\%$ over baseline models, with an additional gain of up to $9\%$ due to the SM interaction matrix. This study also provides one of the broadest comparisons of event classifiers to date, demonstrating how various architectures perform across this task. A simplified statistical analysis demonstrates that these enhanced architectures yield significant improvements in signal significance compared to a graph network baseline.

  1 citation

• Effective description of non-equilibrium currents in cold magnetized plasma

  Nabil Iqbal

  SciPost Phys. 12, 078 (2022) · published 28 February 2022 | Toggle abstract · pdf

  The dynamics of cold strongly magnetized plasma -- traditionally the domain of force-free electrodynamics -- has recently been reformulated in terms of symmetries and effective field theory, where the degrees of freedom are the momentum and magnetic flux carried by a fluid of cold strings. In physical applications where the electron mass can be neglected one might expect the presence of extra light charged modes -- electrons in the lowest Landau level -- propagating parallel to the magnetic field lines. We construct an effective description of such electric charges, describing their interaction with plasma degrees of freedom in terms of a new collective mode that can be thought of as a bosonization of the electric charge density along each field line. In this framework QED phenomena such as charged pair production and the axial anomaly are described at the classical level. Formally, our construction corresponds to gauging a particular part of the higher form symmetry associated with magnetic flux conservation. We study some simple applications of our effective theory, showing that the scattering of magnetosonic modes generically creates particles and that the rotating Michel monopole is now surrounded by a cloud of electric charge.

  1 citation

• The Giant Radio Array for Neutrino Detection (GRAND) Project

  Bruno Lazarotto Lago

  SciPost Phys. Proc. 10, 027 (2022) · published 11 August 2022 | Toggle abstract · pdf

  GRAND is designed to detect ultra-high-energy cosmic particles -- specially neutrinos, cosmic rays and gamma rays using radio antennas. With $\sim$20 mountainous sites around the world it will cover a total area of 200,000 km$^{2}$. The planned sensitivity of 10$^{-10}$ GeV cm$^{-2}$ s$^{-1}$ sr$^{-1}$ above $5\times10^{17}$ eV will likely ensure the detection of cosmogenic neutrinos predicted by most common scenarios enabling neutrino astronomy. Furthermore, PeV--EeV neutrinos can test particle interactions at energies above those achieved in accelerators. The pathfinder stage GRANDProto300 is planned to start taking data in 2021. We present the current overall status of the project with emphasis on the neutrino physics.

  1 citation

• Search for low mass WIMP dark matter with DarkSide-50

  Masato Kimura on behalf of DarkSide-50 Collaboration

  SciPost Phys. Proc. 12, 022 (2023) · published 3 July 2023 | Toggle abstract · pdf

  DarkSide-50 is a direct dark matter detection experiment at Laboratori Nazionali del Gran Sasso that uses argon as the target material. Exploiting the ionization signal from a dual-phase time projection chamber filled with low-radioactivity argon, it has set the most stringent exclusion limit on WIMPs with a mass of few $\mathrm{GeV}/c^2$. A new analysis has recently been carried out with a larger exposure, profiting from an improved understanding of the detector response and background model. An improvement of about a factor 10 in sensitivity is expected for a WIMP mass of 2 GeV/c$^2$.

  1 citation

• Measurement for p–3He elastic scattering with a 65 MeV polarized proton beam

  S. Nakai, K. Sekiguchi, K. Miki, A. Watanabe, S. Shibuya, M. Watanabe, K. Kawahara, D. Sakai, Y. Wada, H. Umetsu, M. Itoh, K. Hatanaka, A. Tamii, N. Kobayashi, A. Inoue, S. Nakamura, T. Wakasa, S. Mitsumoto, H. Ohshiro, S. Goto, Y. Maeda, H. Sakai

  SciPost Phys. Proc. 3, 019 (2020) · published 25 February 2020 | Toggle abstract · pdf

  We measured the cross section and the proton analyzing power Ay for p–3He elastic scattering at the angles θ = 26.9◦–170.1◦ in the center of mass system with a 65 MeV polarized proton beam. We compared the data with the rigorous numerical calculations based on the various nucleon–nucleon potentials. For the cross section, clear discrepancy is seen at the angles where the cross section takes minimum. For the proton analyzing power Ay, the calculations have moderate agreements to the data. In this proceedings, we show only the experimental results.

  1 citation

• Reduction in radioactivity-induced backgrounds using a novel active veto detector for rare event search experiments

  Mouli Chaudhuri, Andrew Jastram, Glenn Agnolet, Samir Banik, Hao Chen, Vijay Iyer, Varchaswi K. S. Kashyap, Andrew Kubik, Matthew Lee, Rupak Mahapatra, Sandro Maludze, Nader Mirabolfathi, Nityasa Mishra, Bedangadas Mohanty, Himangshu Neog, Mark Platt

  SciPost Phys. Proc. 12, 017 (2023) · published 3 July 2023 | Toggle abstract · pdf

  The results of a newly developed annular cryogenic phonon-mediated active veto detector are discussed which shows a significant reduction of radioactivity-induced backgrounds in rare event search experiments. The veto detector is made up of germanium weighing $\sim$500 g with an outer diameter of 76 mm and an inner diameter of 28 mm. The detector can host a 25 mm diameter germanium inner target detector of mass $\sim$10 g. A GEANT4 simulation with the active veto and inner target detector shows a gamma background reduction of 50 - 80% which is further improved (> 90%) with 4$\pi$ veto coverage. Experimental measurements with the detector assembly agree well with the simulation.

  1 citation