Publications

Order by: publication date number of citations

• Investigations of the few-nucleon systems within the LENPIC project

  Jacek Golak, Evgeny Epelbaum, Alessandro Grassi, Hiroyuki Kamada, Hermann Krebs, Patrick Reinert, Roman Skibiński, Volodymyr Soloviov, Kacper Topolnicki, Vitalii Urbanevych, Yuriy Volkotrub, Henryk Witała

  SciPost Phys. Proc. 3, 002 (2020) · published 24 February 2020 | Toggle abstract · pdf

  Results presented in this contribution are obtained within the Low Energy Nuclear Physics International Collaboration (LENPIC). LENPIC aims to develop chiral nucleon-nucleon and many-nucleon interactions complete through at least the fourth order in the chiral expansion. These interactions will be used together with consistently derived current operators to solve the structure and reactions of light and medium-mass nuclei including electroweak processes. In this contribution the current status of the chiral nuclear forces and current operators will be briefly discussed. A special role played by the calculations of nucleon-deuteron scattering will be explained.

  1 citation

• Measurement of spin correlation coefficients p-$^{3}$He scattering at 65 MeV

  M. Inoue, K. Sekiguchi, K. Miki, A. Watanabe, S. Nakai, S. Shibuya, D. Sakai, Y. Utsuki, H. Umetsu, K. Hatanaka, H. Kanda, H. J. Ong, T. Wakasa, S. Goto, S. Mitsumoto, D. Inomoto, H. Kasahara, T. Ino, H. Sakai, Y. Maeda, K. Nonaka, T. Wakui, M. Itoh

  SciPost Phys. Proc. 3, 004 (2020) · published 24 February 2020 | Toggle abstract · pdf

  We performed the experiment of p–$^{3}$He scattering at 65 MeV by using polarized proton beams and the newly constructed polarized $^{3}$He target. The proton analyzing power $A_{y}$, the 3He analyzing power $A^{T}_{y}$, and the spin correlation coefficient $C_{yy}$ were measured. In the conference, the experimental data were compared with the rigorous numerical calculations based on various nuclear potentials. Large discrepancies between the experimental data and the calculations were found in the $A^{T}_{y}$ and the $C_{yy}$ at the backward angles.

  1 citation

• Generating long-distance magnetic couplings with flat bands

  Georges Bouzerar, Maxime Thumin

  SciPost Phys. 19, 011 (2025) · published 8 July 2025 | Toggle abstract · pdf

  One of the great challenges for the large-scale development of quantum technologies is to generate and control the entanglement of quantum bits through interactions of sufficiently long range. Two decades ago, spin chains have been proposed for quantum communication. Unfortunately, couplings are of very short range in general which drastically limits the communication to very short distances. Here, we demonstrate that the presence of flat bands (FBs) can trigger very long-distance magnetic couplings in spin chains. Furthermore, we show that the typical decaying lengthscale is directly related to the quantum metric of the flat band eigenstates. We have validated the robustness of our results in the case where flat bands become weakly dispersive. We believe that our unexpected findings could open up an alternative route to enable long-distance quantum communication.

  1 citation

• Non-invertible symmetries in finite-group gauge theory

  Clay Cordova, Davi Bastos Costa, Po-Shen Hsin

  SciPost Phys. 18, 019 (2025) · published 16 January 2025 | Toggle abstract · pdf

  We investigate the invertible and non-invertible symmetries of topological finite-group gauge theories in general spacetime dimensions, where the gauge group can be abelian or non-abelian. We focus in particular on the 0-form symmetry. The gapped domain walls that generate these symmetries are specified by boundary conditions for the gauge fields on either side of the wall. We investigate the fusion rules of these symmetries and their action on other topological defects including the Wilson lines, magnetic fluxes, and gapped boundaries. We illustrate these constructions with various novel examples, including non-invertible electric-magnetic duality symmetry in 3+1d $\mathbb{Z}_2$ gauge theory, and non-invertible analogs of electric-magnetic duality symmetry in non-abelian finite-group gauge theories. In particular, we discover topological domain walls that obey Fibonacci fusion rules in 2+1d gauge theory with dihedral gauge group of order 8. We also generalize the Cheshire string defect to analogous defects of general codimensions and gauge groups and show that they form a closed fusion algebra.

  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

• Field theory of collinear and noncollinear magnetic order

  Oleg Tchernyshyov

  SciPost Phys. Lect. Notes 85 (2024) · published 5 September 2024 | Toggle abstract · pdf

  These lecture notes from the 2023 Summer School "Principles and applications of symmetry in magnetism" introduce the reader to the classical field theory of ferromagnets and antiferromagnets.

  1 citation

• Top-quark mass determination in the optimised threshold scan

  Kacper Nowak, Aleksander Filip Zarnecki

  SciPost Phys. Proc. 8, 173 (2022) · published 14 July 2022 | Toggle abstract · pdf

  One of the important goals at the future e$^+$e$^−$ colliders is to measure the top-quark mass and width in a scan of the pair production threshold. Presented in this work is the most general approach to the top-quark mass determination from the threshold scan at CLIC, with all relevant model parameters and selected systematic uncertainties included in the fit procedure. In the baseline scan scenario the top-quark mass can be extracted with precision of the order of 30 to 40 MeV, already for 100 fb$^{−1}$ of data collected at the threshold. We present the optimisation procedure based on the genetic algorithm with which the statistical uncertainty of the mass measurement can be reduced by about 20%.

  1 citation

• Non-invertible symmetries of two-dimensional non-linear sigma models

  Guillermo Arias-Tamargo, Chris Hull, Maxwell L. Velásquez Cotini Hutt

  SciPost Phys. 19, 126 (2025) · published 11 November 2025 | Toggle abstract · pdf

  Global symmetries can be generalised to transformations generated by topological operators, including cases in which the topological operator does not have an inverse. A family of such topological operators are intimately related to dualities via the procedure of half-space gauging. In this work we discuss the construction of non-invertible defects based on T-duality in two dimensions, generalising the well-known case of the free compact boson to any Non-Linear Sigma Model with Wess-Zumino term which is T-dualisable. This requires that the target space has an isometry with compact orbits that acts without fixed points. Our approach allows us to include target spaces without non-trivial 1-cycles, does not require the NLSM to be conformal, and when it is conformal it does not need to be rational; moreover, it highlights the microscopic origin of the topological terms that are responsible for the non-invertibility of the defect. An interesting class of examples are Wess-Zumino-Witten models, which are self-dual under a discrete gauging of a subgroup of the isometry symmetry and so host a topological defect line with Tambara-Yamagami fusion. Along the way, we discuss how the usual 0-form symmetries match across T-dual models in target spaces without 1-cycles, and how global obstructions can prevent locally conserved currents from giving rise to topological operators.

  1 citation

• The charged $Z_c$ and $Z_b$ structures in a constituent quark model approach

  Pablo Garcia Ortega, Jorge Segovia, David Rodriguez Entem and Francisco Fernández

  SciPost Phys. Proc. 3, 013 (2020) · published 25 February 2020 | Toggle abstract · pdf

  The nature of the recently discovered $Z_c$ and $Z_b$ structures is intriguing. Their charge forces its minimal quark content to be $Q\bar Q q\bar q$ (where $Q=\{c,b\}$ and $q=\{u,d\}$). In this work we perform a molecular coupled-channels calculation of the $I^G(J^{PC})=1^+(1^{+-})$ charm and bottom sectors in the framework of a constituent quark model which satisfactorily describes a wide range of properties of (non-)conventional hadrons containing heavy quarks. All the relevant channels are included for each sector, i.e.: The $D^{(\ast)}\bar D^{\ast}+h.c.$, $\pi J/\psi$ and $\rho\eta_c$ channels for the $Z_c$ and $B^{(\ast)}B^{\ast}$ and $\Upsilon(nS)\pi$ ($n=1,2,3$) channels for the $Z_b$ analysis. Possible structures of these resonances will be discussed

  1 citation

• Three dimensional topological field theories and Nahm sum formulas

  Dongmin Gang, Heeyeon Kim, Byoungyoon Park, Spencer Stubbs

  SciPost Phys. 19, 128 (2025) · published 12 November 2025 | Toggle abstract · pdf

  It is known that a large class of characters of 2d conformal field theories (CFTs) can be written in the form of a Nahm sum. In [D. Zagier, in Frontiers in number theory, physics, and geometry II, Springer, Berlin (2007)], D. Zagier identified a list of Nahm sum expressions that are modular functions under a congruence subgroup of $SL(2,\mathbb{Z})$, which can be thought of as candidates for characters of rational CFTs. Motivated by the observation that the same formulas appear as the half-indices of certain 3d $\mathcal{N}=2$ supersymmetric gauge theories, we perform a general search over low-rank 3d $\mathcal{N}=2$ Abelian Chern-Simons matter theories which either flow to unitary TFTs or $\mathcal{N}=4$ rank-zero SCFTs in the infrared. These are exceptional classes of 3d theories, which are expected to support rational and $C_2$-cofinite chiral algebras on their boundary. We compare and contrast our results with Zagier's and comment on a possible generalization of Nahm's conjecture.

  1 citation