Publications

Order by: publication date number of citations

• 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

• Anisotropic scaling of the two-dimensional Ising model II: surfaces and boundary fields

  Hendrik Hobrecht, Alfred Hucht

  SciPost Phys. 8, 032 (2020) · published 2 March 2020 | Toggle abstract · pdf

  Based on the results published recently [SciPost Phys. 7, 026 (2019)], the influence of surfaces and boundary fields are calculated for the ferromagnetic anisotropic square lattice Ising model on finite lattices as well as in the finite-size scaling limit. Starting with the open cylinder, we independently apply boundary fields on both sides which can be either homogeneous or staggered, representing different combinations of boundary conditions. We confirm several predictions from scaling theory, conformal field theory and renormalisation group theory: we explicitly show that anisotropic couplings enter the scaling functions through a generalised aspect ratio, and demonstrate that open and staggered boundary conditions are asymptotically equal in the scaling regime. Furthermore, we examine the emergence of the surface tension due to one antiperiodic boundary in the system in the presence of symmetry breaking boundary fields, again for finite systems as well as in the scaling limit. Finally, we extend our results to the antiferromagnetic Ising model.

  2 citations

• Microscopic theory of fractional excitations in gapless quantum Hall states: semi-quantized quantum Hall states

  Oğuz Türker, Tobias Meng

  SciPost Phys. 8, 031 (2020) · published 28 February 2020 | Toggle abstract · pdf

  We derive the low-energy theory of semi-quantized quantum Hall states, a recently observed class of gapless bilayer fractional quantum Hall states. Our theory shows these states to feature gapless quasiparticles of fractional charge coupled to an emergent Chern-Simons gauge field. These gapless quasiparticles can be understood as composites of electrons and Laughlin-like quasiparticles. We show that semi-quantized quantum Hall states exhibit perfect interlayer drag, host non-Fermi liquid physics, and serve as versatile parent states for fully gapped topological phases hosting anyonic excitations.

  2 citations

• The $D_{03}(2380)$ dibaryon resonance excitation in the $pd\to pd\pi\pi$ reaction.

  Nurbek Tursunbayev, Yuriy Uzikov

  SciPost Phys. Proc. 3, 056 (2020) · published 27 February 2020 | Toggle abstract · pdf

  The recent ANKE@COSY data on the differential cross section of reaction $pd \to pd\pi\pi$ demonstrate a peak at invariant mass of the final $d\pi\pi$ system $2.38~GeV$, that corresponds to the isocalar $J^P = 3^+$ dibaryon $D_{03}$, and also enhancement in the distribution over the invariant mass of two final pions. The two-resonance model involving the $t$-channel $\sigma$-meson exchange between the proton and deuteron in the subprocess $pd\to pD_{03}$ and the sequential decays $D_{03}\to D_{12}+\pi$ and $D_{12}\to d +\pi$ was applied to describe the shapes of these distributions with the lowest orbital angular momenta in the corresponding vertices. A possible role of higher orbital momenta in those vertices is studied here.

  1 citation

• Correlations among 3N observables

  Yuriy Volkotrub, Jacek Golak, Roman Skibiński, Kacper Topolnicki, Henryk Witała

  SciPost Phys. Proc. 3, 055 (2020) · published 27 February 2020 | Toggle abstract · pdf

  We use a correlation matrix of two-nucleon (2N) potential parameters to investigate correlations among three-nucleon (3N) observables for the elastic nucleon-deuteron (Nd) scattering process. We employ the up-to-date 2N semilocal momentum-space regularized chiral interactions and the phenomenological OPE-Gaussian potential and using the Faddeev formalism we calculate 3N observables and their correlations. As an example, we present the correlation between the differential cross section and the deuteron analyzing power T20.

  1 citation

• Three-nucleon force effects in nucleon-deuteron scattering at backward angles

  Souichi Ishikawa

  SciPost Phys. Proc. 3, 054 (2020) · published 27 February 2020 | Toggle abstract · pdf

  Elastic and breakup cross sections in nucleon-deuteron scattering at intermediate energies are calculated using a realistic two-nucleon potential and three-nucleon potentials based on the exchange of two pions among three nucleons. Attractive effects of the pion-exchange at medium range region in the three-nucleon potential are recovered by using a shorter range cutoff. It is shown that these effects increase the cross sections at backward angles, which tends to reduce discrepancies between theoretical calculations and experimental data.

  2 citations

• Study of deuteron-proton backward elastic scattering at intermediate energies

  Nadezhda Ladygina

  SciPost Phys. Proc. 3, 053 (2020) · published 27 February 2020 | Toggle abstract · pdf

  We study deuteron- proton elastic scattering in the deuteron energy range between 500 MeV and 2~GeV at the cms scattering angle $\theta^*\ge 140^\circ$. The reaction is considered in the relativistic multiple scattering expansion framework. The four reaction mechanisms are included into consideration: one-nucleon exchange, single scattering, double scattering, and the term corresponding to the delta excitation in the intermediate state. The model is applied to describe the angular dependence of the differential cross section at the deuteron energies of between 880 and 1300 MeV. Also the energy dependence of the differential cross section and polarisation observables such as tensor analyzing power $T_{20}$ and polarization transfer from the deuteron to proton $\varkappa$ are considered at the scattering angle equal to 180$^\circ$. Contributions of the different reaction mechanisms into the reaction amplitude are demonstrated in comparison with the existing experimental data.

  2 citations

• Lattice phase shifts and mixing angles for an arbitrary number of coupled channels

  Lukas Bovermann, Evgeny Epelbaum, Hermann Krebs, Dean Lee

  SciPost Phys. Proc. 3, 052 (2020) · published 27 February 2020 | Toggle abstract · pdf

  We present a lattice method for determining scattering phase shifts and mixing angles for the case of an arbitrary number of coupled channels. The proposed method combines a spherical wall boundary condition and a channel-mixing auxiliary potential to extract the full-rank S-matrix from the radial wave functions. We consider the scattering problem of two spin-1 bosons interacting with a test potential involving up to four coupled channels. For this benchmark system, the phase shifts and mixing angles are shown to agree on the lattice and in the continuum. Our method should allow to extend previous two-channel nuclear lattice EFT simulations to mixing of more than two partial waves.

• Three-body correlations in mesonic-atom-like systems

  Hajime Moriya, Wataru Horiuchi, Jean-Marc Richard

  SciPost Phys. Proc. 3, 051 (2020) · published 27 February 2020 | Toggle abstract · pdf

  Three-body correlations in three-body exotic atoms are studied with simple models that consist of three bosons interacting through a superposition of long- and short-range potentials. We discuss the correlations among particles by comparing the energy shifts given by precise three-body calculations and by the Deser-Trueman formula, in which the long- and short-range contributions are factorized. By varying the coupling of the short-range potential, we evaluate the ranges of the strength where the two-body correlations dominate and where the three-body correlations cannot be neglected.

  1 citation

• An investigation of the appearance of a long range nuclear potential in ultra low energy nuclear synthesis

  Shinsho Oryu, Takashi Watanabe, Yasuhisa Hiratsuka, Masayuki Takeda

  SciPost Phys. Proc. 3, 050 (2020) · published 27 February 2020 | Toggle abstract · pdf

  A new potential, the $general$ $particle$ $transfer$ $potential$: so called ``GPT'' potential was represented in the previous paper which indicates a Yukawa-type potential for shorter range, but a $1/r^n$-type potential for longer range where $n=2$ includes the Efimov-like potential in the hadron system. In order to confirm the existence of a GPT potential, we investigate the possibility of Cs+2d$\rightarrow$La reaction on the three-ion quasi-molecule CsD$_2$ which is covered by twelve Pd or a CsD$_2$Pd$_{12}$-cluster, where the three-body bound states and wave functions for D-Cs-D molecular and d-Cs-d nuclear systems are calculated. We obtain an approximate E2-transition from the molecular states to the nuclear states. The transition ratio between the short range nuclear potential with the $1/r^2$-type long range potential and without long range potential is $W_{i\rightarrow f}^{E2';L}/W_{i\rightarrow f}^{E2';S}\approx 10^8$. If the reaction Cs+2D$\rightarrow$La is experimentally observed, then the existence of the GPT potential could be confirmed.

  2 citations