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Nuclear Theory·nucl-th

Monday·November 4, 2024

7 papers—3 primary·4 cross-listed

All7Primary3Cross-lists4
  1. 01

    A New Class of Three Nucleon Forces and their Implications

    V. Cirigliano🇺🇸 · M. Dawid🇺🇸 · W. Dekens🇺🇸 · S. Reddy🇺🇸

    We identify a new class of three-nucleon forces that arises in the low-energy effective theory of nuclear interactions including pions. We estimate their contribution to the energy of neutron and nuclear matter and find that it can be as important as the leading-order three-nucleon forces previously considered in the literature. The magnitude of this force is set by the strength of the coupling of pions to two nucleons and is presently not well constrained by experiments. The implications for nuclei, nuclear matter, and the equation of state of neutron matter are briefly discussed.

    nucl-thastro-ph.HEhep-lathep-phPRL(2025)·16 citations
  2. 02

    Scale-(in)dependence in quantum 4-body scattering

    Sourav Mondal · Rakshanda Goswami · Udit Raha · Johannes Kirscher

    We investigate the multi-channel 4-body scattering system using regularized 2- and 3-body contact interactions. The analysis determines the sensitivity of bound-state energies, scattering phase shifts and cross sections on the cutoff parameter (), and the energy gaps between scattering thresholds. The latter dependency is obtained with a 2-body scale fixed to an unnaturally large value and a floating 3-body parameter. Specifically, we calculate the binding energies of the shallow 3- and 4-body states, dimer-dimer and trimer-atom scattering lengths, and the trimer-atom to dimer-dimer reaction rates. Employing a potential renormalized by a large 2-body scattering length and a 3-body scale, we find all calculated observables to remain practically constant over the range . Divergences in scattering lengths emerge for critical 3-body parameters at which thresholds are degenerate. Such threshold effects are found to be independent of the regulator cutoff. Furthermore, at those critical points where the dimer-dimer and trimer-atom thresholds overlap, we predict an enhancement of the inelastic over the elastic scattering event. Such an inversion between elastic- and rearrangement-collision probabilities indicates a strong sensitivity of the 4-body reaction dynamics on the 3-body parameter at finite 2-body scale. This phenomenon is absent in earlier studies which differ in the renormalization scheme. As this discrepancy arises for all considered cutoffs, a more comprehensive parametrization of short-distance structure is necessary: sole cutoff variation does not reveal non-perturbative change in reaction rates conjectured to be due to a combined effect of the finite 2-body range and the specific choice for the 3-body parameter.

    nucl-thcond-mat.quant-gasphysics.atom-phEPJA(2025)·1 citation
  3. 03

    Unlocking "imprints" of conserved charges in the initial state of heavy-ion collisions

    Fernando G. Gardim · Dekrayat Almaalol · Jordi Salinas San Martín · Christopher Plumberg · Jacquelyn Noronha-Hostler

    Hydrodynamic approaches to modeling relativistic high-energy heavy-ion collisions are based on the conservation of energy and momentum. However, the medium formed in these collisions also carries additional conserved quantities, including baryon number (B), strangeness (S), and electric charge (Q). In this Letter, we propose a new set of anisotropic flow observables designed to be exclusively sensitive to the effects of conserved BSQ charge fluctuations, providing insight into the initial state. Using the recently developed hydrodynamic framework \iccing{}+\ccake{}, we show that these new observables provide a measurable effect of initial BSQ charge fluctuations (ranging up to 10\%), which can be tested by experiments.

    nucl-thhep-phnucl-ex4 citations
  4. 04

    The quark gap equation in light-cone gauge

    Roberto Correa da Silveira🇧🇷 · Fernando E. Serna🇨🇴 · Bruno El-Bennich🇧🇷

    We calculate the quark self-energy correction in light-cone gauge motivated by distribution amplitudes whose definition implies a Wilson line. The latter serves to preserve the gauge invariance of the hadronic amplitudes and becomes trivial in light-cone gauge. Therefore, the calculation of the distribution amplitudes simplifies significantly provided that wave functions and propagators are obtained in that gauge. In here, we explore the corresponding Dyson-Schwinger equation in its leading truncation and with a dressed vertex derived from a Ward identity in light-cone gauge. The quark's mass and wave renormalization functions, as well as a third complex-valued amplitude, are found to depend on the relative orientation of the quark momentum and a light-like four-vector, which expresses a geometric gauge dependence of the propagator.

    ↳ hep-phnucl-thPRD(2025)·0 citations
  5. 05

    Estimate of the -wave scattering length in the isospin-0 channel from Belle and LHCb data

    N. N. Achasov🇷🇺 · G. N. Shestakov🇷🇺

    It is shown that the Belle and LHCb data on the interference of the amplitudes of the and partial waves in the decays and allow us to obtain an estimate of the -wave scattering length in the channel with isospin : fm. The possibility of explaining the found value by the contribution of the resonance is discussed. The decay of is also briefly discussed.

    ↳ hep-phhep-exnucl-exnucl-thPRD(2025)·0 citations
  6. 06

    Isospin breaking in the Kr and Br mirror system

    A. Algora🇪🇸 · A. Vitéz-Sveiczer🇭🇺 · A. Poves🇪🇸 · G. G. Kiss🇭🇺 · B. Rubio🇪🇸 · G. de Angelis🇮🇹 · F. Recchia🇮🇹 · S. Nishimura🇯🇵 · T. Rodriguez🇪🇸 · P. Sarriguren🇪🇸 · J. Agramunt🇪🇸 · V. Guadilla🇪🇸 and 56 other authors

    Isospin symmetry is a fundamental concept in nuclear physics. Even though isospin symmetry is partially broken, it holds approximately for most nuclear systems, which makes exceptions very interesting from the nuclear structure perspective. In this framework, it is expected that the spins and parities of the ground states of mirror nuclei should be the same, in particular for the simplest systems where a proton is exchanged with a neutron or vice versa. In this work, we present evidence that this assumption is broken in the mirror pair Br and Kr system. Our conclusions are based on a high-statistics decay study of Kr and on state-of-the-art shell model calculations. In our work, we also found evidence of a new state in Se, populated in the -delayed proton emission process which can be interpreted as the long sought coexisting 0 state.

    ↳ nucl-exnucl-thPRL(2025)·6 citations
  7. 07

    Heavy element abundances from a universal primordial distribution

    G. Roepke · D. Blaschke · F. K. Roepke

    We present a freeze-out approach to the formation of heavy elements in expanding nuclear matter. Applying concepts used in the description of heavy-ion collisions or ternary fission, we determine the abundances of heavy elements taking into account in-medium effects such as Pauli blocking and the Mott effect, which describes the dissolution of nuclei at high densities of nuclear matter. With this approach, we search for a universal primordial distribution in an equilibrium state from which the gross structure of the solar abundances of heavy elements freezes out via radioactive decay of the excited states. The universal primordial state is characterized by the Lagrangian parameters of temperature and chemical potentials of neutrons and protons. We show that such a state exists and determine a temperature of 5.266 MeV, a neutron chemical potential of 940.317 MeV and a proton chemical potential of 845.069 MeV, at a baryon number density of 0.013 fm and a proton fraction of 0.13. Heavy neutron-rich nuclei such as the hypothesized double-magic nucleus Sn appear in the primordial distribution and contribute to the observed abundances after fission. We discuss astrophysical scenarios for the realization of this universal primordial distribution for heavy element nucleosynthesis, including supernova explosions, neutron star mergers and the inhomogeneous Big Bang. The latter scenario may be of interest in the light of early massive objects observed with the James Webb Space Telescope and opens new perspectives to explain universality of the observed r-process patterns and the lack of observations of population III stars.

    ↳ astro-ph.SRastro-ph.COastro-ph.HEnucl-th3 citations

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first authorsco-authorsvia INSPIRE