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Nuclear Theory·nucl-th

Wednesday·September 11, 2024

10 papers—3 primary·7 cross-listed

All10Primary3Cross-lists7
  1. 04

    Are these quasi-normal modes?

    Gustavo Godinho🇧🇷 · Willians Barreto🇧🇷

    We discuss how to extract numerically the expected lowest quasi-normal mode (QNM) associated with the pressure anisotropy for a Bjorken flux evolution to equilibrium. This QNM was easily decoded subtracting the hydrodynamical attractors and was compared with other authors calculations. After evolutions with transients close to the expected lowest QNM the system goes to a tail (pure imaginary frequency) for late times. We analyze the relevance of Navier-Stokes, second order and Borel attractors at each stage of the evolution, which begins far-from-equilibrium and ends close to equilibrium.

    ↳ hep-thhep-phnucl-thRevista Brasileira de Fisica, vol. 4, num…·1 citation
  2. 05

    Polarizabilities from kaon Compton scattering

    Dominik Stamen🇩🇪 · Jan Luca Dammann🇩🇪 · Yannis Korte🇩🇪 · Bastian Kubis🇩🇪

    The polarizabilities of light pseudoscalar mesons can be extracted from differential cross sections for Compton scattering near threshold. While this has been accomplished for charged pions employing Primakoff reactions, a corresponding measurement for kaons will be affected by the presence of the resonance not too far from threshold. We propose a method to extend the energy range serviceable for this purpose by reconstructing the contribution model-independently from its intermediate state, using dispersion theory. We point out that, in contrast to the charged-pion analog, there is likely no strong hierarchy between sum and difference of electric and magnetic dipole polarizabilities; we discuss the sensitivity to disentangling both by improved experimental angular coverage.

    ↳ hep-phhep-exnucl-thEPJC(2024)·7 citations
  3. 06

    Factorization for jet production in heavy-ion collisions

    Yacine Mehtar-Tani🇺🇸 · Felix Ringer🇺🇸 · Balbeer Singh🇺🇸 · Varun Vaidya🇺🇸

    We develop an Effective Field Theory approach for jet observables in heavy-ion collisions, where the jet is treated as an open quantum system interacting with a hot and dense QCD medium. Within this framework, we derive a novel factorization formula for inclusive jet production, expressed as a series expansion with an increasing number of radiating subjet functions that encode forward scattering with the Quark-Gluon Plasma, convolved with perturbative matching coefficients. This work provides a systematic framework for computing jet observables at higher order and understanding their non-perturbative aspects, paving the way for future applications in heavy-ion phenomenology.

    ↳ hep-phhep-exnucl-exnucl-thPLB(2025)·18 citations
  4. 07

    Big Bang Nucleosynthesis

    Ryan Cooke (Centre for Extragalactic Astronomy, Durham University)🇬🇧

    One of the most compelling pieces of evidence of the Hot Big Bang model is the realisation and confirmation that some nuclides were created shortly after the Big Bang. This process is referred to as Big Bang nucleosynthesis (or, sometimes, primordial nucleosynthesis), and is the end-product of putting neutrons and protons in a hot, expanding Universe. Big Bang nucleosynthesis currently provides our earliest test of cosmology, and it is the only experiment currently designed that is simultaneously sensitive to all four known fundamental forces: the gravitational force, the electromagnetic force, the strong force and the weak force. Our theoretical understanding of Big Bang nucleosynthesis and the measurement of the primordial abundances together represents one of the strongest pillars of the standard cosmological model. In this chapter, we will develop an intuitive understanding of Big Bang nucleosynthesis, discuss modern calculations of this process, and provide a summary of the current state-of-the-art measurements that have been made. Overall, Big Bang nucleosynthesis is in remarkable agreement with various cosmological probes, and it is this agreement that serves to strengthen our confidence in the general picture of cosmology that we have today.

    ↳ astro-ph.COnucl-exnucl-th18 citations
  5. 08

    Implication of a negative effective range on the interaction and the nature of

    Yi-Bo Shen🇨🇳 · Ming-Zhu Liu🇨🇳 · Zhi-Wei Liu🇨🇳 · Li-Sheng Geng🇨🇳

    A recent analysis of the LHCb data [Phys. Rev. D 105 (2022) L031503] obtained a sizable negative effective range for the . This has attracted intensive discussions on whether can be deemed as a molecular state. This work explicitly demonstrates that the negative effective range of the does not contradict the molecular picture, adopting an effective field theory formulation of the interaction that can simultaneously reproduce the binding energy and effective range of the . We elaborate on the implications of the large negative effective range of and the small binding energy on the underlying interaction. Such results are relevant for a better understanding of hadronic molecules and their binding mechanism.

    ↳ hep-phnucl-thPRD(2025)·8 citations
  6. 09

    Simulating continuous-space systems with quantum-classical wave functions

    Friederike Metz · Gabriel Pescia · Giuseppe Carleo

    Most non-relativistic interacting quantum many-body systems, such as atomic and molecular ensembles or materials, are naturally described in terms of continuous-space Hamiltonians. The simulation of their ground-state properties on digital quantum computers is challenging because current algorithms require discretization, which usually amounts to choosing a finite basis set, inevitably introducing errors. In this work, we propose an alternative, discretization-free approach that combines classical and quantum resources in a global variational ansatz, optimized using the framework of variational Monte Carlo. We introduce both purely quantum as well as hybrid quantum-classical ansatze and benchmark them on three paradigmatic continuous-space systems that are either very challenging or beyond the reach of current quantum approaches: the one-dimensional quantum rotor model, a system of Helium-3 particles in one and two dimensions, and the two-dimensional homogeneous electron gas. We embed relevant constraints such as the antisymmetry of fermionic wave functions directly into the ansatz. Many-body correlations are introduced via backflow transformations represented by parameterized quantum circuits. We demonstrate that the accuracy of the simulation can be systematically improved by increasing the number of circuit parameters and study the effects of shot noise. Furthermore, we show that the hybrid ansatz improves the ground-state energies obtained using the purely classical wave function.

    ↳ quant-phcond-mat.str-elnucl-thphysics.comp-ph3 citations
  7. 10

    Structure of near-threshold resonances with new interpretation scheme of complex compositeness

    Tomona Kinugawa🇯🇵 · Tetsuo Hyodo🇯🇵

    The nature of near-threshold resonances is quantitatively studied with a new interpretation scheme using the complex compositeness. A difficulty was known in the understanding of the internal structure of unstable resonances because their complex compositeness is not an interpretable measure. To overcome this problem, we develop a new interpretation scheme respecting the ambiguous aspects of the identification of the internal structure of resonances. We then apply the interpretation scheme to the near-threshold resonances slightly above the threshold, described by the effective range expansion. With the new interpretation scheme, we show that near-threshold resonances are dominated by the non-molecular component. Namely, even in the near-threshold region, the nature of resonances is sharply contrasted with bound states whose internal structure is usually molecular dominant.

    ↳ hep-phnucl-thJ.Subatomic Part.Cosmol.(2024)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE