Nuclear Theory·nucl-th

Wednesday·September 11, 2024

10 papers—3 primary·7 cross-listed

01
Quantum computing for extracting nuclear resonances
Hantao Zhang🇨🇳 · Dong Bai🇨🇳 · Zhongzhou Ren🇨🇳
Quantum computing has been increasingly applied in nuclear physics. In this work, we combine quantum computing with the complex scaling method to address the resonance problem. Due to the non-Hermiticity introduced by complex scaling, standard quantum computing cannot solve for complex eigenvalues directly. Therefore, it is necessary to embed the non-Hermitian operator into a larger dimensional unitary operator. Additionally, for the case of two basis vectors, we improve the traditional direct measurement method and optimize the quantum circuit. Ultimately, using the $α + α$ system as an example, we obtain the complex eigenenergies from the quantum computer that are consistent with those obtained from direct Hamiltonian diagonalization.
nucl-thPLB(2025)·13 citations
02
Strangeness in Astrophysics
Laura Tolos🇪🇸
In this contribution the role of strangeness in astrophysics is discussed and, more precisely, strange hadronic matter in the interior of neutron stars. A special attention is payed to certain phenomena involving strange hadronic matter, such as the hyperon puzzle, kaon condensation and the thermal behaviour of hyperons in neutron star mergers.
nucl-thastro-ph.HEEPJ Web Conf.(2025)·1 citation
03
Beam energy dependence of net-hyperon yield and its implication on baryon transport mechanism
Chun Yuen Tsang🇺🇸 · Rongrong Ma🇺🇸 · Prithwish Tribedy🇺🇸 · Zhangbu Xu🇺🇸
In the constituent quark model, each quark inside a baryon carries 1/3 unit of the baryon number. An alternative picture exists where the center of a Y-shaped topology of gluon fields, called the baryon junction, carries a unit baryon number. Studying baryon transport over a large rapidity gap ( $δ y$ ) in nuclear collisions provides a possible tool to distinguish these two pictures. A recent analysis of global data on net-proton yield at mid-rapidity in Au+Au collisions showed an exponential dependence on $δ y$ and the exponential slope does not vary with event centrality, favoring the baryon junction picture. Since junctions are flavor blind, hyperons -- baryons containing valence strange quarks -- are expected to exhibit a similar behavior as the proton. This study aims to test this prediction by analyzing hyperon yields in Au+Au collisions at various energies. We observe that net-hyperon yields, after correcting for the strangeness production suppression, adhere to the expected exponential form. The extracted slope parameters for net- $Λ$ , net- $Ξ$ and net- $Ω$ are consistent with each other and with those of net-proton within uncertainties, and exhibit no centrality dependence, further substantiating the baryon junction picture. Various implementations of the \texttt{PYTHIA} event generator, primarily based on valence quarks for baryon transport, are unable to simultaneously describe the slope parameters for all baryons.
nucl-thnucl-exPLB(2025)·3 citations
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
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 $K^{*} (892)$ resonance not too far from threshold. We propose a method to extend the energy range serviceable for this purpose by reconstructing the $K^{*} (892)$ contribution model-independently from its $K π$ 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
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
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
08
Implication of a negative effective range on the $D D ˉ^{*}$ interaction and the nature of $X (3872)$
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 $X (3872)$ . This has attracted intensive discussions on whether $X (3872)$ can be deemed as a $D D ˉ^{*}$ molecular state. This work explicitly demonstrates that the negative effective range of the $X (3872)$ does not contradict the molecular picture, adopting an effective field theory formulation of the $D D ˉ^{*}$ interaction that can simultaneously reproduce the binding energy and effective range of the $X (3872)$ . We elaborate on the implications of the large negative effective range of $X (3872)$ and the small binding energy on the underlying $D D ˉ^{*}$ interaction. Such results are relevant for a better understanding of hadronic molecules and their binding mechanism.
↳ hep-phnucl-thPRD(2025)·8 citations
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
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