Nuclear Theory·nucl-th

Tuesday·December 27, 2022

8 papers—5 primary·3 cross-listed

01
Diquarkyonic matter: quarks, diquarks and baryons
Aaron Park🇰🇷 · Su Houng Lee🇰🇷
In this work, we investigate the color-spin interaction of a quark, a diquark and a baryon with their surrounding baryons and/or quark matter. We extend our previous work by increasing the maximum number of surrounding baryons to 5 and additionally consider all possible diquark probes that are immersed in such surroundings. This is accomplished by classifying all possible flavor and spin states of the resulting multiquark configuration in both the flavor SU(2) and SU(3) symmetric cases. We also discuss the three-body confinement potential and show that this does not contribute to the outcome. Furthermore, we find that a quark becomes more stable than a baryon when the number of surrounding baryons is three or more. Finally, when we consider the internal color-spin factor of a probe, our results show that the effects of the color-spin interaction of a multiquark configuration is consistent with the so-called diquarkyonic configuration.
nucl-thhep-phPRD(2023)·4 citations
02
Implications of Large- $N_{c}$ QCD for the NN Interaction
Thomas R. Richardson🇩🇪 · Matthias R. Schindler🇺🇸 · Roxanne P. Springer🇺🇸
We present a method for ordering two-nucleon interactions based upon their scaling with the number of QCD colors, $N_{c}$ , in the limit that $N_{c}$ becomes large. Available data in the two-nucleon sector shows general agreement with this ordering, indicating that the method may be useful in other contexts where data is less readily available. However, several caveats and potential pitfalls can make the large- $N_{c}$ ordering fragile and/or vulnerable to misinterpretation. We discuss the application of the large- $N_{c}$ analysis to two- and three-nucleon interactions, including those originating from weak and beyond-the-standard-model interactions, as well as two-nucleon external currents. Finally, we discuss some open questions in the field.
nucl-thhep-phAnn.Rev.Nucl.Part.Sci.(2023)·6 citations
03
Gamow shell model description of the radiative capture reaction $^{8}$ B $(p, γ)$ $^{9}$ C
G.X. Dong🇨🇳 · X.B. Wang🇨🇳 · N. Michel🇨🇳 · M. Płoszajczak🇫🇷
In low metallicity supermassive stars, the hot $pp$ chain can serve as an alternative way to produce the CNO nuclei. In the astrophysical environment of high temperature, the proton capture of $^{8}$ B can be faster than its beta decay, thus $^{8}$ B $(p, γ)$ $^{9}$ C reaction plays an important role in the hot $pp$ chain. Due to the unstable nature of $^{8}$ B and the lack of the $^{8}$ B beam, the measurement of $^{8}$ B $(p, γ)$ $^{9}$ C reaction can only be achieved by the indirect method, and large uncertainties exist. The Gamow shell model in the coupled-channel representation (GSM-CC) is applied to study the proton radiative capture reaction $^{8}$ B $(p, γ)$ $^{9}$ C. For the calculation of the $^{8}$ B $(p, γ)$ $^{9}$ C astrophysical factors, all E1, M1, and E2 transitions from the initial continuum states to the final bound states $3/2_{1}^{-}$ of $^{9}$ C are considered. The resonant capture to the first resonant state $1/2_{1}^{-}$ of $^{9}$ C is also calculated. The experimental low-energy levels and the proton emission threshold in $^{9}$ C are reproduced by the GSM-CC. The calculated astrophysical factors agrees with the existed experimental data from the indirect measurements. The reaction rates from the direct capture and resonant capture are calculated for the temperature range of astrophysical interest. The calculated total astrophysical $S$ factor is dominated by the E1 transition to the ground state of $^{9}$ C. The GSM-CC calculations suggest that $S$ first increase with the energy of the center of mass $E_{c.m.}$ , and then decrease with the energy. This agrees with the existing data, which has smaller values at around zero energy and larger value in the energy range of 0.2 MeV $\leq E_{c.m.} \leq$ 0.6 MeV.
nucl-thPRC(2023)·5 citations
04
Nuclear-matter saturation and symmetry energy within $Δ$ --full chiral effective field theory
W. G. Jiang🇸🇪 · C. Forssén🇸🇪 · T. Djärv🇸🇪 · G. Hagen🇺🇸
Nuclear saturation and the symmetry energy are key properties of low-energy nuclear physics that depend on fine details of the nuclear interaction. The equation-of-state around saturation is also an important anchor for extrapolations to higher densities and studies of neutron stars. Here we develop a unified statistical framework that uses realistic nuclear forces to link the theoretical modeling of finite nuclei and infinite nuclear matter. We construct fast and accurate emulators for nuclear-matter observables and employ an iterative history-matching approach to explore and reduce the enormous parameter domain of $Δ$ -full chiral interactions. We perform rigorous uncertainty quantification and find that model calibration including \nuc{16}{O} observables gives saturation predictions that are more precise than those that only use few-body data.
nucl-thPRC(2024)·22 citations
05
Emulating \emph{ab initio} computations of infinite nucleonic matter
W. G. Jiang🇸🇪 · C. Forssén🇸🇪 · T. Djärv🇸🇪 · G. Hagen🇺🇸
We construct efficient emulators for the \emph{ab initio} computation of the infinite nuclear matter equation of state. These emulators are based on the subspace-projected coupled-cluster method for which we here develop a new algorithm called small-batch voting to eliminate spurious states that might appear when emulating quantum many-body methods based on a non-Hermitian Hamiltonian. The efficiency and accuracy of these emulators facilitate a rigorous statistical analysis within which we explore nuclear matter predictions for $> 1 0^{6}$ different parametrizations of a chiral interaction model with explicit $Δ$ -isobars at next-to-next-to leading order. Constrained by nucleon-nucleon scattering phase shifts and bound-state observables of light nuclei up to \nuc{4}{He}, we use history matching to identify non-implausible domains for the low-energy coupling constants of the chiral interaction. Within these domains we perform a Bayesian analysis using sampling/importance resampling with different likelihood calibrations and study correlations between interaction parameters, calibration observables in light nuclei, and nuclear matter saturation properties.
nucl-thPRC(2024)·35 citations
06
Unpolarized proton PDF at NNLO from lattice QCD with physical quark masses
Xiang Gao🇺🇸 · Andrew D. Hanlon🇺🇸 · Jack Holligan🇺🇸 · Nikhil Karthik🇺🇸 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Sergey Syritsyn🇺🇸 · Yong Zhao🇺🇸
We present a lattice QCD calculation of the unpolarized isovector quark parton distribution function (PDF) of the proton utilizing a perturbative matching at next-to-next-to-leading-order (NNLO). The calculations are carried out using a single ensemble of gauge configurations generated with $N_{f} = 2 + 1$ highly-improved staggered quarks with physical masses and a lattice spacing of $a = 0.076$ fm. We use one iteration of hypercubic smearing on these gauge configurations, and the resulting smeared configurations are then used for all aspects of the subsequent calculation. For the valence quarks, we use the Wilson-clover action with physical quark masses. We consider several methods for extracting information on the PDF. We first extract the lowest four Mellin moments using the leading-twist operator product expansion approximation. Then, we determine the $x$ dependence of the PDF through a deep neural network within the pseudo-PDF approach and additionally through the framework of large-momentum effective theory utilizing a hybrid renormalization scheme. This is the first application of the NNLO matching coefficients for the nucleon directly at the physical point.
↳ hep-lathep-exhep-phnucl-ex+1PRD(2023)·57 citations
07
Collective flow of light nuclei and hyper-nuclei in Au+Au collisions at $s_{N N}$ = 3, 14.6, 19.6, 27, and 54.4 GeV using the STAR detector
Rishabh Sharma🇮🇳
Light nuclei and hyper-nuclei are produced in abundance in heavy-ion collisions. The production mechanism of these species in heavy-ion collisions still remains to be understood. In these proceedings, we report the transverse momentum and centrality dependence of elliptic flow ( $v_{2}$ ) of $d$ , $t$ , and $^{3} He$ in Au+Au collisions at $s_{N N}$ = 14.6, 19.6, 27, and 54.4 GeV. Mass number scaling of $v_{2} (p_{T})$ of light nuclei is shown. We also report the first observation of hyper-nuclei $_{Λ}^{3}$ H and $_{Λ}^{4}$ H directed flow ( $v_{1}$ ) in $s_{N N}$ = 3 GeV mid-central (5-40\%) Au+Au collisions in the fixed target mode.
↳ nucl-exhep-exhep-phnucl-thEPJ Web Conf.(2023)·2 citations
08
Unbound states in 17C and p-sd shell-model interactions
Sunji Kim🇰🇷 · Jongwon Hwang🇰🇷 · Yoshiteru Satou🇰🇷 · Nigel A. Orr🇫🇷 · Takashi Nakamura🇯🇵 · Yosuke Kondo🇯🇵 · Julien Gibelin🇫🇷 · Nadia Lynda Achouri🇫🇷 · Thomas Aumann🇩🇪 · Hidetada Baba🇯🇵 · Franck Delaunay🇫🇷 · Pieter Doornenbal🇯🇵 and 33 other authors
Unbound states in 17C were investigated via one-neutron removal from a 18C beam at an energy of 245 MeV/nucleon on a carbon target. The energy spectrum of 17C, above the single-neutron decay threshold, was reconstructed using invariant mass spectroscopy from the measured momenta of the 16C fragment and neutron, and was found to exhibit resonances at Er=0.52(2), 0.77(2), 1.36(1), 1.91(1), 2.22(3) and 3.20(1) MeV. The resonance at Er=0.77(2) MeV [Ex=1.51(3) MeV] was provisionally assigned as the second 5/2+ state. The two resonances at Er=1.91(1) and 3.20(1) MeV [Ex=2.65(2) and 3.94(2) MeV] were identified, through comparison of the energies, cross sections and momentum distributions with shell-model and eikonal reaction calculations, as p-shell hole states with spin-parities 1/2- and 3/2-, respectively. A detailed comparison was made with the results obtained using a range of shell-model interactions. The YSOX shell-model Hamiltonian, the cross-shell part of which is based on the monopole-based universal interaction, was found to provide a very good description of the present results and those for the neighbouring odd-A carbon isotopes - in particular for the negative parity cross-shell states.
↳ nucl-exnucl-thPLB(2023)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE