Nuclear Theory·nucl-th

Monday·May 30, 2022

7 papers—3 primary·4 cross-listed

01
[Submitted on 27 May 2022]
Two-dimensional extrapolation procedure for ab initio study of nuclear size parameters and the properties of halo nucleus 6He
D. M. Rodkin · Yu. M. Tchuvil'sky
A new two-dimensional procedure for extrapolation of the values of matter, neutron, and proton radii obtained in no-core shell model (NCSM) calculations to infinite size of its basis is proposed. A relationship between the radii is used as an additional test. Together with the JISP16 potential, which is frequently used in NCSM calculations of the radii, the Daejeon16 potential is applied for these purposes for the first time. Halo nucleus 6He is the object of studies. The small spread of radii values, successful testing using relationship between the values of these three radii, and reasonable agreement between the obtained results and experimental data as well as the results of other advanced ab initio calculations demonstrate the high efficiency of the developed approach and, therefore, good prospects for its application. The performed investigations and analysis of the results of other studies indicate that the halo of 6He has a large size 0.7 - 0.8 fm.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2205.13798 [pdf]
PRC(2022)·10 citations
02
[Submitted on 27 May 2022]
Quantum design in study of pycnonuclear reactions in compact stars and new quasibound states
Sergei P. Maydanyuk (1 and 2)🇭🇺 · Kostiantyn A. Shaulskyi (2) ((1) Wigner Research Center for Physics, Budapest (2) Institute for Nuclear Research, National Academy of Sciences of Ukraine, Kyiv)🇺🇦
Pycnonuclear reactions in the compact stars at zero temperatures are studied on quantum mechanical basis in the paper. Formalism of multiple internal reflections is generalized for analysis, that was developed for nuclear decays and captures by nuclei with high precision and tests. For the chosen reaction $^{12}$ C + $^{12}$ C = $^{24}$ Mg, we find the following. A quantum study of the pycnonuclear reaction requires a complete analysis of quantum fluxes in the internal nuclear region. This reduces rate and number of pycnonuclear reactions by 1.8 times. This leads to the appearance of new states (called as quasibound states) where the compound nuclear system is formed with maximal probability. As shown, minimal energy of such a state is a little higher than energy of zero-point vibrations in lattice sites in pycnonuclear reaction, however probability of formation of compound system at the quasibound state is essentially larger than the corresponding probability at state of zero-point vibrations. Hence, there is a sense to tell about reaction rates in such quasibound states as more probable, rather than states of zero-point vibrations. This can lead to the essential changes in estimation of the rates of nuclear reactions in stars.
Comments:
19 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Theory (hep-th)
arXiv:
2205.13895 [pdf]
EPJA(2022)·3 citations
03
[Submitted on 27 May 2022]
$^{10}$ Be-nucleus optical potentials developed from chiral effective field theory $N N$ interactions
V. Durant · P. Capel
We present a determination of optical potentials for $^{10}$ Be-nucleus collisions using the double-folding method to compute the real part and Kramers-Kronig dispersion relations to derive the imaginary part. As microscopic inputs we use chiral effective field theory nucleon-nucleon interactions at next-to-next-to-leading order combined with state-of-the-art nucleonic densities. With these potentials, we compute elastic scattering cross sections for the exotic nucleus 10 Be off various targets, and compare them to experiment. Without any fitting parameter, we obtain good agreement with data. For collisions on light targets, we observe significant uncertainty related to the short-range physics, whereas for heavy targets that uncertainty remains small.
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2205.13987 [pdf]
PRC(2022)·5 citations
04
[Submitted on 26 May 2022] (cross-list from hep-ph)
Light- and heavy-quark symmetries and the $Y (4230)$ , $Y (4360)$ , $Y (4500)$ , $Y (4620)$ and $X (4630)$ resonances
Fang-Zheng Peng🇨🇳 · Mao-Jun Yan🇨🇳 · Mario Sánchez Sánchez🇫🇷 · Manuel Pavon Valderrama🇨🇳
The heavy hadron spectrum is constrained by symmetries, of which two of the most important ones are heavy-quark spin and SU(3)-flavor symmetries. Here we argue that in the molecular picture the $Y (4230)$ (or $Y (4260)$ ), the $Y (4360)$ and the recently discovered $Y (4500)$ and $Y (4620)$ vector-like resonances are linked by these two symmetries. By formulating a contact-range effective field theory for the $D D ˉ_{1}$ and $D_{s} D ˉ_{s 1}$ family of S- and P-wave charmed meson-antimeson systems, we find that if the $Y (4230)$ were to be a pure $D D ˉ_{1}$ molecular state, there would be a $D^{*} D ˉ_{1}$ partner with a mass similar to the $Y (4360)$ , a $D_{s} D ˉ_{s 1}$ partner with a mass close to the $Y (4500)$ and three $J = 1, 2$ $D_{s}^{*} D ˉ_{s 1}$ and $J = 3$ $D_{s}^{*} D ˉ_{s 2}^{*}$ bound states with a mass in the vicinity of $4630 MeV$ , of which the first one ( $J = 1$ ) might correspond with the $Y (4620)$ . The previous predictions can in turn be improved by modifying the assumptions we have used to build the effective field theory. In particular, if we consider the closeness of the $D^{*} D ˉ_{1}$ - $D^{*} D ˉ_{2}^{*}$ and $D_{s}^{*} D ˉ_{s 1}$ - $D_{s}^{*} D ˉ_{s 2}^{*}$ thresholds and include the related coupled channel dynamics, we predict a $J = 2$ positive C-parity state with a mass around $4650 MeV$ . This hidden-strange and hidden-charm state might in turn be identified with the $X (4630)$ that has been discovered past year by the LHCb in the $J / ψ ϕ$ invariant mass distribution.
Comments:
21 pages, 7 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2205.13590 [pdf]
PRD(2023)·31 citations
05
[Submitted on 26 May 2022] (cross-list from hep-ph)
Heavy + heavy and heavy + light pseudoscalar to vector semileptonic transitions
Hui-Yu Xing🇨🇳 · Zhen-Ni Xu🇨🇳 · Zhu-Fang Cui🇨🇳 · Craig D. Roberts🇨🇳 · Chang Xu🇨🇳
Using a symmetry-preserving regularisation of a vector $\times$ vector contact interaction (SCI), we complete a systematic treatment of twelve semileptonic transitions with vector meson final states: $D \to ρ$ , $D_{(s)} \to K^{*}$ , $D_{s} \to ϕ$ , $B \to ρ$ , $B_{s} \to K^{*}$ , $B_{(s)} \to D_{(s)}^{*}$ , $B_{c} \to B_{(s)}^{*}, J / ψ, D^{*}$ ; and thereby finalise a unified analysis of semileptonic decays of heavy+heavy and heavy+light pseudoscalar mesons to both pseudoscalar and vector meson final states. The analysis is marked by algebraic simplicity, few parameters, and the ability to consistently describe systems from Nambu-Goldstone modes to heavy+heavy mesons. Regarding the behaviour of the transition form factors, the SCI results compare well wherever sound experimental or independent theory analyses are available; hence, the SCI branching fraction predictions should be a reasonable guide. Considering the ratios $R (D_{(s)}^{(*)})$ , $R (J / ψ)$ , $R (η_{c})$ , whose values are key tests of lepton universality in weak interactions, the SCI values agree with Standard Model predictions. The $B_{(s)} \to D_{(s)}^{*}$ transitions are used to predict the precursor functions that evolve into the universal Isgur-Wise function in the heavy-quark limit, with results that conform with those from other sources where such are available. The study also exposes effects on the transition form factors that flow from interference between emergent hadron mass from the strong interaction and Higgs boson couplings via current-quark masses, including flavour symmetry violation.
Comments:
18 pages, 9 figures, 3 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2205.13642 [pdf]
EPJC(2022)·24 citations
06
[Submitted on 27 May 2022] (cross-list from hep-ph)
Core-collapse supernovae and neutrino properties
Maria Cristina Volpe (APC, Paris)🇫🇷
We highlight developments in the domain of supernova neutrinos. We discuss the importance of the future observation, by running and upcoming experiments, of the neutrino signals from the next supernova as well as of the diffuse supernova neutrino background.
Comments:
Proceedings for the plenary talk to the "10th Symposium on Large TPCs for low-energy rare event detection", 15th-17th December 2021, 9 pages, 10 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
arXiv:
2205.13868 [pdf]
J.Phys.Conf.Ser.(2023)·1 citation
07
[Submitted on 27 May 2022] (cross-list from hep-ph)
Diffusion Monte Carlo calculations of fully-heavy compact hexaquarks
J.M. Alcaraz-Pelegrina🇪🇸 · M. C. Gordillo🇪🇸
We used a diffusion Monte Carlo technique to describe the properties of fully-heavy compact arrangements (no dibaryon molecules) including six quarks and no antiquarks within the framewok of a constituent quark model. Only arrangements whose wavefunctions were eigenvectors of $L^{2}$ with eigenvalue $ℓ$ = 0 were taken into account, what means that we only considered the subset of all the possible color-spin combinations that make the total wavefunctions antisymmetric with respect to the interchange of any two quarks of the same type. This means arrangements with spin $S = 0$ for $cccccc$ , $bbbbbb$ , $ccccc b$ , $bbbbb c$ and $ccc bbb$ and spin $S = 0, 1, 2$ for the $cccc bb$ and $bbbb cc$ hexaquarks. In all cases, the masses of the six-quark arrangements are larger that the ones corresponding to the sum of any of the two baryons we can split them into, but smaller that the ones for a set of six isolated quarks, i.e., all them are bound systems. The analysis of their structure indicates that all the hexaquarks considered in this work are compact objects, except the $ccc bbb$ , that appears to be a loose association of two baryons.
Comments:
5 pages, 4 figures; Paper has been structured in parts. Method part has been rewritten to clarify some steps. Results for cccccb and bbbbbc 1+ states and cccbbb 1+, 2+ and 3+ states has been added
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2205.13886 [pdf]
PRD(2022)·28 citations

Affiliations

first authorsco-authorsvia INSPIRE

Two-dimensional extrapolation procedure for ab initio study of nuclear size parameters and the properties of halo nucleus 6He

Quantum design in study of pycnonuclear reactions in compact stars and new quasibound states

10Be-nucleus optical potentials developed from chiral effective field theory NN interactions

Light- and heavy-quark symmetries and the Y(4230), Y(4360), Y(4500), Y(4620) and X(4630) resonances

Heavy + heavy and heavy + light pseudoscalar to vector semileptonic transitions

Core-collapse supernovae and neutrino properties

Diffusion Monte Carlo calculations of fully-heavy compact hexaquarks

Affiliations

$^{10}$ Be-nucleus optical potentials developed from chiral effective field theory $N N$ interactions

Light- and heavy-quark symmetries and the $Y (4230)$ , $Y (4360)$ , $Y (4500)$ , $Y (4620)$ and $X (4630)$ resonances