Nuclear Theory·nucl-th

Wednesday·June 9, 2021

15 papers—8 primary·7 cross-listed

01
[Submitted on 8 Jun 2021]
Evolution of octupole deformation and collectivity in neutron-rich lanthanides
K. Nomura · R. Rodríguez-Guzmán · L. M. Robledo · J. E. García-Ramos · N. C. Hernández
The onset of octupole deformation and its impact on related spectroscopic properties is studied in even-even neutron-rich lanthanide isotopes Xe, Ba, Ce, and Nd with neutron number $86 ⩽ N ⩽ 94$ . Microscopic input comes from the Hartree-Fock-Bogoliubov approximation with constrains on the axially symmetric quadrupole and octupole operators using the Gogny-D1M interaction. At the mean-field level, reflection asymmetric ground states are predicted for isotopes with neutron number around $N = 88$ . Spectroscopic properties are studied by diagonalizing the interacting boson model Hamiltonian, with the parameters obtained via the mapping of the mean-field potential energy surface onto the expectation value of the Hamiltonian in the $s$ , $d$ , and $f$ boson condensate state. The results obtained for low-energy positive- and negative-parity excitation spectra as well as the electric dipole, quadrupole, and octupole transition probabilities indicate the onset of pronounced octupolarity for $Z \approx 56$ and $N \approx 88$ nuclei.
Comments:
15 pages, 13 figures, 2 tables
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2106.04076 [pdf]
PRC(2021)·34 citations
02
[Submitted on 8 Jun 2021]
Revisiting the variational two-particle reduced density matrix for nuclear systems
J. G. Li · N. Michel · W. Zuo · F. R.Xu
In most nuclear many-body methods, observables are calculated using many-body wave functions explicitly. The variational two-particle reduced density matrix method is one of the few exceptions to the rule. Ground-state energies of both closed-shell and open-shell nuclear systems can indeed be evaluated by minimizing a constrained linear functional of the two-particle reduced density matrix. However, it has virtually never been used in nuclear theory, because nuclear ground states were found to be well overbound, contrary to those of atoms and molecules. Consequently, we introduced new constraints in the nuclear variational two-particle reduced density matrix method, developed recently for atomic and molecular systems. Our calculations then show that this approach can provide a proper description of nuclear systems where only valence neutrons are included. For the nuclear systems where both neutrons and protons are active, however, the energies obtained with the variational two-particle reduced density matrix method are still overbound. The possible reasons for the noticed discrepancies and solutions to this problem will be discussed.
Comments:
14 pages, 9 figures
Subjects:
Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph); physics.chem-ph (physics.chem-ph)
arXiv:
2106.04103 [pdf]
PRC(2021)·1 citation
03
[Submitted on 8 Jun 2021]
Constraints on the phase transition and nuclear symmetry parameters from PSR $J 0740 + 6620$ and multimessenger data of other neutron stars
Shao-Peng Tang🇨🇳 · Jin-Liang Jiang🇨🇳 · Ming-Zhe Han🇨🇳 · Yi-Zhong Fan🇨🇳 · Da-Ming Wei🇨🇳
Recently, the radius of neutron star (NS) PSR J0740+6620 was measured by Neutron Star Interior Composition Explorer (NICER) and an updated measurement of neutron skin thickness of $^{208}$ Pb ( $R_{skin}^{208}$ ) was reported by the PREX-II experiment. These new measurements can help us better understand the unknown equation of state (EOS) of dense matter. In this work, we adopt a hybrid parameterization method, which incorporates the nuclear empirical parameterization and some widely used phenomenological parameterizations, to analyze the results of nuclear experiments and astrophysical observations. With the joint Bayesian analysis of GW170817, PSR J0030+0451, and PSR J0740+6620, the parameters that characterize the ultradense matter EOS are constrained. We find that the slope parameter $L$ is approximately constrained to $7 0_{- 18}^{+ 21}$ MeV, which predicts $R_{skin}^{208} = 0.20 4_{- 0.026}^{+ 0.030} fm$ by using the universal relation between $R_{skin}^{208}$ and $L$ . The bulk properties of canonical $1.4 M_{⊙}$ NS (e.g., $R_{1.4}$ and $Λ_{1.4}$ ) as well as the pressure ( $P_{2 ρ_{sat}}$ ) at two times the nuclear saturation density are well constrained by the data; i.e., $R_{1.4}$ , $Λ_{1.4}$ , and $P_{2 ρ_{sat}}$ are approximately constrained to $12.3 \pm 0.7$ km, $33 0_{- 100}^{+ 140}$ , and $4. 1_{- 1.2}^{+ 1.5} \times 1 0^{34} dyn c m^{- 2}$ , respectively. Besides, we find that the Bayes evidences of the hybrid star and normal NS assumptions are comparable, which indicates that current observation data are compatible with quarkyonic matter existing in the core of massive star. Finally, in the case of normal NS assumption, we obtain a constraint for the maximum mass of nonrotating NS $M_{TOV} = 2.3 0_{- 0.18}^{+ 0.30}$ $M_{⊙}$ . All of the uncertainties reported above are for 68.3% credible levels.
Comments:
12 pages, 7 figures, published in PRD
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2106.04204 [pdf]
PRD(2021)·41 citations
04
[Submitted on 8 Jun 2021]
Production cross sections of $_{Λ}^{3, 4}$ H bound states in $^{3, 4}$ He( $K^{-}$ , $π^{0}$ ) reactions at 1 GeV/ $c$
Toru Harada🇯🇵 · Yoshiharu Hirabayashi🇯🇵
We investigate theoretically productions of $_{Λ}^{3, 4}$ H bound states in the exothermic ( $K^{-}$ , $π^{0}$ ) reactions on $^{3, 4}$ He targets at $p_{K^{-}} =$ 1.0 GeV/c in a distorted-wave impulse approximation with the optimal Fermi-averaging $K^{-} p \to π^{0} Λ$ $t$ matrix. We calculate angular distributions of the laboratory differential cross sections $d σ / d Ω_{lab}$ and the integrated cross sections $σ_{lab}$ for a $J^{P} = 0^{+}$ ground state and a $J^{P} = 1^{+}$ excited state of $_{Λ}^{4}$ H at $π^{0}$ forward-direction angles of $θ_{lab} =$ 0 $^{\circ}$ -20 $^{\circ}$ , and those for a $J^{P} = 1/ 2^{+}$ ground state of $_{Λ}^{3}$ H. The production of a $J^{P} = 3/ 2^{+}$ excited state of $_{Λ}^{3}$ H as a virtual state is also evaluated. The comparison in $d σ / d Ω_{lab}$ and $σ_{lab}$ between $_{Λ}^{4}$ H and $_{Λ}^{3}$ H provides examining the mechanism of the production and structure of $_{Λ}^{3, 4}$ H, as well as in the endothermic ( $π^{-}$ , $K^{0}$ ) reactions at $p_{π^{-}} =$ 1.05 GeV/c. This investigation confirms the feasibility of lifetime measurements of $_{Λ}^{3}$ H at the J-PARC experiments.
Comments:
22 pages, 5 figures, 4 tables
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2106.04256 [pdf]
NPA(2021)·7 citations
05
[Submitted on 8 Jun 2021]
$^{12} C +^{12} C$ Fusion $S^{*}$ -factor from a Full-microscopic Nuclear Model
Yasutaka Taniguchi · Masaaki Kimura
The $^{12} C +^{12} C$ fusion reaction plays a vital role in the explosive phenomena of the universe. The resonances in the Gamow window rule its reaction rate and products. Hence, the determination of the resonance parameters by nuclear models is indispensable as the direct measurement is not feasible. Here, for the first time, we report the resonances in the $^{12} C +^{12} C$ fusion reaction described by a full-microscopic nuclear model. The model plausibly reproduces the measured low-energy astrophysical $S$ -factors and predicts the resonances in the Gamow window. Contradictory to the hindrance model, we conclude that there is no low-energy suppression of the $S$ -factor.
Comments:
5 pages, 2 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2106.04321 [pdf]
PLB(2021)·30 citations
06
[Submitted on 8 Jun 2021]
Implications of PREX--2 data on the electron--neutrino opacity in dense matter
Parada T.P. Hutauruk🇰🇷
Motivated by the recent measurement of the neutron distribution radius of $^{208}$ Pb from the PREX--2 data, I study the effects of the new G3(M) parameter set constrained by PREX--2 data on the electron--neutrino scattering in dense matter using the extended relativistic mean field (E--RMF) model. I employ the G3(M) parameter set to describe the nuclear matter. The obtained equation of state for the G3(M) parameter set has an excellent agreement with experimental data and the chiral effective field theory calculation with N $^{3}$ LO 3N forces. I analyze both differential cross section of electron--neutrino and electron--neutrino mean free path to observe their sensitivity to the G3(M) parameter set. One finds that the differential cross sections of electron--neutrino for different baryon densities have higher values compared with that obtained for the TM1e and FSU Garnet parameter sets. The higher cross section decreases the electron--neutrino mean free path.
Comments:
8 pages, 7 figures, to appear in Phys. Rev. C
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2106.04474 [pdf]
PRC(2021)·5 citations
07
[Submitted on 8 Jun 2021]
Ground State Properties of Charmed Hypernuclei with Mean Field Approach
H. Güven🇫🇷 · K. Bozkurt🇫🇷 · E. Khan🇫🇷 · J. Margueron🇫🇷
Closed shell charmed hypernuclei $_{Λ_{c}}^{5}$ Li, $_{Λ_{c}}^{17}$ F, $_{Λ_{c}}^{41}$ Sc, $_{Λ_{c}}^{57}$ Cu, $_{Λ_{c}}^{133}$ Sb and $_{Λ_{c}}^{209}$ Bi are calculated within Hartree-Fock approach by using three different force sets derived from microscopic Brueckner-Hartree-Fock calculations of $Λ$ hypernuclei. Ground state properties (binding energies, $Λ_{c}$ separation energies, $Λ_{c}$ single particle energies and $Λ_{c}$ densities) of charmed nuclei are examined. Due to the Coulomb repulsion between protons and the $Λ_{c}$ baryon, charmed hypernuclei are most bound for $16 \leq$ A $\leq 41$ , where $_{Λ_{c}}^{17}$ F can be considered as an excellent candidate to measure charmed hypernuclei. The competition between the attractive nucleon- $Λ_{c}$ interaction and the Coulomb repulsion is discussed, and we compare $Λ$ and $Λ_{c}$ hypernuclei properties.
Comments:
9 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2106.04491 [pdf]
PRC(2021)·5 citations
08
[Submitted on 8 Jun 2021]
Hubble Expansion and Freeze-Out at RHIC-BES Energies from UrQMD
Gabriele Inghirami🇩🇪 · Tom Reichert🇩🇪 · Marcus Bleicher🇩🇪
The freeze-out process in heavy ion collisions is driven by the competition between the scattering rate and the expansion rate of the matter. We analyse the expansion rate $Θ$ (often called Hubble flow) in relativistic heavy ion collisions in the FAIR and RHIC-BES energy regimes and compare it to the scattering rate $Γ$ using the UrQMD transport model. We observe that the time evolution of the system is clearly separated into a compression phase and an expansion phase with time dependent $Θ_{∥}$ and $Θ_{⊥}$ . The calculated values of the Hubble expansion at kinetic decoupling are in line with previous simple estimates by statistical hadronization models with a Siemens-Rasmussen type emission source. However, the actual shape of the expanding matter is, as expected, found to be between a spherically symmetric and a purely longitudinal expansion. We confirm for the first time in a microscopic simulation that the decoupling hypersurface is indeed determined by the competition of the expansion rate $Θ$ and the scattering rate $Γ$ as suggested previously. This suggests that, in the range of collision energies explored in this study, simple iso-thermal/iso-energy density criteria that are often used in hybrid models to couple hydrodynamic and transport simulations may not capture the true decoupling hyper-surface.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2106.04543 [pdf]
5 citations
09
[Submitted on 6 Jun 2021] (cross-list from hep-lat)
Lattice QCD Equation of State for Nonvanishing Chemical Potential by Resumming Taylor Expansion
Sourav Mondal🇮🇳 · Swagato Mukherjee🇺🇸 · Prasad Hegde🇮🇳
Taylor expansion in powers of baryon chemical potential ( $μ_{B}$ ) is an oft-used method in lattice QCD to compute QCD thermodynamics for $μ_{B} > 0$ . Based only upon the few known lowest order Taylor coefficients, it is difficult to discern the range of $μ_{B}$ where such an expansion around $μ_{B} = 0$ can be trusted. We introduce a resummation scheme for the Taylor expansion of the QCD equation of state in $μ_{B}$ that is based on the $n$ -point correlation functions of the conserved current ( $D_{n}$ ). The method resums the contributions of the first $N$ correlation function $D_{1}, \dots, D_{N}$ to the Taylor expansion of the QCD partition function to all orders in $μ_{B}$ . We show that the resummed partition function is an approximation to the reweighted partition function at $μ_{B} \neq = 0$ . We apply the proposed approach to high-statistics lattice QCD calculations using 2+1 flavors of Highly Improved Staggered Quarks with physical quark masses on $3 2^{3} \times 8$ lattices and for temperatures $T \approx 145$ -176 MeV. We demonstrate that, as opposed to the Taylor expansion, the resummed version not only leads to improved convergence but also reflects the zeros of the resummed partition function and severity of the sign problem, leading to its eventual breakdown. We also provide a generalization of our scheme to include resummation of powers of temperature and quark masses in addition to $μ_{B}$ , and show that the alternative expansion scheme of [S. Borsányi et al., Phys. Rev. Lett. 126, 232001 (2021).] is a special case of this generalized resummation.
Comments:
Resubmitted to match with the journal version of the paper
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2106.03165 [pdf]
PRL(2022)·45 citations
10
[Submitted on 7 Jun 2021] (cross-list from hep-ph)
Partonic collinear structure by quantum computing
Tianyin Li🇨🇳 · Xingyu Guo🇨🇳 · Wai Kin Lai🇨🇳 · Xiaohui Liu🇨🇳 · Enke Wang🇨🇳 · Hongxi Xing🇨🇳 · Dan-Bo Zhang🇨🇳 · Shi-Liang Zhu🇨🇳
We present a systematic quantum algorithm, which integrates both the hadronic state preparation and the evaluation of real-time light-front correlators, to study parton distribution functions (PDFs). As a proof of concept, we demonstrate the first direct simulation of the PDFs in the 1+1 dimensional Nambu-Jona-Lasinio model. We show the results obtained by exact diagonalization and by quantum computation using classical hardware. The agreement between these two distinct methods and the qualitative consistency with QCD PDFs validate the proposed quantum algorithm. Our work suggests the encouraging prospects of calculating QCD PDFs on current and near-term quantum devices. The presented quantum algorithm is expected to have many applications in high energy particle and nuclear physics.
Comments:
6 pages, 3 figures, published version in PHYSICAL REVIEW D (Letter)
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2106.03865 [pdf]
PRD(2022)·76 citations
11
[Submitted on 7 Jun 2021] (cross-list from hep-lat)
Bayesian-Wilson coefficients in lattice QCD computations of valence PDFs and GPDs
Nikhil Karthik🇺🇸 · Raza Sabbir Sufian🇺🇸
We propose an analysis method for the leading-twist operator product expansion based lattice QCD determinations of the valence parton distribution function (PDF). In the first step, we determine the confidence-intervals of the leading-twist $MS$ Wilson coefficients, $C_{n} (μ^{2} z^{2})$ , of the equal-time bilocal quark bilinear, given the lattice QCD matrix element of Ioffe-time distribution for a particular hadron $H$ as well as the prior knowledge of the valence PDF, $f (x, μ)$ of the hadron $H$ determined via global fit from the experimental data. In the next step, we apply the numerically estimated $C_{n}$ in the lattice QCD determinations of the valence PDFs of other hadrons, and for the zero-skewness generalized parton distribution (GPD) of the same hadron $H$ at non-zero momentum transfers. Our proposal still assumes the dominance of leading-twist terms, but it offers a pragmatic alternative to the usage of perturbative Wilson coefficients and their associated higher-loop uncertainties such as the effect of all-order logarithms at larger sub-Fermi quark-antiquark separations $z$ .
Comments:
13 pages, 5 figures; published version
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2106.03875 [pdf]
PRD(2021)·9 citations
12
[Submitted on 7 Jun 2021] (cross-list from hep-ph)
Orbital Angular Momentum Distribution of Gluons at Small- $x$ : Analytic interpolation between Ji and Jaffe-Manohar
Raktim Abir🇮🇳 · Khatiza Banu🇮🇳 · Nahid Vasim🇮🇳
In this work, we first introduced a generalized Wilson line gauge link that reproduces both staple and near straight links along the light cone in different parameter limits. We then studied the gauge-invariant bi-local orbital angular momentum operator with such a general gauge link, in the framework of Chen et. al. decomposition of gauge fields. At the appropriate combination of limits, the operator reproduces both Jaffe-Manohar and Ji's operator structure and offers a continuous analytical interpolation between the two.
Comments:
13 pages, 3 figures, version to appear in Physical Review D
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2106.03896 [pdf]
PRD(2022)·8 citations
13
[Submitted on 8 Jun 2021] (cross-list from nucl-ex)
Measurement and Modeling of Proton-Induced Reactions on Arsenic from 35 to 200 MeV
Morgan B. Fox🇺🇸 · Andrew S. Voyles🇺🇸 · Jonathan T. Morrell🇺🇸 · Lee A. Bernstein🇺🇸 · Jon C. Batchelder🇺🇸 · Eva R. Birnbaum🇺🇸 · Cathy S. Cutler🇺🇸 · Arjan J. Koning🇦🇹 · Amanda M. Lewis🇺🇸 · Dmitri G. Medvedev🇺🇸 · Francois M. Nortier🇺🇸 · Ellen M. O'Brien🇺🇸 · Christiaan Vermeulen🇺🇸
$^{72}$ As is a promising positron emitter for diagnostic imaging that can be employed locally using a $^{72}$ Se generator. However, current reaction pathways to $^{72}$ Se have insufficient nuclear data for efficient production using regional 100-200 MeV high-intensity proton accelerators. In order to address this deficiency, stacked-target irradiations were performed at LBNL, LANL, and BNL to measure the production of the $^{72}$ Se/ $^{72}$ As PET generator system via $^{75}$ As(p,x) between 35 and 200 MeV. This work provides the most well-characterized excitation function for $^{75}$ As(p,4n) $^{72}$ Se starting from threshold. Additional focus was given to report the first measurements of $^{75}$ As(p,x) $^{68}$ Ge and bolster an already robust production capability for the highly valuable $^{68}$ Ge/ $^{68}$ Ga PET generator. Thick target yield comparisons with prior established formation routes to both generators are made. In total, high-energy proton-induced cross sections are reported for 55 measured residual products from $^{75}$ As, Cu, and Ti targets, where the latter two materials were present as monitor foils. These results were compared with literature data as well as the default theoretical calculations of the nuclear model codes TALYS, CoH, EMPIRE, and ALICE. Reaction modeling at these energies is typically unsatisfactory due to few prior published data and many interacting physics models. Therefore, a detailed assessment of the TALYS code was performed with simultaneous parameter adjustments applied according to a standardized procedure. Particular attention was paid to the formulation of the two-component exciton model in the transition between the compound and pre-equilibrium regions, with a linked investigation of level density models for nuclei off of stability and their impact on modeling predictive power.
Comments:
35 pages (+5 for references), 69 figures, preprint prepared for Physical Review Journals, minor revisions for references to recently published work
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2106.04115 [pdf]
PRC(2021)·13 citations
14
[Submitted on 8 Jun 2021] (cross-list from hep-ph)
From quarks and gluons to color superconductivity at supranuclear densities
Jens Braun🇩🇪 · Benedikt Schallmo🇩🇪
We study the emergence of color superconductivity in the theory of the strong interaction at supranuclear densities. To this end, we follow the renormalization group (RG) flow of dense strong-interaction matter with two massless quark flavors from the fundamental quark and gluon degrees of freedom at high energies down to the non-perturbative low-energy regime which is found to be governed by the dynamical formation of diquark states. With the strong coupling at the initial RG scale as the only input parameter, we compute the (chirally symmetric) scalar diquark condensate and analyze its scaling behavior over a wide range of the quark chemical potential. Approximations entering our computations are critically assessed. Since our approach naturally allows us to study the scale dependence of couplings, we also monitor the strength of couplings appearing in low-energy models of dense strong-interaction matter. The observed dependence of these couplings on the quark chemical potential may help to amend model studies in the future. Finally, we estimate the speed of sound of dense QCD matter. Our results indicate that the speed of sound exceeds the value of the noninteracting quark gas at high densities and even increases as the density is decreased, across a wide range, suggesting the existence of a maximum at supranuclear densities.
Comments:
22 pages, 5 figures; v2: typos fixed, comments and references added, one section added, two figures added, two appendices added
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2106.04198 [pdf]
PRD(2022)·38 citations
15
[Submitted on 8 Jun 2021] (cross-list from physics.atom-ph)
Relativistic Fock space coupled cluster study of bismuth electronic structure to extract the Bi nuclear quadrupole moment
L.V. Skripnikov · A.V. Oleynichenko · A.V. Zaitsevskii · D.E. Maison · A.E. Barzakh
We report the value of the electric quadrupole moment of $^{209}$ Bi extracted from the atomic data. For this, we performed electronic structure calculations for the ground $^{4} S_{3/2}^{o}$ and excited $^{2} P_{3/2}^{o}$ states of atomic Bi using the Dirac-Coulomb-Breit Hamiltonian and the Fock space coupled cluster method with single, double, and full triple amplitudes for the three-particle Fock space sector. The value of the quadrupole moment of $^{209}$ Bi, $Q (^{209}$ Bi $) = - 418 (6)$ ~mb, derived from the resulting electric field gradient values and available atomic hyperfine splittings is in excellent agreement with molecular data. Due to the availability of the hyperfine constants for unstable isotopes of Bi, current atomic calculation allows also to correct their quadrupole moments.
Subjects:
Atomic Physics (physics.atom-ph); Nuclear Theory (nucl-th); physics.chem-ph (physics.chem-ph)
arXiv:
2106.04308 [pdf]
PRC(2021)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE