Nuclear Theory·nucl-th

Thursday·March 2, 2023

12 papers—6 primary·6 cross-listed

01
[Submitted on 1 Mar 2023]
Low-Energy Deuteron-Alpha Elastic Scattering in Cluster Effective Field Theory
Farzaneh Nazari · Mahdi Radin · Mahdi Moeini Arani
In this paper, we study the low-energy $d - α$ elastic scattering within the two-body cluster effective field theory (EFT) framework. The importance of the $d (α, α) d$ scattering in the $^{6} Li$ production reaction leads us to study this system in an effective way. In the beginning, the scattering amplitudes of each channel are written in a cluster EFT with two-body formalism. Using the effective range expansion analysis for the elastic scattering phase shift of $S$ , $P$ and $D$ partial waves, the unknown EFT low-energy coupling constants are determined and the leading and next-to-leading orders EFT results for the phase shift in each channel are presented. To verify the accuracy of the results, we compare experimental phase shift and differential cross section data with obtained results. The accuracy of the EFT results and consistency with the experimental data indicate that the EFT is an effective approach for describing low-energy systems.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2303.00338 [pdf]
EPJA(2023)·2 citations
02
[Submitted on 1 Mar 2023]
Isospin dependence in single-nucleon removal cross sections explained through valence-core destruction effects
M. Gomez-Ramos · J. Gomez-Camacho · A.M. Moro
The discrepancy between experimental data and theoretical calculations in one-nucleon removal reactions at intermediate energies (quantified by the so-called "quenching factors") and its dependence on the isospin asymmetry of the nuclei has been an open problem in nuclear physics for the last fifteen years. In this work, we propose an explanation for this long-standing problem, which relies on the inclusion of the process of core destruction due to its interaction with the removed nucleon. To include this effect, we extend the commonly used eikonal formalism via an effective nucleon density, and apply it to a series of nucleon knockout reactions. The effect of core destruction is found to depend strongly on the binding energy of the removed nucleon, leading to a significant reduction of the cross section for deeply bound nucleons, which reduces the isospin dependence of the "quenching factors", making them more consistent with the trends found in transfer and (p,pN) reactions.
Comments:
7 pages, 4 figures, Submitted to Physical Review Letters
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2303.00426 [pdf]
PLB(2023)·12 citations
03
[Submitted on 1 Mar 2023]
Proton \textit{s}-resonance states of $^{12}$ C and $^{14, 15}$ O within the Skyrme Hartree-Fock mean-field framework
Le-Anh Nguyen · Young-ho Song · Minh-Loc Bui
The excitation functions of proton elastic scattering on $^{12}$ C and $^{14, 15}$ O nuclei at the energies near the proton-emission threshold are calculated using the Skyrme Hartree-Fock (SHF) in continuum approach. For each excitation function, the first resonance is identified as the $s$ -state resonance of the mean-field theory. For $^{15}$ O, whose ground-state spin is nonzero, the $s$ -state resonance splits into two resonances via the spin-spin component of the optical potential. With a slight adjustment of the strength of central potential, which is obtained from the SHF in continuum approach, the excitation functions of proton elastic scattering for the three nuclei can be explained with high accuracy. The proposed framework can provide a practical method to explain nuclear scattering at the energies near the proton-emission threshold with minimal experimental input.
Comments:
14 pages, 4 figures, 1 table. Accepted by Phys. Rev. C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2303.00472 [pdf]
PRC(2023)·4 citations
04
[Submitted on 1 Mar 2023]
Review of magnetic- and antimagnetic-rotational structures in nuclei
Sushil Kumar · Sukhjeet Singh · Balraj Singh · Amita · Ashok Kumar Jain
This work is an update of the 2000 publication of magnetic-rotational bands by Amita et al. [1], followed by an unpublished update of 2006 [2], and reviews detailed experimental data extracted from original publications for 228 magnetic-rotational (MR or Shears) structures spread over 117 nuclides, and 40 antimagnetic-rotational (AMR) structures in 28 nuclei, with a brief commentary about each band. Many of these nuclei are located at or near the semi-magic nucleon numbers, mostly for protons. For example, 88 MR bands are currently known for the Pb (Z=82) nuclei, and 29 AMR band in Pd, Cd and In nuclei. It is interesting that the proton magic numbers appear to play a major role in the MR phenomenon, which seems less well understood. A brief discussion of the salient features of the MR and AMR bands and their theoretical interpretation has been presented in the present review. The tables contain gamma-ray energies, associated level energies with spins and parities, level lifetimes, B(M1), B(E2), and B(M1)/B(E2) ratios and probable spherical quasiparticle configurations. We find that many bands claimed in the literature as MR and AMR bands still have tentative assignments, as level lifetimes, thus B(M1) and B(E2) values, for a large number of MR and AMR bands, which can potentially provide critical criteria for firm identification of such structures, are lacking. Additionally, theoretical model calculations for many of these bands, which could provide insight for a better description of nuclear structure, are also lacking in literature. While this review is mainly based on original research articles, nuclear structure databases ENSDF [3], XUNDL [4], and NSR [5] have been consulted for completeness. The literature cut-off date March 31, 2025.
Comments:
105 pages, 4 figures, 3 tables
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2303.00499 [pdf]
Atom.Data Nucl.Data Tabl.(2025)·4 citations
05
[Submitted on 1 Mar 2023]
The optimal detection angles for producing N=126 neutron-rich isotones in the multinucleon transfer reactions
Zehong Liao · Long Zhu · Zepeng Gao · Jun Su · Cheng Li
The challenge of isotopic identification over a wide angular distribution has limited the measurement of neutron-rich nuclei produced via the multinucleon transfer (MNT) process. To investigate the optimal detection angles for the N=126 isotones, we propose a method to construct the reasonable scattering angles of the MNT products in the dinuclear system (DNS-sysu) model. The reactions $^{136, 144}$ Xe + $^{208}$ Pb are investigated. The calculated results are in rather good agreement with the available experimental data in the reaction $^{136}$ Xe + $^{208}$ Pb. The entrance channel effects on the scattering angle are investigated. It is found that the scattering angular distribution strongly depends on the isospin and the impact parameter of the collision system. The optimal angle ranges for detecting $N = 126$ neutron-rich nuclides $^{204}$ Pt, $^{203}$ Ir, $^{202}$ Os, and $^{201}$ Re in the $^{136}$ Xe + $^{208}$ Pb reaction at the incident energy $E_{c . m .} = 526 M e V$ are predicted. Our results suggest that the angle range $4 5^{\circ} ⩽ θ_{lab} ⩽ 5 0^{\circ}$ is most favorable for detecting unknown N=126 isotones. Given the current difficulties in separating and identifying experimental MNT fragments, the results of this work could provide significant contributions to future experiments.
Comments:
6 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2303.00519 [pdf]
PRResearch(2023)·18 citations
06
[Submitted on 1 Mar 2023]
Ab Initio Symmetry-Adapted Emulator for Studying Emergent Collectivity and Clustering in Nuclei
Kevin S. Becker · Kristina D. Launey · Andreas Ekström · Tomas Dytrych
We discuss emulators from the ab initio symmetry-adapted no-core shell-model framework for studying the formation of alpha clustering and collective properties without effective charges. We present a new type of an emulator, one that utilizes the eigenvector continuation technique but is based on the use of symplectic symmetry considerations. This is achieved by using physically relevant degrees of freedom, namely, the symmetry-adapted basis, which exploits the almost perfect symplectic symmetry in nuclei. Specifically, we study excitation energies, point-proton root-mean-square radii, along with electric quadrupole moments and transitions for 6Li and 12C. We show that the set of parameterizations of the chiral potential used to train the emulators has no significant effect on predictions of dominant nuclear features, such as shape and the associated symplectic symmetry, along with cluster formation, but slightly varies details that affect collective quadrupole moments, asymptotic normalization coefficients, and alpha partial widths up to a factor of two. This makes these types of emulators important for further constraining the nuclear force for high-precision nuclear structure and reaction observables.
Comments:
11 pages including references, 47 cited references, 1 table, 6 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2303.00667 [pdf]
Front.in Phys.(2023)·15 citations
07
[Submitted on 8 Apr 2019] (cross-list from hep-ph)
The LPM effect in sequential bremsstrahlung: from large-N QCD to N=3 via the SU(N) analog of Wigner 6-j symbols
Peter Arnold🇺🇸
Consider a high-energy parton showering as it traverses a QCD medium such as a quark-gluon plasma. Interference effects between successive splittings in the shower are potentially very important but have so far been calculated (even in idealized theoretical situations) only in soft emission or large- $N_{c}$ limits, where $N_{c}$ is the number of quark colors. In this paper, we show how one may remove the assumption of large $N_{c}$ and so begin investigation of $N_{c} = 3$ without soft-emission approximations. Treating finite $N_{c}$ requires (i) classifying different ways that four gluons can form a color singlet and (ii) calculating medium-induced transitions between those singlets, for which we find application of results for the generalization of Wigner 6- $j$ symbols from angular momentum to SU( $N_{c}$ ). Throughout, we make use of the multiple scattering ( $q^$ ) approximation for high-energy partons crossing quark-gluon plasmas, and we find that this approximation is self-consistent only if the transverse-momentum diffusion parameter $q^$ for different color representations satisfies Casimir scaling (even for strongly-coupled, and not just weakly-coupled, quark-gluon plasmas). We also find that results for $N_{c} = 3$ depend, mathematically, on being able to calculate the propagator for a coupled non-relativistic quantum harmonic oscillator problem in which the spring constants are operators acting on a 5-dimensional Hilbert space of internal color states. Those spring constants are represented by constant $5 \times 5$ matrices, which we explicitly construct. We are unaware of any closed form solution for this type of harmonic oscillator problem, and we discuss prospects for using numerical evaluation.
Comments:
27 pages, 6 figures. Difference from v2: An erroneous assertion in section IV, that the two-dimensional harmonic oscillator problem could be reduced to one-dimensional harmonic oscillator problems, has been fixed
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1904.04264 [pdf]
PRD(2019)·14 citations
08
[Submitted on 9 Feb 2022] (cross-list from hep-ph)
The LPM Effect in sequential bremsstrahlung: $1/ N_{c}^{2}$ corrections
Peter Arnold🇺🇸 · Omar Elgedawy🇺🇸
An important question concerning in-medium high-energy parton showers in a quark-gluon plasma or other QCD medium is whether consecutive splittings of the partons in a given shower can be treated as quantum mechanically independent, or whether the formation times for two consecutive splittings instead have significant overlap. Various previous calculations of the effect of overlapping formation times have either (i) restricted attention to a soft bremsstrahlung limit, or else (ii) used the large- $N_{c}$ limit (where $N_{c} = 3$ is the number of quark colors). In this paper, we make a first study of the accuracy of the large- $N_{c}$ limit used by those calculations of overlap effects that avoid a soft bremsstrahlung approximation. Specifically, we calculate the $1/ N_{c}^{2}$ correction to previous $N_{c} = \infty$ results for overlap $g \to g g \to g g g$ of two consecutive gluon splittings $g \to g g$ . At order $1/ N_{c}^{2}$ , there is interesting and non-trivial color dynamics that must be accounted for during the overlap of the formation times.
Comments:
47 pages, 19 figures. Changes from v1: some clarification added through new footnotes and a new figure
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2202.04662 [pdf]
JHEP(2022)·12 citations
09
[Submitted on 28 Feb 2023] (cross-list from astro-ph.HE)
What neutron stars tell about the hadron-quark phase transition: a Bayesian study
János Takátsy🇭🇺 · Péter Kovács🇭🇺 · György Wolf🇭🇺 · Jürgen Schaffner-Bielich🇩🇪
The existence of quark matter inside the heaviest neutron stars has been the topic of numerous recent studies, many of them suggesting that a phase transition to strongly interacting conformal matter inside neutron stars is feasible. Here we examine this hybrid star scenario using a soft and a stiff hadronic model, a constituent quark model with three quark flavours, and applying a smooth crossover transition between the two. Within a Bayesian framework, we study the effect of up-to-date constraints from neutron star observations on the equation-of-state parameters and various neutron star observables. Our results show that a pure quark core is only possible if the maximum mass of neutron stars is below $\sim 2.35 M_{⊙}$ . However, we also find, consistently with other studies, that a peak in the speed of sound, exceeding $1/3$ , is highly favoured by astrophysical measurements, which might indicate the percolation of hadrons at $\sim 3 - 4 n_{0}$ . Even though our prediction for the phase transition parameters varies depending on the specific astrophysical constraints utilized, the position of the speed of sound peak only changes slightly, while the existence of pure quark matter below $\sim 4 n_{0}$ , using our parameterization, is disfavoured. On the other hand, the preferred range for the EoS shows signs of conformality above $\sim 4 n_{0}$ . Additionally, we present the difference in the upper bounds of radius estimates using the full probability density data and sharp cut-offs, and stress the necessity of using the former.
Comments:
23 pages, 13 figures, accepted by Phys. Rev. D
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2303.00013 [pdf]
PRD(2023)·63 citations
10
[Submitted on 28 Feb 2023] (cross-list from nucl-ex)
Quantum Information Science and Technology for Nuclear Physics. Input into U.S. Long-Range Planning, 2023
Douglas Beck · Joseph Carlson · Zohreh Davoudi · Joseph Formaggio · Sofia Quaglioni · Martin Savage · Joao Barata · Tanmoy Bhattacharya · Michael Bishof · Ian Cloet · Andrea Delgado · Michael DeMarco and 89 other authors
In preparation for the 2023 NSAC Long Range Plan (LRP), members of the Nuclear Science community gathered to discuss the current state of, and plans for further leveraging opportunities in, QIST in NP research at the Quantum Information Science for U.S. Nuclear Physics Long Range Planning workshop, held in Santa Fe, New Mexico on January 31 - February 1, 2023. The workshop included 45 in-person participants and 53 remote attendees. The outcome of the workshop identified strategic plans and requirements for the next 5-10 years to advance quantum sensing and quantum simulations within NP, and to develop a diverse quantum-ready workforce. The plans include resolutions endorsed by the participants to address the compelling scientific opportunities at the intersections of NP and QIST. These endorsements are aligned with similar affirmations by the LRP Computational Nuclear Physics and AI/ML Workshop, the Nuclear Structure, Reactions, and Astrophysics LRP Town Hall, and the Fundamental Symmetries, Neutrons, and Neutrinos LRP Town Hall communities.
Comments:
A white paper for the 2023 nuclear physics long-range planning activity, emerging from the workshop "Quantum Information Science for U.S. Nuclear Physics Long Range Planning'', held in Santa Fe, New Mexico on January 31 - February 1, 2023. 26 pages with 7 figures
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2303.00113 [pdf]
67 citations
11
[Submitted on 28 Feb 2023] (cross-list from hep-ph)
Deeply-virtual Compton process $e^{-} N \to e^{-} γ π N$ to study nucleon to resonance transitions
Kirill M. Semenov-Tian-Shansky🇰🇷 · Marc Vanderhaeghen🇩🇪
We study the deeply-virtual Compton scattering (DVCS) process $e^{-} N \to e^{-} γ π N$ involving the transition between a nucleon and a nucleon resonance in the $π N$ system, within the framework of generalized parton distributions (GPDs). For the four lowest-lying nucleon resonances, $Δ (1232)$ , $P_{11} (1440)$ , $D_{13} (1520)$ , and $S_{11} (1535)$ , we express the DVCS amplitude in the Bjorken limit in terms of corresponding nucleon-to-resonance GPDs. Building upon the knowledge of the well studied electromagnetic nucleon-to-resonance transition form factors, which map the quark charge densities in transverse position space, the corresponding GPDs will open the prospect to also access the longitudinal momentum distributions of quarks in the transition. We provide estimates for cross sections and beam-spin asymmetries in the first and second $π N$ resonance regions in the kinematics of forthcoming CLAS12 data from Jefferson Lab.
Comments:
23 pages, 11 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2303.00119 [pdf]
PRD(2023)·24 citations
12
[Submitted on 1 Mar 2023] (cross-list from nucl-ex)
Coexistence of single particle and collective excitation in $^{61}$ Ni
Soumik Bhattacharya · Vandana Tripathi · E. Rubino · Samuel Ajayi · L. T. Baby · C. Benetti · R. S. Lubna · S. L. Tabor · J. Döring · Y. Utsuno · N. Shimizu · J. M. Almond · G. Mukherjee
The high spin states in 61 Ni have been studied using the fusion evaporation reaction, Ti( $^{14}$ C,3n) $^{61}$ Ni at an incident beam energy of 40 MeV. A Compton suppressed multi-HPGe detector setup, consisting of six Clover detectors and three single crystal HPGe detectors was used to detect the de-exciting $γ$ rays from the excited states. The level scheme has been extended up to an excitation energy of 12.8 MeV and a tentative J $_{π}$ = 35/2 $^{+}$ . The low-lying negative parity levels are found to be generated by single particle excitation within the f p shell and also excitations to the g $_{9/2}$ orbitals as explained well with shell model calculations using the GXPF1Br+V M U (modified) interaction. Two rotational structure of regular E2 sequences with small to moderate axial deformation have been established at higher excitation energy. Most interestingly, two sequences of M1 transitions are reported for the first time and described as magnetic rotational bands. The shears mechanism for both the bands can be described satisfactorily by the geometrical model. The shell model calculation involving the cross shell excitation beyond the fp shell well reproduce the M1 and E2 sequences. The shell model predicted B(M1) values for the magnetic rotational band B1 show the decreasing trend with spin as expected with closing of the shears.
Comments:
18 pages, 17 Fig
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2303.00588 [pdf]
PRC(2023)·10 citations

Affiliations

first authorsco-authorsvia INSPIRE