Nuclear Theory·nucl-th

Monday·February 12, 2024

15 papers—8 primary·7 cross-listed

01
[Submitted on 8 Feb 2024]
The unexpected uses of a bowling pin: exploiting $^{20}$ Ne isotopes for precision characterizations of collectivity in small systems
Giuliano Giacalone🇩🇪 · Benjamin Bally🇫🇷 · Govert Nijs🇨🇭 · Shihang Shen🇩🇪 · Thomas Duguet🇫🇷 · Jean-Paul Ebran🇫🇷 · Serdar Elhatisari🇹🇷 · Mikael Frosini🇫🇷 · Timo A. Lähde🇩🇪 · Dean Lee🇺🇸 · Bing-Nan Lu🇨🇳 · Yuan-Zhuo Ma🇺🇸 and 7 other authors
Whether or not femto-scale droplets of quark-gluon plasma (QGP) are formed in so-called small systems at high-energy colliders is a pressing question in the phenomenology of the strong interaction. For proton-proton or proton-nucleus collisions the answer is inconclusive due to the large theoretical uncertainties plaguing the description of these processes. While upcoming data on collisions of $^{16}$ O nuclei may mitigate these uncertainties in the near future, here we demonstrate the unique possibilities offered by complementing $^{16}$ O $^{16}$ O data with collisions of $^{20}$ Ne ions. We couple both NLEFT and PGCM ab initio descriptions of the structure of $^{20}$ Ne and $^{16}$ O to hydrodynamic simulations of $^{16}$ O $^{16}$ O and $^{20}$ Ne $^{20}$ Ne collisions at high energy. We isolate the imprints of the bowling-pin shape of $^{20}$ Ne on the collective flow of hadrons, which can be used to perform quantitative tests of the hydrodynamic QGP paradigm. In particular, we predict that the elliptic flow of $^{20}$ Ne $^{20}$ Ne collisions is enhanced by as much as 1.170(8) $_{stat.}$ (30) $_{syst.}$ for NLEFT and 1.139(6) $_{stat.}$ (39) $_{syst.}$ for PGCM relative to $^{16}$ O $^{16}$ O collisions for the 1% most central events. At the same time, theoretical uncertainties largely cancel when studying relative variations of observables between two systems. This demonstrates a method based on experiments with two light-ion species for precision characterizations of the collective dynamics and its emergence in a small system.
Comments:
17 pages, 14 figures. The Trajectum code can be found at https://sites.google.com/view/govertnijs/trajectum and plotting routines can be found at http://wilkevanderschee.nl/trajectum
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2402.05995 [pdf]
PRL(2025)·105 citations
02
[Submitted on 8 Feb 2024]
Exploring the competition between $α$ -decay and proton radioactivity: A comparative study of proximity potential formalisms
A. Adel · Karim H. Mahmoud · Haitham A. Taha
We have conducted a comprehensive and systematic study of the proton radioactivity and $α$ -decay half-lives of neutron-deficient nuclei. This investigation involved the utilization of various Proximity potentials and also considered the incorporation of thermal effects. For the half-life calculations, we employed both temperature-independent and temperature-dependent interaction potentials. We observed that proton radioactivity serves as the dominant mode of decay for nuclides situated very close to the proton drip-line. We explored a universal curve that examines the correlation between the decimal logarithm of experimental half-lives and the negative decimal logarithm of the penetrability for both proton radioactivity and $α$ -decay.
Comments:
11 pages,7 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2402.06069 [pdf]
NPA(2024)·7 citations
03
[Submitted on 9 Feb 2024]
The $ppp$ correlation function with a screened Coulomb potential
A. Kievsky🇮🇹 · E. Garrido🇪🇸 · M. Viviani🇮🇹 · M. Gattobigio🇫🇷
The correlation function is a useful tool to study the interaction between hadrons. The theoretical description of this observable requires the knowledge of the scattering wave function, whose asymptotic part is distorted when two or more particles are charged. For a system of three (or more) particles, with more than two particles asymptotically free and at least two of them charged, the asymptotic part of the wave function is not known in a closed form. In the present study we introduce a screened Coulomb potential and analyze the impact of the screening radius on the correlation function. As we will show, when a sufficiently large screening radius is used, the correlation function results almost unchanged if compared to the case in which the unscreened Coulomb potential is used. This fact allows the use of free asymptotic matching conditions in the solution of the scattering equation simplifying noticeably the calculation of the correlation function. As an illustration we discuss the $pp$ and $ppp$ correlation functions.
Comments:
14 pages, 4 figures, belonging to the collection Advances on Few-Body Problems in Physics, Few-Body Systems
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2402.06317 [pdf]
Few Body Syst.(2024)·5 citations
04
[Submitted on 9 Feb 2024]
Elliptic flow of deuterons in ultrarelativistic heavy-ion collisions
Radka Vozabova🇨🇿 · Boris Tomasik🇨🇿
We calculate the elliptic flow of deuterons in Pb+Pb collisions at 2.76 TeV per colliding nucleon-nucleon pair and show that it can be used to discriminate between direct statistical production and coalescence. The emission from the fireball is parametrized and tuned to reproduce transverse momentum spectra and the elliptic flow of protons and pions. Coalescence leads to higher deuteron elliptic flow than statistical production and agrees better with experimental data. We attribute this observation to the varying size of the nucleon-producing region for the emission in different azimuthal angles.
Comments:
12 pages, 10 figures, v2: references added, v3: parametrisation of model anisotropy better explained around eqs. 5 and 6, figures reformatted for better readability, content and results unchanged, accepted in Physical Review C
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2402.06327 [pdf]
PRC(2024)·7 citations
05
[Submitted on 9 Feb 2024]
Correlation between the Shape Coexistence and Stability in Mo and Ru isotopes
Mamta Aggarwal (1) · G. Saxena (2) · Pranali Parab (1)
In a rapidly changing shape phase region, the presence of shape coexistence and its possible impact on the decay modes and half $-$ lives, has been explored in astrophysically interesting Mo and Ru isotopes, in an extensive study within the microscopic theoretical framework using Nilsson Strutinsky Method and Relativistic Mean Field Model. The isotopic chains of Mo and Ru exhibit rapid shape phase transitions, triaxial $γ$ softness, shape instability along with many coexisting states mostly with oblate and triaxial shapes. Proton and neutron separation energies have been calculated and compared with the available data. Results obtained from both the formalisms are in good agreement with each other as well as the available experimental data. Our computed $β -$ decay half $-$ lives and separation energy for nuclei exhibiting shape coexistence were examined for the decay mode from second minima state of the parent nuclei to the ground or excited state of the daughter nuclei. The second minima state of the coexisting shapes in Mo and Ru isotopes, were seen to impact the structural properties, $β -$ decay half $-$ lives, separation energy and hence the stability of the nuclei.
Comments:
23 pages, 13 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2402.06403 [pdf]
NPA(2024)·7 citations
06
[Submitted on 9 Feb 2024]
Electron-nucleus scattering and the polarization sum rules
D.H.Jakubassa-Amundsen
A formal derivation of the polarization correlations between the incident electron and the scattered electron is given for a general class of transition operators. In correspondence to the case of bremsstrahlung emission, three sum rules for the polarization correlations are predicted, which reduce to the known one for potential scattering. Further examples, including the 1_2^+ and 2_1^+ excitations of the 12C nucleus and a 1^- excitation of the 208Pb nucleus, are discussed and the validity of the corresponding sum rules is investigated.
Comments:
12 pages, 9 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2402.06418 [pdf]
0 citations
07
[Submitted on 9 Feb 2024]
Reaction rate of the radiative capture proton by 10B
S.B. Dubovichenko · N.A. Burkova · A.S. Tkachenko · D.M. Zazulin
The 10B(p,{\gamma})11C reaction is of significant interest in nuclear astrophysics and in the field of controlled thermonuclear fusion. This reaction is one of the reactions of 11B production, which is carried out through the 10B(p,{\gamma})11C(\b{eta}+{\nu})11B chain. The rate of the 10B(p,{\gamma})11C reaction (occurring in the interiors of first-generation stars) can be of great importance for the amount of 10B and 11B observed today in the interstellar medium and in the Earth's crust. In thermonuclear reactors, structural elements containing boron can be used as neutron absorbers, etc. Therefore, in this work, within the framework of a modified potential cluster model with a classification of orbital states according to Young's diagrams and taking into account allowed and forbidden states, we examined the possibility of describing the available experimental data for the total cross sections of the radiative p10B capture to the ground state of the 11C nucleus at energies up to 1 MeV. It is shown that only on the basis of E1 and M1 transitions from the p10B scattering states, taking into account the first resonance for the ground state of the 11C nucleus, it is quite possible to explain the magnitude and shape of the experimental astrophysical S-factor. The work presents comparisons the astrophysical S-factors of the radiative p10B capture to the ground state of the 11C nucleus found by us with the experimental data available in the literature. Based on the obtained theoretical S-factor, the rate of this reaction was calculated in the temperature range from 0.01 to 1 T9. The calculated results for rates are approximated by a simple expression, which simplifies their use in applied thermonuclear and astrophysical research.
Comments:
10 P., 2 FIG., 1 TAB
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2402.06433 [pdf]
REPORTS OF THE ACADEMY OF SCIENCES OF THE…·0 citations
08
[Submitted on 9 Feb 2024]
Recent progress in the electroweak structure of light nuclei using quantum Monte Carlo methods
Garrett B. King🇺🇸 · Saori Pastore🇺🇸
Nuclei will play a prominent role in searches for physics beyond the Standard Model as the active material in experiments. In order to reliably interpret new physics signals, one needs an accurate model of the underlying nuclear dynamics. In this review, we discuss recent progress made with quantum Monte Carlo approaches for calculating the electroweak structure of light nuclei. We place particular emphasis on recent $β$ -decay, muon capture, $0 ν β β$ -decay, and electron scattering results.
Comments:
23 pages, 8 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2402.06602 [pdf]
Ann.Rev.Nucl.Part.Sci.(2024)·17 citations
09
[Submitted on 7 Feb 2024] (cross-list from hep-ph)
Can quantum statistics help distinguish Dirac from Majorana neutrinos?
Evgeny Akhmedov🇩🇪 · Andreas Trautner🇩🇪
Finding out if neutrinos are Dirac or Majorana particles is known to be extremely difficult due to the smallness of neutrino mass and the fact that in the limit $m_{ν} = 0$ both Dirac and Majorana neutrinos become Weyl particles, i.e. are indistinguishable. There have been suggestions in the literature that in the case of processes with production of a neutrino-antineutrino pair (if neutrinos are Dirac particles) or two neutrinos (if they are of Majorana nature) quantum statistics may be of help. This is because for Majorana neutrinos quantum indistinguishability of identical particles requires the amplitude of the process to be antisymmetrized with respect to the interchange of the final-state neutrinos, whereas no such antisymmetrization must be done for Dirac neutrinos. It has been claimed that the resulting differences between the cross sections for Dirac and Majorana neutrinos persist even for arbitrarily small but not exactly vanishing neutrino mass. We demonstrate that, at least in the framework of the Standard Model, this is not the case. We also give a general proof that within the Standard Model quantum statistics does not help tell Dirac and Majorana neutrinos apart in the limit of negligibly small $m_{ν} / E$ .
Comments:
LaTeX, 20 pages, 2 figures. v2: Notes, references and acknowledgements added. Results and conclusions unchanged
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2402.05172 [pdf]
JHEP(2024)·9 citations
10
[Submitted on 8 Feb 2024] (cross-list from hep-ph)
Possible scenario of dynamical chiral symmetry breaking in the interacting instanton liquid model
Yamato Suda🇯🇵 · Daisuke Jido🇯🇵
We compute the vacuum energy density as a function of the quark condensate in the interacting instanton liquid model (IILM) and examine the pattern of dynamical chiral symmetry breaking from its behavior around the origin. This evaluation is performed by using simulation results of the IILM. We find that chiral symmetry is broken in the U(1)_A anomaly assisted way in the IILM with three-flavor dynamical quarks. We call such a symmetry breaking the anomaly-driven breaking which is one of the scenarios of chiral symmetry breaking proposed in the context of the chiral effective theories. We also find that the instanton-quark interaction included in the IILM plays a crucial role for the anomaly-driven breaking by comparing the full and the quenched IILM calculations.
Comments:
12 pages, 7 figures, 11 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2402.05425 [pdf]
PRD(2024)·4 citations
11
[Submitted on 8 Feb 2024] (cross-list from hep-th)
$ϕ^{n}$ trajectory bootstrap
Wenliang Li🇨🇳
We perform an extensive bootstrap study of Hermitian and non-Hermitian theories based on the novel analytic continuation of $⟨ ϕ^{n} ⟩$ or $⟨(i ϕ)^{n} ⟩$ in $n$ . We first use the quantum harmonic oscillator to illustrate various aspects of the $ϕ^{n}$ trajectory bootstrap method, such as the large $n$ expansion, matching conditions, exact quantization condition, and high energy asymptotic behavior. Then we derive highly accurate solutions for the anharmonic oscillators with the parity invariant potential $V (ϕ) = ϕ^{2} + ϕ^{m}$ and the $P T$ invariant potential $V (ϕ) = - (i ϕ)^{m}$ for a large range of integral $m$ , showing the high efficiency and general applicability of this new bootstrap approach. For the Hermitian quartic and non-Hermitian cubic oscillators, we further verify that the non-integer $n$ results for $⟨ ϕ^{n} ⟩$ or $⟨(i ϕ)^{n} ⟩$ are consistent with those from the wave function approach. In the $P T$ invariant case, the existence of $⟨(i ϕ)^{n} ⟩$ with non-integer $n$ allows us to bootstrap the non-Hermitian theories with non-integer powers, such as fractional and irrational $m$ .
Comments:
v4: 22 pages, 11 figures, typos corrected, discussions improved; v3: 21 pages, 9 figures, abstract and introduction rewritten, many minor improvements made, hopefully more reader-friendly; v2: 24 pages, 9 figures, irrational example added, typos corrected, discussion improved, references added
Subjects:
High Energy Physics — Theory (hep-th); Statistical Mechanics (cond-mat.stat-mech); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2402.05778 [pdf]
PRD(2025)·14 citations
12
[Submitted on 8 Feb 2024] (cross-list from hep-lat)
Chiral spin symmetry and hot QCD
L. Ya. Glozman🇦🇹
In this talk we overview main results indicating existence in QCD of three qualitatively different regimes connected by smooth crossovers upon heating: a hadron gas, a stringy fluid and a quark-gluon plasma. In the combined large N_c and chiral limit these regimes likely become distinct phases separated by phase transitions: a chiral restoration phase transition around T_{ch} ~ 130 MeV and a deconfinement phase transition around T_d ~ 300 MeV. It should be an important task to verify this issue on the lattice. We will introduce a chiral spin symmetry, which is a symmetry of the electric part of electrodynamics and of QCD with light quarks. It is realized approximately in QCD above the chiral restoration crossover and disappears in the QGP regime. The center symmetry of the pure glue action and the chiral spin symmetry of the electric part of the QCD Lagrangian with light quarks are complementary to distinguish the confining regime and its disappearance. We also address other lattice evidences for stringy fluid: hadron resonances extracted from the lattice correlators; breakdown of the thermal perturbation theory at T < ~ 600 MeV and fluctuations of conserved charges that point out the N_c scaling above T ~ 155 MeV.
Comments:
11 pages. Overview talk given at Excited QCD 2024, Benasque, January 2024
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2402.05852 [pdf]
Acta Phys.Polon.Supp.(2024)·3 citations
13
[Submitted on 8 Feb 2024] (cross-list from hep-ph)
Contact interaction study of proton parton distributions
Yang Yu🇨🇳 · Peng Cheng🇨🇳 · Hui-Yu Xing🇨🇳 · Fei Gao🇨🇳 · Craig D. Roberts🇨🇳
Using a symmetry-preserving formulation of a vector $\times$ vector contact interaction (SCI) and treating the proton as a quark + interacting-diquark bound state, whose structure is obtained by solving a Poincaré-covariant Faddeev equation, we provide a comprehensive, coherent set of predictions for unpolarised and polarised proton parton distribution functions (DFs): valence, glue, and four-flavour separated sea. The results enable many themes to be addressed, including: the asymmetry of antimatter in the proton; the neutron:proton structure function ratio; helicity retention in hard scattering processes; the charm quark momentum fraction; the sign and size of the polarised gluon DF; and the origin of the proton spin. In all cases where sound analyses of data are available, SCI predictions are semiquantitatively in agreement with the results. Those mismatches which exist are typically attributable to the momentum-independence of the underlying interaction. Judiciously interpreted, the SCI delivers a sound and insightful explanation of proton structure as expressed in DFs.
Comments:
23 pages, 15 figures, 6 tables. To appear in Eur. Phys. J. C
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:
2402.06095 [pdf]
EPJC(2024)·24 citations
14
[Submitted on 9 Feb 2024] (cross-list from hep-ph)
Damping of density oscillations from bulk viscosity in quark matter
Jose Luis Hernandez🇪🇸 · Cristina Manuel🇪🇸 · Laura Tolos🇪🇸
We study the damping of density oscillations in the quark matter phase that might occur in compact stars. To this end we compute the bulk viscosity and the associated damping time in three-flavor quark matter, considering both nonleptonic and semileptonic electroweak processes. We use two different equations of state of quark matter, more precisely, the MIT bag model and perturbative QCD, including the leading-order corrections in the strong coupling constant. We analyze the dependence of our results on the density, temperature and value of strange quark mass in each case. We then find that the maximum of the bulk viscosity is in the range of temperature from 0.01 to 0.1 MeV for frequencies around 1 kHz, while the associated minimal damping times of the density oscillations at those temperatures might be in the range of few to hundreds milliseconds. Our results suggest that bulk viscous damping might be relevant in the postmerger phase after the collision of two neutron stars if deconfined matter is achieved in the process.
Comments:
12 pages, 9 figures, 7 tables, published revised version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2402.06595 [pdf]
PRD(2024)·19 citations
15
[Submitted on 9 Feb 2024] (cross-list from hep-ph)
Real-time Dynamics of the Schwinger Model as an Open Quantum System with Neural Density Operators
Joshua Lin🇺🇸 · Di Luo🇺🇸 · Xiaojun Yao🇺🇸 · Phiala E. Shanahan🇺🇸
Ab-initio simulations of multiple heavy quarks propagating in a Quark-Gluon Plasma are computationally difficult to perform due to the large dimension of the space of density matrices. This work develops machine learning algorithms to overcome this difficulty by approximating exact quantum states with neural network parametrisations, specifically Neural Density Operators. As a proof of principle demonstration in a QCD-like theory, the approach is applied to solve the Lindblad master equation in the 1+1d lattice Schwinger Model as an open quantum system. Neural Density Operators enable the study of in-medium dynamics on large lattice volumes, where multiple-string interactions and their effects on string-breaking and recombination phenomena can be studied. Thermal properties of the system at equilibrium can also be probed with these methods by variationally constructing the steady state of the Lindblad master equation. Scaling of this approach with system size is studied, and numerical demonstrations on up to 32 spatial lattice sites and with up to 3 interacting strings are performed.
Comments:
24 pages, 12 figures. v2: Updated to journal version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th); Computational Physics (physics.comp-ph); Quantum Physics (quant-ph)
arXiv:
2402.06607 [pdf]
JHEP(2024)·18 citations

Affiliations

first authorsco-authorsvia INSPIRE