Nuclear Theory·nucl-th

Tuesday·March 5, 2024

18 papers—11 primary·7 cross-listed

01
[Submitted on 2 Mar 2024]
Quantum-number projected generator coordinate method for $^{21}$ Ne with a chiral two-nucleon-plus-three-nucleon interaction
W. Lin · E. F. Zhou · J. M. Yao · H. Hergert
We report a study of the low-lying states of deformed $^{21}$ Ne within the framework of quantum-number projected generator coordinate method (PGCM), starting from a chiral two-nucleon-plus-three-nucleon (NN+3N) interaction. The wave functions of states are constructed as a linear combination of a set of axially-deformed Hartree-Fock-Bogliubov (HFB) wave functions with different quadrupole deformations. These HFB wave functions are projected onto different angular momenta and the correct neutron and proton numbers for $^{21}$ Ne. The results of calculations based on the effective Hamiltonians derived by normal-ordering the 3N interaction with respect to three different reference states, including the quantum-number projected HFB wave functions for $^{20}$ Ne, $^{22}$ Ne, and an ensemble of them with equal weights, are compared. This study serves as a key step towards ab initio calculations of odd-mass deformed nuclei with the in-medium GCM.
Comments:
22page, 8 figures, an invited contribution to the special issue of Symmetry journal: "Restoration of Broken Symmetries in the Nuclear Many-Body Problem", edited by Prof. Javid Sheikh and Prof. Peter Ring
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2403.01177 [pdf]
Symmetry(2024)·8 citations
02
[Submitted on 3 Mar 2024]
Neutron stars as a dense liquid drop at equilibrium within the effective surface approximation
A.G. Magner · S.P. Maydanyuk · A. Bonasera · H. Zheng · T. Depastas · A.I. Levon · U.V. Grygoriev
The macroscopic model is formulated for a neutron star (NS) as a perfect liquid drop at the equilibrium. We use the leptodermic approximation $a / R ≪ 1$ , where $a$ is the crust thickness of the effective NS surface (ES), and $R$ is the mean radius of the ES curvature. Within the approximate Schwarzschild metric solution to the general relativity theory equations for the spherically symmetric systems, the macroscopic gravitation is taken into account in terms of the total separation particle energy and incompressibility. Density distribution $ρ$ across the ES in the normal direction to the ES was obtained analytically for a general form of the energy density $E (ρ)$ . For the typical crust thickness, and effective radius, one finds the leading expression for the density $ρ$ . NS masses are analytically calculated as a sum of the volume and surface terms, taking into account the radial curvature of the metric space, in reasonable agreement with the recently measured masses for several neutron stars. We derive the simple macroscopic equation of state (EoS) with the surface correction. The analytical and numerical solutions to Tolman-Oppenheimer-Volkoff equations for the pressure are in good agreement with the volume part of our EoS.
Comments:
32 pages, 8 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2403.01445 [pdf]
IJMPE(2024)·4 citations
03
[Submitted on 4 Mar 2024]
Shell-cluster transition in $^{48}$ Ti
M. Okada · W. Horiuchi · N. Itagaki
Background: Whether or not the $α$ ( $^{4}$ He nucleus) clustering exists in the medium-mass region of nuclear systems is a fundamental and intriguing question. However, the recent analysis of the $α$ knockout reaction on $^{48}$ Ti [Phys. Rev. C 103, L031305 (2021)] poses a puzzle: The microscopic wave function gives an $α$ knockout cross section that is two orders of magnitude smaller than the experiment, while basic nuclear properties such as the charge radius and the electromagnetic transition probabilities are well explained. Purpose: The ground-state structure of $^{48}$ Ti is investigated by using proton- and $α$ -nucleus elastic scattering at a few to several hundred MeV, which offers different sensitivity to the region of the nuclear density profiles. Method: Four types of density distributions, the $j j$ -coupling shell model and three cluster model configurations, are generated in a single scheme by the antisymmetrized quasi-cluster model (AQCM). The angular distribution of the proton- and $α$ - $^{48}$ Ti elastic scattering cross sections are obtained with a reliable high-energy reaction theory, the Glauber model. Results: The $j j$ -coupling shell model configuration is found to best reproduce the proton-nucleus elastic scattering cross section. On the other hand, the trace of the $α$ cluster structure in the tail region of the wave function is embedded in the $α$ -nucleus elastic scattering cross section. Conclusion: Our results suggest that the structure of the nucleus changes as a function of distance from the center, from the $j j$ -coupling shell model structure in the surface region to the $α$ + $^{44}$ Ca cluster structure in the tail region. This picture is consistent with the finding of the $α$ knockout reaction on $^{48}$ Ti.
Comments:
8 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2403.01685 [pdf]
PRC(2024)·4 citations
04
[Submitted on 4 Mar 2024]
Density-dependent quark mean-field model for nuclear matter and neutron stars
Kaixuan Huang🇨🇳 · Jinniu Hu🇨🇳 · Ying Zhang🇨🇳 · Hong Shen🇨🇳
We develop a density-dependent quark mean-field (DDQMF) model to study the properties of nuclear matter and neutron stars, where the coupling strength between $σ$ meson and nucleon is generated by the degree of freedom of quarks, while other meson coupling constants are regarded as density-dependent ones. Two values for the nucleon effective mass, $M_{N 0}^{*} / M_{N} = 0.556, 0.70$ at the saturation density are chosen based on the consideration of the core-collapse supernova simulation and finite nuclei when the meson-nucleon coupling constants are fixed. We find that the equation of state (EOS) of nuclear matter, the symmetry energy, the mass-radius relations, and the tidal deformabilities of neutron stars with larger nucleon effective mass are more sensitive to the skewness coefficient $J_{0}$ . The EOSs with $M_{N 0}^{*} / M_{N} = 0.70$ are softer when the skewness coefficient $J_{0} = - 800$ MeV. However, the maximum masses of the neutron star can be around $2.32 M_{⊙}$ with $J_{0} = 400$ MeV regardless of the value of the nucleon effective mass. By manipulating the coupling strength of the isovector meson to generate different slopes of symmetry energy, we construct the neutron star EOSs that can satisfy the different variables from the simultaneous mass-radius measurements of PSR J0030+0451, PSR J0740+6620 by the NICER collaboration, the mass-radius relations of HESS J1731-347, and the radius constraints from the gravitational-wave signal GW170817 in the framework of DDQMF model. At the same time, most of these constructed EOSs can also satisfy the constraints of the tidal deformability from GW170817 event.
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2403.01711 [pdf]
PRC(2024)·5 citations
05
[Submitted on 4 Mar 2024]
Eigenphase shift decomposition of the RPA strength function based on the Jost-RPA method
K. Mizuyama · T. Dieu Thuy · T. V. Nhan Hao
The S-matrix which satisfies the unitarity, giving the poles as RPA excited states, is derived using the extended Jost function within the framework of the RPA theory. An analysis on the correspondence between the component decomposition of the RPA strength function by the eigenphase shift obtained by diagonalisation of the S-matrix and the S- and K-matrix poles was performed in the calculation of the $^{16}$ O quadrupole excitations. The results show the possibility that the states defined by the eigenphase shift can be expressed as RPA-excited eigenstates corresponding to the S-matrix poles in the continuum region.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2403.01720 [pdf]
PRC(2024)·4 citations
06
[Submitted on 4 Mar 2024]
Isospin-forbidden electric dipole transition of the 9.64 MeV state of $^{12}$ C
Y. Suzuki · W. Horiuchi · M. Kimura
The electric dipole transition of the 3 $^{-}$ state at 9.64 MeV of $^{12}$ C to the 2 $^{+}$ state at 4.44 MeV is speculated to play a key role in the triple- $α$ reaction at high temperatures. A theoretical prediction of its transition width is a challenge to nuclear theory because it belongs to a class of isospin-forbidden transitions. We extend a microscopic 3 $α$ cluster-model to include isospin 1 impurity components, and take into account both isovector and isoscalar electirc dipole operators. Several sets of $2^{+}$ and $3^{-}$ wave functions are generated by solving a radius-constrained equation of motion with the stochastic variational method, resulting in reproducing very well the electric quadrupole and octupole transition probabilities to the ground state. The electric dipole transition width is found to be 7--31 meV, 16 meV on the average, and more than half of the width is contributed by the isospin mixing of $α$ particles.
Comments:
7 pages, 3 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2403.01793 [pdf]
PRC(2024)·1 citation
07
[Submitted on 4 Mar 2024]
Dynamical Model of $J /Ψ$ photo-production on the nucleon
S. Sakinah🇰🇷 · T.-S. H. Lee🇺🇸 · Ho-Meoyng Choi🇰🇷
A dynamical model based on a phenomenological charm quark-nucleon( $c$ -N) potential $v_{c N}$ and the Pomeron-exchange mechanism is constructed to investigate the $J /Ψ$ photo-production on the nucleon from threshold to invariant mass $W = 300$ GeV. The $J /Ψ$ -N potential, $V_{J /Ψ N} (r)$ ,is constructed by folding $v_{c N}$ into the wavefunction $Φ_{J /Ψ} (c c ˉ)$ of $J /Ψ$ within a Constituent Quark Model(CQM) of Ref.[43]. A photo-production amplitude is also generated by $v_{c N}$ by a $c c ˉ$ -loop integration over the $γ \to c c ˉ$ vertex function and $Φ_{J /Ψ} (c c ˉ)$ . No commonly used Vector Meson Dominance assumption is used to define this photo-production amplitude which is needed to describe the data near the threshold. The potential $v_{c N} (r)$ is parameterized in a form such that the predicted $V_{J /Ψ N} (r)$ at large distances has the same Yukawa potential form extracted from a Lattice QCD(LQCD) calculation of Ref.[18]. The parameters of $v_{c N}$ are determined by fitting the total cross section data of JLab by performing calculations that include $J /Ψ$ -N final state interactions(FSI). The resulting differential cross sections are found in good agreements with the data. It is shown that the FSI effects dominate the cross section in the very near threshold region, allowing for sensitive testing of the predicted $J /Ψ$ -N scattering amplitudes. By imposing the constraints of $J /Ψ$ -N potential extracted from the LQCD calculation, we have obtained three $J /Ψ$ -N potentials which fit the JLab data equally well. The resulting $J /Ψ$ -N scattering lengths are in the range of $a = (- 0.05$ fm $\sim$ $- 0.25$ fm). With the determined $v_{c N} (r)$ and the wavefunctions generated from the same CQM, the constructed model is used to predict the cross sections of photo-production of $η_{c} (1 S)$ and $Ψ (2 S)$ mesons for future experimental tests.
Comments:
14 pages, 20 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2403.01958 [pdf]
PRC(2024)·17 citations
08
[Submitted on 4 Mar 2024]
Systematic study of cluster radioactivity in trans-lead nuclei within various versions of proximity potential formalisms
Xiao Liu · Jie-Dong Jiang · Xi-Jun Wu · Xiao-Hua Li
In this work, based on the framework of the Coulomb and proximity potential model (CPPM), we systematically study the cluster radioactivity half-lives of 26 trans-lead nuclei by considering the cluster preformation probability which is found to possess a simple mass dependence on the emitted cluster by R. Blendowske and H. Walliser [Phys. Rev. Lett. 61, 1930(1988)]. Meanwhile, we investigate 28 different versions of the proximity potential formalisms, which are the most complete known proximity potential formalisms and have been proposed for the description of proton radioactivity, two-proton radioactivity, {\alpha} decay, heavy-ion radioactivity, quasi-elastic scattering, fusion reactions and other applications. The calculated results show that the modified forms of proximity potential 1977 denoted as Prox.77-12 and the proximity potential 1981 denoted as Prox.81 are the most appropriate proximity potential formalisms for the study of cluster radioactivity as the root-mean-square deviation between experimental data and relevant theoretical results obtained are least and the both values are 0.681. For comparison, a universal decay law (UDL) proposed by Qi et al. [Phys. Rev. C 80, 044326 (2009)], a unified formula of half-lives for {\alpha} decay and cluster radioactivity proposed by Ni et al. [Phys. Rev. C 78, 044310 (2008)] and a scaling law (SL) in cluster decay proposed by Horoi et al. [J. Phys. G 30, 945 (2004)] are also used. In addition, utilizing CPPM with Prox.77- 12, Prox.77-1, Prox.77-2 and Prox.81, we predict the half-lives of 51 potential cluster radioactive candidates whose cluster radioactivity is energetically allowed or observed but not yet quantified in NUBASE2020. The predicted results are in the same order of magnitude with those obtained by using the compared semi-empirical and/or empirical formulae.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2403.01992 [pdf]
CPC(2024)·10 citations
09
[Submitted on 4 Mar 2024]
Relativistic corrections to energy spectrum of hydrogen due to the full one-photon-exchange interaction
Zi-Wen Zhang🇨🇳 · Hai-Qing Zhou🇨🇳
In this work, we present expressions for the full effective potential corresponding to the one-photon exchange interaction within the framework of an effective Schrödinger-like equation, which is derived exactly from the Bethe-Salpeter equation in quantum electrodynamics. The final effective potential is expressed in terms of eight scalar functions. When these eight scalar functions are expanded in terms of velocities order by order, we can return to the non-relativistic effective potential systematically organized by velocities. By retaining the exact momentum dependence in the effective potential, we estimate its corrections to the energy spectrum of hydrogen using a highly precise numerical method. The comparison of the numerical results with those obtained using conventional bound-state perturbative theory is discussed. Our calculations suggest that it is possible to accurately account for all relativistic contributions using this method. It would be interesting to extend these calculations to positronium, muonic hydrogen, and scenarios involving nuclear structure and radiative corrections.
Comments:
2 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Atomic Physics (physics.atom-ph)
arXiv:
2403.02003 [pdf]
CPC(2025)·0 citations
10
[Submitted on 4 Mar 2024]
The utilization of magneto-hydrodynamics framework in expansion of magnetized viscous conformal flow
M. karimabadi🇮🇷 · A.F. Kord🇮🇷 · B. Azadegan🇮🇷
The evolution of magnetized quark gluon plasma (QGP) in the framework of magneto-hydrodynamics is the focus of our study. We are investigating the temporal and spatial evolution of QGP using a second order viscous hydrodynamic framework. The fluid is considered to be magnetized and subjected to the influence of a magnetic field that is generated during the early stages of relativistic heavy ion collisions.We assume boost invariance along the beam line, which is represented by the $z$ coordinate, and fluid expansion in the $x$ direction. Additionally, we assume that the magnetic field is perpendicular to the reaction plane, which corresponds to the $y$ direction. The fluid is considered to have infinite electrical conductivity. To analyze this system, we solve the coupled Maxwell and conservation equations. By doing so, we are able to determine the time and space dependence of the energy density, velocity, and magnetic field in the transverse plane of the viscous magnetized hot plasma. Furthermore, we obtain the spectrum of hadrons and compare it with experimental data.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Theory (hep-th)
arXiv:
2403.02134 [pdf]
EPJA(2025)·2 citations
11
[Submitted on 4 Mar 2024]
Study of forbidden $β$ decays within the realistic shell model
G. De Gregorio🇮🇹 · R. Mancino🇨🇿 · L. Coraggio🇮🇹 · N. Itaco🇮🇹
For the first time, half-lives and energy spectra of forbidden $β$ decays are calculated within the realistic shell model. Namely, we approach this issue starting from a realistic nucleon-nucleon potential and deriving effective Hamiltonians and decay operators. Our goal is to explore the sensitivity of the shape of calculated energy spectra to the renormalization of forbidden $β$ -decay operators, an operation that allows to take into account those configurations that are not explicitly included in the chosen model space. The region that has been considered for this investigation are nuclei outside the $^{78}$ Ni core, more precisely we have studied the second-forbidden $β$ decays of $^{94}$ Nb and $^{99}$ Tc, and fourth-forbidden $β$ decays of $^{113}$ Cd and $^{115}$ In, that are currently of a renewed experimental interest in terms of novel spectroscopic techniques. Our results evidence that the introduction of a renormalized $β$ -decay operator leads to a marked improvement of the reproduction of experimental half-lives. As regards the spectra of both second-forbidden and fourth-forbidden decays, we have found that their calculated shapes are in good agreement with the observed ones, even if scarcely responsive to the renormalization of the decay operator. We carry out also a detailed inspection of the different components of the calculated spectra for a deeper insight about their role in reproducing the experimental shapes.
Comments:
13 pages, 2 figures, to be published in Phys Rev. C
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex)
arXiv:
2403.02272 [pdf]
PRC(2024)·11 citations
12
[Submitted on 2 Mar 2024] (cross-list from hep-ph)
Strangeness plus-one ( $S = + 1$ ) resonance-state $P_{0}^{+*}$ via $K^{+} n \to K^{* 0} p$
Dayoung Lee🇰🇷 · Seung-il Nam🇰🇷
In our current study, we delve into the peak-like structure observed during the reaction process of $K^{+} n \to K^{0} p$ at approximately $s \sim 2.5$ GeV. Our focus centers on exploring the potential $S = + 1$ resonance $P_{0}^{+*} \equiv P_{0}^{*}$ as an excited state within the extended vector-meson and baryon ( $V B$ ) antidecuplet. To achieve this aim, we employ the effective Lagrangian method in conjunction with the $(u, t)$ -channel Regge approach, operating within the tree-level Born approximation. We thoroughly examine various spin-parity quantum numbers for the resonance, resulting in a compelling description of the data, where $M_{P_{0}^{*}} \approx 2.5$ GeV and $Γ_{P_{0}^{*}} \approx 100$ MeV. Furthermore, we propose an experimental technique to amplify the signal-to-noise ratio ( $S / N$ ) for accurately measuring the resonance. Notably, our findings reveal that background interference diminishes significantly within the $K^{*}$ forward-scattering region in the center-of-mass frame when the $K^{*}$ is perpendicularly polarized to the reaction plane. Additionally, we explore the recoil-proton spin asymmetry to definitively determine the spin and parity of the resonance. This study stands to serve as a valuable reference for designing experimental setups aimed at investigating and comprehending exotic phenomena in QCD. Specifically, our insights will inform future J-PARC experiments, particularly those employing higher kaon beam energies.
Comments:
9 pages, 5 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2403.01191 [pdf]
PRC(2024)·2 citations
13
[Submitted on 2 Mar 2024] (cross-list from hep-ph)
Study of identified particle production as a function of transverse event activity classifier, $S_{T}$ in p $-$ p collisions
Rahul Verma🇮🇳 · Vishu Saini🇮🇳 · Basanta Nandi🇮🇳 · Sadhana Dash🇮🇳
A new observable, $S_{T}$ , is introduced in terms of the sum of the transverse momentum of charged particles ( $\sum_{i} p_{T_{i}}$ ) produced in proton proton (p $-$ p) collisions at LHC energies to probe the underlying events (UE). The UE are defined as those aspects of proton-proton collisions that are not attributed to the primary hard scattering process, but rather to the accompanying interactions of the rest of the proton. The conventional approach of studying underlying events is usually carried out by defining topological regions with respect to the leading particle in an event. The transverse region is generally sensitive to UE and various classifiers have been used to discriminate the extent of UE activity regions. The production of identified particles like $π^{\pm}$ , $K^{\pm}$ , p , $K_{S}^{0}$ , and $Λ^{0}$ are studied in different ranges of transverse activity classifier in p $-$ p collisions at $s = 13$ TeV using pQCD inspired PYTHIA 8 event generator. A comparative analysis of the identified particle spectra, mean multiplicity and mean transverse momentum has been carried out with respect to $S_{T}$ and the performance of this new observable is gauged by comparing the results with previously defined $R_{T}$ observable.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2403.01224 [pdf]
Eur.Phys.J.Plus(2025)·2 citations
14
[Submitted on 2 Mar 2024] (cross-list from hep-ph)
Analyzing the transport coefficients and observables of a rotating QGP medium in kinetic theory framework with a novel approach to the collision integral
Shubhalaxmi Rath🇨🇱 · Sadhana Dash🇮🇳
In the present work, we have studied how the rotation of the QGP medium affects the transport coefficients and observables in heavy ion collisions. For the noncentral collisions, although most of the angular momentum gets carried away by the spectators, there still remains a finite angular momentum with a finite range of angular velocity, which thus incites rotation in the produced matter. As a result, various properties of the QGP medium including its transport properties are most likely to be modulated by the rotation. We have calculated the transport coefficients and observables, such as the electrical conductivity, the thermal conductivity, the Knudsen number, the elliptic flow, the specific heat at constant pressure, the specific heat at constant volume, the trace anomaly, the thermal diffusion constant and the isothermal compressibility using the kinetic theory to see the effect of rotation on them. In particular, we have used the novel relaxation time approximation for the collision integral in the relativistic Boltzmann transport equation to derive the transport coefficients and compared them with their values in the relaxation time approximation within the kinetic theory approach in conjunction with the finite angular velocity. We have found that the emergence of angular velocity enhances the flow of charge and heat in the medium. Further, as compared to the relaxation time approximation, the electrical and the thermal conductivities have smaller values in the novel relaxation time approximation and these differences between the conductivities in the said approximations are more pronounced at high temperatures than at low temperatures. Furthermore, all the aforesaid observables are found to be sensitive to the rotation of the QGP medium.
Comments:
32 pages, 9 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2403.01240 [pdf]
EPJC(2025)·7 citations
15
[Submitted on 4 Mar 2024] (cross-list from hep-ph)
Identification of the $G (3900)$ as the P-wave $D D ˉ^{*} / D ˉ D^{*}$ resonance
Zi-Yang Lin🇨🇳 · Jun-Zhang Wang🇨🇳 · Jian-Bo Cheng🇨🇳 · Lu Meng🇩🇪 · Shi-Lin Zhu🇨🇳
The BESIII Collaboration recently performed a precise measurement of the $e^{+} e^{-} \to D D ˉ$ Born cross sections, and confirmed the $G (3900)$ structure reported by BaBar and Belle with high significance. We identify the $G (3900)$ as the first P-wave $\DDbar$ molecular resonance. The experimental and theoretical identification of the P-wave dimeson state holds paramount importance in enhancing our comprehension of the non-perturbative QCD and few-body physics. Its existence is firmly established in a unified meson-exchange model which simultaneously depicts the features of the $χ_{c 1} (3872)$ , $Z_{c} (3900)$ and $T_{cc} (3875)$ . This scenario can be directly examined in the $e^{+} e^{-} \to D D ˉ^{*} / D ˉ D^{*}$ cross section by seeing whether a resonance exists at the threshold. The credibility of the investigations is also ensured by the fact that the P-wave interaction dominantly arises from the well-known long-range pion exchange. Additionally, thanks to the centrifugal barrier, it is easier to form resonances in P-wave than in S-wave. We extensively calculate all systems up to P-wave with various quantum numbers and predict a dense population of the $\DDbar$ and $\DD$ states, where the S-wave $\DDbar$ state with $I^{G} (J^{P C}) = 0^{-} (1^{+-})$ , P-wave $\DDbar$ state with $I^{G} (J^{P C}) = 0^{+} (0^{-+})$ , and P-wave $\DD$ state with $I (J^{P}) = 0 (0^{-})$ are more likely to be observed in experiments.
Comments:
8 pages, 4 figures. PRL(in press)
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2403.01727 [pdf]
PRL(2024)·35 citations
16
[Submitted on 4 Mar 2024] (cross-list from hep-ph)
A Global View of the EDM Landscape
Skyler Degenkolb🇩🇪 · Nina Elmer🇩🇪 · Tanmoy Modak🇩🇪 · Margarete Mühlleitner🇩🇪 · Tilman Plehn🇩🇪
Permanent electric dipole moments (EDMs) are sensitive probes of the symmetry structure of elementary particles, which in turn is closely tied to the baryon asymmetry in the universe. A meaningful interpretation framework for EDM measurements has to be based on effective quantum field theory. We interpret the measurements performed to date in terms of a hadronic-scale Lagrangian, using the SFitter global analysis framework. We find that part of this Lagrangian is constrained very well, while some of the parameters suffer from too few high-precision measurements. Theory uncertainties lead to weaker model constraints, but can be controlled within the global analysis.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2403.02052 [pdf]
SciPost Phys.(2026)·18 citations
17
[Submitted on 4 Mar 2024] (cross-list from astro-ph.HE)
Neutron star cooling and mass distributions
H. C. Das🇮🇹 · Jin-Biao Wei🇨🇳 · G. F. Burgio🇮🇹 · H.-J. Schulze🇮🇹
We study the cooling of isolated neutron stars, employing different nuclear equations of state with or without active direct Urca process, and investigate the interplay with the nuclear pairing gaps. We find that a consistent description of all current cooling data requires fast direct Urca cooling and reasonable proton 1S0 gaps, but no neutron 3P2 pairing. We then deduce the neutron star mass distributions compatible with the cooling analysis and compare with current theoretical models. Reduced 1S0 gaps and unimodal mass distributions are preferred by the analysis. The importance of statistical and systematic errors is also investigated.
Comments:
14 pages, 10 figures, 2 tables, Published in Phys. Rev. D
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2403.02222 [pdf]
PRD(2024)·9 citations
18
[Submitted on 4 Mar 2024] (cross-list from hep-ph)
On the study of new proxies for second order cumulants of conserved charges in heavy-ion collisions with EPOS4
Johannes Jahan🇺🇸 · Claudia Ratti🇺🇸 · Maria Stefaniak🇺🇸 · Klaus Werner🇫🇷
Proxies for cumulants of baryon number $B$ , electric charge $Q$ and strangeness $S$ are usually measured in heavy-ion collisions via moments of net-number distribution of given hadronic species. Since these cumulants of conserved charges are expected to be sensitive to the existence of a critical point in the phase diagram of nuclear matter, it is crucial to ensure that the proxies used as substitutes are as close to them as possible. Hence, we use the EPOS4 framework to generate Au+Au collisions at several collision energies of the RHIC Beam Energy Scan. We compute $2^{nd}$ order net-cumulants of $π$ , $K$ and $p$ , for which experimental data has been published, as well as the corresponding conserved charge cumulants. We then compare them with proxies, defined in previous lattice QCD and Hadron Resonance Gas model studies, which are shown to reproduce more accurately their associated conserved charge cumulants. We investigate the impact of hadronic re-scatterings occurring in the late evolution of the system on these quantities, as well as the amount of signal actually originating from the bulk medium which endures a phase transition.
Comments:
14 pages, 11 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2403.02306 [pdf]
PRC(2024)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE

Tuesday·March 5, 2024

Quantum-number projected generator coordinate method for $^{21}$ Ne with a chiral two-nucleon-plus-three-nucleon interaction

Neutron stars as a dense liquid drop at equilibrium within the effective surface approximation

Shell-cluster transition in $^{48}$ Ti

Density-dependent quark mean-field model for nuclear matter and neutron stars

Eigenphase shift decomposition of the RPA strength function based on the Jost-RPA method

Isospin-forbidden electric dipole transition of the 9.64 MeV state of $^{12}$ C

Dynamical Model of $J /Ψ$ photo-production on the nucleon

Systematic study of cluster radioactivity in trans-lead nuclei within various versions of proximity potential formalisms

Relativistic corrections to energy spectrum of hydrogen due to the full one-photon-exchange interaction

The utilization of magneto-hydrodynamics framework in expansion of magnetized viscous conformal flow

Study of forbidden $β$ decays within the realistic shell model

Strangeness plus-one ( $S = + 1$ ) resonance-state $P_{0}^{+}$ via $K^{+} n \to K^{ 0} p$

Study of identified particle production as a function of transverse event activity classifier, $S_{T}$ in p $-$ p collisions

Analyzing the transport coefficients and observables of a rotating QGP medium in kinetic theory framework with a novel approach to the collision integral

Identification of the $G (3900)$ as the P-wave $D D ˉ^{} / D ˉ D^{}$ resonance

A Global View of the EDM Landscape

Neutron star cooling and mass distributions

On the study of new proxies for second order cumulants of conserved charges in heavy-ion collisions with EPOS4

Affiliations