Nuclear Theory·nucl-th

Wednesday·December 7, 2022

7 papers—4 primary·3 cross-listed

01
Model-independent determination of nuclear weak form factors and implications for Standard Model precision tests
Chien-Yeah Seng🇺🇸
We analyze the recoil corrections in superallowed beta decays of $T = 1$ , $J^{P} = 0^{+}$ nuclei by fixing the mean square charge weak radius model-independently using the data of multiple charge radii across the nuclear isotriplet. By comparing to model estimations, we argue that the existing theory uncertainty in the statistical rate function $f$ might have been substantially underestimated. We discuss the implications of our proposed strategy for precision tests of Standard Model, including a potential alleviation of the first-row CKM unitarity deficit, and motivate new experiments for charge radii measurements.
nucl-thhep-exhep-phnucl-exPRL(2023)·26 citations
02
Half-lives for proton emission and {\alpha} decay within the deformed Gamow-like model
Qiong Xiao · Jun-Hao Cheng · Tong-Pu Yu
In the present work, we study {\alpha} decay and proton emission half-lives within the modified Gamow-like model, which introduces the effects of the nucleus's deformation. The calculations show that it is necessary to consider the deformation in the calculation for nuclei far from the shell. Moreover, we use the improved model to predict the proton emission half-lives of the nuclei far from the shell. The calculation results indicate that our model is in good agreement with most models. Furthermore, the deformed Gamow-like model is used to find the following neutron magic number. This work is meaningful for future research on superheavy nuclei.
nucl-thJ.Phys.G(2023)·7 citations
03
Event-by-event investigation of the two-particle source function in $s_{_{NN}} = 2.76$ TeV PbPb collisions with EPOS
Balázs Kórodi🇭🇺 · Dániel Kincses🇭🇺 · Máté Csanád🇭🇺
The investigation of the two-particle source function in lead-lead collisions simulated by the EPOS model at a center of mass energy per nucleon pair of $s_{_{NN}} = 2.76$ TeV is presented. The two-particle source functions are reconstructed directly on an event-by-event basis for pions, kaons and protons separately, using the final stage of EPOS. A Lévy source shape is observed for all three particle species in the individual events, deviating significantly from a Gaussian shape. The source parameters are extracted as functions of collision centrality and pair average transverse mass ( $m_{T}$ ). The Lévy exponent is found to be ordered accordingly to particle mass. The Lévy scale parameter is found to scale for all particle species with $m_{T}$ according to Gaussian hydrodynamical predictions; however, there is no $m_{T}$ -scaling found across these species. In case of pions, the effects of the decay products and hadronic rescattering are also investigated. The Lévy exponent is decreased when decay products are also included in the analysis. Without hadronic rescattering and decay products, the source shape is close to a Gaussian.
nucl-thhep-phnucl-exPLB(2023)·23 citations
04
Impact of globally spin-aligned vector mesons on the search for the chiral magnetic effect in heavy-ion collisions
Diyu Shen🇨🇳 · Jinhui Chen🇨🇳 · Aihong Tang🇺🇸 · Gang Wang🇺🇸
In high-energy heavy-ion collisions, the chiral magnetic effect (CME) is predicted to arise from the interplay between the chirality imbalance of quarks in the nuclear medium and the intense magnetic field, and will cause a charge separation along the magnetic field direction. While the search for the CME is still ongoing in experiments at Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), the CME-sensitive observables need to be scrutinized to exclude the non-CME contributions. In this work, we examine the influence of globally spin-aligned $ρ$ mesons on the $γ_{112}$ correlator, the $R_{Ψ_{2}} (Δ S)$ correlator, and the signed balance functions, via a toy model and a multiphase transport model (AMPT). The global spin alignment of vector mesons could originate from non-CME mechanisms in heavy-ion collisions, and is characterized by the 00-component of the spin density matrix, $ρ_{00}$ . We find that the CME observables show similar dependence on $ρ_{00}$ , and could receive a positive (negative) contribution from $ρ$ -decay pions, if the $ρ_{00}$ of $ρ$ mesons is larger (smaller) than 1/3. Since pions are the most abundant particles in such collisions, the $ρ_{00}$ measurements for $ρ$ mesons become crucial to the interpretation of the CME data.
nucl-thnucl-exPLB(2023)·17 citations
05
Understanding the nature of $Ω (2012)$ in a coupled-channel approach
Qi-Fang Lü🇨🇳 · Hideko Nagahiro🇯🇵 · Atsushi Hosaka🇯🇵
We perform a systematic analysis of the mass and strong decays of the $Ω (2012)$ resonance in a coupled-channel approach of a bare three-quark state and a composite meson-baryon state. Besides the coupling of the bare state and $Ξ^{*} K ˉ$ channel, the effective meson-baryon interactions are also included. We find a pole with mass of $2008$ MeV by solving the Bethe-Salpeter equation. The calculated decay widths and its ratios of branching fractions $R_{Ξ K ˉ}^{Ξ π K ˉ}$ agree well with the new experimental measurement by Belle Collaboration. Our results suggest that both three-quark core and $Ξ^{*} K ˉ$ channel are essential for the description of the $Ω (2012)$ resonance. We expect that present calculations can help us to better understand the nature of $Ω (2012)$ resonance.
↳ hep-phhep-exnucl-thPRD(2023)·23 citations
06
Phenomenological model for the $γ γ \to π^{+} π^{-} π^{0}$ reaction
Xiu-Lei Ren🇩🇪 · Igor Danilkin🇩🇪 · Marc Vanderhaeghen🇩🇪
We present a phenomenological model for the $γ γ \to π^{+} π^{-} π^{0}$ reaction by including the production mechanism of the $a_{2} (1320)$ resonance, as well as the contributions from the $σ / f_{0} (500) π^{0}$ and $f_{2} (1270) π^{0}$ production channels. Furthermore, the $γ γ \to ρ^{\pm} π^{\mp} \to π^{+} π^{-} π^{0}$ channel, which is essential for a description in the low-energy region, is investigated carefully by introducing the complete set of gauge invariant and Lorentz-covariant tensors for the $γ γ \to ρ^{\pm} π^{\mp}$ subprocess. The full amplitude is constructed to yield a correct high-energy Regge behavior. Within our model, we achieve a very reasonable description of ARGUS and L3 data of the total cross section, as well as of the $π^{\pm} π^{0}$ and $π^{+} π^{-}$ invariant mass distributions. We also predict the invariant mass distributions in the $γ γ$ center-of-mass energy range from $0.8$ GeV to $2.0$ GeV, which will be studied by the forthcoming data of the BESIII collaboration.
↳ hep-phnucl-thPRD(2023)·6 citations
07
Nuclear Transition in the Strong Coupling Limit
Jangho Kim🇩🇪 · Pratitee Pattanaik🇩🇪 · Wolfgang Unger🇩🇪
Lattice QCD at finite baryon chemical potential has the infamous sign problem which hinders Monte Carlo simulations. This can be remedied by a dual representation that makes the sign problem mild. In the strong coupling limit, the dual formulation with staggered quarks is well established. We have used this formulation to study the quark mass dependence of the baryon mass and the nuclear transition. This allows us to quantify the nuclear interaction. We have also compared our Monte Carlo results with mean field predictions.
↳ hep-latnucl-thPoS(2023)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE

Model-independent determination of nuclear weak form factors and implications for Standard Model precision tests

Half-lives for proton emission and {\alpha} decay within the deformed Gamow-like model

Event-by-event investigation of the two-particle source function in sNN​​​=2.76 TeV PbPb collisions with EPOS

Impact of globally spin-aligned vector mesons on the search for the chiral magnetic effect in heavy-ion collisions

Understanding the nature of Ω(2012) in a coupled-channel approach

Phenomenological model for the γγ→π+π−π0 reaction

Nuclear Transition in the Strong Coupling Limit

Affiliations

Event-by-event investigation of the two-particle source function in $s_{_{NN}} = 2.76$ TeV PbPb collisions with EPOS

Understanding the nature of $Ω (2012)$ in a coupled-channel approach

Phenomenological model for the $γ γ \to π^{+} π^{-} π^{0}$ reaction