Neutron-rich nuclei near the <math altimg='si6.svg'><mrow><mi>N</mi><mo linebreak='goodbreak'>=</mo><mn>126</mn></mrow></math> shell closure are vital for <italic>r</italic>-process nucleosynthesis but remain challenging to produce. Multinucleon transfer reactions offer a promising route. We investigate the role of shell effects in such processes by extending the CLIM-H model with a deformation-dependent mass formula and a scaling factor <italic>a</italic> that linearly adjusts the shell-correction strength. Calculations for 136Xe on 208Pb, 204Hg, and 208Hg targets reveal a dual role: shell effects enhance few-nucleon transfers near the entrance channel but strongly suppress fragments requiring the transfer of many nucleons, most severely for the doubly magic 208Pb. This suppression stems from the cumulative transfer probabilities and is aggravated by lower survival after deexcitation. Thus, optimal production of exotic <math altimg='si6.svg'><mrow><mi>N</mi><mo linebreak='goodbreak'>=</mo><mn>126</mn></mrow></math> nuclei requires avoiding strongly shell-closed collision partners at <math altimg='si6.svg'><mrow><mi>N</mi><mo linebreak='goodbreak'>=</mo><mn>126</mn></mrow></math>, as exemplified by doubly magic 208Pb. We propose 238U + 204Hg at <italic>E</italic> <inf>c.m.</inf>&#8239;&#8771;&#8239;1.45 <italic>V<inf>B</inf></italic> as a superior system, predicting significantly enhanced yields.

China

F.C. Dai

P.W. Wen

C.J. Lin

J.J. Liu

X.X. Xu

K.L. Wang

Y.D. Chen

H.L. Yang

Role of shell effects on producing neutron-rich nuclei in the <math altimg='si6.svg'><mrow><mi>N</mi><mo linebreak='goodbreak'>=</mo><mn>126</mn></mrow></math> region via multinucleon transfer reactions

The Schwinger effect, a non-perturbative mechanism for particle production in strong fields, plays a crucial role in understanding quantum vacuum decay and high-energy phenomena, including heavy-ion collisions (HIC). Although holographic quantum chromodynamics (QCD) models have been widely used to study this effect, most treatments assume isotropy or consider only a single type of anisotropy, neglecting the interplay between spatial and magnetic anisotropies that arise in realistic HIC scenarios. A unified framework accounting for both anisotropies is needed to accurately model particle production. We investigate the Schwinger effect in a twice anisotropic holographic QCD model incorporating both spatial and magnetic anisotropies. Using the anti-de Sitter/conformal field theory correspondence, we compute the total potential of a particle-antiparticle pair to quantify how these anisotropies influence pair production. Our results show that the magnetic field (parameterized by $c_B$ and $q_3$ ) enhances the Schwinger effect by lowering and narrowing the potential barrier, while increasing spatial anisotropy (controlled by $\nu$ ) suppresses the process by raising and widening the barrier. These findings demonstrate that magnetic and spatial anisotropies exert competing effects on particle production, emphasizing the necessity of treating both concurrently in holographic models. This work advances the theoretical description of the Schwinger effect in anisotropic environments, with implications for understanding non-equilibrium dynamics in HIC and other strongly coupled systems.

Wen-Bin Chang

Defu Hou

Schwinger effect in a twice anisotropic holographic model * Defu Hou's research is supported in part by the National Key Research and Development Program of China (2022YFA1604900). Additionally, Defu Hou receives partial support from the National Natural Science Foundation of China (NSFC) (12435009, 12275104). Wen-Bin Chang is supported by the Ph.D. Research Startup Project at Hubei Minzu University (RZ2500000857)

This paper introduces a novel systematic construction of gapped domain walls (GDWs) within the Levin-Wen (LW) model. By gluing two LW models along their open sides in a compatible way, we achieve a complete GDW classification by subsets of bulk input data, which encompass the classifications in terms of bimodule categories. A generalized bimodule structure is introduced to capture domain-wall excitations. Furthermore, we demonstrate that folding along any GDW yields a gapped boundary (GB) described by a Frobenius algebra of the input UFC for the folded model, thus bridging our GDW classification and the GB classification in [1].

Yanyan Chen

Siyuan Wang

Yu Zhao

Yuting Hu

Yidun Wan

Classification of gapped domain walls of topological orders in 2+1 dimensions: a Levin-Wen model realization

Back-angle quasi-elastic (QE) scattering provides critical barrier information in massive nuclear reactions leading to the synthesis of superheavy nuclei. The shapes and peaks of QE barrier distributions serve as fingerprints of nuclear structures and reaction dynamics. Couplings to collective movements can lead to distinctive peaks in the barrier distributions, but the role of multi-phonon and high-spin states has not been thoroughly investigated. In this work, we extend the high-accuracy R-matrix method and the finite element method to solve coupled-channel equations for massive systems. These two methods are demonstrated to be more stable than the widely used modified Numerov method and allows us to include more vibrational and rotational couplings. Using the reactions <math altimg='si1.svg'><mmultiscripts><mrow><mi mathvariant='normal'>Ti</mi></mrow><mprescripts /><none /><mrow><mn>48</mn></mrow></mmultiscripts></math>+ <math altimg='si2.svg'><mmultiscripts><mrow><mi mathvariant='normal'>Pb</mi></mrow><mprescripts /><none /><mrow><mn>208</mn></mrow></mmultiscripts></math> and <math altimg='si3.svg'><mmultiscripts><mrow><mi mathvariant='normal'>V</mi></mrow><mprescripts /><none /><mrow><mn>51</mn></mrow></mmultiscripts><mo linebreak='goodbreak' linebreakstyle='after'>+</mo><msup><mrow /><mrow><mn>248</mn></mrow></msup><mrow><mi mathvariant='normal'>Cm</mi></mrow></math> as examples, calculations show that multi-phonon and high-spin states significantly smooth the barrier distributions, improving the agreement with experimental data. The comparison between the coupled-channel results and those obtained from the orientation average formula is examined. This work can advance the study of superheavy element synthesis by providing reliable barrier information and capture cross sections based on constraints from QE reactions.

Russia

Mongolia

O. Chuluunbaatar

Belgium

P. Descouvemont

A.A. Gusev

S.I. Vinitsky

Role of multi-phonon and high-spin states on the quasi-elastic barrier distributions of massive systems

Levin-Wen string-net models provide a construction of (2+1)D topologically ordered phases of matter with anyonic localized excitations described by the Drinfeld center of a unitary fusion category. Anyon condensation is a mechanism for phase transitions between (2+1)D topologically ordered phases. We construct an extension of Levin-Wen models in which tuning a parameter implements anyon condensation. We also describe the classification of anyons in Levin-Wen models via representation theory of the tube algebra, and use a variant of the tube algebra to classify low-energy localized excitations in the condensed phase.

United States

Jessica Christian

David Green

Peter Huston

David Penneys

A lattice model for condensation in Levin-Wen systems

A realistic material may possess defects, which often bring the material new properties that have practical applications. The boundary defects of a two-dimensional topologically ordered system are thought of as an alternative way of realizing topological quantum computation. To facilitate the study of such boundary defects, in this paper, we construct an exactly solvable Hamiltonian model of topological orders with gapped boundary junctions, where the boundary defects reside, by placing the Levin-Wen model on a disk, whose gapped boundary is separated into multiple segments by junctions. We derive a formula of the ground state degeneracy and an explicit ground-state basis of our model. We propose the notion of mobile and immobile charges on the boundary and find that they are quantum observables and label the ground-state basis. Our model is computation friendly.

Hongyu Wang

Extend the Levin-Wen model to two-dimensional topological orders with gapped boundary junctions

The mechanism of reactions with weakly-bound proton-rich nuclei at energies near the Coulomb barrier is a long-standing open question owing to the paucity of experimental data. In this study, a complete kinematics measurement was performed for the proton drip-line nucleus $^{17}$F interacting with $^{58}$Ni at four energies near the Coulomb barrier. Thanks to the powerful performance of the detector array, exhaustive information on the reaction channels, such as the differential cross sections for quasielastic scattering, exclusive and inclusive breakup, as well as for fusion-evaporation protons and alphas, was derived for the first time. The angular distributions of quasielastic scattering and exclusive breakup can be described reasonably well by the continuum-discretized coupled-channels calculations. The inclusive breakup was investigated using the three-body model proposed by Ichimura, Austern, and Vincent, and results indicate the non-elastic breakup is the dominant component. The total fusion cross sections were determined by the fusion-evaporation protons and alphas. Based on the measured exclusive breakup data, the analysis of the classical dynamical simulation code PLATYPUS demonstrates that the incomplete fusion plays a minor role. Moreover, compared with $^{16}$O+$^{58}$Ni, both the reaction and total fusion cross sections of $^{17}$F+$^{58}$Ni exhibit an enhancement in the sub-barrier energy region, which mainly arises from couplings to the continuum states. This work indicates that the information of full reaction channels is crucially important to comprehensively understand the reaction mechanisms of weakly bound nuclear systems.

L. Yang

Japan

H. Yamaguchi

Jin Lei

Italy

M. Mazzocco

N.R. Ma

L.J. Sun

D.X. Wang

G.X. Zhang

K. Abe

South Korea

S.M. Cha

K.Y. Chae

United Kingdom

A. Diaz-Torres

Brazil

J.L. Ferreira

S. Hayakawa

H.M. Jia

D. Kahl

A. Kim

M.S. Kwag

M. La Commara

R. Navarro Pérez

C. Parascandolo

D. Pierroutsakou

J. Rangel

Y. Sakaguchi

C. Signorini

E. Strano

F. Yang

Y.Y. Yang

G.L. Zhang

F.P. Zhong

J. Lubian

Insight into the reaction dynamics of proton drip-line nuclear system F+ Ni at near-barrier energies

Even though the Bayesian method has been proved to be powerful in the field of nuclear physics, it has not yet been implemented to study the properties of the reaction systems with exotic nuclei, for instance, the gross feature of the phenomenological interaction potential. So far, the optical model potential was typically evaluated by the traditional frequentist approach. However, contradictive conclusions were drawn, especially on the near-threshold behavior of the imaginary potential: threshold anomaly and abnormal threshold anomaly were derived for $^{6}$Li+$^{209}$Bi and $^{6}$He+$^{208}$Pb even with the same elastic scattering data. In this study, we first applied the Bayesian framework to analyze the elastic scattering data of $^{6}$Li+$^{209}$Bi. It was found that the results of Bayesian statistics strongly depend on the imposed prior distributions. Therefore, the Bayesian method has to be used with extreme caution, since the improper prior knowledge could lead to completely wrong conclusions. Since the elastic scattering data is not informative enough to constrain the prior and posterior distributions, our analysis further indicates that the results from the non-constraint frequentist approach or the flat prior distribution with a reasonable physical-boundary can be employed as convincing prior knowledge of the Bayesian framework. Based on this result, we further applied the Bayesian approach to the transfer reaction $^{208}$Pb($^{7}$Li,$^{6}$He)$^{209}$Bi, to investigate the optical potentials of the neutron halo system $^{6}$He+$^{209}$Bi in the outgoing channel. With the proper prior distributions, the Bayesian analysis on both the $^{6}$Li+$^{209}$Bi and $^{6}$He+$^{208}$Pb confirm the presence of the abnormal threshold anomaly. Therefore the applicability of the dispersion relation remains in doubt.

Y.X. Zhang

S.H. Zhong

T.P. Luo

Bayesian analysis on interactions of exotic nuclear systems

The mass of $^{27}$P is expected to impact the X-ray burst (XRB) model predictions of burst light curves and the composition of the burst ashes, but large uncertainties and inconsistencies still exist in the reported $^{27}$P masses. We have used the β-decay spectroscopy of $^{27}$S to determine the most precise mass excess of $^{27}$P to date to be <math><mo>−</mo><mn>659</mn><mo>(</mo><mn>9</mn><mo>)</mo></math> keV, which is 63 keV (2.3σ) higher and a factor of 3 more precise than the value recommended in the 2016 Atomic Mass Evaluation. Based on the new $^{27}$P mass, the <math><mmultiscripts><mrow><mi>Si</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>26</mn></mrow></mmultiscripts><msup><mrow><mo>(</mo><mi>p</mi><mo>,</mo><mi>γ</mi><mo>)</mo></mrow><mrow><mn>27</mn></mrow></msup></math>P reaction rate and its uncertainty were recalculated using Monte Carlo techniques. We also estimated the previously unknown mass excess of $^{27}$S to be 17678(77) keV, based on the measured β-delayed two-proton energy and the Coulomb displacement energy relations. The impact of these well-constrained masses and reaction rates on the modeling of the explosive astrophysical scenarios has been investigated by post-processing XRB and hydrodynamic nova models. Compared to the model calculations based on the masses and rates from databases, the abundance of <math><mi>A</mi><mo>=</mo><mn>26</mn></math> in the burst ashes is increased by a factor of 2.4, while no substantial change was found in the XRB energy generation rate or the light curve. Our calculation also suggests that $^{27}$S is not a significant waiting point in the rapid proton capture process, and the change of the <math><mmultiscripts><mrow><mi>Si</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>26</mn></mrow></mmultiscripts><msup><mrow><mo>(</mo><mi>p</mi><mo>,</mo><mi>γ</mi><mo>)</mo></mrow><mrow><mn>27</mn></mrow></msup></math>P reaction rate is not sufficiently large to affect the conclusion previously drawn on the nova contribution to the synthesis of galactic $^{26}$Al.

Hong Kong

S.Q. Hou

Spain

J. José

J. Lee

J.J. He

Z.H. Li

J.S. Wang

C.X. Yuan

Canada

F. Herwig

J. Keegans

T. Budner

H.Y. Wu

P.F. Liang

Y.H. Lam

P. Ma

F.F. Duan

Z.H. Gao

Q. Hu

Z. Bai

J.B. Ma

J.G. Wang

C.G. Wu

D.W. Luo

Y. Jiang

Y. Liu

D.S. Hou

R. Li

W.H. Ma

G.Z. Shi

G.M. Yu

D. Patel

S.Y. Jin

Y.F. Wang

Y.C. Yu

Q.W. Zhou

P. Wang

L.Y. Hu

X. Wang

H.L. Zang

P.J. Li

Q.Q. Zhao

M. Pan

X.Y. Wang

Z.G. Hu

R.F. Chen

M.L. Liu

W.Q. Yang

Y.M. Zhao

Experimentally well-constrained masses of P and S: Implications for studies of explosive binary systems

The honeycomb lattice Kitaev model <math><msub><mrow><mi>H</mi></mrow><mrow><mi>K</mi></mrow></msub></math> with two kinds of Wen–Toric-code four-body interactions <math><msub><mrow><mi>H</mi></mrow><mrow><mi>W</mi><mi>T</mi></mrow></msub></math> is investigated exactly using a new fermionization method, and the ground state phase diagram is obtained. Six kinds of three-body interactions are also considered. A Hamiltonian equivalent to the honeycomb lattice Kitaev model is also introduced. The fermionization method is generalized to two-dimensional systems, and the two-dimensional Jordan–Wigner transformation is obtained as a special case of this formula. The model <math><msub><mrow><mi>H</mi></mrow><mrow><mi>K</mi></mrow></msub><mo>+</mo><msub><mrow><mi>H</mi></mrow><mrow><mi>W</mi><mi>T</mi></mrow></msub></math> is symmetric in four-dimensional space of coupling constants, and the anyon type excitations appear in each phase.

Kazuhiko Minami

Honeycomb lattice Kitaev model with Wen–Toric-code interactions, and anyon excitations