The Galactic Center GeV Excess (GCE) remains a compelling but enigmatic signal from the inner regions of our galaxy. Muonphilic dark matter (DM), which couples exclusively to muons via a new mediator, provides a viable explanation for the GCE and relic density while naturally evading constraints from direct detection, collider searches, and other multimessenger observations. Based on the viable nonresonant parameter space identified in previous global fits, we perform a comprehensive study on the prospects for discovering such muonphilic DM in the context of a future 3 TeV muon collider, focusing on simplified models with a $Z_2$ -even mediator. Four distinct search strategies are investigated: visible on-shell mediator decays ( $\mu^{+}\mu^{-}\gamma$ final state), invisible on-shell mediator decays (mono-photon plus missing energy), mono-photon production via off-shell mediators, and vector boson fusion production. Through a detailed signal-background analysis using cut-and-count methods, we project the exclusion limits at $ 95 $ % confidence level for seven representative models across a wide range of mediator masses. Our results demonstrate that the projected limits cover a significant portion of viable parameter space that explains the GCE, establishing a muon collider as a decisive machine for testing the muonphilic DM hypothesis.

China

Wanyun Chen

Haoqi Li

Chih-Ting Lu

Qiulei Wang

Exploring muonphilic dark matter with the $\textit{Z}$ $_{2}$-even mediator at muon colliders * Chih-Ting Lu, Wanyun Chen and Haoqi Li are supported by the National Natural Science Foundation of China (NNSFC) (12335005, 12575118) and the Special funds for postdoctoral overseas recruitment, Ministry of Education of China

Positive and negative flows of the Chen-Lee-Liu model and its various reductions, including Burgers hierarchy, are formulated within the framework of Riemann-Hilbert-Birkhoff decomposition with the constant grade two generator. Two classes of vacua, namely zero vacuum and constant non-zero vacuum can be realized within a centerless Heisenberg algebra. The tau functions for soliton solutions are obtained by a dressing method and vertex operators are constructed for both types of vacua. We are able to select and classify the soliton solutions in terms of the type of vertices involved. A judicious choice of vertices yields in a closed form a particular set of multi soliton solutions for the Burgers hierarchy. We develop and analyze a class of gauge-Bäcklund transformations that generate further multi soliton solutions from those obtained by dressing method by letting them interact with various integrable defects.

Brazil

Ireland

Y.F. Adans

United States

H. Aratyn

C.P. Constantinidis

J.F. Gomes

G.V. Lobo

T.C. Santiago

New soliton solutions for Chen-Lee-Liu and Burgers hierarchies and its Bäcklund transformations

In this study, we compute the next-to-leading-order QCD corrections to the Dirac electromagnetic form factors of the Σ hyperons within the hard-collinear factorization framework at leading power. The corresponding short-distance coefficient functions are extracted from the relevant seven-point partonic correlation functions. We find that the one-loop radiative corrections to the leading-twist hard-scattering contributions are numerically significant over a broad range of momentum transfer. Combining the perturbatively calculated hard kernels with nonperturbative Σ distribution amplitudes determined from lattice QCD, we present state-of-the-art theoretical predictions for the Σ hyperon electromagnetic form factors.

Bo-Xuan Shi

Hui-Xin Yu

Xue-Chen Zhao

Next-to-leading-order QCD predictions for the Σ Dirac form factors * This research is supported by the National Natural Science Foundation of China (12475097, 12535006) and the Natural Science Foundation of Tianjin (25JCZDJC01190). Xue-Chen Zhao is supported by the Postdoctoral Fellowship Program of CPSF (GZB20250794)

Electroweak (EW) amplitudes in the gauge-Goldstone five-component formalism have a distinctive property: gauge symmetry is imprinted in the amplitudes, manifested as the massive Ward identity (MWI) $ k^M{\cal{M}}_M=0 $ . In this study, we used the HELAS package to numerically study gauge symmetry in EW amplitudes. First, we directly tested gauge symmetry by examining the MWI of amplitudes. Second, we modified the couplings within a vertex and among vertices to check if and how the MWI changes. Third, we tested gauge symmetry by considering the couplings modified by operators from the standard model effective field theory (SMEFT). Similar to the standard model, there are relations between different couplings that are protected by gauge symmetry. We observed that, if we modify the couplings to deviate from the relations, the MWI is violated. In contrast, the MWI is restored when the relations between couplings reduce to those in the SMEFT.

Wang-Fa Li

Junmou Chen

Qian-Jiu Wang

Zhao-Huan Yu

Numerical study on the gauge symmetry of electroweak amplitudes * Junmou Chen is supported by National Natural Science Foundation of China (12205118), Wang-Fa Li, Qian-Jiu Wang, and Zhao-Huan Yu are supported by the Guangzhou Science and Technology Planning Project (2024A04J4026)

We investigate proton emission from the highly deformed nucleus 131Eu within the angular-momentum-conserving core-quasiparticle coupling (CQPC) model. The calculations reproduce well the observed energy spectra and decay properties, and demonstrate that the dominant emitting configuration originates from the <italic>d</italic> <inf>3/2</inf> spherical component of a deformed configuration, consistent with experimental assignments. Complementary calculations for the triaxially deformed nucleus 145Tm and the weakly deformed nucleus 151Lu further confirm that the CQPC framework provides a unified and reliable description of proton emission across a wide deformation range. The results highlight the importance of coherent single-particle-collective coupling in shaping proton decay from deformed nuclei beyond the drip line and provide a fresh perspective on the interpretation of decays traditionally assigned to deformed Nilsson orbitals.

Yeruoxi Chen

Q.B. Chen

Sweden

Romania

C. Qi

Angular-momentum conserved description of the proton decay from highly deformed 131Eu

A Magnetic Rotational (MR) band in 57Fe nucleus has been newly identified and established from the decreasing behaviour of the experimental electric dipole transition probabilities, B(M1), determined from the measured lifetimes of the states. This becomes the first nucleus in the lighter mass ( <math altimg='si1.svg'><mi>A</mi><mo linebreak='goodbreak' linebreakstyle='after'>&lt;</mo><mn>60</mn></math>) region in which, the B(M1) values of an MR band are measured. A single-particle configuration of <math altimg='si2.svg'><mi>&#960;</mi><msubsup><mrow><mi>f</mi></mrow><mrow><mn>7</mn><mo stretchy='false'>/</mo><mn>2</mn></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>&#8722;</mo><mn>2</mn></mrow></msubsup><mo>&#8855;</mo><mi>&#957;</mi><msup><mrow><mo stretchy='false'>(</mo><msub><mrow><mi>p</mi></mrow><mrow><mn>3</mn><mo stretchy='false'>/</mo><mn>2</mn></mrow></msub><msub><mrow><mi>f</mi></mrow><mrow><mn>5</mn><mo stretchy='false'>/</mo><mn>2</mn></mrow></msub><msub><mrow><mi>p</mi></mrow><mrow><mn>1</mn><mo stretchy='false'>/</mo><mn>2</mn></mrow></msub><mo stretchy='false'>)</mo></mrow><mrow><mn>3</mn></mrow></msup></math> has been assigned to this MR band. This configuration, which involves only the negative parity proton and neutron orbitals below and above the Z,N = 28 shell closures, respectively, is a unique one which was not identified before for an MR band. The range of observed angular momenta for this band is congruent with this configuration and the experimental data are found to be in agreement with the SPAC (Shears mechanism with Principal Axis Cranking) and semi-classical calculations. Shell model calculations with GXPF1A interaction reproduce the observed levels in 57Fe including the band head of the MR band. This validates the assigned configurations of this band.

India

S. Basu

G. Mukherjee

S. Rajbanshi

Japan

Y. Utsuno

Noritaka Shimizu

France

S. Nandi

S.S. Nayak

S. Pal

S. Bhattacharyya

S. Chakraborty

Soumik Bhattacharya

Shabir Dar

Sneha Das

S. Basak

D. Kumar

D. Paul

K. Banerjee

Pratap Roy

S. Manna

Samir Kundu

T.K. Rana

R. Pandey

S. Samanta

S. Chatterjee

R. Raut

S.S. Ghugre

H. Pai

A. Karmakar

S. Chattopadhyay

S. Das Gupta

P. Pallav

R. Banik

S. Ali

Y.M. Wang

Conclusive evidence of magnetic rotational band in 57Fe: Extending the shears mechanism to the fp shell orbital

The potential presence of wobbling motions in even-even nuclei $^{112}$Ru, $^{114}$Pd, $^{150}$Nd, and $^{188}$Os are explored by the five-dimensional collective Hamiltonian based on the relativistic density functional theory (5DCH-RDFT). The theoretical results successfully reproduce experimental energy spectra and electromagnetic transition probabilities. Analyses of the potential energy surfaces and probability density distributions in the <math><mo>(</mo><mi>β</mi><mo>,</mo><mi>γ</mi><mo>)</mo></math> deformation plane as well as the quadrupole asymmetry parameter <math><mo>〈</mo><mi>cos</mi><mo>⁡</mo><mn>3</mn><mi>δ</mi><mo>〉</mo></math> reveal that $^{150}$Nd shows near-axial symmetry in contrast to the triaxial deformation in $^{112}$Ru, $^{114}$Pd, and $^{188}$Os. Additionally, spin coherent state (SCS) map is introduced for the first time to the 5DCH framework to visualize the geometry of angular momentum. It is revealed that the wobbling mode, characterized by oscillations of total angular momentum J about the medium axis, is present in $^{112}$Ru but absent in $^{150}$Nd.

Exploring wobbling motion in triaxial even-even nuclei

Two new negative-parity bands have been identified in the odd-odd $^{104}$Rh nucleus. According to their experimentally observed properties, they have the same <math><mi>π</mi><msup><mrow><mo>(</mo><mn>1</mn><msub><mrow><mi>g</mi></mrow><mrow><mn>9</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>)</mo></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>⊗</mo><mi>ν</mi><msup><mrow><mo>(</mo><mn>1</mn><msub><mrow><mi>h</mi></mrow><mrow><mn>11</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>)</mo></mrow><mrow><mn>1</mn></mrow></msup></math> high-j configuration as the previously known negative-parity chiral doublet bands. This observation raises the possibility of the existence of multiple chiral doublet bands, MχD, in this nucleus. Comparing the properties of the observed bands with results of detailed theoretical calculations, one can conclude that the lower energy parts of bands 1 and 2 are chiral partner bands with the <math><mi>π</mi><msup><mrow><mo>(</mo><mn>1</mn><msub><mrow><mi>g</mi></mrow><mrow><mn>9</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>)</mo></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>⊗</mo><mi>ν</mi><msup><mrow><mo>(</mo><mn>1</mn><msub><mrow><mi>h</mi></mrow><mrow><mn>11</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>)</mo></mrow><mrow><mn>1</mn></mrow></msup></math> two-quasiparticle configuration, while bands 3 and 4 are chiral partner bands with the <math><mi>π</mi><msup><mrow><mo>(</mo><mn>1</mn><msub><mrow><mi>g</mi></mrow><mrow><mn>9</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>)</mo></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>⊗</mo><mi>ν</mi><msup><mrow><mo>(</mo><mn>1</mn><msub><mrow><mi>g</mi></mrow><mrow><mn>7</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>)</mo></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup><msup><mrow><mo>(</mo><mn>1</mn><msub><mrow><mi>h</mi></mrow><mrow><mn>11</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>)</mo></mrow><mrow><mn>1</mn></mrow></msup></math> four-quasiparticle configuration. Thus, MχD based on different configurations is observed in $^{104}$Rh.

Hungary

A. Krakó

D. Sohler

J. Timár

I. Kuti

S.Q. Zhang

J. Meng

Canada

K. Starosta

T. Koike

United Kingdom

E.S. Paul

D.B. Fossan

C. Vaman

Multiple chiral doublet bands in Rh

The critical spin <math><msub><mrow><mi>I</mi></mrow><mrow><mi>c</mi></mrow></msub></math> (or critical frequency <math><mi>ħ</mi><msub><mrow><mi>ω</mi></mrow><mrow><mi>c</mi></mrow></msub></math>) represents the minimum spin (or rotational frequency) required for stable chiral solutions in nuclear systems. The effect of pairing on the critical spin has been examined for the particle-hole configuration <math><mi>π</mi><mo>(</mo><mn>1</mn><msub><mrow><mi>h</mi></mrow><mrow><mn>11</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>)</mo><mo>⊗</mo><mi>ν</mi><msup><mrow><mo>(</mo><mn>1</mn><msub><mrow><mi>h</mi></mrow><mrow><mn>11</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>)</mo></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> with a triaxial deformation parameter of <math><mi>γ</mi><mo>=</mo><msup><mrow><mn>30</mn></mrow><mrow><mo>∘</mo></mrow></msup></math> using the particle rotor model, which treats the total angular momentum as a good quantum number. Increasing pairing interaction keeps the critical spin <math><msub><mrow><mi>I</mi></mrow><mrow><mi>c</mi></mrow></msub></math> constant, but decreases the critical rotational frequency <math><mi>ħ</mi><msub><mrow><mi>ω</mi></mrow><mrow><mi>c</mi></mrow></msub></math>. This is due to that the enhanced pairing interaction causes valence nucleons angular momenta to align preferentially along the medium axis, resulting in a larger effective collective moment of inertia and facilitating the emergence of chiral rotation at a lower frequency. However, even with an increase in pairing gap from 0.0 to <math><mn>2.0</mn><mspace width="0.25em"></mspace><mtext>MeV</mtext></math>, the resulting increase in medium axis alignment is less than 1ħ, which is insufficient to change the value of the critical spin <math><msub><mrow><mi>I</mi></mrow><mrow><mi>c</mi></mrow></msub></math>. This study suggests that the critical spin remains robust against the influence of pairing interaction.

Y. Wu

Pairing effect on critical spin in chiral rotation

Abstract The open N = 2 string theory is defined on the 4D space-time with the split signature (+, +, −, −). The string field theory action of the open N = 2 string theory is described by the 4D Wess–Zumino–Witten (WZW$_{4}$) model. The equation of motion of the WZW$_{4}$ model is the Yang equation, which is equivalent to the anti-self-dual Yang–Mills equation. In this paper, we study soliton-type classical solutions of the WZW$_{4}$ model in the split signature by calculating the action density of the WZW$_{4}$ model. We find that the action density of the one-soliton solutions is localized on a 3D hyperplane. This shows that there would be codimension-one-solitonic objects, or equivalently some kind of three-branes in the open N = 2 string theory. We also prove that, in the asymptotic region of the space-time, the action density of the n-soliton solutions is a “non-linear superposition” of n one-solitons. This suggests the existence of n intersecting three-branes in the N = 2 strings. Finally we make a reduction to a (1 + 2)D real space-time to calculate the energy densities of the soliton solutions. We can successfully evaluate the energy distribution for the two-soliton solutions and find that there is no singularity in the interacting region. This implies the existence of smooth intersecting codimension-one branes in the whole region. Soliton solutions in the Euclidean signature are also discussed.

Masashi Hamanaka

Shan-Chi Huang

Hiroaki Kanno

Solitons in open = 2 String Theory Kahler-Chen-Simons theory A tour through N=2 strings On soliton solutions of the anti-self-dual Yang-Mills equations from the perspective of integrable systems Soliton solutions in an integrable chiral model in 2+1 dimensions On the space-time monopole equation A review on tachyon condensation in open string field theories Soliton equations as dynamical systems on infinite dimensional Grassmann manifold