We study the equation of state (EoS) of QCD matter in a bottom-up holographic setup that combines an Einstein-Maxwell-dilaton (EMD) sector with an improved Karch-Katz-Son-Stephanov (KKSS) flavor action. In the probe approximation, we perform an inverse reconstruction of the model functions by parameterizing them with neural networks and solving the EMD equations via a differentiable ODE solver (a neural ODE framework), calibrating the model to a reference thermodynamic table for $(2+1)$ -flavor QCD at finite temperature and finite baryon chemical potential. The reconstructed model functions are then parameterized and kept fixed across thermodynamic states. Next, viewing the EMD sector as an effective description of pure Yang-Mills theory, we fix its parameters by fitting the $\mu_B=0$ lattice pure-glue EoS using a hybrid optimization strategy. Finally, we go beyond the probe limit and solve the coupled EMD+KKSS equations with back-reaction, using the pure-glue-calibrated EMD sector as a fixed input and varying the KKSS couplings to compare with the $\mu_B=0$ two-flavor lattice EoS. We find a visible mismatch and a high-temperature behavior in which the back-reacted dimensionless ratios approach a nearly $\beta_1$ -insensitive plateau close to the pure-glue baseline, providing a simple structural diagnostic for the present flavor-sector truncation.

China

Yutian Deng

Mei Huang

Lin Zhang

Holographic QCD equation of state constrained by lattice QCD: neural-ODE for probe-limit and a back-reaction test * Start-up funding from Sun Yat-sen University (SYSU) (Y. Deng and L. Zhang); National Natural Science Foundation of China (NSFC) (12235016) (L. Zhang and M. Huang) and 12221005 (M. Huang)

We investigated the effect of an isospin chemical potential ( $ \mu_{I} $ ) within the quark-meson model, which approximates quantum chromodynamics (QCD) by modeling low-energy phenomena such as chiral symmetry breaking and phase structure under varying conditions of temperature and chemical potential. Using the functional renormalization group (FRG) flow equations, we calculated the phase diagram in the chiral limit within the two-flavor quark-meson model in a finite $ \mu_{I} $ with $\textit{ρ}$ vector meson interactions. Fluctuation effects significantly decrease the critical chemical potential from the mean-field (MF) value $\mu_{I,{\rm MF}} \gt m_\rho$ to a lower value at which the $\textit{ρ}$ vector meson condensates alongside the chiral condensate once the isospin chemical potential exceeds the critical value $ \mu_{I}^{{\rm{crit}}} $ . This $\textit{ρ}$ condensation was investigated numerically for different meson coupling strengths. The $\textit{ρ}$ meson dominated region is delineated from other phases by a second-order phase transition at lower $ \mu_{I} $ and a first-order transition at slightly higher $ \mu_{I} $ .

Mohammed Osman

Defu Hou

Wentao Wang

United States

Hui Zhang

Functional renormalization group study of $\textit{ρ}$ meson condensate at a finite isospin chemical potential in the quark meson model * Supported in part by the National Key Research and Development Program of China (2022YFA1604900). This work is also partly supported by the National Natural Science Foundation of China (NSFC) (12435009, 12275104). Hui Zhang acknowledges the financial support from the Guangdong Major Project of Basic and Applied Basic Research (2020B0301030008) and the National Natural Science Foundation of China (12047523, 12105107)

We report a search for ultraheavy dark matter (UHDM) with the CDEX-10 experiment at the China Jinping Underground Laboratory. Using a Monte Carlo framework that incorporates Earth shielding effects, we simulated UHDM propagation and energy deposition in p-type point-contact germanium detectors. Analysis of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>205.4</mn><mtext> </mtext><mtext> </mtext><mi>kg</mi><mo>·</mo><mi>day</mi></mrow></math> exposure in the 0.16–4.16 keVee range showed no excess above background. Our results exclude the spin-independent UHDM-nucleon scattering with two cross section scales, with the UHDM mass from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>10</mn><mn>6</mn></msup></math> to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>10</mn><mn>11</mn></msup><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, and provide the most stringent constraints with solid-state detectors below <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>10</mn><mn>8</mn></msup><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>.

Y.F. Wang

L.T. Yang

Q. Yue

K.J. Kang

Y.J. Li

H.P. An

Taiwan

Greeshma C.

J.P. Chang

H. Chen

Y.H. Chen

J.P. Cheng

J.Y. Cui

W.H. Dai

Z. Deng

Y.X. Dong

C.H. Fang

H. Gong

Q.J. Guo

T. Guo

X.Y. Guo

L. He

J.R. He

H.X. Huang

T.C. Huang

S. Karmakar

Y.S. Lan

H.B. Li

H.Y. Li

J.M. Li

J. Li

M.C. Li

Q.Y. Li

R.M.J. Li

X.Q. Li

Y.L. Li

Y.F. Liang

B. Liao

F.K. Lin

S.T. Lin

J.X. Liu

R.Z. Liu

S.K. Liu

Y.D. Liu

Y. Liu

Y.Y. Liu

H. Ma

Y.C. Mao

A. Mureed

H. Pan

N.C. Qi

J. Ren

X.C. Ruan

M.B. Shen

H.Y. Shi

M.K. Singh

T.X. Sun

W.L. Sun

C.J. Tang

Y. Tian

H.F. Wan

G.F. Wang

J.Z. Wang

L. Wang

Q. Wang

Y.X. Wang

H.T. Wong

Y.C. Wu

H.Y. Xing

K.Z. Xiong

R. Xu

Y. Xu

T. Xue

Y.L. Yan

N. Yi

C.X. Yu

H.J. Yu

X. Yu

M. Zeng

Z. Zeng

F.S. Zhang

P. Zhang

Z.Y. Zhang

M.G. Zhao

J.F. Zhou

Z.Y. Zhou

J.J. Zhu

Constraints on ultraheavy dark matter from the CDEX-10 experiment at the China Jinping Underground Laboratory

We present the first results of the search for sub-MeV fermionic dark matter absorbed by electron targets of germanium using the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>205.4</mn><mtext> </mtext><mtext> </mtext><mi>kg</mi><mo>·</mo><mi>day</mi></mrow></math> data collected by the CDEX-10 experiment, with the analysis threshold of 160 eVee. No significant dark matter (DM) signals over the background are observed. Results are presented as limits on the cross section of DM–electron interaction. We present new constraints of cross section in the DM range of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>0.1</mn><mi>–</mi><mn>10</mn><mtext> </mtext><mtext> </mtext><mi>keV</mi><mo>/</mo><msup><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math> for vector and axial-vector interaction. The upper limit on the cross section is set to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>6.8</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>46</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>cm</mi></mrow><mn>2</mn></msup></math> for vector interaction, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.3</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>46</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>cm</mi></mrow><mn>2</mn></msup></math> for axial-vector interaction at DM mass of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5</mn><mtext> </mtext><mtext> </mtext><mi>keV</mi><mo>/</mo><msup><mi>c</mi><mn>2</mn></msup></math>.

X.P. Geng

J.W. Hu

L. Jiang

Q.Y. Nie

B.T. Zhang

L. Zhang

Z.H. Zhang

J.Z. Zhao

K.K. Zhao

First search for light fermionic dark matter absorption on electrons using germanium detector in CDEX-10 experiment

We present limits on spin-independent inelastic weakly interacting massive particle (WIMP)-nucleus scattering using the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>737.1</mn><mtext> </mtext><mtext> </mtext><mi>kg</mi><mo>·</mo><mi>day</mi></mrow></math> dataset from the CDEX-1B experiment. Expected nuclear recoil spectra for various inelastic WIMP masses <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>χ</mi></msub></math> and mass splittings <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>δ</mi></math> are calculated under the standard halo model. An accurate background model of CDEX-1B is constructed by simulating all major background sources. The model parameters are then determined through maximum likelihood estimation and Markov chain Monte Carlo fitting. The resulting 90% confidence level upper limits on the WIMP-nucleon cross section <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>σ</mi><mi mathvariant="normal">n</mi></msub></math> exclude certain DAMA/LIBRA allowed regions: the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>χ</mi><mn>2</mn></msup><mo>&lt;</mo><mn>4</mn></math> regions for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>δ</mi><mo>&lt;</mo><mn>30</mn><mtext> </mtext><mtext> </mtext><mi>keV</mi></math> at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>χ</mi></msub><mo>=</mo><mn>250</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> and the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>χ</mi><mn>2</mn></msup><mo>&lt;</mo><mn>9</mn></math> region for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>δ</mi><mo>&lt;</mo><mn>50</mn><mtext> </mtext><mtext> </mtext><mi>keV</mi></math> at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>χ</mi></msub><mo>=</mo><mn>500</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>. The method is applicable to other inelastic dark matter scenarios, and the upcoming CDEX-50 experiment is expected to improve sensitivity by four orders of magnitude.

Constraints on inelastic dark matter from the CDEX-1B experiment

Supernova shocks can boost dark matter (DM) particles to high, yet nonrelativistic, velocities, providing a suitable mechanism for analysis within the framework of the nonrelativistic effective field theory (NREFT). These accelerated DM sources extend the experimental ability to scan the parameter space of light DM into the sub-GeV region. In this study, we specifically analyze DM accelerated by the Monogem Ring supernova remnant, whose age (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>∼</mo><mn>68000</mn><mtext> </mtext><mtext> </mtext><mi>yr</mi></math>) and distance to Earth (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>∼</mo><mn>300</mn></math> parsec) are strategically matched to enable detection with current terrestrial detectors. Utilizing the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>205.4</mn><mtext> </mtext><mtext> </mtext><mi>kg</mi><mo>·</mo><mi>day</mi></mrow></math> data obtained from the CDEX-10 experiment at the China Jinping Underground Laboratory, we derive new constraints on boosted DM within the NREFT framework. The NREFT coupling constant exclusion regions now penetrate the sub-GeV mass range, with optimal sensitivity achieved for operators <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">O</mi><mn>3</mn></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">O</mi><mn>6</mn></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">O</mi><mn>15</mn></msub></math> in the 0.4–0.6 GeV mass range.

Constraints on dark matter boosted by supernova shock within the effective field theory framework from the CDEX-10 experiment

The production cross sections for primary and residual fragments produced in two reaction systems $^{136}$Xe + $^{198}$Pt and $^{238}$U + $^{198}$Pt at incident energy 8 MeV/nucleon are calculated by improved quantum molecular dynamics (ImQMD) model incorporated with the statistical evaporation model (HIVAP code). It is found that the cross sections for n-rich <math><mi>N</mi><mo>=</mo><mn>126</mn></math> residual fragments are several times larger in $^{238}$U<math><mo>+</mo><msup><mrow></mrow><mrow><mn>198</mn></mrow></msup></math>Pt than in $^{136}$Xe<math><mo>+</mo><msup><mrow></mrow><mrow><mn>198</mn></mrow></msup></math>Pt due to the larger cross sections and lower excitation energies of primary fragments in $^{238}$U induced reactions. In both systems, <math><mi>N</mi><mo>=</mo><mn>126</mn></math> semi-magic residues are produced via neutron emission in the decay of primary fragments, which survive in the semi-central collisions and have lower excitation energies.

K. Zhao

Z. Liu

N. Wang

Production of neutron-rich = 126 nuclei in multinucleon transfer reactions: Comparison between Xe + Pt and U + Pt reactions

Fine structure in the α decay of $^{223}$U was observed in the fusion-evaporation reaction $^{187}$Re($^{40}$Ar, p3n) by using fast digital pulse processing technique. Two α-decay branches of $^{223}$U feeding the ground state and 244 keV excited state of $^{219}$Th were identified by establishing the decay chain $^{223}$U <math><mover><mrow><mo>→</mo></mrow><mrow><msub><mrow><mi>α</mi></mrow><mrow><mn>1</mn></mrow></msub></mrow></mover></math> $^{219}$Th <math><mover><mrow><mo>→</mo></mrow><mrow><msub><mrow><mi>α</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></mover></math> $^{215}$Ra <math><mover><mrow><mo>→</mo></mrow><mrow><msub><mrow><mi>α</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></mover></math> $^{211}$Rn. The α-particle energy for the ground-state to ground-state transition of $^{223}$U was determined to be 8993(17) keV, 213 keV higher than the previous value, the half-life was updated to be 62<math><msubsup><mrow></mrow><mrow><mo>−</mo><mn>10</mn></mrow><mrow><mo>+</mo><mn>14</mn></mrow></msubsup></math> μs. Evolution of nuclear structure for N = 131 even-Z isotones from Po to U was discussed in the frameworks of nuclear mass and reduced α-decay width, a weakening octupole deformation in the ground state of $^{223}$U relative to its lighter isotones $^{219}$Ra and $^{221}$Th was suggested.

M.D. Sun

T.H. Huang

W.Q. Zhang

United Kingdom

Japan

A.N. Andreyev

B. Ding

J.G. Wang

X.Y. Liu

H.Y. Lu

D.S. Hou

Z.G. Gan

L. Ma

H.B. Yang

L. Yu

J. Jiang

K.L. Wang

Y.S. Wang

M.L. Liu

Z.H. Li

X. Wang

A.H. Feng

C.J. Lin

L.J. Sun

N.R. Ma

W. Zuo

H.S. Xu

X.H. Zhou

G.Q. Xiao

Sweden

C. Qi

Fine structure in the Decay of U

We present a systematic short time expansion for the generating function of the one point height probability distribution for the KPZ equation with droplet initial condition, which goes much beyond previous studies. The expansion is checked against a numerical evaluation of the known exact Fredholm determinant expression. We also obtain the next order term for the Brownian initial condition. Although initially devised for short time, a resummation of the series allows to obtain also the long time large deviation function, found to agree with previous works using completely different techniques. Unexpected similarities with stationary large deviations of TASEP with periodic and open boundaries are discussed. Two additional applications are given. (i) Our method is generalized to study the linear statistics of the Airy point process, i.e. of the GUE edge eigenvalues. We obtain the generating function of the cumulants of the empirical measure to a high order. The second cumulant is found to match the result in the bulk obtained from the Gaussian free field by Borodin and Ferrari [1,2], but we obtain systematic corrections to the Gaussian free field (higher cumulants, expansion towards the edge). This also extends a result of Basor and Widom [3] to a much higher order. We obtain large deviation functions for the Airy point process for a variety of linear statistics test functions. (ii) We obtain results for the counting statistics of trapped fermions at the edge of the Fermi gas in both the high and the low temperature limits.

France

Alexandre Krajenbrink

Pierre Le Doussal

Sylvain Prolhac

Systematic time expansion for the Kardar–Parisi–Zhang equation, linear statistics of the GUE at the edge and trapped fermions

Excited states in $^{63,65,67}$Mn were studied via in-beam γ-ray spectroscopy following knockout reactions from $^{68}$Fe. Similar level schemes, consisting of the 11/2$^{−}$, 9/2$^{−}$, 7/2$^{−}$ and 5/2<math><msubsup><mrow></mrow><mrow><mi>g</mi><mo>.</mo><mi>s</mi><mo>.</mo></mrow><mrow><mo>−</mo></mrow></msubsup></math> level sequence, connected by <math><mi>I</mi><mo>→</mo><mi>I</mi><mo>−</mo><mn>1</mn></math> transitions, were established, the first time for $^{65,67}$Mn. Their level structures show features consistent with strongly-coupled rotational bands with <math><mi>K</mi><mo>=</mo><mn>5</mn><mo>/</mo><mn>2</mn></math>. State-of-the-art shell-model calculations with the modified LNPS effective interaction reproduce the observed levels remarkably well and suggest the dominance of 4-particle-4-hole neutron configurations for all the states. The data on the low-lying excited states of odd-mass $^{53−67}$Mn provide a textbook example of nuclear structure evolution from weak coupling through decoupling to strong coupling along a single isotopic chain on the n-rich side of the β stability line. These results help to deepen our understanding of the <math><mi>N</mi><mo>=</mo><mn>40</mn></math> “island of inversion”.