Correlation $ \chi^{BQ}_{11} $ and quadratic fluctuations $ \chi^B_2,\ \chi^Q_2,\ \chi^T_2 $ of baryon number $\textit{B}$, electric charge $\textit{Q,}$ and temperature $\textit{T}$ are investigated in a two-flavor Polyakov loop extended Nambu-Jona-Lasinio (PNJL) model at finite temperature and magnetic field. The inverse magnetic catalysis (IMC) effect is introduced through magnetic-field-dependent parameters $ G(eB) $ and $ T_0(eB) $ , and we compare the results in scenarios with and without the IMC effect. Under a nonvanishing magnetic field, correlation $ \chi^{BQ}_{11} $ and fluctuations $ \chi^B_2,\ \chi^Q_2,\ \chi^T_2 $ increase with temperature and then exhibit a peak around the pseudocritical temperatures of chiral restoration and deconfinement phase transitions in the cases with and without the IMC effect. The correlation and fluctuations along the phase transition line under an external magnetic field are characterized by scaled correlation ${\hat {\chi}}_{11}^{BQ}={\chi_{11}^{BQ}(eB,T_{pc}^c(eB))}/{\chi_{11}^{BQ}(eB=0,T_{pc}^c(eB=0))}$ and scaled fluctuations ${\hat {\chi}}_2^{B(Q,T)}={\chi_2^{B(Q,T)}(eB,T_{pc}^c(eB))}/{\chi_2^{B(Q,T)}(eB=0,T_{pc}^c(eB=0))}$ at pseudocritical temperature $ T_{pc}^c $ of chiral restoration phase transition. $ {\hat {\chi}}_{11}^{BQ},\ {\hat {\chi}}_2^{B} $ , and $ {\hat {\chi}}_2^{Q} $ increase with the magnetic field, and the inclusion of the IMC effect enhances their values somewhat. However, $ {\hat {\chi}}_2^{T} $ is altered by the IMC effect. Without the IMC effect, $ {\hat \chi}^T_2 $ increases slightly and then decreases with the magnetic field. Considering the IMC effect using $ G(eB) $ , $ {\hat \chi}^T_2 $ monotonically increases with the magnetic field, and that using $ T_0(eB) $ is a nonmonotonic function of the magnetic field.

China

Correlations and fluctuations in a magnetized PNJL model with and without the inverse magnetic catalysis effect * Supported by the National Natural Science Foundation of China (12275204)

We search for the leptonic decay $ D^+\to e^+\nu_{e} $ using an $ e^+e^- $ collision data sample with an integrated luminosity of 20.3 fb $ ^{-1} $ collected with the BESIII detector at a center-of-mass energy of 3.773 GeV. Significant signal is not observed, and an upper limit on the branching fraction of $ D^+\to e^+\nu_{e} $ is set as $ 9.7 \times 10^{-7} $ , at a confidence level of 90%. Our upper limit is an order of magnitude smaller than the previous limit for this decay mode.

Russia

Sweden

Germany

Italy

Poland

Mongolia

United States

Türkiye

Search for the leptonic decay ${\boldsymbol D^{\bf +}{\bf\to}{\boldsymbol e}^{\bf +}\boldsymbol\nu_{\boldsymbol e}}$ * Supported in part by the National Key R&D Program of China (2023YFA1606000, 2020YFA0406400, 2020YFA0406300), the National Natural Science Foundation of China(NSFC) (11635010, 11735014, 11935015, 11935016, 11875054, 11935018, 12025502, 12035009, 12035013, 12061131003, 12192260, 12192261, 12192262, 12192263, 12192264, 12192265, 12221005, 12225509, 12235017, 12361141819), the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program, the CAS Center for Excellence in Particle Physics (CCEPP), the Joint Large-Scale Scientific Facility Funds of the NSFC and CAS (U2032104, U1832207), the 100 Talents Program of CAS, the Excellent Youth Foundation of Henan Scientific Commitee (242300421044), the Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology, the German Research Foundation DFG (FOR5327), the Istituto Nazionale di Fisica Nucleare, Italy, the Knut and Alice Wallenberg Foundation (2021.0174, 2021.0299), the Ministry of Development of Turkey (DPT2006K-120470), the National Research Foundation of Korea (NRF-2022R1A2C1092335), the National Science and Technology Fund of Mongolia, the National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources & Institutional Development, Research, and Innovation of Thailand (B16F640076, B50G670107), the Polish National Science Center (2019/35/O/ST2/02907), the Swedish Research Council (2019.04595), the Swedish Foundation for International Cooperation in Research and Higher Education (CH2018-7756), and the US Department of Energy (DE-FG02-05ER41374).

We present the first lattice result of the near threshold $ \Lambda_c\Lambda_c $ scattering with $ I(J^P) = 0(0^+) $ . The calculation is performed on two $ N_f = 2+1 $ Wilson-Clover ensembles with pion mass $ m_\pi \sim 303 $ MeV and lattice spacing $ a = 0.07746 $ fm. Lüscher's finite volume method is utilized to extract the scattering parameters from the finite-volume spectrum. The coupled channel $ \Xi_{cc}N $ is ignored in the scattering analysis based on the observation that the energy levels computed from the $ \Lambda_c\Lambda_c $ and $ \Xi_{cc}N $ operators do not mix. The $ \Sigma_c\Sigma_c $ channel is not included either since the energy range explored in this study is well below its threshold. Our results indicate that the interaction in the $ \Lambda_c\Lambda_c $ single channel is repulsive, and the scattering length is determined to be $ a_0 = -0.21(4)(8) $ fm, where the first error is statistical and the second is systematic.

Lattice QCD study of Λ $\textit{c}$ Λ $\textit{c}$ scattering * Supported by NSFC (12293060, 12293061, 12293063, 12175279, 12435002, 12322503, 12175239). L. Liu also acknowledges the Strategic Priority Research Program of the Chinese Academy of Sciences with (XDB34030301) and Guangdong Major Project of Basic and Applied Basic Research (2020B0301030008). We also acknowledge the Science and Education Integration Young Faculty Project of University of Chinese Academy of Sciences (YSBR-101)

We introduce a relative $\textit{P}$-wave to construct the doubly charmed diquark $ (\widetilde{V}) $ vector. Therefore, scalar and tensor four-quark currents were constructed to investigate the decay widths of the fully charmed tetraquark states with $ J^{PC}=0^{++} $ , $ 1^{+-} $ and $ 2^{++} $ via quantum chromodynamics (QCD) sum rules. We observed that the total width of the ground state $ \widetilde{V}\overline{\widetilde{V}} $ -type scalar tetraquark state is compatible with that of the $ X(6552) $ within uncertainties, and the branching ratios are quite different from that of the first radial excitation of the $ A\bar{A} $ -type scalar tetraquark state. Other predictions can be verified in future experiments to shed light on the nature of the fully charmed tetraquark states.

Strong decays of the fully charmed tetraquark states with explicit $\textit{P}$-waves via QCD sum rules * Supported by the National Natural Science Foundation (12175068), and the Fundamental Research Funds for the Central Universities

A traversable wormhole generally violates the averaged null energy condition, typically requiring exotic matter. Recently, it was discovered that a traversable wormhole can be realized with non-exotic matter in Einstein-Dirac-Maxwell theories in flat space. This study extends the discussion to AdS spacetime and finds traversable wormholes with spherical and planar topologies. Furthermore, based on the AdS/CFT correspondence, we compute the entanglement entropy of strips and disks on the two AdS boundaries of the wormhole. We find that the entanglement entropy undergoes a phase transition as the subsystem size increases.

Traversable wormholes in AdS and entanglement * Supported by the National Natural Science Foundation of China (12275366)

In the maximally-helicity-violating (MHV) configuration, tree-level single-trace Einstein-Yang-Mills (EYM) amplitudes with one or two gravitons have been shown to satisfy a formula in which each graviton splits into a pair of collinear gluons. In this study, we extend this formula to more general cases. We present a general formula that expresses tree-level single-trace MHV amplitudes in terms of pure gluon amplitudes. In this formula, each graviton turns into a pair of collinear gluons.

Note on single-trace EYM amplitudes with MHV configuration

The roles of the $ \Delta (1232) $ , $ {N}^{*}(1520) $ , and $ {N}^{*}(1650) $ resonances in the $ \gamma p\to{\pi }^{0}{\pi }^{0}p $ reaction near threshold is investigated within an effective Lagrangian approach. The differential cross sections of the $ \gamma p\to{\pi }^{0}{\pi }^{0}p $ reaction was calculated including contributions from the $ \Delta (1232) $ , $ {N}^{*}(1520) $ , and $ {N}^{*}(1650) $ intermediate states decaying into $ \pi^0 p $ via the $\textit{s}$-channel nucleon pole and $\textit{t}$-channel $\textit{ρ}$ exchange. Current experimental measurements were well reproduced. The production of $ \Delta(1232) $ was mainly from the mechanism of the $\textit{s}$-channel nucleon pole, while the $ {N}^{*}(1520) $ and $ {N}^{*}(1650) $ were produced from the mechanism of the $\textit{t}$-channel $\textit{ρ}$ exchange. More experimental data on the $ \gamma p \to \pi^0 \pi^0 p $ reaction could be used to explore the properties of the low-lying excited baryon state.

Roles of ${\boldsymbol\Delta(\bf 1232)}$ , ${\boldsymbol N^*(\bf 1520)}$ , and ${\boldsymbol N^*(\bf 1650)}$ resonances in ${\boldsymbol\gamma \boldsymbol p\to \boldsymbol\pi^{\bf 0} \boldsymbol\pi^{\bf 0}\boldsymbol p}$ reaction within an effective Lagrangian approach * Supported by the National Key R&D Program of China (2023YFA1606703, 2024YFE0105200), the Natural Science Foundation of Henan Province, China (232300421140, 222300420554), and the National Natural Science Foundation of China (12435007, 12361141819, 12475086, 12192263)

We present the first calculation of the connected scalar matrix element and the momentum fraction of the charm quark within the ${3}/{2}^{+}$ and ${3}/{2}^{-}$ triply charmed baryons on lattice QCD. The results are based on overlap valence fermions on two ensembles of $ N_f=2+1 $ domain wall fermion configurations with two lattice spacings. The corresponding sea quark pion masses are 300 MeV and 278 MeV. The separated contributions to the triply charmed baryon mass are derived through the decomposition of the QCD energy-momentum tensor. The contribution of the connected charm quark matrix element to the triply charmed baryon is about 3/2 times that of the charmonium, and it is almost 70% of the total mass. The mass splitting of ${3}/{2}^{+}$ and ${3}/{2}^{-}$ triply charmed baryons is mainly from the $ \langle H_{E}\rangle $ of the QCD energy-momentum tensor. A mass decomposition based on the quark model is also studied for comparison.

Triply charmed baryons mass decomposition from lattice QCD * Supported by the National Natural Science Foundation of China (12175036, 11935017, 12175073, 12205311, 12222503), the Natural Science Foundation of Hunan Province, China (2023JJ30380, 2024JJ6300), the Department of Education Foundation of Hunan Province, China (20A310, 22B0044), and the Major Project of Basic and Applied Basic Research of Guangdong Province, China (2020B0301030008)

Using the AdS/CFT correspondence, we investigate the holographic image of an AdS black hole in Einstein-power-Yang-Mills gravity. The AdS boundary hosts a Gaussian oscillation source, which induces a lensed response on the opposite side of the boundary during propagation through bulk spacetime. The optical system enables observers at the north pole to continuously capture holographic images that exhibit an axisymmetric bright ring known as the Einstein ring. As the observation position shifts, the bright ring gradually transforms into a luminous arc and eventually transitions into a light point. Additionally, we examine the impact of variations in relevant physical quantities on the ring and present the corresponding brightness curve. The results indicate that, as the temperature $\textit{T}$ and nonlinear Yang Mills charge parameter $\textit{q}$ increase, the ring radius increases, whereas an increase in chemical potential $\textit{u}$ leads to a decrease in ring radius. However, the peak brightness curve of the ring invariably decreases as the values of $\textit{T}$, $\textit{u}$, and $\textit{q}$ increase, albeit to varying degrees. Comparing the outcomes of geometric optics, we observe that the position of the ring in holography images is consistent with that of the photon ring.

Holographic image features of an AdS black hole in Einstein-power-Yang-Mills gravity * Supported by the National Natural Science Foundation (11875095), the Innovation and Development Joint Foundation of Chongqing Natural Science Foundation (CSTB2022NSCQ-LZX0021), the Basic Research Project of Science and Technology Committee of Chongqing, China (CSTB2023NSCQ-MSX0324), and the Natural Science Foundation of Chongqing, China (CSTB2023NSCQ-MSX0594)

Affleck-Dine baryogenesis generated high baryon density in the early Universe. The baryon chemical potential enhanced the potential barrier and significantly reduced the decay rate of false vacuum, which decreased from infinity at the critical end point to zero at the critical nucleation point. When the decay rate reached zero, the false vacuum of high baryon density quark matter was unlikely to decay and could persist over cosmological time scales. Therefore, primordial quark nuggets (PQNs) could form and survive in the early Universe as the seeds of compact stars. This new mechanism for the formation of PQNs is different from Witten's stable droplet of quark matter.

Nanohertz gravitational waves and primordial quark nuggets from dense QCD matter in the early Universe * Supported in part by the National Natural Science Foundation of China (12235016, 12221005), and the Strategic Priority Research Program of Chinese Academy of Sciences (XDB34030000)