In this paper, we systematically explore the mass spectrum of fully strange tetraquark candidates within the framework of QCD sum rules, focusing on states with quantum numbers $ J^{PC}=0^{++} $ , $ 0^{-+} $ , $ 0^{--} $ , $ 1^{--} $ , $ 1^{+-} $ , and $ 1^{++} $ . The analysis reveals the existence of fully strange tetraquark states with masses ranging from approximately $ 2.07 $ to $ 3.12 $ GeV. These predictions are compared with existing experimental observations of potential fully strange tetraquark resonances, notably the $ X(2300) $ recently reported by the BESIII Collaboration, which may be interpreted as a fully strange tetraquark state. Furthermore, the possible decay modes of these fully strange tetraquark states are analyzed, providing guidance for their identification in current and future high-energy experiments, such as BESIII, Belle II, and LHCb.

China

Bing-Dong Wan

Ji-Chong Yang

Fully strange tetraquark states via QCD sum rules * Supported in part by the National Natural Science Foundation of China (12575106, 12147214) and Specific Fund of Fundamental Scientific Research Operating Expenses for Undergraduate Universities in Liaoning Province (LJ212410165019)

Small neutrino masses can be generated through the well-known seesaw mechanisms, among which the type-II scenario predicts a triplet scalar with doubly charged components. Except for the Drell-Yan production at the Large Hadron Collider (LHC), the doubly charged scalars $\Delta^{\pm\pm}$ can also be produced through photon fusion along with the ultraperipheral collision of protons, from which the outgoing protons can be detected by forward detectors at the LHC, providing a promising means to explore related new physics. We study the pair production through such processes at the 14 TeV LHC, focusing on the final states of $\mu^{+}\mu^{+}\mu^{-}\mu^{-}$ and $e^{+}e^{+}e^{-}e^{-}$ under the normal hierarchy (NH) and inverted hierarchy (IH) of the neutrino mass spectra, respectively. Promising sensitivity can be reached via our proposed search strategy. At a luminosity of 36.1 fb$^{-1}$(100 fb $^{-1}$ ), $m_{\Delta}\sim430(520)$ GeV can be excluded at 95% C.L. under the NH via $\mu^{+}\mu^{+}\mu^{-}\mu^{-}$ state searching, while the mass bound can be extended to 730(880) GeV under the IH via $e^{+}e^{+}e^{-}e^{-}$ states. The exclusion limits on $m_{\Delta}$ can be improved up to 1 TeV and even higher with integrated luminosity accumulated to 3 ab $^{-1}$ .

Hang Zhou

Ning Liu

Search for doubly charged scalars in type-II seesaw mechanism through photon fusion at the LHC * Supported by the National Natural Science Foundation of China (12405118) and the Natural Science Foundation of Jiangsu Province (BK20230623)

We investigate thermal photon production in the quark-gluon plasma (QGP) under strong magnetic fields using a magnetohydrodynamic (MHD) framework. We employ relativistic ideal fluid dynamics under the non-resistive approximation by adopting the Bjorken flow model with power-law decaying magnetic fields $ \mathbf{B}(\tau) = \mathbf{B}_0 (\tau_0/\tau)^a $ , span> $\textit{a}$ controls the decay rate, $ B_0 = \sqrt{\sigma} T_0^2 $ , and $\textit{σ}$ characterizes the initial field strength. The resulting QGP temperature evolution exhibits distinct $\textit{a}$- and $\textit{σ}$-dependent behaviors. Thermal photon production rates are calculated for three dominant processes: Compton scattering with $ q\bar{q} $ annihilation (C+A), bremsstrahlung (Brems), and $ q\bar{q} $ annihilation with additional scattering (A+S). These rates are integrated over the space-time volume to obtain the photon transverse momentum $ (p_T) $ spectrum. Our results demonstrate that increasing $\textit{a}$ enhances photon yields across all $ p_T $ , with $ a \to \infty $ (super-fast decay) providing an upper bound. For $ a = 2/3 $ , a larger $\textit{σ}$ suppresses yields through accelerated cooling, whereas for $ a \to \infty $ , a larger $\textit{σ}$ enhances yields via prolonged thermal emission. Low- $ p_T $ photons receive significant contributions from all QGP evolution stages, while high- $ p_T $ photons originate predominantly from early times. The central rapidity region $ (y=0) $ dominates the total yield. This work extends the photon yield studies to the MHD regime under strong magnetic fields, clarifying the magnetic field effects on QGP electromagnetic signatures and establishing foundations for future investigations of magnetization and dissipative phenomena.

Jie Xiong

Xiang Fan

Jing Jing

Weishan Yang

Duan She

Ze-Fang Jiang

Thermal photon emission from quark-gluon plasma: 1+1D magnetohydrodynamics results * Supported by the National Natural Science Foundation of China (NSFC) (12305138). Duan She's research is funded by the Startup Research Fund of Henan Academy of Sciences (231820058) and the 2024 Henan Province International Science and Technology Cooperation Projects (242102521068)

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)

Russia

P. Baikov

Addendum to: Solving recurrence relations for multiloop integrals in the limit of large values of the dimensional regularization parameter

<p>The study of nuclear modification factor is crucial in advancing our knowledge of the hot and dense nuclear matter created during high energy heavy-ion collision. In this direction, we have developed a theoretical model for the nuclear modification factor using the Boltzmann transport equation in relaxation time approximation with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>q</mi></math>-Weibull distribution as the final state distribution and studied the experimental data of nuclear modification factor of charged hadrons as well as identified particles at various energies ranging from 7.7 GeV measured at RHIC up to the maximum value of 5.44 TeV studied in LHC. We observed a good agreement between the model and the experimental data as can be quantified using the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>χ</mi><mn>2</mn></msup><mo>/</mo><mi>N</mi><mi>D</mi><mi>F</mi></math> values. We have also studied the mass dependence of different fit parameters that appears in the theoretical model and observe a linear mass dependence of some parameters.</p>

India

Rohit Gupta

Investigation of the nuclear modification factor from RHIC to LHC energies using the Boltzmann transport equation in conjunction with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>q</mi></math>-Weibull distribution

We consider holographic entanglement entropy in AdS black hole backgrounds by using the limit of large number of dimensions. By dividing the geometry to two patches (with one patch covering the vicinity of the black hole horizon and another covering the other regions), we are able to obtain fully analytic expressions for the entropy when the entanglement region is a strip. We argue that apart from conformal field theories at finite temperature in high number of dimensions, our method works for nearly critical theories in 3+1 dimensions. In the case of extremal black holes, dual to quantum critical systems, the results take a particularly simple form. We also comment on the case of soliton geometries. Finally, we analyze entanglement entropy for wide strips, and propose a general formula for the first subleading term in the expansion of the entropy in (inverse) system size for generic entanglement regions.

Parul Jain

South Korea

Matti Järvinen

An analytic approach for holographic entanglement entropy at (quantum) criticality

The quantum induced stress tensor of 3+1-dimensional Einstein gravity, with conformally coupled matter, is studied in an effective field theory approach. In this context, Riegert’s non-local effective action is sufficient to reproduce the trace anomaly in curved spacetime but in general the effective action can include additional non-local but scale invariant terms that influence the semiclassical physics without affecting the trace anomaly. Here, a truncated model, with only one additional term involving the square of the Weyl tensor, is used to find the induced stress tensor in a black hole background. With suitable physical conditions, a solution of the resulting 4th order equations leads, in a static limit, to a unique quantum state matching expected properties of the Unruh state.

Bing-Nan Liu

David Lowe

Iceland

Larus Thorlacius

Generalized effective field theory for four-dimensional black hole evaporation

In this paper, we computed the logarithmic corrections of entropy for the near-extremal Kerr-Newman black holes in $$ \mathcal{N} $$ = 2 supergravity theory applying the Euclidean path integral approach in near-horizon geometry. In the near-horizon extremal Kerr geometry, analogous to the AdS × $\textit{S}$ structure, there exists a set of normalizable zero modes associated with reparameterization of boundary time. The one-loop approximation to the Euclidean near-horizon extremal Kerr partition function exhibits an infrared divergence because of the path integral over these zero modes. Carrying out the leading finite temperature correction in the near-horizon extremal Kerr scaling limit, we control this divergence. Further, treating the near-horizon geometry of the near-extremal black hole as a perturbation around its extremal counterpart, we computed the corresponding corrections using a modified heat kernel approach. This method incorporates both extremal and near-extremal contributions and represents a novel solution within the context of charged rotating black holes in $$ \mathcal{N} $$ = 2 supergravity theories.

Ashes Modak

Aditya Singh

Binata Panda

Logarithmic corrections for near-extremal Kerr-Newman Black holes

<p>Motivated by several mild excesses around 95 GeV, we investigate the prospects for a light scalar <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi></math> produced via Higgsstrahlung, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo stretchy="false">→</mo><mi>Z</mi><mo stretchy="false">(</mo><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup><mo stretchy="false">)</mo><mi>S</mi></math>, at future <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> Higgs factories. We take the CEPC as a benchmark, with a center-of-mass energy of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>240</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> and an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>L</mi><mo>=</mo><mn>20</mn><mtext> </mtext><mtext> </mtext><msup><mi>ab</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>. We focus on the decay modes <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo stretchy="false">→</mo><msup><mi>τ</mi><mo>+</mo></msup><msup><mi>τ</mi><mo>−</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo stretchy="false">→</mo><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover></math>. To maximize sensitivity, we employ the particle-level transformer networks particle transformer (ParT) and its more-interactive variant MIParT, which exploit the features of all reconstructed objects and their correlations. For a representative signal benchmark, this approach improves the expected statistical precision on the signal strength by factors of 2.3 in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>τ</mi><mo>+</mo></msup><msup><mi>τ</mi><mo>−</mo></msup></math> channel and 1.4 in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover></math> channel compared to a cut-based analysis. Within the flipped next-to-two-Higgs-doublet model (N2HDM-F), the CEPC can measure the signal strength with a statistical precision down to 1.0% in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>τ</mi><mo>+</mo></msup><msup><mi>τ</mi><mo>−</mo></msup></math> channel and 0.69% in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover></math> channel using MIParT. It can achieve a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5</mn><mi>σ</mi></math> discovery for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>μ</mi><mrow><mi>τ</mi><mi>τ</mi></mrow><mrow><mi>Z</mi><mi>S</mi></mrow></msubsup><mo>&gt;</mo><mn>1.6</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>2</mn></mrow></msup></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>μ</mi><mrow><mi>b</mi><mi>b</mi></mrow><mrow><mi>Z</mi><mi>S</mi></mrow></msubsup><mo>&gt;</mo><mn>5.0</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></math>, and reach 1% precision for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>μ</mi><mrow><mi>τ</mi><mi>τ</mi></mrow><mrow><mi>Z</mi><mi>S</mi></mrow></msubsup><mo>&gt;</mo><mn>0.93</mn></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>μ</mi><mrow><mi>b</mi><mi>b</mi></mrow><mrow><mi>Z</mi><mi>S</mi></mrow></msubsup><mo>&gt;</mo><mn>0.14</mn></math>. These gains are expected to qualitatively carry over to other future lepton colliders such as FCC-ee and the ILC. Our results demonstrate the potential of particle-level machine-learning techniques to strengthen light Higgs searches at future <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> Higgs factories.</p>

Yabo Dong

Manqi Ruan

Kun Wang

Haijun Yang

Jingya Zhu

Particle-level transformers for 95 GeV Higgs boson searches at future <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> Higgs factories