In this study, we investigate the possibility of enhancing the di-jet resonance searches by tagging the final state radiation (FSR) jet using an event-level deep neural network. It is found that solely relying on the 4-momenta of the leading three jets allows the algorithm to achieve good discriminating power that can identify the hardest FSR jet in the signal while rejecting other soft jets. Once the invariant mass is corrected with the tagged FSR jet, the mass resolution of the signal is greatly enhanced, and the sensitivity of the search is also improved by more than 10%. By crafting the input variables carefully, the algorithm introduces minimal mass sculpting for the background, and its applicability extends to a broad mass range. This work proves that FSR jet tagging can potentially enhance di-jet resonance searches, suiting various stages of the physics programmes at the Large Hadron Collider (LHC) and High-Luminosity LHC (HL-LHC).

China

Bingxuan Liu

Yuxuan Shen

Yuanshunzi Sui

Enhancing di-jet resonance searches via a final-state radiation jet tagging algorithm * Bingxuan Liu is supported by Shenzhen Campus of the Sun Yat-sen University under project 74140-12255011, and by the Young Scientists Fund (C Class) of the National Natural Science Foundation of China (12405122). Both Yuxuan Shen and Yuanshunzi Sui are supported by College Students’ Innovative Entrepreneurial Training Plan Program

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)

Cosmogenic muon-induced radioactive isotopes pose a significant background source for deep-underground low-background experiments. Although rock overburdens at underground sites substantially attenuate the cosmogenic muon flux, residual muon-induced backgrounds still require active suppression. For future multi-kiloton liquid scintillator (LS) detectors, such as the Jiangmen Underground Neutrino Observatory (JUNO), shower muons contribute to more than 88% of all muon-induced isotopes. Consequently, precise reconstruction of shower vertices is essential for implementing localized spatial vetoes. We propose a novel waveform-based method to reconstruct the shower vertex, defined as the energy-deposition centroid in radius of 2 m. By subtracting the track contributions from non-shower muons in the recorded waveforms, the isolated shower component is extracted. Subsequently, using a photon propagation model and an iterative optimization algorithm, the shower vertex positions are reconstructed. Simulations show that for 68% of events, the single shower vertex resolution is better than 0.16 m, 0.15 m, and 0.26 m along X, Y, and Z respectively. Furthermore, the reconstruction efficiency exceeds 96% when requiring the distance between the reconstructed and true vertices to be less than 3.0 m. This method provides a critical technical foundation for muon-induced background suppression in JUNO and other large-scale LS detectors.

Junwei Zhang

Yongpeng Zhang

Yongbo Huang

Jilei Xu

Junyou Chen

Yi Wang

Reconstruction of the effective energy-deposition vertex of muon showers using PMT waveform in a large-scale liquid scintillator detector

The study of heavy-flavored baryon and meson production in proton-proton (pp) collisions provides crucial insight into the hadronization mechanisms of quantum chromodynamics (QCD). In this work an attempt has been made to describe the existing ALICE and LHCb results on the <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>p</mi><mi mathvariant="normal">T</mi></msub></math>-differential production cross section of <math xmlns="http://www.w3.org/1998/Math/MathML"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo>,</mo><mo> </mo><msup><mi>D</mi><mn>0</mn></msup><mo>,</mo><mo> </mo><msubsup><mi mathvariant="normal">Λ</mi><mi>b</mi><mn>0</mn></msubsup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mover accent="true"><mi>B</mi><mo>¯</mo></mover><mn>0</mn></msup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>p</mi><mi mathvariant="normal">T</mi></msub></math>-dependent <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo>/</mo><msup><mi>D</mi><mn>0</mn></msup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msubsup><mi mathvariant="normal">Λ</mi><mi>b</mi><mn>0</mn></msubsup><mo>/</mo><msup><mover accent="true"><mi>B</mi><mo>¯</mo></mover><mn>0</mn></msup><mrow><mo>(</mo><msup><mi>B</mi><mn>0</mn></msup><mo>)</mo></mrow></mrow></math> ratios, in light of the color-string junction inspired PYTHIA-8.314 model. A comparison of the results obtained with various event samples generated with different tuning parameters and the existing experimental results of ALICE and LHCb at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msqrt><mi>s</mi></msqrt><mo>=</mo></mrow></math> 7 and 13 TeV underlines the relevance of string-junction dynamics in heavy-flavored particle production. The results of the present investigation reveal that while stopping the junction-antijunction reconfiguration in the nonperturbative PYTHIA-8.314 model successfully describes the considered ALICE experimental observables of the charm sector, on the other hand, allowing junction-antijunction reconfiguration, keeping other fragmentation parameters the same, better describes the LHCb experimental observables of both charm and bottom sectors.

India

Tonmoy Sharma

Banajit Barman

Buddhadeb Bhattacharjee

Production of heavy flavored particles in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>p</mi><mi>p</mi></mrow></math> collisions: A unified model description for results of experimental measurements by ALICE and LHCb

The quark anomalous magnetic moments (AMMs) are investigated in a two-flavor low-energy effective theory within the functional renormalization group (FRG) approach under an external magnetic field. The Schwinger formalism is adopted for quark propagators, and Fierz-complete four-quark scatterings are self-consistently included through the renormalization group flows. We find that the quark AMMs are dynamically generated with the chiral symmetry breaking, and the magnitude of the AMM of the down quark is around four times larger than that of the up quark. The transverse AMMs and the longitudinal d-quark AMM monotonically decrease with the magnetic field strength, while the longitudinal u-quark AMM slightly increases with the magnetic field strength. At <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo>=</mo><mn>0</mn></math>, the magnetic moments of proton and neutron are computed using the constituent quark model, which are close to the experimental values.

Rui Wen

Germany

Chuang Huang

Mei Huang

Functional renormalization group study of anomalous magnetic moment in a low-energy effective theory

A comprehensive study of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> energy correlator as a probe of nonperturbative hadronization in color-octet <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover></math> production is performed. The energy correlator measures the energy flow as a function of the angular distance (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>χ</mi></math>) from the identified <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> meson. Using the pythia8 Monte Carlo event generator, the correlator is computed at both parton and hadron levels. At high-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> transverse momentum (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi>T</mi></msub><mo>&gt;</mo><mn>7</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>/</mo><mi>c</mi></math>), the parton-level correlator in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>cos</mi><mi>χ</mi><mo>&gt;</mo><mn>0</mn></math> region is dominated by soft gluon emission during the hadronization of the color-octet state, a contribution clearly distinguishable from other partonic sources, such as underlying multiparton interactions. The transition to the hadron level, however, introduces substantial modifications, suppressing the correlator in this region by approximately an order of magnitude and underscoring the complexity of the hadronization mapping. Further analysis reveals that the hadron-level observable exhibits notable sensitivity to model parameters: increasing the mass splitting between colored <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover></math> pre-resonances and the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> meson from 0.2 to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>0.8</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>/</mo><msup><mi>c</mi><mn>2</mn></msup></math> enhances the correlator by up to 60%, while extending the color reconnection range yields a milder enhancement of about 10%. These findings demonstrate that precise measurements of the hadron-level <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> energy correlator, when interpreted within robust event-generator frameworks, can provide novel constraints on hadronization dynamics and help clarify the production mechanisms of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> state.

Jin-Peng Zhang

Qian Yang

Wen-Chao Zhang

Yu-jiao Zhao

Hadronization impact on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> energy correlators: A pythia8 study from partonic to hadronic observables

In this work, we study the effective running coupling constant of heavy quark pair and jet quenching parameter in the spinning background. Ultralocally, the boosted fluid is described by the boosted parameter and dual to a globally rotating system. Our results show that the angular momentum suppresses the effective running coupling constant and reduces its maximum value. The results demonstrate that the angular momentum promotes the dissociation of quarkonium and has a stronger effect on the effective running coupling constant when the axis of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Q</mi><mover accent="true"><mi>Q</mi><mo stretchy="false">¯</mo></mover></math> is transverse to the direction of the angular momentum. We also find that the angular momentum enhances the jet quenching parameter and has a stronger effect when the jet moves transversely to the direction of the angular momentum, namely <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>q</mi><mo stretchy="false">^</mo></mover><mo>⊥</mo></msub><mo>&gt;</mo><msub><mover accent="true"><mi>q</mi><mo stretchy="false">^</mo></mover><mo stretchy="false">∥</mo></msub></math>. We discuss the dependence of the jet quenching parameter on the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi><mo>/</mo><mi>s</mi></math> at strong coupling in the presence of the angular momentum.

Zhou-Run Zhu

Sheng Wang

Man-Li Tian

Effective running coupling constant and jet quenching parameter in a spinning background from holography

In higher-dimensional theories, we often assume that the extra dimensions form an orientable space, perhaps with singularities. However, many physical theories are well defined on nonorientable spaces, and many spaces are not orientable, so it is reasonable to explore what happens if the assumption of orientability is relaxed. Here we consider the simplest example of free 6D theories compactified on a flat Klein bottle. We focus on a Dirac fermion in 6D, with boundary conditions that define <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>pin</mi><mo>+</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>pin</mi><mo>−</mo></msup></math> structures. Translation invariance is broken by the boundary conditions, which leads to sharp features localized near the parity walls (fixed points of the reflection used to construct the Klein bottle). For a scalar field, there is a position-dependent energy density, peaked near the parity walls. A Dirac fermion can lead to breaking of parity, charge conjugation, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><mo>+</mo><mn>1</mn></math> dimensions. Order parameters for this breaking are provided by the vacuum expectation values of certain fermion bilinears, again peaked near the parity walls. As one potential application, these results suggest mechanisms for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation and baryogenesis, enabled by compactification on a Klein bottle.

Brian Greene

Daniel Kabat

Janna Levin

Massimo Porrati

Compactification without orientation, or a topological scenario for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation

This article explores traversable wormhole geometries obtained in the context of the symmetric teleparallel gravity theory and highlights their distinctive physical characteristics. Our methodology involves determining the tidal force by employing a specified form of the shape function along with an appropriate equation of state for Case I. In order to extract the shape functions associated with the wormhole solution, we apply the null-complexity condition with tidal force in Case II. In Case III, we utilize the balancing Tolman–Oppenheimer–Volkoff equation in conjunction with a tidal force to obtain viable wormhole shape function. The analysis focuses on the dependence of wormhole characteristics on the parameter $$\zeta $$ . The energy conditions are examined within their respective validity domains for various ranges of the model parameters. We also calculate, the volume integral quantifier, the extent of exotic matter needed to uphold the traversable wormhole structure. Through the effective potential for timelike geodesics, the influence of angular momentum on trajectories is clarified, and the corresponding deflection angle evaluation points to significant light bending close to the throat. By introducing small radial perturbations around the equilibrium shell radius, we examine the stability characteristics for all considered shape functions.

Sweeti Kiroriwal

Oman

Azerbaijan

S. Maurya

Jitendra Kumar

Wormhole solutions under tidal force constraints in $\textit{f}$($\textit{Q}$) gravity: a unified approach

Cosmological correlators are fundamental observables in an expanding universe and are highly non-trivial functions even at tree-level. In this work, we uncover novel structures in the space of such tree-level correlators that enable us to develop a new recursive algorithm for their explicit computation. We begin by formulating cosmological correlators as solutions to GKZ systems and develop a general strategy to construct additional differential operators, called reduction operators, when a GKZ system is reducible. Applying this framework, we determine all relevant reduction operators, and show that they can be used to build up the space of functions needed to represent the correlators. Beyond relating different integrals, these operators also yield a large number of algebraic relations, including cut and contraction relations between diagrams. This implies a significant reduction in the number of functions needed to represent each tree-level cosmological correlator. We present first steps to quantify the complexity of our reduction algorithm by using the Pfaffian framework. While we focus on tree-level cosmological correlators, our approach provides a blueprint for other perturbative settings.

Netherlands

Thomas Grimm

Arno Hoefnagels

Mick Vliet

A reduction algorithm for cosmological correlators: cuts, contractions, and complexity