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)

We propose a field-theoretic framework for ideal hydrodynamics of charged relativistic fluids formulated in terms of a complex scalar field defined on a spacelike hypersurface comoving with the fluid. In the normal phase, the dynamics of charge-carrying fluids is constrained by the restrictive chemical shift symmetry, which locks charges to fixed positions in the comoving plane as they are transported through space by the fluid’s motion. On the other hand, in the superfluid phase, the chemical shift symmetry is relaxed to a constant shift, allowing charges to redistribute freely across the comoving hypersurface. We demonstrate that both models recover the respective nonlinear hydrodynamic equations and provide explicit expressions for the collective variables of hydrodynamics in terms of the theory’s fields. Introduced models provide a UV completion to the effective field theories of hydrodynamics constructed in terms of the Goldstone fields. Finally, we propose a relativistic fracton fluid phase as a natural interpolation between the normal and superfluid phases, in which the mobility of elementary charges is constrained by a linear shift symmetry in the comoving space.

Poland

Aleksander Głódkowski

A complex scalar field theory for charged fluids, superfluids, and fracton fluids

We develop a twistor-space framework to compute boundary correlators via a boundary limit of nested Penrose transforms in (A)dS . Starting from correlators of (anti-)self-dual bulk fields, the boundary limit reproduces the correlators of the dual conserved currents; we demonstrate this explicitly for two- and three-point functions. The two-point correlator is rendered finite by working in Euclidean signature. At three points, we obtain compact rational twistor-space representatives obeying a double-copy relation, thereby clarifying the twistor-space origin of the results in . We further extend the analysis to non-conserved currents with integer conformal dimension, dual to massive bulk fields, as well as to the free scalar.

United Kingdom

Mariana Carrillo González

Théo Keseman

Spinning boundary correlators from (A)dS4 twistors

We propose a flavor model based on an <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>A</mi><mn>4</mn></msub></math> symmetry combined with a type-II seesaw mechanism for neutrino mass generation. The resulting neutrino mass matrix obeys a sum rule that, together with the measured mass-squared differences, fully determines the absolute neutrino mass spectrum. The constrained flavor structure yields correlated predictions for lepton mixing parameters, leads to inverted ordering after imposing mixing constraints, restricts the Majorana phases and implies a neutrinoless double beta decay rate close to its maximal value for inverted ordering. In the charged lepton sector an approximate triality symmetry arises in the seesaw limit, suppressing muon flavor-violating processes and allowing only specific <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math> decay channels. The model provides a tightly constrained and experimentally testable framework linking neutrino masses, lepton mixing, and lepton-number-violating observables.

Spain

Salvador Centelles Chuliá

South Korea

India

Ranjeet Kumar

Minimal <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>A</mi><mn>4</mn></msub></math> type-II seesaw realization of testable neutrino mass sum rules

Within a scotogenic neutrino mass model we explore the cogenesis of matter from the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violating decay of a heavy <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="double-struck">Z</mi><mn>2</mn></msub></math>-odd right handed neutrino that simultaneously populates the visible and a multipartite dark sector. The relic density of a sub-GeV scale freeze-in dark matter is generated by the late time decay of the next-to-lightest dark particle dynamically regulated by an interplay with the thermal scattering processes. We show that this model can simultaneously explain visible matter asymmetry and provide a cosmologically viable sub-GeV dark matter while remaining in consonance with the neutrino parameters and flavor observables.

Debajit Bose

Rohan Pramanick

Tirtha Sankar Ray

Cogenesis of visible and dark matter in a scotogenic model

In this paper, we initiate the study of lepton flavor violating (LFV) dark matter (DM) interactions, expanding our focus beyond the flavor-conserving DM interactions typically considered in conventional direct and indirect detections. We work in an effective field theory (EFT) framework, focusing on the leading-order local operators of the form, $$ {\overline{\ell}}_j\Gamma {\ell}_i{\textrm{DM}}^2 $$ , where ($\textit{ij}$) = ($\textit{eμ, eτ, μτ}$) and the DM includes the three well-known scenarios: a scalar, a fermion, and a vector. We derive the invariant-mass distribution for the three-body decay $\textit{ℓ}$ → $\textit{ℓ}$ + DM + DM and demonstrate that it can be used to distinguish between different operator structures and to determine the DM mass. By utilizing current experimental bounds on the charged muon LFV decay involving neutrinos and the ratio of tau leptonic decay widths, we establish stringent limits on the effective scale associated with each operator. Additionally, for the $\textit{eμ}$ flavor combination, we investigate the muon four-body radiative decay ($\textit{μ}$ → $\textit{e}$ + DM + DM + $\textit{γ}$) to complement our probe of such interactions. Finally, we examine muonium invisible decays based on the derived bounds on the effective operators and find that the branching ratios can be significantly enhanced compared to the predictions of the standard model. In particular, any future observation of the para-muonium invisible decay serves as a compelling signature for these flavored DM interactions.

Sahabub Jahedi

Yi Liao

Xiao-Dong Ma

Charged lepton flavor violating decays with a pair of light dark matter and muonium invisible decay

We show that the coupling of a massive spin-2 field to undeformed $$ \mathcal{N}=1 $$ supergravity in four dimensions is unique, leading to a specific non-minimal coupling to the Riemann tensor. The massive spin-2 coupling reproduces the one of an oscillator mode in open string theory, while the massive spin-1 coupling includes a higher-derivative term that is expected to violate causality in the background of a gravitational shock wave. We argue that the resolution of causality and the unitarity bound in the Regge limit require the introduction of infinitely many higher-spin fields similar to the Regge trajectories in string theory, therefore providing an argument in favour of the string lamppost principle with minimal supersymmetry in four dimensions. To obtain this result, we construct the general stress-energy tensor multiplet for the massive spin-2 multiplet with $$ \mathcal{N}=1 $$ supersymmetry.

France

Guillaume Bossard

Gabriele Casagrande

Emilian Dudas

Adrien Loty

A unique coupling of the massive spin-2 field to supergravity

Studying heavy-quark hadrons is crucial due to the nonperturbative nature of low-energy QCD, with Heavy-Quark Symmetry (HQS) serving as a key framework for understanding their spin and flavor symmetries. However, a key issue is that the theoretically expected $$B^{(*)}\bar{K}$$ molecular states have not yet been observed, although they are considered the bottom-quark counterparts of the observed $$\bar{D}^{(*)}\bar{K}$$ molecular states (corresponding to $$D_{s0}(2317/2460)^{-}$$ ), which challenges the universality of HQS. The main goal of this work is to search for the theoretically predicted $$B\bar{K}$$ and $$B^{*}\bar{K}$$ molecular states, namely $$B_{s0}^{*}(5725)$$ and $$B_{s1}^{*}(5778)$$ , via the reactions $$K^{-}p \rightarrow \varLambda _{b}^{0} B_{s0}^{*}$$ and $$K^{-}p \rightarrow \varLambda _{b}^{0} B_{s1}^{*}$$ . Within an effective Lagrangian framework, we compute the relevant cross sections, considering $\textit{t}$-channel $$B^{(*)}$$ exchanges and $$K^{-}p$$ initial-state interactions (ISI). The results show that the production cross sections of $$B_{s0}^{*}(5725)$$ and $$B_{s1}^{*}(5778)$$ can reach the order of 0.01 nb, and we suggest that experiments searching for $$B_{s0}^{*}(5725)$$ are best performed at $$P_{K^{-}} = 12.18~\textrm{GeV}$$ , while higher energies are most favorable for producing $$B_{s1}^{*}(5778)$$ . The ISI play a crucial role, as they not only significantly enhance the production cross sections of $$B_{s0}^{*}(5725)$$ and $$B_{s1}^{*}(5778)$$ (by roughly one order of magnitude) but also markedly affect the angular distributions of the produced particles. We also calculated the production cross sections of the conventional quark–antiquark states $$B_{s0}^*(5700)$$ and $$B_{s1}^*(5720)$$ , which are found to be nearly the same as those of $$B_{s0}^{*}(5725)$$ and $$B_{s1}^{*}(5778)$$ . Although their internal structures remain ambiguous, these results can inform future experimental searches at CERN and J-PARC.

Min Yuan

Yin Huang

A search for $$B_{s0}^{*}$$ and $$B^{*}_{s1}$$ through the $$K^{-}p$$ interaction

We investigate medium-induced modifications to jet substructure observables that characterize hard components in central Pb-Pb collisions at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo>=</mo><mn>5.02</mn></mrow></math> TeV. Using a multistage Monte Carlo simulation of in-medium jet shower evolution, we explore flavor-dependent medium effects through simulations of inclusive and <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>γ</mi></math>-tagged jets. The results show that quark jets undergo a nonmonotonic modification compared with gluon jets in observables such as the Pb-Pb to <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>p</mi><mtext>−</mtext><mi>p</mi></mrow></math> ratio of the soft drop prong angle <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>r</mi><mi>g</mi></msub></math>, the relative prong transverse momentum <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>k</mi><mrow><mi>T</mi><mo>,</mo><mi>g</mi></mrow></msub></math>, and the groomed mass <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>m</mi><mi>g</mi></msub></math> distributions. Due to this nonmonotonic modification, <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>γ</mi></math>-tagged jets, enriched in quark jets, provide surprisingly clear signals of medium-induced structural modifications, distinct from effects dominated by selection bias. Further systematic studies demonstrate that these effects are dominated by recoil medium response. This work highlights the potential of hard substructures in <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>γ</mi></math>-tagged jets as powerful tools for probing the jet-medium interactions in high-energy heavy-ion collisions, in particular by enabling detailed investigations of jet-medium parton scatterings via their associated medium response. All simulations for <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>γ</mi></math>-tagged jet analyses carried out in this paper used triggered events containing at least one hard photon, which highlights the utility of these observables for future Bayesian analysis.

Japan

Y. Tachibana

C. Sirimanna

A. Majumder

A. Angerami

R. Arora

S.A. Bass

Y. Chen

R. Datta

Canada

L. Du

R. Ehlers

Germany

H. Elfner

R.J. Fries

C. Gale

Y. He

B.V. Jacak

P.M. Jacobs

S. Jeon

Y. Ji

F. Jonas

L. Kasper

M. Kordell

A. Kumar

R. Kunnawalkam-Elayavalli

J. Latessa

Y.J. Lee

R. Lemmon

Brazil

M. Luzum

S. Mak

A. Mankolli

C. Martin

H. Mehryar

T. Mengel

C. Nattrass

J. Norman

C. Parker

J.F. Paquet

J.H. Putschke

H. Roch

G. Roland

B. Schenke

L. Schwiebert

A. Sengupta

C. Shen

M. Singh

D. Soeder

R.A. Soltz

Finland

I. Soudi

J. Velkovska

G. Vujanovic

X.N. Wang

X. Wu

W. Zhao

Effect of recoils on soft-drop-groomed observables in <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>γ</mi></math>-tagged jets in a multistage approach