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

Heavy Majorana neutrinos ($\textit{N}$) are predicted in many models of physics beyond the Standard Model. In this work, we explore the production and detection prospects of TeV-scale heavy neutrinos ( $ m_N \gtrsim 1 $ TeV) at a future 3 TeV Compact Linear Collider (CLIC). We focus on two distinct decay topologies: (i) $ N \to \ell^\pm W^\mp $ with hadronic $\textit{W}$ boson decay, leading to a final state with one charged lepton and a hadronic fat jet $ J_W $ ; and (ii) $ N \to \nu h $ with subsequent Higgs decay $ h \to b\bar{b} $ , yielding a Higgs-tagged fat jet $ J_h $ and $\not {E}_T$ . Based on comprehensive detector-level simulations and background analysis, we present both $ 2\sigma $ exclusion limits and $ 5\sigma $ discovery reaches in the $ m_N $ – $ |V_{\ell N}|^2 $ plane. We further extract 95% confidence level upper limits on the mixing parameter $ |V_{\ell N}|^2 $ and perform a detailed comparison with existing constraints from direct searches at future colliders and indirect global fits. Our findings demonstrate that a 3 TeV CLIC can improve the sensitivity to $ |V_{\ell N}|^2 $ by about two orders of magnitude compared with the projected reaches of future hadron colliders while remaining competitive with other CLIC search channels.

Yao-Bei Liu

Jing-Wei Lian

Searches for heavy neutrinos at a 3 TeV CLIC in fat jet final states * Yao-Bei Liu is supported by the Natural Science Foundation of Henan Province, China (252300421988), Jing-Wei Lian is supported by the National Natural Science Foundation of China (12447140) and the Natural Science Foundation of Henan Province, China (252300421771)

The 2HDM+S is the singlet extension of the two-Higgs-doublet model (2HDM). The singlet field and its mixing with the 2HDM Higgs sector lead to new contributions to the electroweak precision observables, in particular, the oblique parameters. In this study, we performed a systematic investigation of the impacts of each mixing angle on the oblique parameters. We adopted the mixing angles and physical Higgs masses as our parameters, which allow a mapping when a specific symmetry structure of the Higgs potential and various theoretical considerations are taken into account. We identified five benchmark cases, where at most one mixing angle was nonzero, and analyzed the 95% C.L. allowed parameter space using the oblique parameters. In the alignment limit of the 2HDM, we find that, other than the usual mass relations of $m_H\sim m_{H^\pm}$ or $m_A\sim m_{H^\pm}$ , electroweak precision measurements also impose an upper limit on the neutral Higgs masses. In the cases with nonzero singlet mixing with the 2HDM Higgses $\textit{H}$ or $\textit{A}$, we find approximate mass relations of $c^2_{\alpha_{HS}} m_{H} + s^2_{\alpha_{HS}}m_{h_S} = m_{H^\pm}$ or $c^2_{\alpha_{AS}} m_{A} + s^2_{\alpha_{AS}}m_{A_S} = m_{H^\pm}$ . These relations are universal to the 2HDM+S models, with or without further symmetry assumption. We also studied the non-alignment limit of the 2HDM+S, which typically has tighter constraints on the masses and mixing angles. Finally, we examined the complementarity between the electroweak precision analyses and the Higgs coupling precision measurements.

Cheng Li

Juxiang Li

Shufang Su

Wei Su

Electroweak precision constraints of the 2HDM+S * Cheng Li, Juxiang Li, and Wei Su are supported by the Natural Science Foundation of China (NSFC) (12305115), Shenzhen Science and Technology Program (202206193000001, 20220816094256002), Guangdong Provincial Key Laboratory of Gamma-Gamma Collider and Its Comprehensive Applications (2024KSYS001), and Guangdong Provincial Key Laboratory of Advanced Particle Detection Technology (2024B1212010005). Juxiang Li is also supported by the Fundamental Research Funds for the Central Universities, and the Sun Yat-sen University Science Foundation. Shufang Su is supported by the Department of Energy (DEFG02-13ER41976/DE-SC0009913)

The goal of our work is to analyze the thermodynamic topology of accelerated charged anti-de Sitter black holes with a generalized Barrow modification of the entropy. Using Duan’s $$\phi $$ -mapping theory and generalized Gibbs free energy, we analyze the topological classes of black holes. These tools enable us to calculate integer values that represent the topological features of the black hole. We examine the system within three distinct thermodynamic frameworks: the canonical, mixed canonical, and grand canonical ensembles. In the canonical ensemble, the system maintains fixed electric and magnetic charges. In the mixed canonical ensemble, the electric and magnetic potentials are kept constant. In contrast, the grand canonical ensemble maintains fixed electric and magnetic potentials but allows for charge exchange with the surroundings. These distinct ensembles provide a platform to study how black holes respond to various physical conditions. Specifically, we examine the charged and uncharged topological characteristics related to thermodynamic stability criteria. By applying these analytical methods, we aim to uncover new insights into the thermodynamic and topological properties of black holes. Additionally, we examine the geodesic deviation in an accelerated charged black hole, focusing on the influence of electric and magnetic charges on the courses of nearby geodesics. The complex effects of space-time curvature in this situation are reflected in the tendency of angular geodesics to converge as one advances away from the black hole, in contrast to radial geodesics. This study provides a deeper understanding of how black holes depend on gravitational frameworks and thermodynamic conditions, offering a fresh perspective on their nature and expanding our knowledge in this field.

Muhammad Yasir

Pakistan

Tehreem Aslam

Shahid Qaisar

Wei Liu

Azerbaijan

Faisal Javed

Saudi Arabia

Mansoor Alshehri

Thermodynamic topology and geodesics analysis of accelerated charged-AdS black hole with Barrow entropy corrections

We study the sensitivity of the CMS search to displaced showers arising from the decays of long-lived particles in the muon system, within the framework of hidden valley scenarios. To establish our simulation setup, we employ a parametrization of hidden valley theory space and adopt a hybrid strategy where the lifetime is treated as a free parameter to provide model-independent hidden valley quark production cross-section upper limits. Our results indicate that the CMS search is broadly sensitive to variations in hidden valley parameters such as the overall scale and relevant mass ratios, while showing comparatively weak dependence on the number of hidden valley colors or flavors. The exact quantitative results we derive depend on the underlying hadronization model employed and thus, we urge caution in interpreting the results. Within these limitations, we also establish model-dependent limits on the maximum strength of the mediator coupling to hidden valley quarks. Our approach illustrates how one can move beyond simplified model strategies by employing a first-principles-inspired theory setup, while highlighting the theoretical uncertainties inherent in modeling hidden valley phenomenology.

Austria

Joshua Lockyer

Suchita Kulkarni

Hidden valley scenario sensitivity in the CMS muon end cap detector

We study the inelastic charmonium ( $ J/\psi $ , $ \psi(2S) $ ) and bottomonium ( $ \Upsilon(nS) $ ) photoproduction and fragmentation processes in $\textit{p}$-$\textit{p}$ and $ \rm Pb$ - $\rm Pb$ collisions at LHC energies, where the ultra-incoherent photon emission is included. Using the NRQCD factorization approach, an exact treatment is developed. This approach recovers the Weizsäcker-Williams approximation (WWA) near the $ Q^{2}\sim0 $ region, where the Martin-Ryskin and BCCKL methods are used to avoid double counting. We calculated the $ Q^{2} $ , $\textit{y}$, $\textit{z}$, $ \sqrt{s} $ , and $ p_{T} $ dependent and total cross sections. Inelastic photoproduction and fragmentation were observed to contribute to heavy quarkonium production, particularly at large $ p_{T} $ . In addition, the contribution of the ultra-incoherent photon channel, which increases rapidly with quarkonium mass, is significant and begins to dominate the photoproduction processes for large $ p_{T} $ . We also obtained the complete WWA validity scopes of inelastic heavy quarkonium photoproduction in heavy-ion collisions. The WWA had high accuracy at high energies and for $\rm Pb $ - $\rm Pb $ collisions. However, current photon spectra are derived beyond the WWA scope, and double counting can occur when considering different channels simultaneously.

Zhi-Lei Ma

Zhun Lu

Hao Liu

Li Zhang

Inelastic heavy quarkonium photoproduction in $\textit{p}$-$\textit{p}$ and Pb-Pb collisions at LHC energies * Supported in part by the National Natural Science Foundation of China (12305092, 12233006, 12150013), the Xingdian Talent Support Program for Youth Project, and by the Yunnan Fundamental Research Projects (202401AU070206). Hao Liu is supported by the Scientific Research and Innovation Project of Postgraduate Students in the Academic Degree of YunNan University (KC-242410212)

The neutrino floor, a theoretical sensitivity limit for dark matter (DM) direct detection, is being redefined as the boundary of a dynamic ''neutrino fog,'' where neutrino signals become inevitable, obscuring DM detection due to statistical and systematic uncertainties. This study provides the first site-specific analysis of the neutrino floor at China Jinping Underground Laboratory (CJPL), leveraging its unique geographic and environmental characteristics. We quantify how CJPL’s suppressed atmospheric neutrino flux (approximately 30% lower than that of Laboratori Nazionali del Gran Sasso (LNGS)) reshapes the neutrino floor, thereby enabling improved sensitivity to high-mass WIMPs (mass > 10 GeV). Using a gradient-based framework, we derive the CJPL’s neutrino floor and estimate the detection prospects for the PandaX-xT experiment. Our results demonstrate that a 500 tonne-year exposure with PandaX-xT could reach the floor, probing spin independent cross-sections down to $ \sigma_{n}\sim 3\times 10^{-49}\; {\rm{cm}}^2$ at a DM mass of 70 GeV/$\textit{c}$ $^{2}$.

Yingjie Fan

Xuewen Liu

Ning Zhou

Characterizing the CJPL’s site-specific neutrino floor as the neutrino fog boundary * Xuewen Liu is supported by the Project of Shandong Province Higher Educational Science and Technology Program (2022KJ271). Ning Zhou is supported by National Science Foundation of China (12325505)

We study the potential collider discovery for right-handed neutrinos (RHNs) in the minimal left-right symmetric model (LRSM). In this model, the RHNs can be either produced from the right-handed gauge boson <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>W</mi><mi>R</mi><mo>±</mo></msubsup></math>, or the scalar triplet <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Δ</mi></math> decays. The RHNs can subsequently decay via the heavy <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>W</mi><mi>R</mi><mo>±</mo></msubsup></math>, making them potentially long-lived. In looking for such long-lived RHNs, a search for displaced shower at the CMS muon system is reinterpreted for either the processes, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi><mo stretchy="false">→</mo><msubsup><mi>W</mi><mi>R</mi><mo>±</mo></msubsup><mo stretchy="false">→</mo><msup><mo>ℓ</mo><mo>±</mo></msup><mi>N</mi></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi><mo stretchy="false">→</mo><mi mathvariant="normal">Δ</mi><mo stretchy="false">→</mo><mi>N</mi><mi>N</mi></math>. From the former process, we exclude <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>M</mi><msub><mi>W</mi><mi>R</mi></msub></msub><mo>≲</mo><mn>3.6</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math> using current CMS data, or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>≲</mo><mn>8.0</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math> at the future HL-LHC. For the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi><mo stretchy="false">→</mo><mi mathvariant="normal">Δ</mi><mo stretchy="false">→</mo><mi>N</mi><mi>N</mi></math> process, HL-LHC is able to probe much larger parameter space as long as the proper decay length of the RHNs, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>0.01</mn><mtext> </mtext><mtext> </mtext><mi mathvariant="normal">m</mi><mo stretchy="false">≲</mo><msub><mi>L</mi><mn>0</mn></msub><mo>≲</mo><mn>1</mn><mtext> </mtext><mtext> </mtext><mi mathvariant="normal">m</mi></mrow></math>. This implies that the displaced shower searches are able to explore the parameter space of the LRSM which have not been excluded yet.

United Kingdom

Zixiang Chen

Probing a left-right symmetric model from a displaced shower at the CMS muon system

We analyzed two-loop planar contributions to a three-body form factor at next-to-leading power in the high-energy limit, where the masses of the external particles are much smaller than their energies. Calculations were performed by exploiting differential equations for the expansion coefficients, both to facilitate linear relations among them and to derive their analytic expressions. The results are expressed in terms of generalized polylogarithms involving a few simple symbol letters. Our method can readily be applied to calculations of non-planar contributions as well. Our results provide crucial information for establishing sub-leading factorization theorems for massive scattering amplitudes in the high-energy limit.

Yishuai Guo

Zhi-Feng Liu

Mingming Lu

Tianya Xia

Li-Lin Yang

A three-body form factor at sub-leading power in the high-energy limit: planar contributions * Supported in part by the National Natural Science Foundation of China Sunder (12375097, 12347103) and the Fundamental Research Funds for the Central Universities. Zhi-Feng Liu was supported by the China Postdoctoral Science Foundation (2023M733123, 2023TQ0282) and the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation

We explore the potential for detecting the inelastic dark matter (DM) model with an additional <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi>D</mi></msub></math> gauge symmetry at various types of lepton colliders. The new gauge boson <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Z</mi><mo>′</mo></msup></math> resulting from the spontaneous breaking of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi>D</mi></msub></math> can act as a portal connecting the Standard Model fermions and DM fermions <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>χ</mi></math>, thereby facilitating the production of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Z</mi><mo>′</mo></msup></math> and its decay into DM fermions. The mass difference between the excited DM fermion <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mn>2</mn></msub></math> and the ground DM fermion <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mn>1</mn></msub></math> induces the subsequent decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mn>2</mn></msub><mo stretchy="false">→</mo><msub><mi>χ</mi><mn>1</mn></msub><mo>+</mo><mi>vis</mi></math>, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mn>2</mn></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mn>1</mn></msub></math> serve as long-lived particles and the DM candidate, respectively. For the inelastic DM with a mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msub><mi>χ</mi><mn>1</mn></msub></msub></math> in the range of (1–100) GeV, we find that the future lepton colliders can probe many regions not accessible by current experiments and provide greater projected sensitivity than the LHC and Belle in previous studies. This suggests that future colliders can provide complementary exploration of the inelastic dark matter model.

South Korea

Jin Sun

Lepton collider imprints of an inelastic dark matter model