第十二届中国 LHC 物理会议（CLHCP2026）

ATLAS中国组进展情况汇报。

In this talk, I will present the latest results on CP violation in B-hadron decays from LHCb.

"With the High-Luminosity Large Hadron Collider (HL-LHC) upgrade, the instantaneous luminosity will increase by almost an order of magnitude, reaching levels of up to (7.5\times10^{34}\ \mathrm{cm^{-2}s^{-1}}). This will lead to a substantial growth in the average pile-up density, with an expected average number of simultaneous proton-proton collisions per bunch crossing of approximately...

Identifying highly Lorentz-boosted Higgs bosons decaying to bottom-quark pairs is essential to the ATLAS physics programme. This poster reviews the evolution of boosted $X\to b\bar{b}$ tagging in ATLAS and the development of the corresponding calibration strategies. The Run-2 $D_{\rm Xbb}$ algorithm combined large-$R$-jet kinematics with flavour-tagging information from variable-radius track...

Accurate photon identification efficiency measurements are essential for physics analyses with photons at the ATLAS experiment. This poster presents a normalising-flow-based electron-extrapolation method for unconverted photons, with an application to 2022 collision data. A conditional normalising flow trained on simulated electrons and photons transforms the joint distribution of calorimeter...

"High-energy physics experiments are increasingly using FPGAs to deploy machine learning models for low-latency triggering and real-time data processing. Deploying these models on FPGAs requires coordinating several software and hardware tools. We present an agent workflow using reusable skills to support this process. The agent coordinates model conversion, hardware builds, and on-board...

"The High-Luminosity LHC (HL-LHC) will deliver instantaneous luminosities up to $7.5 \times 10^{34}~\rm{cm}^{-2}\rm{s}^{-1}$, resulting in an average of $200$ pile-up interactions per bunch crossing. This poses a serious challenge for the ATLAS detector, particularly in the forward region where detector granularity is reduced. To address this, the High-Granularity Timing Detector (HGTD) will...

The High-Granularity Timing Detector (HGTD) will provide precise timing information to mitigate pile-up effects in the ATLAS Phase-II upgrade. The Peripheral Electronics Board (PEB) interfaces front-end modules with off-detector systems, providing power distribution, data aggregation, control and monitoring. This work presents power-plane simulations and the development of a Diagnostic Test...

"In $H\to\gamma^*\gamma\to ee\gamma$ decays, low-mass electron pairs with high transverse momentum can produce overlapping electromagnetic showers in the calorimeter. A single cluster matched to two opposite-charge tracks forms a merged dielectron candidate, requiring dedicated identification to retain signal and reject photon and jet backgrounds. This poster presents merged dielectron...

A search for non-resonant Higgs boson pair production ($HH$) in the $b\bar{b}\tau^+\tau^-$ final state is performed using $140$~fb$^{-1}$ and $56$~fb$^{-1}$ of proton--proton collision data at centre-of-mass energies of $\sqrt{s} = 13$~\TeV and $13.6$~\TeV, respectively, recorded by the ATLAS detector during 2015--2023 at the CERN Large Hadron Collider. Relative to the previous ATLAS searches...

"Effective event categorization is essential for improving the sensitivity of the H → Zγ analysis. Correlations between classifier outputs and the reconstructed Zγ invariant mass can distort background distributions and complicate signal extraction. This poster presents the application of a mass-decorrelated event classifier transformer to the ATLAS Run 3 H → Zγ analysis, focusing on the Z →...

蔻享直播链接 https://www.koushare.com/live/details/57221

This talk presents an overview of recent measurements on the Higgs boson self-coupling from the ATLAS and CMS experiments. It also discusses their theoretical interpretation and the projected sensitivity at the HL-LHC.

Rare and exotic decays of the Higgs boson offer a unique window into phenomena beyond the Standard Model, probing potential new interactions, hidden sectors, and extended Higgs sectors.This talk will review the latest searches for rare and non-standard Higgs decays performed by the ATLAS and CMS experiments.

On-shell amplitudes reveal the independent interactions of effective field theory (EFT), complementing redundant Lagrangian descriptions. This review follows the on-shell approach from kinematics, factorization, recursion, and soft constraints to nonredundant massless and massive amplitude bases. We discuss harmonic analysis, Young tableaux, and massive spinor-helicity methods, emphasizing...

TBD

"The ALICE collaboration published the first measurement of the skewness and kurtosis of mean $p_T$ fluctuations, which can constrain the initial state of ultra-relativistic nuclear collisions.
In this paper, we investigate the higher-order mean $p_T$ fluctuations using a multiphase transport model for three different collision systems: pp collision at 5.02 TeV, Pb+Pb collision at 5.02 TeV...

This talk will present the latest results of Higgs mass measurement and width constraint in the diphoton final state at CMS

In this talk, I will discuss several different scenarios about testing CP-violation at high energy colliders, based on some recent progresses and forthcoming projects from my group. We studied CP-violation effects both from pure bosonic sector and the Yukawa sector. For pure bosonic sector, we considered a heavy Higgs boson produced through VBF process and decaying through Zh(125) channel,...

PQ solution to the strong CP problem probably encounters the axion domain wall problem. In this article, we propose a simple and testable solution, assuming that the U(1)PQU(1)PQ possesses mixed anomaly to a hidden SU(Nc)SU(Nc) color. Then, the axion field receives a new cosine potential from the hidden instantons, which breaks the ZNDWZNDW subgroup explicitly. The new potential lifts the...

The latest results of Hgg and HZZ mass combination will be presented

腾讯会议：870-930-901

"We perform the first complete $\mathcal{O}(\alpha_s^5)$ analysis of the prompt hadroproduction of $J/\psi$ pairs with large transverse momenta $p_T^{\psi\psi}$ in the nonrelativistic-QCD factorization framework, including all possible Fock state combinations $c\bar{c}(m)+c\bar{c}(n)$, with $m,n=^3S_1^{[1,8]},^1S_0^{[8]},^3P_{J}^{[1,8]}$. We observe that CMS and ATLAS data constrain a...

"Dijet production in high-energy collisions encodes rich information about the surrounding QCD medium, yet computing these multi-particle processes requires non-perturbative input that remains challenging for conventional approaches. In this talk, I present a framework that employs quantum simulation techniques to compute multi-particle processes in such environments by mapping partonic...

腾讯会议：870-930-901

First measurement of time dependent CPV in b->sll decay

"A direct measurement of the Higgs-top Yukawa coupling is essential for testing the Standard Model and probing new physics. The associated production of a Higgs boson with a top-quark pair (ttH) provides the only direct access to this coupling at the LHC, with the multilepton channel regarded as the ‘golden channel’ for ttH measurement owing to its relatively high signal-to-background ratio...

Soft unclustered energy patterns (SUEPs) refer to high-multiplicity, isotropic distributions of low-momentum particles that could arise in strongly-coupled hidden sector theories. A search for SUEPs whose decay products contain muons in the final state is presented using 140 fb−1 of proton–proton collision data at √ = 13 TeV collected by the ATLAS detector at the Large Hadron Collider during...

CP violation measurements in three-body decays

In this report, we will introduce the current status of the Flex Tail (FT) and High Voltage Power Supply (HVPS) systems. In the ATLAS High Granularity Timing Detector (HGTD) project , the FTs are designed for the connection between detector module and Peripheral Electronics Board (PEB). According to different location in the detector sector, there are so many kinds of FTs with different...

Spin-dependent dihadron fragmentation provides a unique way to access the polarization and spin correlations of light quarks and gluons at lepton colliders. In this talk, I will discuss how dihadron fragmentation can serve as a spin analyzer and be used to study a range of phenomena, including Bell inequality violation, anomalous electromagnetic dipole interactions, light-quark Yukawa...

A study of the production of the Higgs boson in association with either a top-quark pair (tt¯H) or a single top quark (tH) in theτ-lepton-pair decay channel will be presented. The analysis relies on final states featuring fully hadronic decays of the top quarks and theτ-leptons. It employs data samples of proton--proton collisions ats√=13and 13.6 TeV recorded with the ATLAS detector at the...

"Motivated by the recent 3.9$\sigma$ evidence for CP violation from the LHCb collaboration in decays of an anti-triplet beauty baryon to a charmonium, an octet baryon, and a pseudoscalar meson,
we perform, for the first time, a systematic analysis of this class of decays within the framework of flavor $SU(3)$ symmetry.
Several predictions for branching ratios and CP violating relations...

Semiconductor detectors, owing to their low material budget, precise spatial resolution, and mature fabrication processes, are widely used in the tracking systems of large-scale spectrometers. Compared with conventional strips or hybrid chips, MAPS detectors use highly integrated commercial semiconductor processes, enabling complex front-end electronics while maintaining low cost in...

This talk reports recent LHCb results on time-dependent CP violation in beauty to charmonium decays.

腾讯会议：800-224-540

We present the first principle calculation of form factors employing 2 + 1 flavor gauge ensembles with lattice spacings ranging from 0.06 to 0.1 fm and pion masses between 230 and 340 MeV.

LHC measurements now reconstruct all fifteen parameters of the $t\bar{t}$ two-qubit spin density matrix, which amounts to a full quantum tomography of the pair. We show that this data constrains CP violation in the top-Yukawa coupling. The coupling enters the density matrix at one loop and produces spin correlations that are odd under CP and do not affect the cross section. Using the first...

"The increasing level of front-end integration in particle detectors has placed new requirements on powering systems, particularly in terms of material budget, power distribution, and system scalability. Serial powering, based on a constant-current scheme with shunt-LDO regulators (SLDO), has been an attractive solution for large-scale detector systems and future collider upgrades.

This...

"Silicon microstrip detectors offer precise position measurements and a modular architecture for charged-particle tracking and beam diagnostics. This report presents the development and testing of lightweight, low-cost silicon microstrip systems for testbeam facilities and cosmic-ray detection, covering both an existing silicon beam monitor and a compact detector system currently under...

Recent progress on baryonic decays of beauty hadrons at LHCb

In recent years, a number of experiments dedicated to searches for long-lived particles (LLPs) have been proposed or approved, or have entered operation. While the sensitivities of these experiments to various LLP scenarios have been extensively studied, key aspects—such as detector geometries, background estimates, and projected operational durations—for several facilities, including...

The color-octet (CO) mechanism is a cornerstone of nonrelativistic QCD, yet knowledge of its long-distance matrix elements remains limited, preventing stringent tests of the theory. We demonstrate that the Artru-Collins asymmetry in hadronic decays of the $P$-wave bottomonium state $\chi_{b2}$ provides a direct probe of CO dynamics. At leading order, the asymmetry arises exclusively from the...

We present a template fitting strategy for the VBF H→μμ search in ATLAS. Among all Higgs production modes, VBF is one of the most important for H→μμ, and its distinct di-jet signature significantly helps reduce background. For high S/B VBF categories, limited sideband statistics become a bottleneck for sensitivity, to address this, a Monte Carlo-based background estimation with a template fit...

The 125  GeV Higgs boson validates the Standard‑Model electroweak symmetry‑breaking mechanism, while open puzzles such as dark matter, neutrino masses, and primordial phase transitions strongly motivate extended scalar‑sector new physics. In this talk, we investigate collider phenomenology of additional scalar particles within 2HDM+S, SM+octet+S, NMSSM and other beyond‑SM frameworks. We...

This work mainly covers the assembly of the UP Bare Stave and the design of the cooling system. The Bare Stave has undergone several design iterations, while the cooling system has been delivered to Hunan University and has passed preliminary testing.

腾讯会议: 952-527-429

A search for pairs of light neutral pseudoscalar bosons ($A$) resulting from the decay of a Higgs boson is performed. The search is conducted using LHC proton-proton collision data at $\sqrt{s}=13~\mathrm{TeV}$, collected with the CMS detector in 2016--2018 and corresponding to an integrated luminosity of $138~\mathrm{fb}^{-1}$. The $A$ boson decays into a highly...

Directly probing light-quark Yukawa couplings and their flavor structure remains a major challenge due to their smallness and overwhelming QCD backgrounds. In this Letter, we propose a theoretical framework to access these couplings at lepton colliders through transverse spin dependent azimuthal modulations in dihadron fragmentation. These modulations arise from the interference between Higgs...

The successful deployment of Monolithic Active Pixel Sensors (MAPS) in the Inner Tracking System 2 (ITS2) in the ALICE experiment at CERN, motivated the use of monolithic sensors in a 65 nm CMOS imaging process for the ALICE ITS3 upgrade and the ALICE 3 upgrade. The ITS3 upgrade aims to replace the three inner tracker layers during LHC Long Shutdown 3 (LS3) with ultra-thin, curved, wafer-scale...

We study forward $\chi_{cJ}$ production in the low-$p_{\perp}$ region in proton-proton ($pp$) and proton-nucleus ($pA$) collisions at the LHC within the framework of nonrelativistic QCD (NRQCD) factorization and the Color Glass Condensate (CGC) effective field theory. Incorporating small-$x$ gluon evolution via the running-coupling Balitsky–Kovchegov equation with various initial conditions,...

Photophobic axion-like particles (ALPs) have suppressed couplings to diphotons but can still interact with electroweak gauge bosons. In this talk, we investigate the discovery prospects for heavy photophobic ALPs at the High-Luminosity Large Hadron Collider (HL-LHC, $\sqrt{s}=14$ TeV) and a future 100 TeV proton–proton collider, with particular emphasis on the latter. Assuming a vanishing...

"IHEP-USTC site is responsible for producing 44% of modules on HGTD. The IHEP-USTC site does module assembly through an automated Gantry System equipped with a vision system, glue dispenser, vacuum plates, and dedicated tools for precise pick-and-place of module components, hybrids, and module flexes.

An automatic workflow is being developed to efficiently handle the high module yield...

A search for the Higgs boson decay to a $Z$ boson and a photon in the $\ell\ell\gamma$ ($\ell = e, \mu$) final state is performed using $pp$ collisions at $\sqrt{s} = 13.6$TeV recorded with the ATLAS detector at the Large Hadron Collider during 2022--2024, corresponding to an integrated luminosity of 165fb$^{-1}$. The signal yield, normalised to the Standard Model prediction, is measured to be...

"A search for the rare decays $B_{(s)}^0\to J/\psi\gamma$ is performed with proton-proton collision data collected by the LHCb experiment, corresponding to integrated luminosities of 3 $\mathrm{fb}^{−1}$ at centre-of-mass energies of 7 and 8 TeV, and 6 $\mathrm{fb}^{−1}$ at 13 TeV. Assuming no
contribution from $B^0\to J/\psi\gamma$ decay, an upper limit is set on the branching fraction...

"The study of charm-quark production and hadronisation provides crucial insights into the mechanisms of Quantum Chromodynamics (QCD) at the interface between the perturbative and non-perturbative regimes. Differential measurements of jets containing charm hadrons further shed light on QCD processes such as parton-shower evolution and hadronisation. In particular, angular correlations between...

We study a generalized NMSSM in which a gauge singlet connects the MSSM $\mu$ problem to neutrino masses from the type-II seesaw. Its vacuum expectation value contributes to $\mu_{\rm eff}$ and generates the supersymmetric mass of a vectorlike electroweak triplet pair. Integrating out the triplets yields the Weinberg operator, while their gauge charges admit a possible messenger...

We present a study of next-to-leading-order (NLO) QCD corrections to double heavy-quarkonium hadroproduction within the nonrelativistic QCD factorization framework. We focus on the color-singlet (CS) contribution to prompt (J/\psi)-pair production at the CERN Large Hadron Collider and compare our predictions with measurements from the LHCb, CMS, and ATLAS collaborations. The NLO CS...

The High-Granularity Timing Detector (HGTD) is a key component of the ATLAS Phase-II upgrade for the HL-LHC. It employs Low-Gain Avalanche Detector (LGAD) sensors to provide precise timing measurement and mitigate pile-up effects in the forward detector region. This talk summarizes the latest production and quality control status of ATLAS HGTD LGAD sensors, including sensor batch...

"arxiv:2608.03369 (submitted to JHEP)
A measurement of the $H \to \gamma^*\gamma$ process in the $\ell\ell\gamma$ final state is performed using proton--proton collision data recorded with the ATLAS detector at $\sqrt{s} = 13.6$ TeV during the years 2022--2024, corresponding to an integrated luminosity of 164 fb$^{-1}$. A simultaneous unbinned maximum-likelihood fit to the reconstructed...

Tencent/VooV Meeting: 817-821-557

"This letter presents a combination of searches for Higgs boson pair (HH) production
performed by the ATLAS and CMS Collaborations using proton–proton collision data
sets recorded at √s = 13 TeV at the LHC Run 2, corresponding to integrated luminosi-
ties ranging between 126 and 140 fb−1. The upper limit at the 95% confidence level
on the total HH production cross section corresponds to...

We investigate the production of open-flavor hadrons in pp collisions at a CM energy of 5.02 TeV using the parton and hadron cascade model PACIAE. We introduce string tension enhancement mechanisms towards dipole and double-junction strings in the string fragmentation hadronization model. The transverse momentum spectra and the baryon-to-meson ratios of light and heavy open-flavor hadrons are...

The latest results of search for ttbar resonances at CMS will be presented

Tencent/VooV Meeting: 952-527-429

The High-Granularity Timing Detector (HGTD) is a key component of the ATLAS Phase-II upgrade for the HL-LHC, employing Low-Gain Avalanche Detector (LGAD) sensors to provide precise timing and mitigate pile-up in the forward region. Each LGAD module is mounted on a dedicated Support Unit (SU) — 48 types of pure-PEEK structures, of which 839 are being fabricated. The SUs must hold the modules in...

"Higgs boson pair production (HH) probes the Higgs boson self-coupling and the structure of the Higgs potential. This talk presents the ATLAS search for non-resonant HH production in the bbττ final state using the full Run 2 dataset and a partial Run 3 dataset.
The measured signal strength relative to the Standard Model (SM) prediction is $\mu_{HH}$ = 2.6, with uncertainties of +1.4 and −1.0,...

The Standard Model Effective Field Theory (SMEFT) offers a model-independent framework to probe new physics. However, conventional "one-operator-at-a-time" analyses often overlook crucial correlations, while global fits face challenges in providing transparent physical interpretations of high-dimensional parameter spaces. We propose an optimized EFT strategy that identifies leading and...

腾讯会议：780-721-666

The latest results of Heavy resonance X-> bbgg at CMS will be presented.

腾讯会议：501-800-566

We investigate the internal structure of the newly observed charm-strange meson $D_{s1}(2933)^{+}$, which was reported by the LHCb Collaboration in $B^{0}\to D^{+}D^{-}K^{+}\pi^{-}$, in the quark model by treating it as the $2P_{1}$ state of the $c\bar{s}$ system. The coupled-channel corrections to the ${}^{1}P_1$--${}^{3}P_1$ mass matrix are evaluated through the two-point self-energy loops...

Non-resonant HH → bbtautau with Run3 data at CMS, will be presented

Tencent/VooV Meeting：620-331-282

格点 QCD 为研究强相互作用非微扰性质提供了第一性原理方法，但从物理问题到实际数值计算通常涉及关联函数构造、Wick 收缩、传播子求解、程序实现以及高性能计算等一系列复杂流程。LQCDMaster 面向这一问题，构建了融合大语言模型、格点 QCD 专业知识与确定性计算工具的科研智能体，将自然语言研究需求自动转化为物理方案、可执行的 PyQUDA 程序和 HPC 计算任务，并对关键步骤进行验证。本报告将介绍 LQCDMaster 的基本架构及其在强子谱、多强子体系、形状因子和非定域关联函数等问题中的应用，并讨论科研智能体如何降低格点 QCD 的工程门槛，推动从 AI Agent 向自主科学研究工作流的发展。

"Searching for Higgs pair production and precisely measuring the Higgs self-coupling modifier $\kappa_\lambda$ are among the key milestones for the next stage of the LHC programme. In Ref.[1], we demonstrated that, in the HH→4b channel, a “jet-free” approach can achieve a surprisingly large >5× improvement in sensitivity, potentially bringing observation-level sensitivity to Higgs pair...

"The High-Granularity Timing Detector (HGTD) is an important upgrade of the ATLAS detector for the HL-LHC, providing precise timing information in the forward region to reduce the impact of high pileup. A reliable timing calibration is therefore essential for stable detector performance.
In this study, different calibration granularities are investigated using simulated samples, from large...

"We study thermal leptogenesis in three predictive type-I seesaw models in which the neutrino Dirac mass matrix is equal to the mass matrix of up-type quarks, or down-type quarks, or charged leptons. In this framework, the seesaw relation permits a full reconstruction of the heavy right-handed neutrino mass matrix from low-energy neutrino
parameters, which greatly reduces the parameter...

Search for nonresonant HH→bbgg in Run 3 at CMS, will be presented

The traditional quark model accounts for the existence of baryons, such as protons and neutrons, which consist of three quarks, as well as mesons, composed of a quark–antiquark pair. Only recently has substantial evidence started to accumulate for exotic states composed of four or five quarks and antiquarks. The exact nature of their internal structure remains uncertain. Here we report the...

"Semi-visible jets (SVJs) provide a characteristic collider signature of strongly interacting dark sectors, in which the key model parameter rinv controls the fraction of dark hadrons decaying to dark matter candidates. Dedicated searches for SVJs have been performed at the LHC. Both CMS and ATLAS have probed resonant s-channel SVJ production and set constraints on the corresponding signal...

The study of non-resonant Higgs boson pair (HH) production provides direct sensitivity to the Higgs boson self-interaction. This talk presents an ongoing search for non-resonant HH production in multilepton final states using 140fb^-1 of ATLAS Run 2 data and 159fb^-1 of partial Run 3 data collected up to 2024. The analysis combines several complementary final states containing light leptons...

Search for X-> bbtautau at CMS, will be presented

Tencent/VooV Meeting：501-800-566

"We investigate the $|V_{cb}|$ determinations from exclusive semi-leptonic $\bar{B} \to D^{(*)}\ell\bar\nu$ decays, together with comprehensive Bayesian fit analyses of the $\bar{B} \to D^{(*)}$ transition form-factors, by taking into account recent updates of experimental distribution data and theoretical evaluations. Several commonly adopted form-factor parameterizations, including BSZ, BGL...

Severe pileup exists at the High-Luminosity LHC. The ETL of CMS MTD adopts LGAD sensors to deliver high-precision timing. Reliable characterization of LGAD sensors is necessary for the ETL upgrade. At USTC, we have built a complete LGAD characterization platform based on probe-station I-V and C-V measurements, equipped with a 16×16 probe card and custom switch matrix board, capable of I-V and...

"The Standard Model (SM) describes the known elementary particles with high precision, yet it does not explain the origin of the electroweak scale, incorporate gravity, or provide a dark-matter candidate — shortcomings motivating the search for physics beyond the Standard Model (BSM). Supersymmetry (SUSY) is a leading BSM candidate; in its gauge-mediated supersymmetry breaking (GMSB) branch,...

"Scotogenic 模型在单圈水平上辐射产生中微子质量，并提供由 Z₂ 对称性保证稳定的暗物质候选粒子。该框架特有的小 Yukawa 耦合和小质量劈裂，使次轻的 Z₂ 奇态粒子自然成为长寿命粒子，其信号大多落在现有 LHC 搜寻的接受度之外。本报告介绍三种互补的搜寻策略，分别针对 scotogenic 质谱的不同区域。

(i) 在压缩质谱区（ΔM = m(η±) − m(N₁) ≈ 8–20 GeV），带电惰性标量衰变为单个软的位移轻子。专门设计的信号区要求轻子 pT > 5 GeV、|d₀| ∈ [5, 300] mm、b 喷注否决、横向丢失动量大于 200 GeV。在 Run 3 的 300 fb⁻¹ 数据下，估计的标准模型本底为 66 ± 24 个事例。九个基准点中有八个超过预期的 95% 置信水平排除阈值，即 cτ = 10–300 mm、m(η±) =...

This presentation provides an overview of the Transformer-based GN3X boosted jet tagger in ATLAS, focusing on its performance and calibration for bb, cc, and tautau identification.

We identify a new spin--flavor entanglement structure in $\Lambda_b\to\Lambda D$ decays, formed by the correlation between the $\Lambda$ spin and the $D$ flavor states ($D=D^0,\overline D^0,D_1,D_2$). The entanglement information is encoded in the decay rates and Lee--Yang parameters of the four neutral-$D$ modes. We then show that the same spin--flavor structure provides a new method to...

The High Luminosity LHC (HL-LHC) phase will provide unprecedented opportunities for precision measurements and searches for rare processes, while posing significant challenges due to the high radiation environment and up to 200 simultaneous interactions per bunch crossing. To mitigate the impact of pile-up, the CMS experiment will install the MIP Timing Detector (MTD), providing...

Searches for low-mass dijet resonances at the LHC use hard initial-state radiation, either an isolated photon or a jet, to reach masses below the unprescaled trigger threshold. As the luminosity rises, more collisions are produced, so the unprescaled trigger has to raise its threshold to stay within the limited bandwidth and storage. Even with initial-state radiation, the low-mass region is...

"A search for nonresonant triple Higgs boson (HHH) production in the final state
with six bottom quarks is performed using proton-proton collisions at √s = 13 TeV
corresponding to an integrated luminosity of 138 fb−1 recorded by the CMS experi-
ment. No significant excess of events over the background prediction is seen. Ob-
served (expected) 95% confidence level upper limits on the signal...

We investigate electroweak corrections to gluon-fusion Higgs pair production in Higgs Effective Field Theory, allowing independent variations of the cubic and quartic self-couplings. We determine the complete self-coupling-dependent NLO cross-section coefficients and the NNLO terms quadratic in the quartic coupling. Combining these results with vector-boson-fusion predictions, we examine their...

IHEP Remote Operation Center Report.

Observation of charged lepton flavor violation would constitute unambiguous evidence for physics beyond the Standard Model (SM). We identify a previously unexplored same-sign dimuon signature in electron--photon collisions, $\gamma e^- \to e^+\mu^-\mu^-$, mediated by an axionlike particle (ALP) with flavor-violating $e$--$\mu$ couplings. The absence of irreducible SM backgrounds and the...

We present SWDSIM, a fast-simulation approach for modelling detector-resolution effects using the Sliced Wasserstein Distance (SWD). The method learns the mapping from generator-level to fully simulated kinematics using existing simulated samples and can be transferred to other decay channels with same final-state. We will introduce the method and its implementation, present validation studies...

Identifying Lorentz-boosted Higgs bosons through their hadronic decay products provides a powerful approach to studying Higgs interactions and searching for new physics at the LHC. This talk presents recent CMS developments in transformer-based jet tagging and their applications to Higgs physics. The Particle Transformer exploits particle-level information and correlations to identify complex,...

"We study the nonleptonic weak decays of doubly charmed baryons (Bcc) into singly charmed baryons (Bc) and vector mesons (V), denoted as Bcc → BcV. The short-distance contributions are calculated within the naive factorization hypothesis, while the long-distance final-state interaction effects are modeled via hadronic triangle diagrams. Unlike previous approaches, which compute only the...

Tencent/VooV Meeting：620-331-282

This paper presents a search for semi-visible Higgs boson decays in final states with a photon ($\gamma$) and missing transverse momentum ($p_T^{miss}$). The analysis is optimised for the gluon-gluon fusion production channel and exploits a novel trigger deployed in 2023, with reduced thresholds down to 50 GeV on the photon transverse momentum ($p_T^\gamma$)...

"We investigate the polarization correlation of back-to-back gluon pairs in unpolarized $pp$ collisions and compute their density matrix. For gluon pairs produced through $q\bar{q}$ annihilation, the linear polarization correlation is sizable, even reaching unity when the final-state gluons are emitted perpendicular to the beam direction in the $q\bar{q}$ rest frame. Combining with the fact...

腾讯会议：381-100-004

A collection of thirteen ATLAS searches for supersymmetry (SUSY) models, optimized for R-parity-conserving (RPC) a nd R-parity-violating (RPV) SUSY, are reinterpreted in SUSY models with variable RPV coupling strength, which determines whether the lightest supersymmetric particle decays promptly or is long-lived. The dataset corresponds to an integrated luminosity of 140 fb-1 proton-proton...

Fragmentation functions (FFs) and parton density functions (PDFs) are crucial non-perturbative inputs in quantum chromodynamics (QCD) for predicting cross sections of high-energy scattering processes. In this talk, we present progress on global fits of collinear FFs and helicity PDFs by the Non-perturbative Physics Collaboration (NPC). Our analyses incorporate a comprehensive set of precision...

Experimental analyses of the semileptonic decays $ B \to D^{(*)} \ell \bar{\nu}$ typically rely on the assumption that the missing energy originates from a massless neutrino, as predicted by the Standard Model. However, this assumption may not hold in scenarios where the invisible final-state particle is instead massive, such as a sterile neutrino or a dark-sector fermion. In this work, we...

This report presents the status of HGCal silicon module mass production at the IHEP MAC, as part of the CMS High-Granularity Endcap Calorimeter upgrade for the HL-LHC. The IHEP MAC, one of six global silicon module assembly centers, focuses on low-density (LD) full silicon modules, with an expected workload of around 5,000 modules. The production chain includes hexaboard taping, electronic...

This report presents the light guide system for the LHCb ECAL Upgrade, focusing on its design and performance, as well as the upgrade schedule.

Searches for the production of $\tau$-sleptons ($\tilde{\tau}$), charginos ($\tilde{\chi}_1^\pm$), and neutralinos ($\tilde{\chi}_2^0$) in events with at least one hadronically decaying $\tau$-lepton are presented, targeting compressed mass spectra scenarios. To enhance sensitivity to compressed mass spectra, production modes with initial-state radiation (ISR) jets are considered. The searches...

We study the spacelike-collinear limit of gauge-theory scattering amplitudes using the Method of Regions. The corresponding splitting amplitude violates strict collinear factorisation through its dependence on the non-collinear partons. While the associated colour dependence has long been known, starting at two loops the splitting amplitude also acquires dependence on their kinematics. We show...

Tetraquarks are an important subject in hadronic physics. In this talk, we first present our study of $T_{c\bar{s}0}^{*}(2900)$. Based on the hidden local gauge symmetry, we construct an effective Lagrangian containing the light-flavor diquark–diquark-meson vertices. By solving the Bethe–Salpeter equation, we find that $T_{c\bar{s}0}^{*}(2900)$ can be interpreted as a mixture of hadronic...

Mass production of bundler and light guide for the LHCb LS3 ECAL upgrade

Square root metric geometry has extra U(4')×U(4)-bundle, then a Pati-Salam model in curved space-time and Einstein-Cartan gravity theory can be constructed based on self-parallel transport principle. A fermions representation scheme is suggested, three families quarks and leptons find the place in the fermions representation scheme; flavor mixing matrices, CKM (Cabibbo-Kobayashi-Maskawa) and...

"Two-particle correlations provide a useful probe of particle production dynamics in high-energy nuclear collisions. The ALICE experiment has measured a variety of azimuthal correlation patterns between identified baryons and mesons in different collision systems. These measurements have been discussed in connection with the mechanisms of baryon production, local conservation laws, and...

"The precision measurement of the W boson mass with the ATLAS experiment represents a meticulous test of the Standard Model of particle physics. During the LHC Run 2, pileup reached a peak of 60 interactions per bunch-crossing; this analysis, however, uses low-pileup data to improve the estimation of the transverse recoil, essential for an accurate MET measurement. This W boson mass...

This talk presents a hadronic rescattering approach to final-state interactions (FSIs), with emphasis on the two-body nonleptonic decays (\Lambda_b^0\to pK^-,p\pi^-,p\rho^-,pK^{*-}). Short-distance weak amplitudes are evaluated in naive factorization. Long-distance contributions arise from intermediate hadrons rescattering into the final state through hadron exchange. Strong vertices are...

We investigate upward-going muons on Earth and the Moon to explore their flux characteristics, production mechanisms, and potential applications. On the Moon, upward-going hadrons escaping the lunar regolith can decay in flight, producing muons detectable by surface or orbital instruments. Using Monte Carlo simulations, we study their energy spectra, angular distributions, and integrated...

The measurement of the Z boson mass with the ATLAS detector provides a stringent test of the Standard Model, such as QCD and electroweak physics, at a new energy frontier.

Achieving a high-precision measurement of the Z boson mass using the dimuon final state requires an accurate calibration of the muon transverse momentum scale.

In this analysis, the calibration is perfomerd using the...

"The LHCb Upgrade II will operate at instantaneous luminosities up to 1.5×10³⁴ cm⁻²s⁻¹ and collect about 300 fb⁻¹ during the HL-LHC era. In the central region of the electromagnetic calorimeter this means MGy-level accumulated dose, more than 50 pile-up interactions per bunch crossing, and the need to keep an energy resolution of about 10%/√E ⊕ 1% while adding timing at the level of O(10 ps)....

Axionic dark matter can form structures known as miniclusters that host an axion star at their center. The axion star feeds on the host, and the axion star mass may grow beyond its stability limit, leading to a potential bosenova. Since a dilute axion star has a stable mass limit only when self-interaction is considered, we include axion self-interaction effects in this paper, and specify the...

This talk presents an observation of the photon-fusion production of W boson pairs using the CMS detector at the LHC. The total cross section of the $W^+W^-$ production in photon fusion is measured using proton-proton collision data with an integrated luminosity of 138$f^{-1}$ collected with the CMS detector in 2016--2018 at a center-of-mass energy of $\sqrt{s}$=13 TeV and is in agreement with...

This talk presents the first observation of the $B_{s0}^{*}(5700)^0$ state using the LHCb Run 1 and Run 2 data sample, revealing an unexpectedly light and narrow beauty-strange resonance in the $B_s^0\pi^0$ mass spectrum.

The LHCb Upgrade II aims to operate at an instantaneous luminosity nearly an order of magnitude higher than that of Upgrade I, placing significantly greater demands on detector performance and reconstruction capabilities. To meet these challenges, a new electromagnetic calorimeter, known as PicoCal, is being developed with substantial improvements in both hardware and software. The redesigned...

The electromagnetic calorimeter (ECAL) of the LHCb experiment in Upgrade II, also known as PicoCal, features the new ability of time measurement. It is necessary that the timing performance of PicoCal is precisely reflected in the LHCb simulation program. The recent progress on the development of PicoCal timing simulation, alongside with the performance studies of the algorithms, are presented...

I will talk about the matching of $B$-meson QCD LCDA onto HQET LCDA and the power correction.

"The enhancement of weak signals and the detection of hypothetical particles facilitated by quantum amplification are crucial for advancing fundamental physics and its practical applications. Recently, it was experimentally observed that a magnetic field can be amplified by using nuclear spins under Markovian noise [H. Su et al., New constraints on axion-mediated spin interactions using...

We present a search for the electroweak production of two Z bosons in association with two jets at a center-of-mass energy of 13 TeV. The analysis focuses on the decay channel with two charged leptons (electrons or muons) and two neutrinos, which features a relatively large branching fraction but also suffers from sizable backgrounds and incomplete event reconstruction due to the presence of...

Physics benchmark studies of $B_s \to \phi \gamma$ channel for LHCb ECAL Upgrade II

We propose a new class of dark-shower signatures in Standard Model extensions featuring Hidden Valleys or dark sectors coupled through an s-channel mediator. In this framework, unstable dark pions appear as long-lived particles (LLPs), with their lifetimes treated as free parameters. The resulting signatures, which we term semi-visible emerging jets (SVEJ), continuously interpolate between the...

This talk presents the mass production of tungsten absorbers for the LHCb ECAL Upgrade II, covering the 3D printing production process, quality control, current status, and performance verification for the requirements.

"IHEP-CC is a crucial partner in the global HEP computing landscape, providing robust and expanding computational and storage resources for current and future scientific discoveries.
We will intrduce the overview of the IHEP Computing Center(IHEPCC) and the grid sites running status and accounting in IHEPCC."

We present an on-shell constructive formalism for massive collinear splitting functions based on Soper-Weinberg collinear spinors, whose transformation properties follow from a light-front Galilean subgroup of the Poincaré group. The leading-order structures are matched to massless three-point amplitudes, while an additional Higgs momentum along an anti-collinear direction probes the...

Optimizing scintillating materials based on Large-Scale AI Models

We propose an analyticity bootstrap method to determine the reduction of Feynman integrals (FIs). The key observation is that, at any kinematic point, a dimensionally regularized FI possesses a Taylor expansion region (analytic region), and the finiteness of the Taylor region strongly constrains the integral reduction coefficients, which are rational functions of the kinematic variables. By...

During Long Shutdown 3 (LS3) of the LHC, the innermost modules of the LHCb electromagnetic calorimeter (ECAL) will be replaced with SpaCal modules to improve performance in Run 4. Pre-series production of SpaCal-Pb modules has started in 2026. The China group has contributed to module assembly and the development of supporting facilities. This presentation will provide an update on the status...

Femtoscopy provides a unique laboratory for studying hadron-hadron interactions via two-particle correlation functions (CFs), yet its predictive power is fundamentally limited by the unknown emission source $\mathcal{S}(r)$. We present a model-independent reconstruction of the proton-proton source by formulating the Koonin-Pratt equation as an inverse problem, stabilized through Tikhonov...

腾讯会议：902-323-809

The USTC computing facility for particle physics groups integrates both CPU and GPU resources, including more than 3,200 CPU cores and over 500,000 CUDA cores. It features four Lustre file systems with a combined disk capacity of over 6 PB. This facility provides critical computing support for research groups working on the LHC, BESIII, STCF, and other experiments.

Run 3 has brought new challenges regarding data storage and processing at LHCb. In recent years, the Offline Distributed Computing team, together with the computing centres supporting the experiment, has implemented solutions that made it possible to meet these challenges and has entered a period of preparation for the upcoming HL-LHC era. This presentation will summarise the current status of...

Tencent/Voov Meeting: 552-247-757

Grid digital certificates form the foundation of identity in distributed high-energy physics computing. Chinese users of the LHC experiments (ATLAS, CMS, LHCb), as well as grid computing for JUNO and Belle II, rely on certificates issued by the IHEP Grid Certification Authority (IHEP CA), a regional CA within the IGTF trust framework.

The legacy IHEP CA, built on OpenCA, has been in service...

腾讯会议：902-323-809

腾讯会议：552-247-757

Multi-boson processes are among the most sensitive tests of the Standard Model. Theoretical predictions for these interactions are extremely precise, so even small discrepancies could point to new physics phenomena. Triboson processes are the rarest of this kind, offering unique sensitivity to probe quartic boson couplings and complementarity with Higgs physics and searches beyond the Standard...

We propose LAYCAST, a cavern surface tracker for LLP searches at future colliders, such as CEPC/FCC-ee, covering four signal scenarios: light scalars, heavy neutral leptons, RPV neutralinos and axion-like particles. We evaluate sensitivity corrections under realistic geometric conditions and focus on estimating K_L backgrounds. Geometric effects are small, and backgrounds can be effectively...

Peking University actively contributes to the CMS GEM upgrade for the CMS muon system. This report presents the latest progress of the ME0 project, including module production and validation, stack assembly and performance tests, and the production and CERN acceptance testing of ME0 GEM electronics boards (GEBs).

腾讯会议：902-323-809

At the end of 2018, after the completion of the LHC Phase II operation, the European Centre for Nuclear (CERN) started the HL-LHC project. In this upgrade, the particles passed through the dipole magnet needed to be corrected again in both the horizontal and vertical directions with a double-aperture orbital corrector magnet. The magnet adopts a new type of Canted-Cosine-Theta (CCT) structure,...

Thermalization is a central topic in non-equilibrium physics. Ultra-relativistic heavy-ion collisions (URHICs) provide the only experimental window into the thermalization of quantum chromodynamic (QCD) matter, the quark-gluon plasma (QGP). In this talk, I will review recent progress in understanding QCD thermalization from a phenomenological perspective, covering promising theoretical...

In this talk, I will present the latest results on CP violation in B-hadron decays from LHCb.

Femtoscopy has long been a powerful tool in imaging particle emission source in high energy collisions. In 3D femto, source sizes are extracted in 3 directions: out, side, and long according to particle pair momentum. Event plane dependent femto, or azimuthal femto further cut correlation function into slices based on pair angle wrt event plane, making it possible to extract final eccentricity...

This paper presents a search for semi-visible Higgs boson decays in final states with a photon ($\gamma$) and missing transverse momentum ($p_T^{miss}$). The analysis is optimised for the gluon-gluon fusion production channel and exploits a novel trigger deployed in 2023, with reduced thresholds down to 50 GeV on the photon transverse momentum ($p_T^\gamma$) and 70 GeV on the $p_T^{miss}$, in...

Z+Jpsi associated production in forward region