CMS探测器是大型强子对撞机LHC上的一个通用探测器。该报告将介绍CMS中国组在近一年内在探测器升级硬件、物理分析、探测器性能、算法等方面取得的新结果和新进展。
Colliders, as powerful instruments at the energy frontier, provide unique opportunities to advance particle physics. They enable both direct searches for new resonances and indirect probes of physics beyond the Standard Model through precision measurements. In this talk, I will use sterile neutrino physics as a case study to illustrate these capabilities. I will present their discovery...
The phenomenon of CP violation is a necessary ingredient for explaining the observed matter-antimatter asymmetry of the universe. The LHCb experiment has a rich program of searching for and measuring CP-violating observables in the heavy quark sector. This presentation reviews recent highlights, including ultra-precise measurements of the CKM angle γ from B→DK decays, studies of CP violation...
A search for resonances in top quark pair ($t\bar{t}$) production in final states with two charged leptons and multiple jets is presented, based on proton-proton collision data collected by the ATLAS and CMS experiment at the CERN LHC at $\sqrt{s}$ = 13 TeV. A significant excess of events is observed near the kinematic $t\bar{t}$ threshold compared to the nonresonant production predicted by...
Multiple Parton Interactions (MPI) represent an essential feature of hadron–hadron collisions, adding significant richness to the event structure observed in high-energy physics. These processes occur when several partons from each colliding hadron undergo interactions within the same collision. Among the MPI mechanisms, Double Parton Scattering (DPS) stands out as the most straightforward...
This report will present the overall development of the High-Granularity Timing Detector (HGTD) for the ATLAS experiment at the Large Hadron Collider (LHC) by the China team.
The precise study of Higgs boson production is essential both for testing the Standard Model and for probing the Higgs self-coupling through di-Higgs processes. Last year, ATLAS presented a combination of Higgs-pair (HH) searches, setting the most stringent limits to date on the Higgs self-coupling. Building on this, we present new results from single-Higgs (H) analyses obtained this year,...
This talk will summarize recent progress of the CEPC accelerator studies, in particular the R&D efforts in the Phase of CEPC Engineering Design Report.
ATLAS high granularity timing detector Module assembly and loading
本分析在核子对撞质心能量$\sqrt{s_{\textrm{NN}}}=5.36$ TeV下，对铅-铅（$Pb+Pb$）超擦边碰撞（UPC）中相干$J/\psi\to\mu^+ \mu^-$产生过程的测量。该测量基于LHC于在2023年采集、积分亮度为$76.5~\text{$\mu$$b$}^{-1}$的数据样本。分析采用了基于ATLAS跃迁辐射探测器的专用径迹敏感触发器来筛选$J/\psi$候选事例。由于感兴趣的缪子横动量范围使得标准的缪子重建与识别算法无法被使用，本分析直接依据内部探测器的缪子径迹来重建双缪子不变质量。我们测量了微分截面随$J/\psi$快度的变化，并将其与理论预言进行了比较。此外，在将结果外推至质心能量$\sqrt{s_{\textrm{NN}}}=5.02$...
The talk with present a study of the CP properties of the Higgs boson produced through vector-boson fusion mode. The analysis is using the full Run2 data collected by the ATLAS experiment at the LHC. The talk will highlight the motivation for this study, the main analysis parts like the background estimation and the signal categorisation, and finally the results will be shown. Results are...
The High Luminosity LHC (HL-LHC) phase, scheduled to start in 2030 and deliver 3000 fb-1 in 10 years, will offer unique potential for precision measurements and searches for rare processes. However, it will also pose significant challenges for the detectors due to extremely high radiation levels and the large number of simultaneous interactions per bunch crossing (up to 200). To mitigate...
A test of CP invariance in Higgs boson production via vector-boson fusion has been performed in the H → γγ channel using 165 fb-1 ATLAS Run-3 pp collision data at $\sqrt{s}$=13.6 TeV. The optimal observable is used to probe the CP structure of interactions between the Higgs boson and electroweak gauge bosons, as described by an effective field theory. Expected constraints on the...
Higgs boson plays a fundamental role in Standard Model. The precise measurement of Higgs couplings can help us have a better understanding of SM and explore potential new physics beyond it. The combination method can give us a higher precision and sensitivity, which is an essential experimental way. In this talk, I will present combined measurements of Higgs boson production and decay using up...
I will give a short summary on the representative topics of neutrino physics at the future high energy lepton collider CEPC.
Quarkonium production serves as a vital testing ground for quantum chromodynamics (QCD), offering critical insights into both perturbative and nonperturbative dynamics.In the nonrelativistic QCD (NRQCD) factorization framework, inclusive production cross sections of quarkonia are expressed as products of perturbatively calculable short-distance coefficients (SDCs) and nonperturbative...
The High Granularity Timing Detector (HGTD) will be installed in the ATLAS experiment as part of the Phase-II upgrade for the High Luminosity-Large Hadron Collider (HL-LHC). It will mitigate pile-up effects in the forward region, and measure per bunch luminosity. The design of HGTD is based on Low Gain Avalanche Detector (LGAD) sensors. This talk presents the results of beam-test campaigns...
CEPC, as a future electroweak, Higgs, and top factory, has great but often overlooked potentials for flavor physics studies. The Tera-Z mode of CEPC will generate O(10^12) Z bosons decaying on-shell, giving rise to a considerable collection of tau leptons and heavy flavored hadrons. Higher energy modes of CEPC also contribute to flavor physics in unique ways.
We discuss the most recent results obtained by the CMS Collaboration on properties of the Higgs boson (mass, natural width, couplings, ..) using diphoton (γγ) decays.
The first part of this report will give a summary of the MTD BTL testbeam results at CERN during 9.10-9.24. The second part will be the low temperature test for the whole tray at TIF CERN.
ALICE, heavy flavor, spin polarization, femtoscopy, momentum correlations
Baryonic two-body $B$ mesons decays have been measured experimentally for some time, which provides an excellent ground for studying the QCD of baryonic $B$ decays. In this work, we investigate the two-body doubly-charmed baryonic $B$ decays in the perturbative QCD (PQCD) approach including higher twist contributions to the light-cone distribution amplitudes (LCDAs). The charmed baryon LCDAs...
A reliable determination of the Higgs production mechanism in hadron collider experiments is essential in the program of the measurements of the Higgs couplings. We employ weak supervision, CWoLa in particular, to train deep neural networks using real data of the diphoton events, in the hope of reducing biases resulting from Monte Carlo simulations. Models based on the convolutional neural...
In heavy-ion collisions, high-$p_{\rm T}$ partons traverse the hot and dense QCD medium, losing energy through induced gluon radiation and elastic scattering. This leads to modifications of jet structure compared to jets produced in vacuum. Measurements of the properties of the medium generated in Pb--Pb collisions at the LHC require reference measurements from more elementary pp and p--Pb...
The Higgs boson’s decay to a pair of muons provides a direct probe of its Yukawa coupling to second-generation fermions. In this talk, I will presents the newest results from the ATLAS experiment based on proton-proton collision data collected in LHC Run 3 during 2022~2024, and the combination with the Run 2 results, incorporating several improvements. This measurement significantly enhance...
The development of next-generation particle detectors capable of precise 4D tracking is crucial for future high-energy physics experiments. AC-LGAD have emerged as a leading technology to achieve excellent spatial and temporal resolution simultaneously. This report details the successful development and characterization of a new batch of AC-LGAD detectors fabricated by the University of...
We researched the two body non-leptonic B decays to radilly excited D mesons under the covariant light-front quark model.
SMEFT and HEFT are two popular EFTs in searching for new physics. We report a comparison between them in predictions for Higgs boson pair production.
Heavy quarks (charm and beauty) are useful probes for investigating the properties of the quark-gluon plasma (QGP) generated in ultra-relativistic heavy-ion collisions. Their participation in the collective motion of the medium can be assessed by measuring the charm-hadron elliptic-flow coefficient , originating from the initial-state spatial asymmetry in non-central heavy-ion collisions....
我们对多轻子末态下的 ttH 产生截面进行了精密测量，并通过控制 ttW 背景提高灵敏度。在标准模型中，tt̄H 的分支比小、信号稀少，且与 tt̄W/tt̄Z 背景强相关，使得信号提取十分具有挑战性。
本分析定义了六类按轻子数与类型划分的末态，并采用全局拟合同时约束信号与背景。测得 tt̄H 产生截面为 321⁺¹⁰²₋₉₉ fb，与 SM 预言一致，显著性为 观测 3.3σ、期望 5.3σ。在 STXS 框架下完成了随希格斯横动量的微分测量；同时进行的 tt̄H/tHq 联合分析得到信号强度：μ(tt̄H)=0.59⁺⁰·²²₋₀·²⁰，μ(tHq)=8.9⁺⁵·⁵₋₅·₀。CP 性质研究结果支持 SM 的 CP-even 预测，并以 1.8σ 排除了纯 CP-odd 假设。
与之前...
A comprehensive study of triple Higgs boson production in the $4\tau 2b$ decay final state is performed for the first time at a future 100 TeV hadron collider. The analysis incorporates modified Higgs self-couplings via trilinear Higgs self-coupling $c_3$ and quartic Higgs self-coupling $d_4$, enabling for a model-independent investigation of potential new physics effects. Higgs bosons are...
As the Large Hadron Collider enters the High-Luminosity era, several sub-detectors require major upgrades. The ATLAS High Granularity Timing Detector (HGTD), currently under development for the HL-LHC, is designed to mitigate pile-up levels of up to ~200 simultaneous proton-proton interactions by providing precise timing information in the forward region (roughly 2.4 < |\eta| < 4.0). When...
A search for nonresonant Higgs boson pair production in the $b\bar{b}\gamma\gamma$ channel is performed using $61.9 \mathrm{fb^{-1}}$ of CMS data at $\sqrt{s} = 13.6\,\mathrm{TeV}$. Two analysis strategies are employed. The 2D fit approach yields a 95% CL upper limit of 11.0 (7.3 expected) times the SM prediction, while the 1D approach gives 7.4 (8.7 expected). Constraints on the self-coupling...
Ongoing signal-integrity tests of the flex cable in the UP detector.
The High-Granularity Timing Detector (HGTD) is a key subdetector in the Phase-II upgrade of the High-Luminosity LHC (HL-LHC), playing a crucial role in mitigating pileup. As a critical step in HGTD module production, ASIC probing of ALTIROC-A directly affects subsequent detector module fabrication and assembly. This talk presents the recent progress and results of the HGTD ASIC probing...
The production cross section of $\Upsilon(\text{nS})$(n=1,2,3) bottomonium states are measured in proton-proton collisions at $\sqrt{s}=13.6$ TeV using a data sample corresponding to an integrated luminosity of $37.4$ $\text{fb}^{-1}$ collected in 2022 by the CMS experiment. The measurement is performed within dimuon transverse momentum range $20$ $\text{GeV/c}< p_T <200$ $\text{GeV/c}$ and...
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. This paper reports the...
A measurement of the cross section of W boson pair production in photon fusion (γγ → WW) is presented, using an integrated luminosity of 138 fb^−1 of protonproton collision data collected in 2016-2018 at a center-of-mass energy of √s = 13 TeV. Events are selected in the final state with one electron, one muon, and a low multiplicity of tracks associated with the electron-muon production...
I would like to introduce the newly released parton level event generator NNLOJET and it's recent progress. The talk would introduce high precision collision processes available on NNLOJET public release and on-going projects regarding jets production at hadron and lepton colliders at NNLO and N3LO QCD accuracy.
In this talk I will discuss the latest measurements of Higgs boson properties from ATLAS and CMS experiments.
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 ATLAS and CMS. Particular emphasis will be placed on decays with small branching fractions or unconventional final...
We present a general algorithm—the Young Tensor Method—for systematically constructing complete and independent operator bases in effective field theories. This method is applied to a variety of theories, including the Standard Model Effective Field Theory (SMEFT) and low-energy effective field theories. In the process, we introduce the concept of the J-basis, a generalized partial wave basis...
This talk provides a comprehensive overview of the latest electroweak and Standard Model results from the ATLAS and CMS experiments, highlighting a year of significant progress in precision physics.
The exploration of physics beyond the Standard Model (BSM) remains a central goal of the LHC program. Despite the success of the SM, open questions such as the nature of dark matter, the matter–antimatter asymmetry, and the origin of electroweak symmetry breaking suggest the existence of new phenomena at the TeV scale. This presentation summarizes recent highlights from the ATLAS and CMS...
This report presents the latest studies of rare decays conducted by the LHCb experiment. These processes, highly suppressed in the Standard Model, provide a powerful probe for discovering new physics. T
Particle correlations are powerful tools for studying quantum chromodynamics in hadron collisions. In heavy-ion collisions, azimuthal angular correlations probe collective phenomena in hot, dense, nuclear media, such as QGP. The LHCb experiment has the ability to study particle correlations in high-energy hadron collisions at forward rapidity, complementing the results from other experiments....
The ATLAS and CMS experiments are unique drivers of our fundamental understanding of nature at the energy frontier. In this contribution to the update of the European Strategy for Particle Physics, we update the physics reach of these experiments at the High-Luminosity LHC (HL-LHC) in a few key areas where they will dominate the state-of-the-art for decades to come.
The most important task in current particle physics is to precisely test the standard model of particle physics and search for new physics beyond the standard model. With the expansion of experimental exploration fields in new physics and increasing demands for exploration precision, detection technology and experimental methods are constantly facing new challenges. In order to fully utilize...
Based on several features observed in the data collected during Run 1 of the LHC, a
simplified model was proposed in which a heavy scalar, H, decays into a combination of the
SM Higgs boson (h) and a new Higgs-like scalar, S. One implication of this model is the
appearance of excesses in lepton production when the decay S →WW dominates. These
excesses, referred to as the multi-lepton...
This report is about the progress of producing CMS HGCal module in IHEP. The CMS China group will undertake approximately one-fifth of the production tasks for silicon modules and most of the CuW baseplates.
Ref. Phys. Rev. D 111 (2025) 032006, arXiv:2411.02040
A search for the production of three Higgs bosons ($HHH$) in the $b\bar{b}b\bar{b}b\bar{b}$ final state is presented. The search uses $126~\text{fb}^{-1}$ of proton-proton collision data at $\sqrt{s}=13$ TeV collected with the ATLAS detector at the Large Hadron Collider. The analysis targets both non-resonant and resonant production of...
The ALICE Forward Calorimeter (FoCal), to be installed during LS3 for Run 4, targets precision measurements of direct photons at forward rapidity and thus constrains gluon distributions in protons and nuclei. The expected performance of the electromagnetic section (FoCal-E) is assessed with SystemC models of ALPIDE-based pixel layers and SPS H2 beam data. In these studies, occupancy and...
The interplay between the chiral anomaly and strong magnetic or vortical fields generated in off-central heavy-ion collisions is theorized to produce anomalous chiral effects in the quark–gluon plasma, such as the Chiral Magnetic Effect (CME) and the Chiral Vortical Effect (CVE). These effects have been actively studied by several experiments for over a decade as they could shed light on the...
The electromagnetic calorimeter (ECAL) is a key component of the LHCb experiment. To cope with the higher performance requirements imposed by the High-Luminosity LHC (HL-LHC) upgrade, the LHCb ECAL will be upgraded with the new PicoCal design. In the upgrade, novel spaghetti calorimeter (SpaCal) modules will replace the existing Shashlik modules in the central region of the ECAL. These modules...
The discovery of the 125 GeV Standard Model (SM) Higgs boson confirmed electroweak symmetry breaking, yet unresolved issues, including the hierarchy problem, dark matter, and baryon asymmetry, point to new physics with extended scalar sectors. Experimental anomalies around 95 GeV in channels like $b\bar{b}$, $\tau^+\tau^-$, and $\gamma\gamma$ have further sparked interest in a potential...
In non-central heavy-ion collisions, the system’s global angular momentum and local vorticity can induce particle polarization. In particular, polarization along the beam direction may arise from asymmetries in the transverse velocity fields associated with elliptic flow.
In this study, we investigate the polarization of Λ and anti-Λ hyperons using ALICE Run 2 and Run 3 data. Since the...
A search for the production of a Higgs boson in association with two vector bosons via vector boson scattering is presented. The search uses CMS data from proton-proton collisions at $\sqrt{s} = 13\mathrm{TeV}$ collected from 2016 to 2018, corresponding to an integrated luminosity of $138\mathrm{fb^{-1}}$. Selected events are consistent with the presence of two jets originating from vector...
Experiments at the CERN Large Hadron Collider (LHC) have accumulated an unprecedented amount of data corresponding to a large variety of quantum states. Although searching for new particles beyond the Standard Model of particle physics remains a high priority for the LHC program, precision measurements of the physical processes predicted in the Standard Model continue to lead us to a deeper...
The measurement of momentum correlations of identical pions serves as a fundamental tool for probing the space-time properties of a particle-emitting source created in high-energy collisions. Recent experimental results have shown that in pp collisions, the size of the one-dimensional primordial source depends on the transverse mass (mT) of the hadron pairs, following a common scaling behavior...
The study of the nucleon–nucleon (NN), hyperon–nucleon (YN) and hyperon–hyperon (YY) interactions is very important in understanding strong interactions, heavy-ion-collisions and neutron stars. Because of their unstable nature, it is hard to extract interactions between like N-$\Xi$or N-$\Omega$, and high energy collisions offer us a chance to further knowledge of those interactions by...
The LHCb experiment at the Large Hadron Collider (LHC) will undergo a major upgrade of its electromagnetic calorimeter (ECAL) during Long Shutdown 4 (LS4). To optimize the ECAL design and enhance its physics performance, we evaluate the energy/time resolution through simulations of a single prototype based on different setups. Additionally, we evaluate the ECAL's response in different physics...
The dark photon portal, a leading framework for connecting the Standard Model (SM) with dark matter, is extended in this work to include several novel and consequential mechanisms. Beyond the standard kinetic mixing with the hypercharge field, we incorporate mass mixing via an additional Higgs doublet. Furthermore, we introduce a non-Abelian kinetic mixing between the $U(1)_X$ and $SU(2)_L$...
This talk will show recent highlights from ATLAS heavy flavor physics group, such as precise lifetime measurements of B mesons, lifetime from rare decay modes, and the all-charm tetraquark state study.
Ref. Phys. Rev. Lett. 134 (2025) 121801
A search is performed for dark matter particles produced in association with a resonantly produced pair of b-quarks with $30 < m_{bb} < 150$ GeV using 140 $fb^{−1}$ of proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector at the LHC. This signature is expected in extensions of the Standard Model predicting the...
The study of vector meson photoproduction in ultraperipheral collisions (UPCs) offers a powerful probe of gluon dynamics in heavy nuclei. In UPCs, photons can interact with the nucleus coherently (involving the entire nucleus) or incoherently (with individual constituents). While coherent processes provide insight into the average gluon density, incoherent photoproduction is uniquely sensitive...
We investigate the phenomenological prospects of the Two Higgs Doublet and Singlet Scalar Extension (2HDMS) In this work, we perform an exhaustive scan to find representative benchmarks which are consistent with all theoretical and experimental constraints. We focus on the relevant signatures at the LHC，especially about the oblique parameters, and at proposed future lepton colliders...
In the phenomenology study of dark photon, its mass origin is usually not under concern. However, in theory construction its mass is often generated via a dark Higgs mechanism, which leads to the presence of a light (non-decoupled) dark Higgs particle.We study the impact of such a dark Higgs particle in the collider detection of the dark photon. We focus on the process of final state dark...
A search for the resonant production of a heavy scalar X decaying into a Higgs boson and a lighter scalar S, through the process X→S ( → b b) H ( → γ γ) , where the two photons are consistent with the Higgs boson decay, is performed. The search is conducted using integrated luminosities of 140 fb^{−1} and 58.6 fb^{−1} of proton--proton collision data at centre-of-mass energies of 13~TeV and...
The LHCb experiment is preparing for its Upgrade II, during which the instantaneous luminosity will increase by at least a factor of five with respect to Run 3, reaching $1.0×10^{34}cm^{−2}s^{−1}$. The increase in luminosity is very demanding on the detectors. To address these challenges, the current silicon micro-strip Upstream Tracker (UT) will be replaced by a new Upstream Pixel (UP)...
Motivated by the multi-lepton anomalies at the LHC, a sideband analysis of γγ, Zγ, and WW spectra in Run 2 data reveals a narrow resonance
at mS = 152 ±1 GeV with a global significance of 5.3σ, while the ZZ channel remains SM-
like. This pattern is consistent with the Real Higgs Triplet (RHT) model with hypercharge
Y = 0, in which S does not couple to ZZ at tree level. In this framework,...
At the future collider High-Luminosity LHC (HL-LHC), the average number of the simultaneous pp interactions per event, or pile-up (μ), will rise to as much as 200. Resolving the pile-ups using time measurement has already been investigated during LHC Phase-Il Upgrade, e.g. the ATLAS High Granularity Timing Detector (HGTD), which will be placed outside the ATLAS Phase-Il Inner Tracker (ITk)...
The latest results of search for light Higgs bosons in diphoton channel at CMS with Run2 data, are presented. The talks will cover both the low-mass results with the paper published by PLB in January 2025, and the very low-mass results which were released in March 2025.
Quantum Chromodynamics (QCD) is characterized by a phenomenon known as color confinement. When quarks are produced at high-energy colliders like the Large Hadron Collider (LHC), they evolve into observable hadrons through a process called hadronization. In the context of QCD, heavy-flavour production is calculated as a convolution of three independent: the PDFs of the incoming protons, the...
The report mainly introduces the development and testing of CuW baseplates used in the CMS experiment HGCal project, as well as the current progress of production and inspection acceptance of the IHEP designed CuW edition
During the third long shutdown of the LHC (LS3), the LHCb experiment will strengthen and upgrade the central area of the electromagnetic calorimeter (ECAL). In the most central area of the ECAL, a new sampling structure and new calorimeter modules will be used to address the performance degradation of the calorimeter in an extremely high radiation environment. The feature of this new sampling...
The CMS experiment reports the observation of three structures in the 𝐽/𝜓𝐽/𝜓→𝜇+𝜇−𝜇+𝜇− channel — 𝑋(6600), 𝑋(6900), and 𝑋(7100) — each with a significance well above 5𝜎, confirming and extending the earlier Run 2 results. Strong interference effects among them, also above 5𝜎, indicate they share the same quantum numbers. A complementary search in the 𝐽/𝜓𝜓(2𝑆) channel reveals two structures...
Boosted boson jet tagging has been a central focus of both theoretical and experimental high-energy physics research over the past decades, serving as a major driver of innovation at the energy frontier. We leverage the powerful ParT tagger in CMS to search for boosted H->WW and W->cb jets across multiple channels. Public results from the 0L-channel H->WW search will be presented, along with...
In this talk, I will give a theoretical review of recent progress in heavy-flavor physics, focusing on power corrections and QED effects.
The study of hadron spectroscopy serves as a crucial experimental probe into the non-perturbative regime of Quantum Chromodynamics (QCD). By precisely measuring the properties, such as masses, widths and quantum numbers of hadrons, we can deepen the understanding of the strong interaction that binds quarks and gluons into matter. The LHCb experiment, with its unique capabilities in...
With the large dataset and excellent detector performance, CMS has made great progress in heavy flavor results. Recent results include in both (exotic) hadron studies, and CP violation and rare decay studies. The spin-parity of all charm tetraquark candidates observed in J/psiJ/psi mass spectrum is found to be prefer 2++. The X(7100) is first observed in J/psiJ/psi channel, and the X(6900) is...
The ATLAS collaboration has developed a new transformer-based flavour tagging algorithm, GN2. It achieves much better performance compared to the previous taggers. In addition, the development-deployment-calibration cycle has been greatly streamlined so that it can be quickly adapted to new use cases. GN2 has already been used in physics analyses, demonstrating its superior performance. Our...
Understanding the structure of protons and nuclei and their energy distributions evolve is a central goal in both heavy-ion collisions and at the future Electron-Ion Collider (EIC). In this talk, I will first discuss how proton and nuclear shape fluctuations can be extracted within the Color Glass Condensate framework using data from electron–nucleon and electron–nucleus collisions. By...
ALICE topical talk, highlighting recent key progress of correlations and flow studies.
ALICE topic talk: heavy flavor physics
The phenomenological Minimal Supersymmetric Standard Model (pMSSM) scan is an analytical approach designed to reinterpret ATLAS Run 2 searches for supersymmetry (SUSY). This study evaluates and summarizes the sensitivity of ATLAS searches from Run 2 and anticipates possibilities for Run 3, all while incorporating additional constraints from dark matter (DM), flavor physics, electroweak...
The results of the first study of CP violation in the charm sector at the CMS experiment are presented. The analysis is based on the proton-proton collision data with the center-of-mass energy of $\sqrt{s} = 13$ TeV. The measured CP violation parameter is $A_{CP} (D^{0} \to K^{0}{S}K^{0}{S}) = (6.2 \pm 3.1(\text{stat.}) \pm 0.2(\text{syst.})\pm 0.8(A_{CP} (D^{0} \to K^{0}_{S}\pi^{+}\pi^{-}))...
With the increasingly demanding requirements of high luminosity collider HL-LHC, High-Voltage CMOS (HV-CMOS) sensors, featured a deep n-well separating the transistors and the depletion region, had great radiation resistance and enhanced hit density processing capabilities, is considered as the technology option for LHCb upstream pixel tracker in LHCb Upgrade II. To reduce power density and...
This report will summarize the new updates or highlights of Chininese LHC computing recently.
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.
Motivated by the recent CPV observation, we investigate the CPV of b-baryon charmless four body decays under the U-spin symmetry. However, we find that only U-spin symmetry cannot provide effective predictions, particularly for $\Lambda_b$ decays. For giving more useful predictions, we also give a simple dynamic analysis. By counting the power($\lambda=\sqrt{\frac{\Lambda_{QCD}}{m_b}}$) of...
The LHCb Tier2 site has been successfully constructed in Lanzhou University and running smoothly, we will present the recent status of the computing cluster.
Shandong University holds the dedicated cluster for high energy physics, currently with approximately 1,500 CPU cores, 2 PB of storage, and 66 GPU cards, supporting various experiments including BESIII, Belle II, LHC, LHAASO, STCF, and STAR.
In the past year, the heavily utilized system supported over 160 users, executing more than 1 million jobs and consuming over 2 million CPU hours....
The ATLAS experiment will replace its Inner Detector with an all‑silicon ITk for Phase‑2. To ensure production quality of ATLAS18 silicon strip sensors—designed to withstand up to 4000 fb−1—we establish a streamlined QA program built on standardized IV, CV , and CCE measurements at IHEP using a dedicated test piece (Mini sensor for CCE, MD8 for IV/CV). Irradiation tests are included as part...
A search for the charmless baryonic decay $B^+\to \bar{\Lambda} p\bar{p}p$ is performed using proton-proton collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 5.4 $\rm{fb}^{-1}$. The branching fraction for this decay is measured for the first time relative to that of the topologically similar decay $B^+\to J/\psi K^+$, with $J/\psi \to \bar{\Lambda} p...
The USTC computing cluster has been updated this year, including software upgrades and worknode expansion.
Currently, CNIC is responsible for the operation and maintenance of two EGI cloud sites in Mainland China: CSTCLOUD-EGI and CENI. This report will detail the operational status and issues concerning these two sites.
A search for the rare decay $B^+\to\bar{\Lambda} p\mu^+\mu^-$ is performed using proton-proton collision data recorded by the LHCb experiment at a centre-of-mass energy of $\sqrt{s}= 13$ TeV, corresponding to an integrated luminosity of 5.4 fb$^{-1}$. An excess of events is found with respect to the background-only expectation, with a signal significance of 3.5 standard deviations, in the...
This report summarizes ALICE computing activities in China. It introduces the participating institutes and the Chinese ALICE community, outlines the establishment and operation of the Tier-2 site at IHEP Beijing, and highlights its integration into the global computing infrastructure. The report also discusses operational experience and future plans for resource expansion and enhanced support...
The ALICE ITS3 is a novel vertex detector that will replace the innermost layers of ITS2 during Long Shutdown 3 (LS3). Composed of three fully cylindrical layers of wafer-sized 65 nm stitched Monolithic Active Pixel Sensors (MAPS), the ITS3 enables high-resolution tracking of charged particles generated in heavy-ion collisions. As stitched sensor prototypes produced in the ER1 phase of the...
ATLAS Computing
As LHC run3 keep taking more and more data (up to 244 fb-1 for CMS now), the demanding on the coumputing and storage, as well as the usage of GPU for machinelearning studies are keep increasing. in this presentation, I will give the status report of Chinese CMS computing resources, its usage, and feedbacks from users.
In this article, we investigate the possibility of enhancing the di-jet resonance
search by tagging the final state radiation (FSR) jets, 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 signal, while rejecting that in...
This summary covers key aspects of UP detector assembly development, including an overview of the detector’s geometric structures, the dummy assembly process for UP detector modules, the design of subsequent automated fixtures, and an exploration of realizing automated assembly via robotic arms and gantries.
A study of the charmless baryonic decays $B^0_{(s)} \to K^0 p \bar{p}$ is reported using $9~\mathrm{fb}^{-1}$ of LHCb data at 7, 8, and 13 TeV. The decay $B^0_s \to K^0 p \bar{p}$ is observed for the first time with a branching fraction of $(9.14 \pm 1.69 \pm 0.90 \pm 0.33 \pm 0.20)\times 10^{-7}$ and a significance of $5.6\sigma$. For $B^0 \to K^0 p \bar{p}$, the branching fraction is...
The LHCb experiment is operating in Run 3 at an unprecedented instantaneous luminosity of 2×10³³ cm⁻²s⁻¹. To process the resulting 30 MHz non-empty bunch-crossing rate, LHCb has deployed a novel, fully software-based trigger for the first time. Its second stage performs offline-quality event reconstruction in real-time, enabled by the continuous processing of alignment and calibration data....
Beam test plays an essential role in validating the performance of silicon strip detectors for the ATLAS Inner Tracker (ITk) upgrade for the High-Luminosity LHC. This contribution presents recent beam test results for two ITk strip detector modules, highlighting both validation of analysis frameworks and insights into irradiation effects. As a cross-check of existing results and an exercise in...
With the increasing size of the machine learning (ML) model and vast datasets, the foundation model has transformed how we apply ML to solve real-world problems. Multimodal language models like chatGPT and Llama have expanded their capability to specialized tasks with common pre-train. Similarly, in high-energy physics (HEP), common tasks in the analysis face recurring challenges that demand...
A search for dark matter (DM) particles produced in association with bottom quarks using proton-proton collision data at a center-of-mass energy of √s= 13 TeV, corresponding to an integrated luminosity of 138fb−1 is presented. The search is performed in a final state with large missing transverse momentum and a pair of jets originating from bottom quarks. No significant excess of data is...
The production of BIS RPC (Resistive Plate Chamber) singlets is a crucial aspect of the ATLAS Phase-II upgrade, designed to enhance the detector's performance for the High-Luminosity LHC (HL-LHC). BIS RPCs are engineered to meet the challenges posed by high radiation and pileup conditions in the HL-LHC environment. This work will focus on the production and assembly methods of BIS RPC...
The first observation of CP violation in the baryon sector was made in the decay $\Lambda_b^0 \to p K^- \pi^+ \pi^-$. In addition, the first evidence of CP violation in beauty baryon decays to charmonium was obtained. In this talk, I will present the analyses of these two decays, discussing the methodology, results, and their implications.
The analysis aims to obtain the results of High gain and Medium gain intercalicration by using data23 and data24 special runs, which were acquired with the threshold to switch from High gain to Medium gain LAr readout in both the first and second layers of the EM calorimeter significantly lowered.
A discrepancy between the reconstructed dielectron invariant mass $𝑚_{𝑒^{+}𝑒^{−}}$ obtained...
Measurements of $W^+W^- \to e^\pm \nu \mu^\mp \nu$ production cross-sections are presented, providing a test of the predictions of perturbative quantum chromodynamics and the electroweak theory. The measurements are based on data from $pp$ collisions at $\sqrt{s} = 13$ TeV recorded by the ATLAS detector at the Large Hadron Collider in 2015-2018, corresponding to an integrated luminosity of 140...
Peking University actively participates in the CMS-GEM upgrade project for CMS muon system. This report will present the status and progress of CMS-GEM ME0 project, including the assembly and testing of the ME0 modules in Peking University in 2025, the acceptance test and the performance of the ME0 GEM electronics boards produced in China.
Charmless B-meson decays into two vector mesons, B → VV, serve as a powerful probe for the dynamics of weak and strong interactions through their angular distributions. This report will introduce recent LHCb results on B → VV decays, including:
- First observation of CP violation and measurement of polarization in B+ → ρ(770)0 K*(892)+ decays
- Measurement of the branching fractions...
A dedicated data acquisition (DAQ) system based on a field-programmable gate array (FPGA) has been developed for the performance evaluation of Resistive Plate Chambers (RPCs) using cosmic rays. The system integrates 144-channel time-to-digital conversion with sub-100 ps precision, enabling accurate measurement of signal timing and charge information. A pipeline architecture with per-channel...
This talk presents the offline reconstruction and identification performance of electrons and photons at CMS using proton-proton collision data collected in 2022 and 2023 at a center of mass energy of 13.6 TeV. The corrections and scale factors derived and applied to collision data and simulation are also discussed.
CP violation plays a crucial role in accounting for the matter–antimatter imbalance observed in the Universe. This talk presents measurements of branching fractions and CP asymmetries in the decays $\Lambda_b^0(\Xi_b^0)\to pK_{\mathrm S}^0h^-$, where $h^-$ denotes either a pion or a kaon, using proton–proton collision data collected by the LHCb experiment, corresponding to an integrated...
The spin-1 nature of gluon caused correlations in subsequent parton radiations insdie jets. Such effects were fully incorporated in limited parton shower models. The correlation is measured for the first time in experiments, and compared to MC models.
We discuss the results obtained by the CMS Collaboration on the performance of jets and missing transverse energy, with a focus on Run3 data.
A search for heavy resonances decaying into a Higgs or a Z boson and a photon, with the Higgs or Z bosons decaying to a pair of bottom quarks ($b\bar{b}$) is presented. The analysis uses proton-proton collision data at $\sqrt{s}$ = 13 TeV collected by the CMS experiment, corresponding to an integrated luminosity of 138 $fb^{-1}$. The analyzed events contain a photon and a massive, large-radius...
In order to cope with the higher flux delivered by the HL-LHC, 3 layers of RPC detectors will be installed in the Barrel Inner (BI) region of ATLAS during the phase-II upgrade. Benefiting from the thin-gap structure and sensitive front end electronics, the new generation RPC has higher rate capability and longevity, together with better time and spatial resolution. This talk will report the...
This work presents dedicated jet energy calibration techniques developed for low pileup proton–proton collision data. The study focuses on adapting standard calibration procedures to the low pileup regime, where detector response and underlying event conditions differ significantly from nominal high-luminosity operations. We describe the methodology, including residual and relative...
A search for Higgs boson pair production in the $b \bar{b} \gamma \gamma$ final state is performed.
The proton--proton collision dataset corresponds to an integrated luminosity of 308 fb$^{-1}$, consisting of two samples, 140 fb$^{-1}$ at a centre-of-mass energy of $\sqrt{s} = 13 TeV$ and 168 fb$^{-1}$ at $\sqrt{s} =13.6 TeV$, recorded between 2015 and 2024 by the ATLAS detector at the CERN...
To meet the challenges brought about by ~7 times as high instantaneous luminosity at the HL-LHC, ATLAS will implement upgrade in the current detector. This talk reports the progress in the past year that has been made by the Chinese institute cluster on the ATLAS subdetectors, including HGTD, ITK and Muon system.
This talk presents the LHCb Upgrade project and the progress achieved in the past year. We will focus on the pivotal contributions from Chinese institutes, which are spearheading the development of core sub-detectors. These include a next-generation Ring-Imaging Cherenkov (RICH) system, a high-granularity Scintillating Fibre tracker, and a novel precision timing detector. Furthermore, Chinese...
This talk will present the current upgrade status of the ALICE experiment detectors and electronics for ALICE 2.1, as well as the future participation of the Chinese collaboration in the ALICE 3 upgrade. Currently, Central China Normal University and China Institute of Atomic Energy are participating in the ALICE 2.1 upgrade, which includes work on the ITS3 (Inner Tracking System 3) and FoCal...
AI and Machine Learning Application in High Energy Physics
We investigate whether collider experiments can reach the quantum limit of precision, defined by the quantum Fisher information (QFI), using only classical observables such as particle momenta. As a case study, we focus on the $\tau^{+} \tau^{-}$system and the decay channel $\tau \rightarrow \pi \nu$, which offers maximal spin-analyzing power and renders the decay a projective measurement. We...
