Contributions to a conference proceedings

Developments of a superconducting radiofrequency(SRF) photoinjector for future continuous-wave (CW) operationof the European XFEL are currently underway atDESY. A superconducting L-band 1.6-cell cavity is consideredas a high brightness electron source capable of supportingCW operation and meeting the stringent beamquality requirements of cutting edge XFEL facilities.Given the limitations of the attainable gradient in the superconductinggun, photocathode laser pulse shaping providesan effective means of mitigating space-charge drivenemittance growth. [...]

Fast data generation based on Machine Learning has become a major research topic in particle physics. This is mainly because the Monte Carlo simulation approach is computationally challenging for future colliders, which will have a significantly higher luminosity. [...]

The higher instantaneous luminosity expected during the upcoming years of LHC Run 3 operations will impose challenges for CMS event reconstruction, and this will be amplified in the HL-LHC era, where luminosity and pileup rates are expected to be significantly higher. One of the approaches for CMS to cope with this challenge is to utilize heterogeneous computing architectures in order to accelerate event reconstruction. [...]

Precise simulations are essential for advancing particle physics research, but they require high computational resources due to the complexity of calorimeter interactions. To reduce this cost, we propose a novel generative model that interprets calorimeter showers as point clouds rather than 3D images. [...]

Computing resources in the Worldwide LHC Computing Grid (WLCG) have been based entirely on the x86 architecture for more than two decades. In the near future, however, heterogeneous non-x86 resources, such as ARM, POWER and Risc-V, will become a substantial fraction of the resources that will be provided to the LHC experiments, due to their presence in existing and planned world-class HPC installations. [...]

The first simultaneous measurement of single and pair production of top quarks in association with a Z boson ($t$Zq, $t$WZ and $t\bar{t}$Z) is presented, including both inclusive and differential cross sections. A multiclass neural network is used to separate the signal and the backgrounds. [...]

Recent searches for dark matter (DM) produced in association with top quarks from the ATLAS and CMS experiments using data collected between 2015 and 2018 are presented. These comprise searches from both experiments for DM in association with a single top quark; an improved ATLAS search for DM in single lepton $t\bar{t}$ final states; an ATLAS search for stop squarks decaying to a top quark, a charm quark and neutralinos; and a CMS search for DM produced in association with a pair of top quarks or a single top. [...]

This note presents an overview of current and potential future applications of machine-learning-based techniques in the study of the top quark. The research community has developed a diverse set of ideas and tools, including algorithms for the efficient reconstruction of recorded collision events and innovative methods for statistical inference. [...]

Environmental sustainability is becoming an increasingly explicit consideration in the design and operation of high-energy physics (HEP) facilities, detectors, and computing systems. This article provides a compact synthesis of selected environmental sustainability efforts in HEP as of August 2026, combining a snapshot of major initiatives across facilities and accelerators, detector technologies, computing, and community and institutional programs with selected recent technical results. [...]

A search for scalar or pseudoscalar states decaying to a top quark-antiquark pair ($\mathrm{t \bar{t}}$), using $138 \mathrm{ fb}^{-1}$ of pp collision data taken at $\sqrt{s} = 13 \mathrm{ TeV}$ using the CMS detector, is presented. Events with one or two leptons are analyzed using the invariant $\mathrm{t \bar{t}}$ mass ($m_{\mathrm{t \bar{t}}}$) as well as angular and spin correlation observables. [...]