Hep-Ex explores the fascinating intersection where particle physics meets experimental reality. This field investigates how scientists build massive detectors and accelerate particles to test the fundamental laws of nature, turning abstract theories into measurable data. It is the rigorous process of searching for new particles or forces that could reshape our understanding of the universe, often requiring years of collaboration and engineering.

At Gist.Science, we ensure these discoveries become accessible to everyone. We process every new preprint in this category directly from arXiv, generating both plain-language explanations for curious readers and detailed technical summaries for specialists. Our goal is to bridge the gap between complex experimental results and public understanding without losing scientific nuance.

Below are the latest papers in Hep-Ex, freshly summarized and ready for you to explore.

First Constraint on P-odd/T-odd Cross Section in Polarized Neutron Transmission through Transversely Polarized 139^{139}La

This paper presents the first constraint on time-reversal invariance violating effects in polarized neutron transmission through a transversely polarized 139^{139}La target by applying a density matrix formalism to existing data, yielding an upper limit of WT<15 eV|W_T|<15~\mathrm{eV} at 90% confidence level despite the data's lack of optimization for such observables.

Rintaro Nakabe, Clayton J. Auton, Shunsuke Endo, Hiroyuki Fujioka, Vladimir Gudkov, Katsuya Hirota, Ikuo Ide, Takashi Ino, Motoyuki Ishikado, Wataru Kambara, Shiori Kawamura, Atsushi Kimura, Masaaki K (…)2026-04-07⚛️ nucl-ex

Measurement of the WμνμW \to \mu \nu_\mu cross-sections as a function of the muon transverse momentum in $pp$ collisions at 5.02 TeV

Using LHCb data from proton-proton collisions at 5.02 TeV, this paper reports the differential and integrated cross-sections of WμνμW \to \mu \nu_\mu production and demonstrates a proof-of-principle method for determining the WW-boson mass from these measurements.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb, C. Abellan Beteta, F. Abudinén, T. Ackernley, A. A. Adefisoye, B. Adeva, M. Adinolfi, P. Adlarson, C. Agapopoulou, C. A. Aidala, Z. Ajaltouni, S. (…)2026-04-07⚛️ hep-ex

dN/dx Reconstruction with Deep Learning for High-Granularity TPCs

This paper introduces GraphPT, a deep learning model based on a graph neural network U-Net architecture that represents TPC data as point clouds to significantly improve dN/dx reconstruction and particle identification performance, achieving a 10% to 20% enhancement in K/π separation power compared to traditional methods.

Guang Zhao, Yue Chang, Jinxian Zhang, Linghui Wu, Huirong Qi, Xin She, Mingyi Dong, Shengsen Sun, Jianchun Wang, Yifang Wang, Chunxu Yu2026-04-07⚛️ hep-ex

Design and Expected Performance for an hKLM at the EIC

This paper presents the design and expected performance of the hKLM, a novel iron-scintillator sampling calorimeter for the Electron Ion Collider that integrates machine learning-driven optimization and multi-dimensional readout to achieve high-resolution identification of neutral hadrons and muons with compact dimensions and excellent timing capabilities.

Rowan Kelleher, Anselm Vossen, William W. Jacobs, Gerard Visser, Simon Schneider, Yordanka Ilieva, Pawel Nadel-Turonski2026-04-07⚛️ hep-ex

Potential divergence in tracing μ\mu and τ\tau flavors of astrophysical neutrinos

This paper derives general formulas for reconstructing the flavor fractions of astrophysical neutrinos at their sources from observed data, revealing an inherent divergence in distinguishing μ\mu and τ\tau flavors due to μ\mu-τ\tau interchange symmetry in the lepton mixing matrix and demonstrating that only specific combinations of flavor fractions can be precisely extracted under exact symmetry conditions.

Zhi-zhong Xing2026-04-07⚛️ hep-ex

Illuminating sequential freeze-in dark matter with dark photon signal at the CERN SHiP experiment

This paper demonstrates that the CERN SHiP experiment can probe sequential freeze-in dark matter mediated by dark photons with masses between 10210^{-2} and $10$ GeV, predicting a specific dark charge and a narrow mixing parameter range (1011\sim 10^{-11}) that survives current constraints while remaining testable via proton bremsstrahlung signals.

Xinyue Yin, Sibo Zheng2026-04-07⚛️ hep-ex

Searching for vector-like leptons decaying into an electron and missing transverse energy in e+^{+}e^{-} collisions with s=240\sqrt{s} = 240 GeV at the FCC-ee

This study utilizes Monte Carlo simulations of electron-positron collisions at the FCC-ee with a center-of-mass energy of 240 GeV and an integrated luminosity of 10.8 ab1^{-1} to search for vector-like leptons decaying into electrons and missing transverse energy within a lepton portal dark matter framework, ultimately establishing 95% confidence level exclusion limits on the vector-like lepton mass and Yukawa coupling in the absence of a signal.

S. Elgammal2026-04-07⚛️ hep-ex