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.

⚛️ high-energy experiments

Evidence for the semileptonic decay Λc+→pπ−e+νe\Lambda_c^{+} \to p \pi^{-} e^+ \nu_e

Using 4.5 fb⁻¹ of e+e−e^+e^- collision data collected by the BESIII detector, researchers performed the first search for the Cabibbo-suppressed semileptonic decay Λc+→pπ−e+νe\Lambda_c^+ \to p\pi^-e^+\nu_e, measuring its branching fraction to be (2.96±0.95stat±0.23syst)×10−4(2.96\pm0.95_{\rm stat}\pm0.23_{\rm syst})\times10^{-4} with a statistical significance of 4.2σ4.2\sigma.

BESIII Collaboration, M. Ablikim, M. N. Achasov, P. Adlarson, X. C. Ai, C. S. Akondi, R. Aliberti, A. Amoroso, Q. An, Y. (…)2026-09-16
⚛️ nuclear experiments

Comment on "Non-Monotonicity of Transverse-Momentum Correlations in Au+Au Collisions at RHIC"

This paper argues that the observed non-monotonic beam-energy dependence of transverse-momentum correlations in Au+Au collisions cannot be reliably attributed to critical phenomena or used to constrain the QCD critical end point due to the absence of a controlled theoretical framework, significant non-critical contributions, and inconsistencies with other susceptibility-based measurements.

Roy A. Lacey2026-09-16
⚛️ high-energy experiments

Cosmological Constrained Axion-Portal Inelastic Dark Matter for the LZ Event

This paper proposes a cosmologically constrained inelastic dark matter model where the long-lived excited state's relic abundance is dynamically determined by early-Universe conversion processes and the Lorentz structure of axion-portal couplings, offering a viable explanation for the high-recoil LZ event through either endothermic or exothermic scattering scenarios that can be distinguished by future annual modulation measurements and collider probes.

Haipeng An, Fei Gao, Jia Liu, Minghao Liu, Changlong Xu2026-09-16
⚛️ high-energy experiments

NuSmear: Fast Simulation of Energy Smearing and Angular Smearing for Neutrino-Nucleon Scattering Events in the GENIE Event Generator

This paper introduces NuSmear, a fast and geometry-independent simulation system built on the GENIE event generator that efficiently models energy and angular smearing for neutrino-nucleon scattering events, offering a computationally efficient alternative to full Monte Carlo simulations while maintaining predictive accuracy through rigorous validation.

Ishaan Vohra2026-09-15
🔭 astrophysics

Phasing out of Darkness: From Sterile Neutrino Dark Matter to Neutrino Masses via Time-Dependent Mixing

This paper proposes a time-dependent mixing model involving a late phase transition that allows sterile neutrinos to serve as dark matter while simultaneously generating neutrino masses, effectively circumventing astrophysical X-ray constraints that typically rule out such scenarios in standard type-I seesaw frameworks.

Florian Goertz, Maya Hager, Giorgio Laverda, Javier Rubio2026-09-15
⚛️ high-energy experiments

Finite Asimov Sample Construction in Unbinned Neural Simulation-Based Inference

This paper proposes a method to construct a finite, weighted reference sample that globally maximizes the likelihood for learned density ratios, demonstrating that such a small dataset can accurately reproduce expected test statistic scans and distributions typically requiring millions of simulated events in neural simulation-based inference.

Rafael Coelho Lopes de Sa, Jay Sandesara2026-09-15