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

In-Situ Performance of FBK VUV-HD3 and HPK VUV4 SiPMs in the LoLX Liquid Xenon Detector

This paper presents a direct in-situ comparison of FBK VUV-HD3 and HPK VUV4 SiPMs within the LoLX liquid xenon detector, revealing that HPK devices detect 33–38% less light than FBK devices under operating conditions and demonstrating that this discrepancy is resolved by an optical simulation incorporating angular and wavelength-dependent surface shadowing effects.

Xiang Li, David Gallacher, Stephanie Bron, Thomas Brunner, Austin de St Croix, Frédéric Girard, Colin Hempel, Mouftahou (…)2026-04-10
⚛️ high-energy experiments

A Way of Axion Detection with Mass 10−4-10−310^{-4} \text{-}10^{-3}eV Using Cylindrical Sample with Low Electric Conductivity

This paper proposes a novel axion detection method for masses between 10−410^{-4} and 10−310^{-3} eV that utilizes a large cylindrical sample with low electrical conductivity to generate a measurable bulk oscillating current under a magnetic field, offering a feasible signal-to-noise ratio even at cryogenic temperatures.

Aiichi Iwazaki2026-04-10
⚛️ nuclear experiments

Precise 136^{136}Xe Double Beta Decay Measurement in PandaX-4T with Implications on the Nuclear Matrix Elements and Majorons

Using 39.1 kg·yr of exposure from the PandaX-4T experiment, this study presents the most precise measurement to date of the 136^{136}Xe two-neutrino double beta decay half-life, provides a consistent measurement of the nuclear matrix element ratio ξ312ν\xi_{31}^{2\nu}, and establishes the world's most stringent limit on Majoron-emitting modes with spectral index n=7n=7.

PandaX Collaboration, Zhe Yuan, Zihao Bo, Wei Chen, Xun Chen, Yunhua Chen, Chen Cheng, Xiangyi Cui, Manna Deng, Yingjie (…)2026-04-10
⚛️ phenomenology

Axion-like Particles and Lepton Flavor Violation in Muonic Atoms

This paper investigates the potential for the Mu2e experiment to detect lepton-flavor-violating μ−e−→e−e−\mu^- e^- \to e^- e^- transitions in muonic atoms mediated by axion-like particles, concluding that while light mediators can parametrically enhance the rate, stringent constraints from electron anomalous magnetic moments and other flavor-violating processes severely limit the observable branching ratio to at most O(10−20)\mathcal{O}(10^{-20}), making the upcoming Mu3e experiment the most promising probe for the viable parameter space.

Girish Kumar, Alexey A. Petrov2026-04-10
⚛️ high-energy experiments

Development of Faster and More Accurate Supernova Localization at Super-Kamiokande

This paper presents significant upgrades to the Super-Kamiokande "SNWATCH" system, including a new HEALPix-based fitter and an optimized maximum-likelihood fitter that leverage gadolinium-enhanced data to reduce supernova alert generation time to approximately 90 seconds while improving the accuracy of pointing direction reconstruction.

K. Abe (Super-Kamiokande collaboration), Y. Asaoka (Super-Kamiokande collaboration), M. Harada (Super-Kamiokande collabo (…)2026-04-10
⚛️ high-energy experiments

Multiplicity dependence of prompt and non-prompt J/ψ\psi production at midrapidity in pp collisions at s=13\sqrt{s} = 13 TeV

This paper presents measurements of prompt and non-prompt J/ψ\psi production yields at midrapidity in 13 TeV pp collisions, revealing a stronger-than-linear increase in self-normalized yields with charged-particle multiplicity that varies depending on the azimuthal region relative to the J/ψ\psi momentum.

ALICE Collaboration2026-04-10
⚛️ high-energy experiments

Bˉ→D(∗)ℓνˉ\bar B\to D^{(*)}\ell\bar \nu Branching Ratios and Evidence for Isospin Breaking in Υ(4S)\Upsilon(4S) Decays

This paper presents a new method and comprehensive analysis of Bˉ→D(∗)ℓνˉ\bar B\to D^{(*)}\ell\bar \nu decays to determine the Υ(4S)\Upsilon(4S) production fraction ratio R±0R^{\pm0}, providing evidence for isospin violation at R±0=1.062(19)R^{\pm0}=1.062(19) and revising branching fractions to potentially alleviate the VcbV_{cb} puzzle.

Martin Jung, Stefan Schacht2026-04-10
⚛️ high-energy experiments

Search for the lepton-flavour violating decays B+→π+μ±e∓B^+ \to \pi^+ \mu^\pm e^\mp

The LHCb collaboration presents the first search for the lepton-flavour violating decay B+→π+μ±e∓B^+ \to \pi^+ \mu^\pm e^\mp using 9 fb−1^{-1} of proton-proton collision data, finding no significant signal and setting a new world-record upper limit on the branching fraction of 1.8×10−91.8 \times 10^{-9}, which provides the first constraint on such b→db \to d transitions at the LHC.

LHCb collaboration, R. Aaij, M. Abdelfatah, A. S. W. Abdelmotteleb, C. Abellan Beteta, F. Abudinén, T. Ackernley, A. A. (…)2026-04-10