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.

Evidence of ZZγ\gamma production and observation of 4γ4\ell\gamma in proton-proton collisions at s\sqrt{s} = 13 TeV

Using 138 fb1^{-1} of proton-proton collision data at 13 TeV, the CMS experiment reports the first evidence for ZZγ\gamma production with a 3.7σ\sigma significance and the first observation of inclusive 4γ\ell\gamma production with a 5.0σ\sigma significance, providing measured fiducial cross sections for both processes.

CMS Collaboration2026-04-06⚛️ hep-ex

Measure charge transport in high-energy nuclear collisions with an energy scan of isobaric collisions

This paper proposes a beam-energy scan of isobaric collisions (Ru+Ru vs. Zr+Zr) to precisely measure electric-charge transport and distinguish between competing microscopic mechanisms of conserved-charge redistribution in QCD matter by comparing the rapidity dependence of charge and baryon transport.

Wendi Lv, Niseem Magdy, Rongrong Ma, Zebo Tang, Prithwish Tribedy, Chun Yuen Tsang, Zhangbu Xu2026-04-06⚛️ nucl-ex

Analytical model for the photomultiplier single photoelectron response including the electron back-scattering contribution

This paper derives and validates a comprehensive analytical model for photomultiplier single photoelectron responses that replaces ad hoc noise descriptions with a physically grounded function accounting for electron back-scattering at the first dynode, alongside analytical descriptions for fully amplified peaks and low-charge signals.

Emanuele Angelino, Veronica Beligotti, Lorenzo Bellagamba, Elena Bonali, Graziano Bruni, Pietro Di Gangi, Gian Marco Lucchetti, Andrea Mancuso, Virginia Mazza, Gabriella Sartorelli, Franco Semeria, Al (…)2026-04-06⚛️ hep-ex

Search for the decays B(s)0J/ψγB_{(s)}^0\to J/\psi\gamma at LHCb

Using proton-proton collision data from the LHCb experiment, this study sets new 90% confidence level upper limits on the branching fractions of the rare decays Bs0J/ψγB_{s}^0\to J/\psi\gamma and B0J/ψγB^0\to J/\psi\gamma, improving the previous limit for the Bs0B_{s}^0 mode by a factor of 2.5.

LHCb collaboration, R. Aaij, M. Abdelfatah, 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. (…)2026-04-06⚛️ hep-ex

Log Gaussian Cox Process Background Modeling in High Energy Physics

This paper introduces a novel Log Gaussian Cox Process (LGCP) method for modeling smooth backgrounds in high energy physics that minimizes assumptions about the underlying shape by utilizing a Gaussian process for the intensity function and Markov Chain Monte Carlo for optimization, demonstrating its effectiveness through synthetic experiments against traditional analytic functional forms.

Yuval Frid, Liron Barak, Pavani Jairam, Michael Kagan, Rachel Jordan Hyneman2026-04-03⚛️ hep-ex

A journey to ITACA: Ion Tracking with Ammonium Cations Apparatus

The paper proposes the ITACA apparatus, which enhances gas xenon time projection chambers for neutrinoless double-beta decay searches by introducing trace ammonia to create slow-drifting ammonium ions, enabling high-resolution ion-track imaging that complements electron tracking to significantly improve background rejection through superior topological discrimination.

J. J. Gómez-Cadenas, L. Arazi, M. Elorza, Z. Freixa, F. Monrabal, A. Pazos, J. Renner, S. R. Soleti, S. Torelli2026-04-03⚛️ hep-ex

Implications of Flavor Symmetries for Baryon Number Violation

This paper systematically classifies dimension-six baryon-number-violating SMEFT operators under various flavor-symmetry assumptions, demonstrating how their interplay with neutrino masses can allow for multi-TeV BNV scales consistent with proton decay constraints, while also identifying UV completions where the effective field theory description may be insufficient.

Arnau Bas i Beneito, Ajdin Palavrić, Andrea Sainaghi2026-04-03⚛️ hep-ex

Tau lepton reconstruction at the Muon Collider: Cross section measurement of the Hτ+τH\rightarrowτ^+τ^- process

This study estimates a 1.3% statistical uncertainty on the cross-section measurement of the Hτ+τH\rightarrow\tau^+\tau^- process at a 10 TeV Muon Collider by utilizing the TauFinder algorithm for efficient hadronic tau reconstruction and comparing results with other future collider sensitivities.

Kevin Dewyspelaere, Giacomo Da Molin, Giovanni Battista Marozzo, Michele Gallinaro2026-04-03⚛️ hep-ex

VUV Reflectance Measurements for Materials Relevant to Argon and Xenon Experiments

This paper presents a new angular-resolved reflectance measurement system operating in a gaseous argon atmosphere that characterizes aluminum and stainless steel materials relevant to DUNE, revealing significantly lower vacuum ultraviolet reflectance (10–15%) compared to UV-VIS values and providing critical data for optimizing future noble gas detector simulations.

J. Soto-Oton, H. Amar, A. Cervera, A. Roche2026-04-03⚛️ hep-ex