⚛️ Category

hep-ex

2591 papers

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.

⚛️ 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
⚛️ high-energy experiments

A framework and implementation for data-driven trigger efficiency estimation at LHCb

This paper introduces a data-driven framework for estimating trigger efficiencies at LHCb and presents the design, implementation, and performance of the centralised software package TriggerCalib, which facilitates these calculations and uncertainty estimations for physics analyses.

Johannes Albrecht, James Andrew Gooding, Maxim Lysenko, Abhijit Mathad, Alessandro Scarabotto, Tomasz Skwarnicki2026-04-09
⚛️ high-energy experiments

Observation of W+W−γW^{+}W^{-}\gamma production in $pp$ collisions at s\sqrt{s} = 13 TeV with the ATLAS detector and constraints on anomalous quartic gauge-boson couplings

Using 140 fb−1^{-1} of 13 TeV proton-proton collision data, the ATLAS experiment reports the first observation of W+W−γW^{+}W^{-}\gamma triboson production with a significance of 5.9 standard deviations and derives constraints on anomalous quartic gauge-boson couplings within the effective field theory framework.

ATLAS Collaboration2026-04-09
⚛️ nuclear experiments

Characterizing the initial state and dynamical evolution in XeXe and PbPb collisions using multiparticle cumulants

Using the CMS detector, this study presents the first measurements of correlations among mixed-order moments of two and three flow harmonics in XeXe and PbPb collisions, leveraging the distinct nuclear shapes of doubly-magic 208^{208}Pb and triaxially deformed 129^{129}Xe to probe initial-state geometry fluctuations and constrain the nonlinear hydrodynamic response of the quark-gluon plasma.

CMS Collaboration2026-04-09
⚛️ high-energy experiments

Observation and investigation of the Tccˉ1(4430)+T_{c\bar{c}1}(4430)^{+} structure in B+→ψ(2S)KS0π+B^{+} \to \psi(2S) K_{\text{S}}^{0} \pi^{+} decays

Using a four-dimensional amplitude analysis of proton-proton collision data from the LHCb experiment, this study confirms the existence of the exotic Tccˉ1(4430)+T_{c\bar{c}1}(4430)^{+} structure in B+→ψ(2S)KS0π+B^{+} \to \psi(2S) K_{\text{S}}^{0} \pi^{+} decays and investigates its properties through both Flatté parametrization and triangle singularity mechanisms.

LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb, C. Abellan Beteta, F. Abudinén, T. Ackernley, A. A. Adefisoye, B. A (…)2026-04-09