The subatomic world is a realm where matter behaves in ways that defy our everyday intuition, and this category explores the fundamental building blocks of our universe. From the intricate dance of quarks inside a proton to the strange properties of electrons, these studies reveal the deep rules that govern everything from the smallest particles to the largest stars.

At Gist.Science, we track every new preprint in this field as it appears on arXiv, ensuring you stay ahead of the curve. For each discovery, we provide both a clear, plain-language explanation of the core ideas and a detailed technical summary for those who want to dive deeper into the mathematics and methodology.

Below are the latest papers in Atom-Ph, offering fresh insights into the structure and behavior of the atomic scale.

MuDirac 1.3.0: A Sustainable Software Tool for Calculating Ground State Nuclear Properties Using Muonic X-Ray Measurements

This paper introduces MuDirac 1.3.0, a sustainable and efficient open-source software tool that enables the negative muon community to accurately calculate nuclear properties, such as the charge radius, by modeling muonic X-ray transition energies under a two-parameter Fermi distribution.

Leandro Liborio, Milan Kumar, Subindev Devadasan, Philip Jones, Martin Plummer, Adrian Hillier, Albert Bartok2026-05-04🔬 physics.atom-ph

Long-range states in collisions of ultracold molecules

Using coupled-channel calculations on a Rb+KRb prototype model, the study reveals that near-threshold bound states with strong long-range character and weak short-range coupling can persist deep below thresholds, exhibiting long lifetimes and the potential to induce narrow Feshbach resonances while remaining largely immune to chaotic short-range dynamics and laser-induced destruction.

James F. E. Croft, Brian K. Kendrick, Jeremy M. Hutson2026-05-01🔬 physics.atom-ph

International Optical Clock Comparison Using the European Optical Fiber Network

This paper reports a successful two-month international comparison of seven optical clocks across four European metrology institutes via a fiber network, achieving frequency ratio uncertainties as low as 7.7×10187.7\times10^{-18} and providing critical data for the future redefinition of the SI second.

Marco Pizzocaro, Clara Zyskind, Anne Amy-Klein, Erik Benkler, Sebastien Bize, Davide Calonico, Etienne Cantin, Christian Chardonnet, Cecilia Clivati, Stefano Condio, E. Anne Curtis, Simone Donadello (…)2026-05-01🔬 physics.atom-ph

Precision Spectroscopy of 2S-nS Transitions in Atomic Hydrogen: A Determination of the Proton Charge Radius

This paper reports high-precision absolute frequency measurements of 2S-nS (n=8, 9, 10) two-photon transitions in cryogenic atomic hydrogen, yielding a proton charge radius of 0.8433(31) fm and a Rydberg frequency that align well with CODATA 2022 recommendations.

R. G. Bullis, W. L. Tavis, M. R. Weiss, J. Orellana Cisneros, A. J. Cheeseman, U. D. Jentschura, D. C. Yost2026-04-30🔬 physics.atom-ph

Development of a compact cryogenic Penning trap with permanent magnets: An intermediate step toward the Shanghai Penning Trap

This paper reports the successful development and demonstration of a compact, cost-effective cryogenic Penning trap utilizing a permanent magnet, which serves as both a functional testbed for the upcoming Shanghai Penning Trap and a versatile platform for ion trapping, cooling, and spectroscopic studies.

Tianhang Zhang, Jiawei Wang, Jialin Liu, Jingtian Wei, Jiaxuan Ji, Jifei Wu, Zichen Su, Yiming Xie, Liangyu Huang, Ke Yao, Yang Shen, Yaming Zou, Baoren Wei, Bingsheng Tu2026-04-30🔬 physics.atom-ph

Quantum Vector Signal Analyzer: Wideband Electric Field Sensing via Motional Raman Transitions

This article proposes and demonstrates a quantum sensing technique based on motional Raman transitions in a single trapped ion to achieve ultrasensitive, broadband detection of high-frequency electric fields with high precision in frequency, phase, and amplitude, surpassing previous methods by more than 800-fold in bandwidth while operating below the standard quantum limit.

Hao Wu, Grant Mitts, Clayton Ho, Joshua Rabinowitz, Eric R. Hudson2026-04-29🔬 physics.atom-ph

Low energy elastic scattering of hydrogen, deuterium and tritium on helium isotopes

Motivated by applications in neutrino mass experiments and precision spectroscopy, this paper presents calculations of energy-dependent elastic scattering cross sections for hydrogen, deuterium, and tritium on helium isotopes, revealing that tritium scattering is significantly enhanced at low energies due to a near-threshold s-wave resonant bound state before converging to a geometric limit at higher energies.

B. J. P. Jones, A. Negi, A. Semakin2026-04-29🔬 physics.atom-ph