Thu·Sep 18, 2025Thursday·September 18, 2025

1. 01*

   Elastic and Spin-Changing Cross Sections of Spin-Polarized Atomic Tritium

   M. G. Elliott🇺🇸 · B. J. P. Jones🇺🇸

   The rates of elastic and inelastic scattering processes of spin-polarized atomic tritium are vital inputs for the design and operation of experiments using cold, magnetically trapped tritium atoms. Elastic scattering dominates the total cross section and dictates the thermophysical properties of the vapor, determining the efficiency of magnetic evaporative cooling and the fluid dynamical properties of the trapped atom cloud. Spin-changing cross sections in both exchange and dipolar channels determine the trap lifetime of the various hyperfine states, imposing constraints on the required atomic tritium supply rate to maintain a given trap density. Motivated by the needs of next-generation spectrometers that will study the tritium beta endpoint to infer the mass of the neutrino, we present new calculations of the elastic, spin-exchange and dipolar cross sections for spin polarized atomic tritium. Cross sections and rate constants are reported for magnetic field strengths of 0-10 T and temperatures from 0-100~K in all relevant Zeeman-hyperfine channels for both tritium and hydrogen. Results are bench-marked against past calculations for atomic hydrogen and the limited available results for tritium, and extend far into the regimes where past calculations have not been available.

   ↳ physics.atom-phnucl-exPRA(2025)·2 citations
2. 02*

   Transverse single-spin asymmetry of forward $\eta$ mesons in $p^{\uparrow }+p$ collisions at $\sqrt{s}=200$ GeV

   PHENIX Collaboration: N.J. Abdulameer · U. Acharya · C. Aidala · N.N. Ajitanand · Y. Akiba · R. Akimoto · J. Alexander · D. Anderson · S. Antsupov · K. Aoki · N. Apadula · H. Asano and 372 other authors

   Utilizing the 2012 transversely polarized proton data from the Relativistic Heavy Ion Collider at Brookhaven National Laboratory, the forward $\eta$-meson transverse single-spin asymmetry ($A_N$) was measured for $p^{\uparrow }+p$ collisions at $\sqrt{s}=200$ GeV as a function of Feynman-x ($x_F$) for $0.2<|x_F|<0.8$ and transverse momentum ($p_T$) for $1.0<p_T<5.0$ GeV/$c$. Large asymmetries at positive $x_F$ are observed ($⟨A_N⟩=0.086\pm 0.019$), agreeing well with previous measurements of ${\pi }^0$ and $\eta$ $A_N$, but with reach to higher $x_F$ and $p_T$. The contribution of initial-state spin-momentum correlations to the asymmetry, as calculated in the collinear twist-3 framework, appears insufficient to describe the data and suggests a significant impact on the asymmetry from fragmentation.

   ↳ hep-exnucl-exPRD(2026)·1 citation
3. 03*

   Double Slit Experiment from Nano to Femto Scale

   Arvind Khuntia🇮🇹 · Raghunath Sahoo🇮🇳

   The evolution of light theories began with Isaac Newton's corpuscular model, which explained reflection and refraction but could not account for diffraction and interference. In contrast, Christiaan Huygens proposed a wave theory, explaining light's behavior through an ether-based medium, supported by his principle that each point in a wavefront acts as a secondary source. This idea was experimentally supported in the early nineteenth century when Thomas Young's double-slit experiment revealed an interference pattern, affirming light's wave nature. Later, James Clerk Maxwell unified electricity and magnetism, establishing light as an electromagnetic wave and extending the electromagnetic spectrum beyond visible light. In the twentieth century, Einstein's photoelectric effect introduced the concept of wave-particle duality, demonstrating that light behaves as discrete photons. Soon after, Louis de Broglie extended the idea of wave-particle duality to matter, a prediction confirmed in 1927 when Clinton Davisson and Lester Germer observed electron diffraction from a crystal and, independently, G.P. Thomson demonstrated electron diffraction through thin films, both proving that electrons also exhibit wave-like properties. This concept was dramatically visualized by Claus Jonsson's 1961 electron double-slit experiment. Recently, the ALICE collaboration observed quantum interference patterns at the femtometer scale in ultra-relativistic nuclear collisions, pushing quantum interference studies to new frontiers.

   ↳ physics.ed-phhep-exhep-phnucl-ex0 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.