Nuclear Experiment·nucl-ex

Thu·Aug 13, 2026Thursday·August 13, 2026

3 papers—2 primary·1 cross-listed

01
First measurement of polarized spin-density matrix elements and differential cross sections d $σ$ /d $t$ in $ω$ ~photoproduction off the proton for $2.7 < E_{γ} < 5.2$ GeV using CLAS at Jefferson Lab
T. Hu🇺🇸 · Z. Akbar🇺🇸 · V. Crede🇺🇸 · J.M. Laget🇺🇸 · V. Mathieu🇪🇸 · M.J. Amaryan🇺🇸 · W.R. Armstrong🇺🇸 · H. Atac🇺🇸 · N.A. Baltzell🇺🇸 · L. Barion🇮🇹 · M. Battaglieri🇮🇹 · I. Bedlinskiy🇷🇺 and 138 other authors
We report on the differential cross sections d $σ$ /d $t$ , the unpolarized spin-density matrix elements $ρ_{00}^{0}$ , $ρ_{1 - 1}^{0}$ , Re\, $ρ_{10}^{0}$ , and the first extraction of the polarized elements Im\, $ρ_{10}^{3}$ , Im\, $ρ_{1 - 1}^{3}$ for the reaction $γ p \to p ω$ using the CLAS spectrometer at Jefferson Laboratory. The $ω$ ~mesons were detected in their dominant charged decay mode, $ω \to π^{+} π^{-} π^{0}$ , and all $t$ -dependent results are presented in a fine binning for incident photon energies between 2.73 and 5.16~GeV (corresponding to the center-of-mass energy range $W \in [2.45, 3.25]$ ~GeV). All matrix elements are first measurements for $- t > 0.6$ ~GeV $^{2}$ . Moreover, differential cross sections d $σ$ /d(cos\, $Θ_{c.m.}^{ω}$ ) and the corresponding angle-dependent unpolarized spin-density matrix elements in the Adair frame are presented for the incident photon energy range 1.56--3.80~GeV (corresponding to $W \in [1.95, 2.83]$ ~GeV). These new $ω$ ~photoproduction data are consistent with earlier CLAS results but extend the energy range well beyond the nucleon resonance region into the Regge regime. The comparison with Regge-theory-based model predictions shows that the new data impose more stringent constraints on our understanding of $ω$ ~photoproduction.
nucl-exhep-exPLB(2026)·0 citations
02
Excited states of $^{148}$ Nd studied via the $^{150}$ Nd $(p, t)^{148}$ Nd reaction and the observation of possible low-spin two-phonon octupole states at $N = 88$
A.L. Conley🇺🇸 · M. Spieker🇺🇸 · R. Aggarwal🇮🇳 · L.T. Baby🇺🇸 · J. Davis🇺🇸 · J. Esparza🇺🇸 · I. Hay🇺🇸 · B. Kelly🇺🇸 · T. Kirk · M.I. Khawaja🇺🇸 · R. Mahajan · M. Mestayer and 6 other authors
We report new data from a $^{150}$ Nd $(p, t)^{148}$ Nd experiment performed at the John D. Fox Accelerator Laboratory of Florida State University. In total, 54 excited states of $^{148}$ Nd were observed up to an excitation energy of 3500 keV. In this work, we focus on $0^{+}$ states and their band members. In contrast to previous work, the $0_{3}^{+}$ band is proposed as the candidate for the two-phonon octupole vibrational band. Supporting $s p df$ IBM-1 calculations are presented. To test the robustness of the IBM calculations, several observables were interrogated and are discussed in this publication. In addition, we make the case that neither the $0_{2}^{+}$ nor the $0_{3}^{+}$ states of the other $N = 88$ isotones are likely good candidates for two-phonon octupole states. Based on our new data for $^{148}$ Nd, we propose candidates in $^{150}$ Sm and $^{152}$ Gd. Using available $γ$ -decay data for states with moderate spins in the yrast sequence and a comparison to IBM calculations, we also show how the staggering of the $B (E 1) / B (E 2)$ ratios in the yrast sequence can possibly be used to probe the appearance of bands with multiple octupole phonons.
nucl-exnucl-thPRC(2026)·0 citations
03
Physics of the Electron-Ion Collider in China
Bo-Wen Xiao🇨🇳 · Yuxiang Zhao🇨🇳 · Jian Zhou🇨🇳
The Electron-Ion Collider in China (EicC), a cutting-edge facility under development, aims to unveil the internal structure of nucleons and nuclei by leveraging collisions of high-intensity polarized electrons and ions (polarized protons, polarized deuterons, polarized $^{3}$ He, and unpolarized heavy ions up to Uranium) at center-of-mass energies of 15-20 GeV and luminosity of (2-4) $\times 1 0^{33}$ cm $^{- 2}$ s $^{- 1}$ . Its primary physics objectives include 3D tomography of nucleon spin and momentum structure, fundamental questions regarding the origin of nucleon mass, partonic structure of nuclei and parton interactions with the nuclear environment, and exploration of exotic hadronic states. In this paper, we review the physics potential of the EicC and highlight its unique capabilities for advancing precision nucleon structure studies by combining its specialized kinematic coverage and high luminosity. Since traditional topics like 3D nucleon structure have already been well-covered by several extensive reviews, we have deliberately dedicated significant space to recent progress in nucleon mass decomposition, nucleon energy-energy correlation, quantum information, and artificial intelligence applications in high-energy nuclear physics, which have been emerging rapidly and attracted a tremendous amount of attention in the community.
↳ hep-phhep-exnucl-exnucl-thPPNP(2026)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

First measurement of polarized spin-density matrix elements and differential cross sections dσ/dt in ω~photoproduction off the proton for 2.7<Eγ​<5.2 GeV using CLAS at Jefferson Lab

Excited states of 148Nd studied via the 150Nd(p,t)148Nd reaction and the observation of possible low-spin two-phonon octupole states at N=88

Physics of the Electron-Ion Collider in China

Affiliations

First measurement of polarized spin-density matrix elements and differential cross sections d $σ$ /d $t$ in $ω$ ~photoproduction off the proton for $2.7 < E_{γ} < 5.2$ GeV using CLAS at Jefferson Lab

Excited states of $^{148}$ Nd studied via the $^{150}$ Nd $(p, t)^{148}$ Nd reaction and the observation of possible low-spin two-phonon octupole states at $N = 88$