Nuclear Theory·nucl-th

Thursday·June 18, 2026

7 papers—3 primary·4 cross-listed

04
[Submitted on 16 Jun 2026] (cross-list from nucl-ex)
First Measurement of the $K^{-}$ Escape Cross Section in the $^{12} C (K^{-}, p)$ Reaction
Fumiya Oura🇯🇵 · Yudai Ichikawa🇯🇵 · Junko Yamagata-Sekihara🇯🇵 · Jung Keun Ahn🇰🇷 · Sung Wook Choi🇰🇷 · Manami Fujita🇯🇵 · Takeshi Harada🇯🇵 · Shoichi Hasegawa🇯🇵 · Shuhei Hayakawa🇯🇵 · Kenneth Hicks🇺🇸 · Satoru Hirenzaki🇯🇵 · Sang Hoon Hwang and 23 other authors
We investigated the $K ˉ$ -nucleus interaction through the simultaneous measurement of the inclusive $^{12} C (K^{-}, p)$ and exclusive $K^{-}$ -escape $^{12} C (K^{-}, p K_{esc}^{-})$ reactions at $1.8$ GeV/ $c$ at J-PARC. The present measurement explicitly focuses on the $K^{-}$ escape process for the first time, successfully accomplishing a direct experimental determination of the imaginary part of the $K^{-}$ optical potential. The differential cross section for the $K^{-}$ -escape reaction was determined to be $436 \pm 6 (stat.) \pm 44 (syst.) μ b/sr$ . A simultaneous likelihood fit yielded real and imaginary potential strengths of $V_{0} = - 72_{- 5}^{+ 3} (stat.)_{- 8}^{+ 0} (syst.) MeV$ and $W_{0} = - 100_{- 1}^{+ 7} (stat.)_{- 16}^{+ 0} (syst.) MeV$ at the nuclear center, respectively. The derived $W_{0}$ is significantly stronger than that predicted by theoretical models based on one-nucleon processes, suggesting possible contribution of multi-nucleon involving processes.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2606.18398 [pdf]
0 citations
05
[Submitted on 17 Jun 2026] (cross-list from nucl-ex)
The electromagnetic decay of $^{250 m}$ No and the stability of neutron deficient Rf isotopes
A. Lopez-Martens🇫🇷 · K. Hauschild🇫🇷 · R. Chakma🇺🇸 · O. Dorvaux🇷🇺 · B. Gall🇷🇺 · K. Kessaci🇫🇷 · M.L. Chelnokov🇫🇷 · V.I. Chepigin🇷🇺 · A.V. Isaev🇷🇺 · I.N. Izosimov🇷🇺 · D.E. Katrasev🇫🇷 · A.A. Kuznetsova🇷🇺 and 7 other authors
The electromagnetic decay of the $\approx$ 40 $μ$ s isomer of $^{250}$ No has been investigated using the \textsc{Geant4} toolkit for the simulations of the interaction of particles through matter. It is concluded that the decay does not follow the pattern established in the lighter isotones, where the isomer decays directly to members of the ground state rotational band. An alternative scenario is proposed. The implications on the location of the isotopic border for neutron deficient Rf isotopes are discussed.
Comments:
14 pages, 13 figures, data taken in 2019
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2606.18748 [pdf]
EPJA(2026)·1 citation
06
[Submitted on 17 Jun 2026] (cross-list from hep-ph)
Diffractive Production of Heavy Quarkonia at the Electron Ion Collider
Mohammad Yousuf Jamal🇨🇳 · Ajaharul Islam🇨🇳 · Aritra Bandyopadhyay🇵🇱 · Santosh K. Das🇮🇳
We study diffractive photo- and electroproduction of the $S$ -wave heavy quarkonia $J / ψ$ , $ψ (2 S)$ , and $Υ (n S)$ at energies relevant for the Electron-Ion Collider (EIC). The production amplitude is evaluated while retaining the full transverse-momentum ( $ℓ_{t}$ ) dependence of the hard two-gluon kernel, that is, without expanding the impact-parameter Bessel kernel as is done in the small-size color-dipole limit. The quarkonia light-cone wave functions are built from Cornell-potential solutions of the Schrödinger equation, normalized to the measured leptonic widths, and combined with a modern collinear gluon distribution. After benchmarking the framework against the full set of HERA charmonium cross-section ratio data, we provide a consistent set of bottomonium cross-section ratio predictions in EIC kinematics. We find that the full $ℓ_{t}$ -resolved treatment systematically improves the description of the radially excited states relative to the leading dipole limit, and we identify the kinematic windows where this difference is largest.
Comments:
8 pages, 7 figures, 2 tables, includes supplemental material, accepted in Physical Review D as a Letter
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2606.18854 [pdf]
PRD(2026)·0 citations
07
[Submitted on 17 Jun 2026] (cross-list from hep-ph)
Three-body unitary determination of the $f_{1} (1285)$ and $f_{1} (1420)$ pole positions
Tao-Ran Hu🇨🇳 · Hai-Long Fu🇩🇪 · Feng-Kun Guo🇨🇳 · Ulf-G. Meißner🇩🇪 · Xu Zhang🇨🇳
We study the $I^{G} (J^{P C}) = 0^{+} (1^{++})$ $K K ˉ π$ system in an infinite-volume three-body unitary framework, focusing on the pole content of the region of the $f_{1} (1285)$ and $f_{1} (1420)$ resonances. The coupled $π a_{0}$ - $K K ˉ^{*}$ amplitude is constructed in the spectator-isobar representation, where the one-particle-exchange interaction required by three-body unitarity automatically incorporates the triangle-singularity mechanism. The short-range three-body interaction is constrained by fitting the $0^{+} (1^{++})$ component of the BESIII $K_{S}^{0} K_{S}^{0} π^{0}$ invariant-mass distribution in the $J / ψ \to γ (K_{S}^{0} K_{S}^{0} π^{0})$ decay. Analytically continuing the fitted amplitude to the relevant unphysical Riemann sheets, we find two robust poles: \begin{align} \sqrt{s_{f_1(1285)}}&= \left(1277\pm2\pm1\right) -i\left(12\pm1\pm0\right)\text{MeV}\,,\notag\\ \sqrt{s_{f_1(1420)}}&= \left(1435\pm2\pm7\right) -i\left(40\pm2\pm1\right)\text{MeV}\,.\notag \end{align} The pole trajectories indicate that the $f_{1} (1285)$ originates from dressing a bare state introduced in the potential. In contrast, the $f_{1} (1420)$ is predominantly dynamically generated, and a single-channel analysis traces it to an $S$ -wave $K K ˉ^{*}$ quasi-bound state mixed with the nearby bare state, supporting its hadronic-molecule interpretation. We also find an additional pole deeper in the complex plane in the best-fit amplitude on the same Riemann sheet as the $f_{1} (1285)$ . This additional pole is generated by the $P$ -wave $π a_{0}$ contact interaction alone. It has a sizable cutoff and two-body-input dependence, and leaves little visible imprint on the physical lineshape. Finally, we provide a detailed and pedagogical appendix on how three-body cuts affect the solution of the integral equation.
Comments:
35 pages, 14 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2606.19040 [pdf]
0 citations

Affiliations

first authorsco-authorsvia INSPIRE

First Measurement of the K− Escape Cross Section in the 12C(K−,p) Reaction

The electromagnetic decay of 250mNo and the stability of neutron deficient Rf isotopes

Diffractive Production of Heavy Quarkonia at the Electron Ion Collider

Three-body unitary determination of the f1​(1285) and f1​(1420) pole positions

Affiliations

First Measurement of the $K^{-}$ Escape Cross Section in the $^{12} C (K^{-}, p)$ Reaction

The electromagnetic decay of $^{250 m}$ No and the stability of neutron deficient Rf isotopes

Three-body unitary determination of the $f_{1} (1285)$ and $f_{1} (1420)$ pole positions