Nuclear Experiment·nucl-ex

Fri·Jul 3, 2026Friday·July 3, 2026

6 papers—2 primary·4 cross-listed

01
$l$ -forbidden $M1$ strengths near $^{100}$ Sn from knockout reactions in Cd and Sn
T. J. Gray🇺🇸 · K. L. Jones · R. Grzywacz🇺🇸 · B. A. Brown🇺🇸 · A. Gade🇺🇸 · B. C. He · T. Miyagi🇩🇪 · A. Peter · M. J. Basson🇺🇸 · T. Beck · C. M. Campbell🇺🇸 · G. Cerizza🇺🇸 and 12 other authors
Neutron knockout reactions on beams of $^{104, 102}$ Cd, and $^{104}$ Sn are presented. States in the residual $^{103, 101}$ Cd and $^{103}$ Sn nuclei are populated, including low-lying $7/ 2^{+}$ states of $ν g_{7/2}$ character. These states have half-lives $\approx 400$ ps due to their low energy and hindered $B (M 1; 7/ 2^{+} \to 5/ 2^{+})$ strengths. The excited-state half-lives were measured using their Doppler-shifted lineshapes, and the resulting $B (M 1)$ strengths are compared to Valence Space In Medium Similarity Renormalization Group (VS-IMSRG) calculations. The VS-IMSRG calculations under-predict the $l$ -forbidden $M 1$ strengths in the $^{100}$ Sn region, as well as in other regions of the nuclear chart near $^{40}$ Ca and $^{208}$ Pb.
nucl-exPRC(2026)·0 citations
02
Gamma-ray production cross sections in proton interactions with natMg, natSi and 56Fe targets: measurement over the energy range of $E_{p} = 66$ -125 MeV, data analysis, results and discussion. Astrophysical implications
M. Debabi🇩🇿 · S. Ouichaoui🇩🇿 · A. Belhout🇩🇿 · J. Kiener🇫🇷 · E. A. Lawrie🇿🇦 · J. J. Lawrie🇿🇦 · D. Moussa🇩🇿 · W. Yahia-Cherif🇿🇦 · Y. Rahma🇩🇿 · H. Benhabiles-Mezhoud🇩🇿 · A. Trabelsi🇩🇿 · T. D. Bucher🇿🇦 and 24 other authors
We have measured nuclear gamma-ray line production cross sections in interactions of highly accelerated proton beams with various target nuclei abundant in astrophysical sites. The experiments were carried out at the 200-MV Separated Sector Cyclotron (SSC) of iThemba LABS (near Cape Town, in South Africa) using a high-energy resolution and high efficiency detection system for registering the emitted gamma-ray photons. We report and discuss in this paper the collected experimental data sets for various gamma-ray lines produced in bombarding natMg, natSi and 56Fe targets with proton beams of incident energies of Ep = 66, 80, 95, 110 and 125 MeV. After describing the experimental set up and the data analysis method used, we report and discuss our total experimental cross section results in comparisons to previous counterparts from the literature, to a semi-empirical compilation and to the predictions of nuclear reaction theory via performed TALYS code calculations. Significantly improved agreements between theory and experiment are point out when using our modified optical model potential and Bêta (lambda) level deformation parameters instead of the default input parameters built in TALYS. Finally, we put into perspective the applications of our results in nuclear physics and astrophysics with drawing relevant conclusions. gammaKeywords: Proton-induced nuclear reactions; gamma-ray production cross sections; gamma-ray spectrometry; gamma-ray spectroscopy; Astrophysical implications
nucl-ex0 citations
03
Nuclear shell evolution near N = 6, 14, 20 and 28: insights from nuclear charge radii of short-lived nuclei derived from binding energies
Xingquan Liu🇨🇳 · Wanjun Chen🇨🇳 · Xing Xu🇨🇳 · Yi Hua Lam🇨🇳 · Hua Zheng🇨🇳 · Jianfeng Han · Weiping Lin · Xi Duan · Xin Zhang🇨🇳 · Peipei Ren
A deep understanding of the evolution of nuclear shell structure correlating with the nucleon number is crucial for unraveling the fundamental properties of the nuclear structure and for exploring new nuclear physics phenomena far from the $β$ -stability line. Although significant progress has been made in probing nuclear shell evolution via the measurements of nuclear root-mean-square charge radii, $R_{ch}$ , the scarcity of new data for short-lived and exotic nuclei due to the increasing difficulty of measurements presents a formidable challenge in obtaining deeper and more universal insights into the nature of shell evolution. To mitigate this issue, we develop an improved method, accounting for the exchange term, charge-symmetry breaking effect, and odd-even staggering effect in the Coulomb energy formulation compared with that proposed by Liu et al. [Phys. Lett. B 872, 140046 (2026)], to determine unmeasured $R_{ch}$ values. Using the improved method, the $R_{ch}$ values of 59 nuclei are determined from their measured binding energies ( $B$ ) and the respective $B$ and $R_{ch}$ of their mirror partners. We then systematically study the shell evolution near $N = 6$ , 14, 20 and 28 (sub)shells by placing the newly obtained $R_{ch}$ values into the corresponding isotopic chains. More comprehensive insights into the properties of nuclear shell evolution, particularly for the neutron-deficient sectors of the studied shell regions, e.g., $p$ , $s d$ and $p f$ shells, are acquired, advancing our understanding of nuclear shell evolution in the light and intermediate mass region.
↳ nucl-thnucl-ex0 citations
04
Determining the dynamic deformation of $^{140}$ Ce by constraining coupled-channels parameters for fusion
Chandra Kumar🇮🇳 · Rohan Biswas · J. Gehlot · Gonika · A. Parihari · N. Madhavan · A. Vinayak · Amritraj Mahato · S. Nath
We present a systematic study of the dynamic deformation of 140Ce using 16O and 36S projectiles in heavy-ion fusion reactions, combining experimental data, a Gaussian analytic-barrier framework and coupled-channels calculations. Fusion cross sections for 16O+140Ce are measured from ~17% above to ~12.4% below the Bass barrier. Fusion data for 36S+140Ce are obtained from the literature. Deformation parameters of 140Ce are extracted via chi-square minimization and Bayesian analysis, with independent Bayesian Model Averaging yielding beta_2 = 0.09 +/- 0.03 and beta_3 = 0.18 +/- 0.02, consistent across both systems. The extracted parameters are tested in the 28Si+140Ce system, where coupled-channels calculations including transfer of a pair of neutrons (2n) reproduce both the fusion excitation function and the barrier distribution. The positive Q-value 2n-pickup channel enhances fusion in this reaction, while the projectile's vibrational or rotational nature results in similar structure of the barrier distribution. This study demonstrates that the Gaussian analytic recipe is quite effective in deriving the fusion barrier distribution which proves to be a sensitive probe of intrinsic nuclear deformation. Further, coupled-channels analysis across multiple systems ensures robustness of the extracted deformation parameters.
↳ nucl-thnucl-ex0 citations
05
Event-axis TMD measurements in $e^{+} e^{-}$ and SIDIS
Daniel Diaz Fernandez🇪🇸 · Patricia Andrea Gutierrez Garcia🇪🇸 · Ignazio Scimemi🇪🇸 · Wouter Waalewijn🇳🇱
Transverse-momentum-dependent (TMD) fragmentation in $e^{+} e^{-}$ collisions can be studied by measuring hadrons with respect to the thrust axis, and has been measured at Belle. This provides a complementary way to extract TMD fragmentation functions, avoiding the need to disentangle the two TMD fragmentation functions that enter conventional back-to-back hadron-pair measurements. Starting from the established factorization theorems for this observable, we complete the operator-level formulation of the soft ingredients and perform one-loop checks using the $δ$ -regulator. We also extend existing results for 1-jettiness factorization in semi-inclusive deep-inelastic scattering (SIDIS), where analogous measurements give access to the TMD parton distribution functions of the incoming hadron. For phenomenology, we discuss the nonperturbative effects and propose a model that captures both the event-shape dependence and correlations between the event-shape and transverse-momentum measurements. We resum the transverse-momentum and thrust logarithms, explore several schemes for treating the latter, and implement it in artemide. As a first validation, we compare to simulated $e^{+} e^{-}$ data from Pythia8.3. We find that the proposed nonperturbative model is flexible enough to describe the simulated data, with fitted parameters of the expected size in powers of $Λ_{QCD} / Q$ . In this test, the resummation of the logarithms of $q_{T} / (τ Q)$ appears to have little impact on the fit quality, but changes the fit parameters.
↳ hep-phhep-exnucl-exnucl-th2 citations
06
Transverse-spin dependent energy-energy correlators in proton-proton collisions within the dihadron fragmentation framework
Zhong-Bo Kang🇺🇸 · Andreas Metz🇺🇸 · Daniel Pitonyak🇺🇸 · Congyue Zhang🇺🇸
We calculate energy-energy correlations for two hadrons produced inside a jet in transversely polarized proton-proton collisions. We make numerical predictions based on a simple model that utilizes a previous global QCD analysis of dihadron fragmentation and transversity parton distribution functions. The results show remarkable agreement with a very recent STAR measurement. We also find the data at large jet transverse momentum have a slight preference for extractions of transversity that are consistent with lattice QCD computations of the nucleon tensor charges. Overall, this work provides further evidence for the underlying non-perturbative mechanism of near-side energy-energy correlators as well as highlights the potential for these observables to probe transverse-spin effects inside the nucleon.
↳ hep-phhep-exnucl-exnucl-th1 citation

Affiliations

first authorsco-authorsvia INSPIRE

l-forbidden M1 strengths near 100Sn from knockout reactions in Cd and Sn

Gamma-ray production cross sections in proton interactions with natMg, natSi and 56Fe targets: measurement over the energy range of Ep​=66-125 MeV, data analysis, results and discussion. Astrophysical implications

Nuclear shell evolution near N = 6, 14, 20 and 28: insights from nuclear charge radii of short-lived nuclei derived from binding energies

Determining the dynamic deformation of 140Ce by constraining coupled-channels parameters for fusion

Event-axis TMD measurements in e+e− and SIDIS

Transverse-spin dependent energy-energy correlators in proton-proton collisions within the dihadron fragmentation framework

Affiliations

$l$ -forbidden $M1$ strengths near $^{100}$ Sn from knockout reactions in Cd and Sn

Gamma-ray production cross sections in proton interactions with natMg, natSi and 56Fe targets: measurement over the energy range of $E_{p} = 66$ -125 MeV, data analysis, results and discussion. Astrophysical implications

Determining the dynamic deformation of $^{140}$ Ce by constraining coupled-channels parameters for fusion

Event-axis TMD measurements in $e^{+} e^{-}$ and SIDIS