Mon·Nov 18, 2024Monday·November 18, 2024

1. 01*

   ${}^{11}$B states above the $\alpha$-decay threshold studied via ${}^{10}$B$(d,p){}^{11}$B

   A.N. Kuchera🇺🇸 · G. Ryan · G. Selby · D. Snider · S. Anderson · S. Almaraz-Calderon · L.T. Baby🇺🇸 · B.A. Brown🇺🇸 · K. Hanselman · E. Lopez-Saavedra🇺🇸 · K.T. Macon · G.W. McCann and 3 other authors

   The resonance region of ${}^{11}$B covering excitation energies from 8.4 MeV to 13.6 MeV was investigated with the $(d,p)$ reaction performed on an enriched ${}^{10}$B target at the Florida State University Super-Enge Split-Pole Spectrograph of the John D. Fox Superconducting Linear Accelerator Laboratory. Complementary measurements were performed with a target enriched in ${}^{11}$B to identify possible ${}^{12}$B contaminants in the $(d,p)$ reaction. Four strongly populated ${}^{11}$B states were observed above the $\alpha$-decay threshold. Angular distributions were measured and compared to DWBA calculations to extract angular momentum transfers and ${}^{10}\mathrm{B}\left(3^{+}\right)+n$ spectroscopic factors. The recently observed and heavily discussed resonance at 11.4 MeV in ${}^{11}$B was not observed in this work. This result is consistent with the interpretation that it is predominantly a ${}^{10}\mathrm{Be}\left(0^{+}\right)+p$ resonance with a possible additional ${}^7\mathrm{Li}+\alpha$ contribution. The predicted ${}^{10}\mathrm{B}\left(3^{+}\right)+n$ resonance at 11.6 MeV, analogous to the 11.4-MeV proton resonance, was not observed either. Upper limits for the ${}^{10}\mathrm{B}\left(3^{+}\right)+n$ spectroscopic factors of the 11.4-MeV and 11.6-MeV states were determined. In addition, supporting configuration interaction shell model calculations with the effective WBP interaction are presented.

   nucl-exnucl-thPRC(2024)·1 citation
2. 02*

   Proton removal from ${}^{73,75}$Br to ${}^{72,74}$Se at intermediate energies

   M. Spieker🇺🇸 · D. Bazin🇺🇸 · S. Biswas · P.D. Cottle🇺🇸 · P.J. Farris · A. Gade🇺🇸 · T. Ginter · S. Giraud🇫🇷 · K.W. Kemper🇺🇸 · J. Li🇨🇳 · S. Noji🇺🇸 · J. Pereira🇺🇸 and 4 other authors

   We report new experimental data for excited states of ${}^{72,74}$Se obtained from proton removal from ${}^{73,75}$Br secondary beams on a proton target. The experiments were performed with the Ursinus-NSCL Liquid Hydrogen Target and the combined GRETINA+S800 setup at the Coupled Cyclotron Facility of the National Superconducting Cyclotron Laboratory at Michigan State University. Within uncertainties, the inclusive cross sections for proton removal from ${}^{73,75}$Br on a proton target are identical suggesting that the same single-particle orbitals contribute to the proton-removal reaction. In addition, details of the partial cross section fragmentation are discussed. The data might suggest that $l=1,2,3$, and 4 angular momentum transfers are important to understand the population of excited states of ${}^{72,74}$Se in proton removal. Available data for excited states of ${}^{74}$Ge populated through the ${}^{75}$As$(d,{}^3\mathrm{He}){}^{74}$Ge proton-removal reaction in normal kinematics suggest indeed that the $fp$ and $sd$ shell as well as the $1g_{9/2}$ orbital contribute. A comparison to data available for odd-$A$ nuclei supports that the bulk of the spectroscopic strengths could be found at lower energies in the even-even Se isotopes than in, for instance, the even-even Ge isotopes. In addition, the population of high-$J$ states seems to indicate that multi-step processes contribute to proton-removal reactions at intermediate energies in these collective nuclei.

   nucl-exnucl-thPRC(2024)·1 citation
3. 03*

   Amplitude Analysis of $\omega {\pi }^0$ Photoproduction at GlueX

   Kevin Scheuer🇺🇸

   Excited meson states can often lie hidden within mass spectra beneath more dominant resonances, making it difficult to extract their physical properties. We can unveil these states through amplitude analysis, which disentangles the overlapping states via fits to their unique production and decay angular distributions. Understanding the light-meson spectrum is essential for confirming Lattice QCD predictions, especially in regards to the search for possible hybrid mesons. The Gluonic Excitation (GlueX) experiment at Jefferson Lab aids this search by studying the production of excited light mesons in $\gamma p$ interactions in the 8.2 - 8.8 GeV photon-beam energy range. We show in these proceedings preliminary results of an amplitude analysis of a large $\omega {\pi }^0$ dataset, concentrating on measuring the interference between the $b_1(1235)$ and an excited $J^{PC}=1^{--}$ vector resonance.

   nucl-exhep-exPoS(2025)·2 citations
4. 04*

   Study of the $i{n}^{34}$Ar($\alpha ,p$)${}^{37}$K reaction rate via proton scattering on ${}^{37}$K, and its impact on properties of modeled X-Ray bursts

   A. Lauer-Coles🇺🇸 · C. M. Deibel🇺🇸 · J. C. Blackmon🇺🇸 · A. Hood🇺🇸 · E. C. Good🇺🇸 · K. T. Macon · D. Santiago-Gonzalez🇺🇸 · H. Schatz🇺🇸 · T. Ahn🇺🇸 · J. Browne · F. Montes🇺🇸 · K. Schmidt🇩🇪 and 12 other authors

   Background: Type I X-Ray bursts (XRBs) are energetic stellar explosions that occur on the surface of a neutron star in an accreting binary system with a low-mass H/He-rich companion. The rate of the ${}^{34}$Ar($\alpha ,p$)${}^{37}$K reaction may influence features of the light curve that results from the underlying thermonuclear runaway, as shown in recent XRB stellar modelling studies. Purpose: In order to reduce the uncertainty of the rate of this reaction, properties of resonances in the compound nucleus ${}^{38}$Ca, such as resonance energies, spins, and particle widths, must be well constrained. Method: This work discusses a study of resonances in the ${}^{38}$Ca compound nucleus produced in the ${}^{34}$Ar($\alpha ,p$) reaction. The experiment was performed at the National Superconducting Cyclotron Laboratory, with the ReA3 facility by measuring proton scattering using an unstable ${}^{37}$K beam. The kinematics were designed specifically to identify and characterize resonances in the Gamow energy window for the temperature regime relevant to XRBs. Results: The spins and proton widths of newly identified and previously known states in ${}^{38}$Ca in the energy region of interest for the ${}^{34}$Ar($\alpha ,p$)${}^{37}$K reaction have been constrained through an R-Matrix analysis of the scattering data. Conclusions: Using these constraints, a newly estimated rate is applied to an XRB model built using Modules for Experiments in Stellar Astrophysics (MESA), to examine its impact on observables, including the light curve. It is found that the newly determined reaction rate does not substantially affect the features of the light curve.

   nucl-exPRC(2026)·1 citation
5. 05*

   Nuclear Dependence of Beam Normal Single Spin Asymmetry in Elastic Scattering from Nuclei

   Ciprian Gal🇺🇸 · Chandan Ghosh🇺🇸 · Sanghwa Park🇺🇸 · Devi Adhikari🇺🇸 · David Armstrong🇺🇸 · Rakitha Beminiwattha🇺🇸 · Alexandre Camsonne🇺🇸 · Shashini Chandrasena · Mark Dalton🇺🇸 · Abhay Deshpande · Dave Gaskell🇺🇸 · Douglas Higinbotham🇺🇸 and 15 other authors

   We propose to measure the beam normal single spin asymmetry in elastic scattering of transversely polarized electron from target nuclei with 12 $\le Z\le$ 90 at Q${}^2$ = 0.0092 GeV${}^2$ to study its nuclear dependence. While the theoretical calculations based on two-photon exchange suggest no nuclear dependence at this kinematics, the results of 208Pb from Jefferson Lab show a striking disagreement from both theoretical predictions and light nuclei measurements. The proposed measurements will provide new data for intermediate to heavy nuclei where no data exists for $Z\ge$ 20 in the kinematics of previous high-energy experiments. It will allow one to investigate the missing contributions that are not accounted in the current theoretical models.

   nucl-ex2 citations
6. 06*

   The hyperfine anomaly in mercury and test of the Moskowitz-Lombardi rule

   J. Vandeleur🇦🇺 · G. Sanamyan🇦🇺 · B. M. Roberts🇦🇺 · J. S. M. Ginges🇦🇺

   The Moskowitz-Lombardi rule gives a simple relation between the magnetic moment of an atomic nucleus and the effect of its radial distribution on the hyperfine structure - the magnetic hyperfine anomaly or "Bohr-Weisskopf" effect. It was originally formulated for mercury, for which experimental data for nuclear magnetic moments and hyperfine constants were available for a number of isotopes. While the relation for the differential effect between isotopes may be completely determined experimentally, the value for the additive constant that is needed to give the Bohr-Weisskopf (BW) effect for a single isotope has remained untested. In this work, we determine the BW effect in singly-ionized and neutral mercury from experimental muonic Hg-199 data together with our atomic calculations. We check this result by directly extracting the BW effect from the hyperfine constant for singly-ionized Hg-199 using state-of-the-art atomic many-body calculations. From this we deduce an empirical value for the additive constant in the Moskowitz-Lombardi rule, which differs significantly from the values advocated previously.

   ↳ physics.atom-phnucl-exnucl-thPRA(2025)·0 citations
7. 07*

   Studying charm hadronisation into baryons with azimuthal correlations of ${\Lambda }_{\mathrm{c}}^{+}$ with charged particles in pp collisions at $\sqrt{s}=13$ TeV

   ALICE Collaboration

   The distribution of angular correlations between prompt charm hadrons and primary charged particles in pp collisions is sensitive to the charm-quark hadronisation process. In this letter, charm-baryon correlations are measured for the first time by studying the azimuthal-angle difference between charged particles and prompt ${\Lambda }_{\mathrm{c}}^{+}$ baryons produced in pp collisions at a centre-of-mass energy of $\sqrt{s}=13$ TeV, with the ALICE detector. ${\Lambda }_{\mathrm{c}}^{+}$ baryons are reconstructed at midrapidity ($|y|<0.5$) in the transverse-momentum interval $3<p_{\mathrm{T}}<16$ GeV/$c$, and correlated with charged particles with $p_{\mathrm{T}}>0.3$ GeV/$c$ and pseudorapidity $|\eta |<0.8$. For $3<p_{\mathrm{T}}^{{\Lambda }_{\mathrm{c}}^{+},\mathrm{D}}<5$ GeV/$c$, the comparison with published measurements of D-meson and charged-particle correlations in the same collision system hints at a larger number of low-momentum particles associated with ${\Lambda }_{\mathrm{c}}^{+}$-baryon triggers than with D-meson triggers, both in the collinear and opposite directions with respect to the trigger particle. These differences can be quantified by the comparison of the properties of the near- and away-side correlation peaks, and are not reproduced by predictions of various Monte Carlo event generators, generally underpredicting the associated particle yields at $p_{\mathrm{T}}^{\mathrm{assoc}}<1$ GeV/$c$. This tension between ${\Lambda }_{\mathrm{c}}^{+}$-baryon and D-meson associated peak yields could suggest a modified fragmentation of the charm quark, or a different hadronisation process, when a charm baryon is produced in the final state.

   ↳ hep-exnucl-exPLB(2025)·3 citations
8. 08*

   Dynamic scaling and quenching for heavy quark in the linear expanding medium

   Boris Blok (Technion)🇩🇪 · Chang Wu (Technion)🇩🇪

   We show that scaling is a good approximation for the energy loss of the heavy quark propagating through linear expanding quark-gluon plasma (QGP), the effective quenching parameter does not depend on quark mass.

   ↳ hep-phnucl-exnucl-thEPJC(2026)·1 citation

* 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.