Wed·Jul 12, 2023Wednesday·July 12, 2023

1. 01*

   Decay Pattern of Pygmy States Observed in Neutron-Rich 26 Ne

   J. Gibelin🇫🇷 · D. Beaumel🇫🇷 · T. Motobayashi🇯🇵 · Y. Blumenfeld🇫🇷 · N. Aoi🇯🇵 · H. Baba🇯🇵 · Z. Elekes🇭🇺 · S. Fortier🇫🇷 · N. Frascaria🇫🇷 · N. Fukuda🇯🇵 · T. Gomi🇯🇵 · K. Ishikawa🇯🇵 and 14 other authors

   Coulomb excitation of the exotic neutron-rich nucleus Ne26 on a Pb208 target was measured at 58 MeV/u in order to search for low-lying E1 strength above the neutron emission threshold. This radioactive beam experiment was carried out at the RIKEN Accelerator Research Facility. Using the invariant mass method in the Ne25+n channel, we observe a sizable amount of E1 strength between 6 and 10 MeV excitation energy. By performing a multipole decomposition of the differential cross section, a reduced dipole transition probability of B(E1)=0.49+-0.16e2fm2 is deduced, corresponding to 4.9+-1.6% of the Thomas-Reiche-Kuhn sum rule. For the first time, the decay pattern of low-lying strength in a neutron-rich nucleus is measured. The extracted decay pattern is not consistent with several mean-field theory descriptions of the pygmy states.

   nucl-exnucl-thPRL(2008)·45 citations
2. 02*

   New Measurements of ${}^{71}$Ge Decay: Impact on the Gallium Anomaly

   J.I. Collar🇺🇸 · S.G. Yoon🇺🇸

   A dedicated high-statistics measurement of the ${}^{71}$Ge half-life is found to be in accurate agreement with an accepted value of 11.43$\pm$0.03 d, eliminating a recently proposed route to bypass the "gallium anomaly" affecting several neutrino experiments. Our data also severely constrain the possibility of ${}^{71}$Ge decay to low-energy excited levels of the ${}^{71}$Ga daughter nucleus as a solution to this puzzle. Additional unpublished measurements of this decay are discussed. Following the incorporation of this new information, the gallium anomaly survives with high statistical significance.

   nucl-exhep-exhep-phnucl-thPRC(2023)·13 citations
3. 03*

   Metastability exchange optical pumping of ${}^3$He at low pressure and high magnetic field

   X. Li🇨🇳 · J. D. Maxwell🇺🇸 · D. Nguyen🇺🇸 · J. Brock🇺🇸 · C. D. Keith🇺🇸 · R. G. Milner🇺🇸 · X. Wei🇺🇸

   Systematic studies on metastability exchange optical pumping of ${}^3$He nuclei have been performed at Jefferson Lab using a 1-torr sealed cell at magnetic fields from 2 to 4 T. The effects of the discharge intensity, pump laser power, and pumping transition schemes on achievable nuclear polarization and pumping rate have been investigated. A maximum steady-state nuclear polarization of about 75% has been obtained. This work provides a baseline for the development of the novel polarized ${}^3$He target for CLAS12 at Jefferson Lab.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2023)·4 citations
4. 04*

   Single-Inclusive Particle Production from $pA$ Collision at Next-to-Leading Order

   Heikki Mäntysaari🇫🇮 · Yossathorn Tawabutr🇫🇮

   We present the first fully consistent NLO calculation of the single-inclusive forward hadron production in proton-nucleus (pA) collisions under the color glass condensate (CGC) framework. In the dilute-dense limit, the NLO cross-section can be written as a convolution of the NLO impact factor, NLO parton distribution function (PDF), NLO fragmentation function (FF) and dipole-target scattering amplitude which satisfies the NLO small-$x$ Balitsky-Kovchegov (BK) evolution. We demonstrate that, without the NLO corrections to the impact factor, we obtain a significant Cronin peak when the dipole amplitude satisfies the NLO BK equation. This would contradict the recent LHCb results. However, the Cronin peak becomes suppressed when the NLO correction to the impact factor is included. This is the main result of this work. The dependence on resummation schemes for the NLO BK evolution will also be discussed.

   ↳ hep-phnucl-exnucl-th0 citations
5. 05*

   Determination of matter radius and neutron-skin thickness of ${}^{60,62,64}$Ni from reaction cross section of proton scattering on ${}^{60,62,64}$Ni targets (published in Results in Physics)

   Shingo Tagami🇯🇵 · Tomotsugu Wakasa🇯🇵 · Masanobu Yahiro🇯🇵

   In our previous work, we determined matter radii $r_{\mathrm{m}}(\exp )$ and neutron-skin thickness $r_{\mathrm{skin}}(\exp )$ from reaction cross sections ${\sigma }_{\mathrm{R}}(\exp )$ of proton scattering on ${}^{208}$Pb, ${}^{58}$Ni, ${}^{40,48}$Ca, ${}^{12}$C targets, using the chiral (Kyushu) $g$-matrix folding model with the densities calculated with Gogny-D1S-HFB (D1S-GHFB) with angular momentum projection (AMP). The resultant $r_{\mathrm{skin}}(\exp )$ agree with the PREX2 and CREX values. As for ${}^{58}$Ni, our value is consistent with one determined from the differential cross section for ${}^{58}$Ni+${}^4$He scattering. As for p+${}^{60,62,64}$N scattering, ${\sigma }_{\mathrm{R}}(\exp )$ are available as a function of incident energies $E_{\mathrm{in}}$, where $E_{\mathrm{in}}=22.8\sim 65.5$~MeV for ${}^{60}$Ni, $E_{\mathrm{in}}=40,60.8$~MeV for ${}^{62}$Ni, $E_{\mathrm{in}}=40,60.8$~MeV for ${}^{64}$Ni. Our aim is to determine matter radii $r_{\mathrm{m}}(\exp )$ for ${}^{60,62,64}$Ni from the ${\sigma }_{\mathrm{R}}(\exp )$. Our method is the Kyushu $g$-matrix folding model with the densities scaled from D1S-GHFB+AMP densities, Our skin values are $r_{\mathrm{skin}}(\exp )=0.076\pm 0.019,0.106\pm 0.192,0.162\pm 0.176$~fm, and $r_{\mathrm{m}}(\exp )=3.759\pm 0.011,3.811\pm 0.107,3.864\pm 0.101$~fm for ${}^{60,62,64}$Ni, respectively.

   ↳ nucl-thnucl-ex2 citations
6. 06*

   Heavy-flavor hadronization mechanism from pp to AA collisions: a theoretical perspective

   Andrea Beraudo🇮🇹

   The interest in studying heavy-flavor hadronization in high-energy nuclear collisions is twofold. On one hand hadronization represents a source of systematic uncertainties in phenomenological attempts of extracting heavy-flavor transport coefficients in the Quark Gluon Plasma which one assumes to be produced in the collision. Hence, developing the most possible reliable model for this process is important to get a precise and accurate estimate of a fundamental property of hot QCD. On the other hand studying how hadronization changes in the presence of a dense medium of colored partons can be considered an issue of interest by itself. In particular, the observation of modifications of heavy-flavor hadronization in proton-proton collisions strongly suggests that also in this case a small droplet of Quark-Gluon Plasma can be formed. Here we try to provide a general overview on heavy-flavor hadronization, from pp to AA collisions, stressing the aspects and challenges common to all mechanisms proposed in the literature. Then, focusing on a particular model, we show how a consistent description of several observables involving heavy-flavor hadrons can be obtained

   ↳ hep-phhep-exnucl-exnucl-thPoS(2024)·2 citations
7. 07*

   Impact of the ${}^6$Li asymptotic normalization constant onto $\alpha$-induced reactions of astrophysical interest

   Chloë Hebborn🇺🇸 · Melina L. Avila · Konstantinos Kravvaris🇺🇸 · Gregory Potel🇺🇸 · Sofia Quaglioni🇺🇸

   Indirect methods have become the predominant approach in experimental nuclear astrophysics for studying several low-energy nuclear reactions occurring in stars, as direct measurements of many of these relevant reactions are rendered infeasible due to their low reaction probability. Such indirect methods, however, require theoretical input that in turn can have significant poorly-quantified uncertainties, which can then be propagated to the reaction rates and have a large effect on our quantitative understanding of stellar evolution and nucleosynthesis processes. We present two such examples involving $\alpha$-induced reactions, ${}^{13}$C($\alpha ,n{)}^{16}$O and ${}^{12}$C$(\alpha ,\gamma {)}^{16}$O, for which the low-energy cross sections have been constrained with ${(}^6$Li$,d)$ transfer data. In this Letter, we discuss how a first-principle calculation of ${}^6$Li leads to a 21% reduction of the ${}^{12}$C$(\alpha ,\gamma {)}^{16}$O cross sections with respect to a previous estimation. This calculation further resolves the discrepancy between recent measurements of the ${}^{13}$C$(\alpha ,n{)}^{16}$O reaction and points to the need for improved theoretical formulations of nuclear reactions.

   ↳ nucl-thastro-ph.SRnucl-exPRC(2024)·12 citations
8. 08*

   Simultaneous study of scattering and fusion hindrance near Coulomb barrier in $F+Pb$ systems

   Kamala Kanta Jena · Bidhubhusan Sahu · Jajati K. Nayak🇮🇳 · Raj Preethi P · B. K. Sharma · Santosh Kumar Agarwalla

   A phenomenological optical potential is used to study the elastic angular distributions for the system ${}^{19}F{+}^{208}Pb$ close to the Coulomb barrier. This potential is constructed by taking into account the flexible potential developed by Ginocchio. The fluctuations in the real and imaginary parts of the optical model potential follow the trends of the threshold anomaly. The set of optical potential parameters needed to analyze the fusion cross sections of the same system are obtained through analysis of the scattering cross sections. Theoretical fusion cross-sections and results from four different experimental groups well agree for a range of energies. Several Fluorine (F) isotopes are used as projectiles in this study of fusion cross-sections by slightly altering the radial parameter. It was found that the fusion process occurs unfettered in the ${}^{19}F{+}^{208}Pb$ system below the Coulomb barrier but is seriously hindered in the case of its isotopic projectiles.

   ↳ nucl-thnucl-exActa Phys.Polon.B(2023)·5 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.