Thu·Jul 11, 2019Thursday·July 11, 2019

1. 01*

   Measurement of ${}^{139}$La(p,x) Cross Sections from 35-60 MeV by Stacked-Target Activation

   Jonathan T. Morrell🇺🇸 · Andrew S. Voyles🇺🇸 · M. S. Basunia · Jon C. Batchelder🇺🇸 · Eric F. Matthews · Lee A. Bernstein

   A stacked-target of natural lanthanum foils (99.9119% ${}^{139}$La) was irradiated using a 60 MeV proton beam at the LBNL 88-Inch Cyclotron. ${}^{139}$La(p,x) cross sections are reported between 35-60 MeV for nine radionuclides. The primary motivation for this measurement was the need to quantify the production of ${}^{134}$Ce. As a positron-emitting analogue of the promising medical radionuclide ${}^{225}$Ac, ${}^{134}$Ce is desirable for in vivo applications of bio-distribution assays for this emerging radio-pharmaceutical. The results of this measurement were compared to the nuclear model codes TALYS, EMPIRE and ALICE (using default parameters), which showed significant deviation from the measured values.

   nucl-exphysics.med-phEPJA(2020)·15 citations
2. 02*

   Masses of ground and isomeric states of ${}^{101}$In and configuration-dependent shell evolution in odd-$A$ indium isotopes

   X. Xu · J. H. Liu · C. X. Yuan · Y. M. Xing🇨🇳 · M. Wang · Y. H. Zhang · X. H. Zhou · Yu. A. Litvinov · K. Blaum🇩🇪 · R. J. Chen · X. C. Chen · C. Y. Fu🇨🇳 and 31 other authors

   We report first precision mass measurements of the $1/2^{-}$ isomeric and $9/2^{+}$ ground states of ${}^{101}$In. The determined isomeric excitation energy continues a smooth trend of odd-$A$ indium isotopes up to the immediate vicinity of $N=50$ magic number. This trend can be confirmed by dedicated shell model calculations only if the neutron configuration mixing is considered. We find that the single particle energies are different for different states of the same isotope. The presented configuration-dependent shell evolution, type II shell evolution, in odd-$A$ nuclei is discussed for the first time. Our results will facilitate future studies of single-particle neutron states.

   nucl-exnucl-thPRC(2019)·21 citations
3. 03*

   Response of CsI[Na] to Nuclear Recoils: Impact on Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS)

   J.I. Collar🇺🇸 · A.R.L. Kavner🇺🇸 · C.M. Lewis🇺🇸

   A new measurement of the quenching factor for low-energy nuclear recoils in CsI[Na] is presented. Past measurements are revisited, identifying and correcting several systematic effects. The resulting global data are well-described by a physics-based model for the generation of scintillation by ions in this material, in agreement with phenomenological considerations. The uncertainty in the new model is reduced by a factor of four with respect to an energy-independent quenching factor initially adopted as a compromise by the COHERENT collaboration. A significantly improved agreement with Standard Model predictions for the first measurement of CE$\nu$NS is generated. We emphasize the critical impact of the quenching factor on the search for new physics via CE$\nu$NS experiments.

   nucl-exhep-exhep-phPRD(2019)·62 citations
4. 04*

   Hyperon production in ${\Lambda }_c^{+}\to K^{-}p{\pi }^{+}$ and ${\Lambda }_c^{+}\to K_S^{0}p{\pi }^0$

   Jung Keun Ahn🇰🇷 · Seongbae Yang🇰🇷 · Seung-il Nam🇰🇷

   We investigate $S=-1$ hyperon production from the ${\Lambda }_c^{+}\to K^{-}p{\pi }^{+}$ and ${\Lambda }_c^{+}\to K_S^{0}p{\pi }^0$ decays within the effective Lagrangian approach. We consider the $\Sigma /\Lambda$ ground states, $\Lambda (1520)$, $\Lambda (1670)(J^p=1/2^{-})$, $\Lambda (1890)(J^p=3/2^{+})$; $\Lambda /\Sigma$-pole contributions from the combined resonances between 1800 MeV and 2100 MeV; and $N/\Delta$-pole and $K^{\ast }$-pole contributions, which include the proton, $\Delta (1232)$, and $K(892)$. We calculate the Dalitz plot density $(d^2\Gamma /d{M}_{K^{-}p}d{M}_{K^{-}{\pi }^{+}}$) for the ${\Lambda }_c^{+}\to K^{-}p{\pi }^{+}$ decay. The calculated result is in good agreement with experimental data from the Belle Collaboration. Using the parameters from the fit, we present the Dalitz plot density for the ${\Lambda }_c^{+}\to K_S^{0}p{\pi }^0$ decay. In our calculation, a sharp peak-like structure near 1665 MeV is predicted in the ${\Lambda }_c^{+}\to K^{-}p{\pi }^{+}$ decay because of the interference effects between the $\Lambda (1670)$ resonance and $\eta$-$\Lambda$ loop channels. We also demonstrate that we can access direct information regarding the weak couplings of $\Lambda (1670)$ and $\Sigma (1670)$ from the ${\Lambda }_c^{+}\to K_S^{0}p{\pi }^0$ decay. Finally, a possible interpretation for the 1665 MeV structure beyond our prediction is briefly discussed.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2019)·11 citations
5. 05*

   Performance study of a directional fast neutron detection system based on TPC and plastic scintillation detectors

   Yidong Fu · Yang Tian · Yulan Li🇨🇳 · Yigang Yang · Yiming Cai🇺🇸 · Jian Yang · Jin Li (Department of Engineering Physics, Tsinghua University)

   A neutron time projection chamber can locate the approximate direction of a neutron hot spot with high efficiency and a 4{\pi} field of view. The angular resolution can be significantly improved by adding several plastic scintillation detectors and using coincidence events. The specific performances of such a coincidence imaging system are studied based on theoretical calculations and experimental results. The calculated value of the angular resolution is approximately 2{\deg} for the current system, which agrees well with the experimental results and sets an upper limit for the angular resolution of traditional back projection based online reconstruction methods. Although the statistical iterative method can breakthrough this limit and further improve the angular resolution, the time consumption is usually a problem. The coincidence imaging system can be further optimized for future applications based on the theoretical model.

   ↳ physics.ins-detnucl-exJINST(2019)·0 citations
6. 06*

   Microscopic studies of production cross sections in multinucleon transfer reaction ${}^{58}$Ni+${}^{124}$Sn

   Zhenji Wu🇨🇳 · Lu Guo

   \item[Background] Multinucleon transfer reaction at low-energy collisions is considered to be a promising method for the production of new exotic nuclei, which are difficult to be produced by other methods. The theoretical studies are required to provide reliable predictions for the experiments and promote the understanding of the microscopic mechanism in multinucleon transfer reactions. \item[Purpose] We provide a predictive approach for production cross sections, and testify how and to what extent the microscopic approach works well in multinucleon transfer reaction. \item[Methods] We employ the approach TDHF+GEMINI, which combines the microscopic time-dependent Hartree-Fock (TDHF) with the state-of-art statistical model GEMINI++, to take into account both the multinucleon transfer dynamics and the secondary deexcitation process. The properties of primary products in multinucleon transfer process, such as transfer probabilities and primary cross sections, are extracted from TDHF dynamics by using the particle-number projection method. Production cross sections for secondary products are evaluated by using the statistical model GEMINI++. \item[Results] We investigate the influence of colliding energies and deformation orientations of target and projectile nuclei on multinucleon transfer dynamics in the reaction ${}^{58}$Ni+${}^{124}$Sn...... \item[Conclusions] The microscopic approach TDHF+GEMINI reasonably reproduces the experimental data at energies close to the Coulomb barrier and well accounts for the multinucleon transfer mechanism. The present studies clearly reveal the applicability of TDHF+GEMINI method in multinucleon transfer reactions, which thus deserves as a promising tool to predict the properties of new reactions.

   ↳ nucl-thnucl-exPRC(2019)·73 citations
7. 07*

   Effect of Octupole correlations on Fission of Light Nuclei

   Guillaume Scamps🇧🇪 · Cédric Simenel🇦🇺

   Fission of ${}^{180}$Hg produces mass asymmetric fragments which are expected to be influenced by deformed shell-effects at N=56 in the heavy fragment and Z=34 in the light fragment [G. Scamps and C. Simenel, arXiv:1904.01275 (2019)]. To investigate both shell-effects and to determine which one has the main influence on the asymmetry in the region of the ${}^{180}$Hg, we produce a systematic of Constraint-Hartree-Fock calculations in nuclei with similar N/Z ratio than the ${}^{178}$Pt. It is found that N=56 determines the asymmetry of systems in this region of the nuclear chart.

   ↳ nucl-thnucl-exJPS Conf.Proc.(2020)·0 citations
8. 08*

   Coulomb Energy Density Functionals for Nuclear Systems: Recent Studies of Coulomb Exchange and Correlation Functionals

   Tomoya Naito🇯🇵 · Ryosuke Akashi · Gianluca Colò🇮🇹 · Haozhao Liang🇯🇵 · Xavier Roca-Maza🇮🇹

   The Coulomb exchange and correlation energy density functionals for electron systems are applied to nuclear systems. It is found that the exchange functionals in the generalized gradient approximation provide agreements with the exact-Fock energy with one adjustable parameter within a few dozen $\mathrm{keV}$ accuracy, whereas the correlation functionals are not directly applicable to nuclear systems due to the existence of the nuclear force.

   ↳ nucl-thnucl-exEPJ Web Conf.(2019)·0 citations
9. 09*

   Characterization of the new Data Acquisition System and the detector alignment of the aSPECT experiment

   Romain Virot🇫🇷

   From April 2013 to the beginning of August 2013, the aSPECT spectrometer was installed on a cold neutron beam facility at the Institut Laue-Langevin (ILL) in order to realize a high-precision measurement of the electron-antineutrino angular correlation coefficient a. Among all the upgrades that were made during the past years, a new state-of-the-art acquisition system has been tested during this beam time. This internship report details the behavior of this new system.

   ↳ physics.ins-detnucl-ex0 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.