Mon·Nov 13, 2023Monday·November 13, 2023

1. 01*

   Total cross sections for the reactions ${}^{10,11,12}$Be+${}^{28}$Si and ${}^{14}$B+${}^{28}$Si

   Yu. G. Sobolev🇷🇺 · S. S. Stukalov🇷🇺 · Yu. E. Penionzhkevich🇷🇺 · M. A. Naumenko · V. V. Samarin

   In this paper, the results of measurements of the total cross sections for the reactions ${}^{10,11,12}$Be+${}^{28}$Si and ${}^{14}$B+${}^{28}$Si in the beam energy range $13A$--$47A$ MeV are presented. The experimental cross sections were obtained by detection of the gamma quanta and neutrons accompanying the interaction of the isotopes of Be and B with ${}^{28}$Si. It was found that the cross sections for ${}^{11,12}$Be are similar, but significantly exceed those for ${}^{10}$Be. A significant increase in the cross sections for ${}^{12}$Be with decreasing energy is observed in the entire measured energy range. A theoretical explanation of the obtained experimental data is given based on the microscopic model of deformed nuclei and the numerical solution of the time-dependent Schrödinger equation for the outer weakly bound neutrons of the projectile nuclei. The calculated total reaction cross sections are in good agreement with the experimental data.

   nucl-ex0 citations
2. 02*

   Fast neutron production at the LNL Tandem from the ${}^7$Li(${}^{14}$N,xn)X reaction

   Pablo Torres-Sánchez (1)🇪🇸 · Hans Th. J. Steiger (2 and 3) · Pierfrancesco Mastinu (4)🇮🇹 · Jeffery L. Wyss (5 and 6) · Lennard Kayser (2) · Luca Silvestrin (5 and 7) · Elizabeth Musacchio-González (4)🇮🇹 · Matthias Raphael Stock (2)🇩🇪 · David Dörflinger (2) · Ulrike Fahrendholz (2)🇩🇪 · Gianfranco Prete (7) · Osvaldo Carletto (4) · Lothar Oberauer (2)🇩🇪 · Ignacio Porras (1) ((1) Dept. Atomic, Molecular and Nuclear Physics, University of Granada, Spain, (2) Technical University of Munich, TUM School of Natural Sciences, Physics Department, Garching, Germany, (3) Cluster of Excellence PRISMA$^{+}$, Johannes Gutenberg University Mainz, Mainz, Germany, (4) Istituto Nazionale di Fisica Nucleare, Legnaro Division, Legnaro, Italy, (5) Istituto Nazionale di Fisica Nucleare, Padova Division, Padova, Italy, (6) University of Cassino and Southern Lazio, Dipartimento di Ingegneria Civile e Meccanica, Cassino, Italy, (7) University of Padova, Dept. of Physics and Astronomy, Padova, Italy )🇪🇸

   Fast neutron beams are of relevance for many scientific and industrial applications. This paper explores fast neutron production using a TANDEM accelerator at the Legnaro National Laboratories, via an energetic ion beam (90 MeV ${}^{14}N$) onto a lithium target. The high energy models for nuclear collision of FLUKA foresee large neutron yields for reactions of this kind. The experiment aimed at validating the expected neutron yields from FLUKA simulations, using two separate and independent set-ups: one based on the multi-foil activation technique, and the other on the time of flight technique, by using liquid scintillator detectors. The results of the experiment show clear agreement of the measured spectra with the FLUKA simulations, both in the shape and the magnitude of the neutron flux at the measured positions. The neutron spectrum is centered around the 8 MeV range with mild tails, and a maximum neutron energy spanning up to 50 MeV. These advantageous results provide a starting point in the development of fast neutron beams based on high energy ion beams from medium-sized accelerator facilities.

   nucl-exphysics.ins-detEPJC(2024)·0 citations
3. 03*

   Coherent interactions of a fast proton with a short-range $NN$ correlation in the nucleus

   A.B. Larionov🇷🇺 · Yu.N. Uzikov🇷🇺

   Nuclear structure at short $NN$-distances is still poorly understood. In particular, the full quantum structure of the nucleus with a correlated $NN$-pair is a challenge to theory. So far, model descriptions have been limited to the average mean-field picture of the remaining nuclear system after removing the $NN$-pair. In the recent experiment of the BM@N Collaboration at JINR \cite{Patsyuk:2021fju}, the reactions ${}^{12}\text{mbox}C(p,2p{n}_s{)}^{10}\text{mbox}B$ and ${}^{12}\text{mbox}C(p,2p{p}_s{)}^{10}\text{mbox}Be$ induced by the hard elastic $pp$ scattering were studied. Here, $n_s$ or $p_s$ denote the undetected slow nucleon in the rest frame of ${}^{12}\text{mbox}C$. In contrast to the previous experiments, the residual bound nucleus was also detected which requires a new level of theoretical understanding. In the present work, we apply the technique of fractional parentage coefficients of the translationally-invariant shell model (TISM) to calculate the spectroscopic amplitude of the system $NN-B$ where $B$ is the remaining nuclear system. The spectroscopic amplitude enters the full amplitude of a nuclear reaction. The relative $NN-B$ wave function is no longer a free parameter of the model but is uniquely related to the internal state of $B$. The interaction of the target proton with the $NN$-pair is considered in the impulse approximation. We also include the initial- and final state interactions of absorptive type as well as the single charge exchange processes. Our calculations are in a reasonable agreement with the BM@N data.

   ↳ nucl-thhep-exhep-phnucl-exPRC(2024)·2 citations
4. 04*

   Neutron Skins: Weak Elastic Scattering and Neutron Stars

   Juliette M. Mammei🇨🇦 · Charles J. Horowitz🇺🇸 · Jorge Piekarewicz🇺🇸 · Brendan Reed🇺🇸 · Concettina Sfienti🇩🇪

   The recently completed PREX-2 campaign - which measured the weak form factor of lead at an optimal momentum transfer - has confirmed that the neutron skin of lead is relatively large and has provided a precise determination of the interior baryon density of a heavy nucleus. In turn, the measured form factor can be related to various nuclear and neutron-star properties. Astrophysical observations by the NICER mission have benefited from improvements in flux, energy resolution, and notably, timing resolution. NICER has the capability to measure pulse profile data, which enables simultaneous mass-radius determinations. During the next decade, measurements in astrophysics, gravitational wave astronomy, and nuclear physics are expected to provide a wealth of more precise data. In this review we provide an overview of the current state of neutron skin measurements and offer insights into the prospects for the future.

   ↳ nucl-thnucl-exAnn.Rev.Nucl.Part.Sci.(2024)·17 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.