Wed·Dec 25, 2024Wednesday·December 25, 2024

1. 01*

   Measurement of charge-dependent directed flow in STAR Beam Energy Scan (BES-II) Au+Au and U+U collisions

   Muhammad Farhan Taseer🇨🇳

   We presented the rapidity dependence of directed flow ($v_1$) and its slope ($d{v}_1/dy$) for ${\pi }^{\pm }$, $K^{\pm }$ and $p(\bar{p}$) in Au+Au collisions at $\sqrt{s_{NN}}$ = 7.7 -- 19.6 GeV from the Beam Energy Scan Phase-II, as well as in U+U collisions at $\sqrt{s_{NN}}$ = 193 GeV measured by the STAR experiment. The $v_1$ values are reported as a function of rapidity and centrality. Additionally, the $d{v}_1/dy$ and the charge dependent difference, $\Delta (d{v}_1/dy)$, of the three identified particles in U+U collisions is compared to those in Au+Au and isobar (Ru+Ru and Zr+Zr) collisions. These findings offer insights into the initial electromagnetic field as well as baryon transport at various system sizes and beam energies.

   nucl-exEPJ Web Conf.(2025)·3 citations
2. 02*

   Measurement of neutron induced reaction cross-section of tantalum with covariance analysis

   Mahima Upadhyay · Mahesh Choudhary · Namrata Singh · Punit Dubey · Shweta Singh🇩🇪 · Sriya Paul · Utkarsha Mishra · G. Mishra · G. Mohanto · Sukanya De · L. S. Danu · B. Lalremruata and 3 other authors

   The current study presents the cross-section measurement of ${}^{181}$Ta(n,$\gamma$)${}^{182}$Ta reaction at 1.37 $\pm$ 0.13, 2.06 $\pm$ 0.14, 2.56 $\pm$ 0.15, and 3.05 $\pm$ 0.17 MeV neutron energies utilizing offline $\gamma$-ray spectroscopy. The neutrons were generated through the ${}^7$Li(p,n)${}^7$Be reaction. The ${}^{115}$In(n,n'$\gamma$)${}^{115m}$In reaction served as a monitor reaction. The covariance analysis was used to quantify the uncertainties in the measured cross-sections for the first time for the ${}^{181}$Ta(n,$\gamma$)${}^{182}$Ta reaction. The present study provides detailed information on the propagation of uncertainty in the overall result. The required corrections for low energy background neutron and $\gamma$-ray coincidence summing effect have been made in the present measurement. The output is compared with the pre-existing cross-section data from the EXFOR database, evaluated data libraries and theoretical model predictions.

   nucl-ex0 citations
3. 03*

   Emulation of the final r-process abundance pattern with a neural network

   Yukiya Saito🇨🇦 · Iris Dillmann🇨🇦 · Reiner Krücken🇨🇦 · Matthew R. Mumpower🇺🇸 · Rebecca Surman🇺🇸

   This work explores the construction of a fast emulator for the calculation of the final pattern of nucleosynthesis in the rapid neutron capture process (the $r$-process). An emulator is built using a feed-forward artificial neural network (ANN). We train the ANN with nuclear data and relative abundance patterns. We take as input the $\beta$-decay half-lives and the one-neutron separation energy of the nuclei in the rare-earth region. The output is the final isotopic abundance pattern. In this work, we focus on the nuclear data and abundance patterns in the rare-earth region to reduce the dimension of the input and output space. We show that the ANN can capture the effect of the changes in the nuclear physics inputs on the final $r$-process abundance pattern in the adopted astrophysical conditions. We employ the deep ensemble method to quantify the prediction uncertainty of the neutal network emulator. The emulator achieves a speed-up by a factor of about 20,000 in obtaining a final abundance pattern in the rare-earth region. The emulator may be utilized in statistical analyses such as uncertainty quantification, inverse problems, and sensitivity analysis.

   ↳ nucl-thnucl-exJ.Phys.G(2025)·2 citations
4. 04*

   Alpha-Particle Monopole Form Factors with Ab Initio No-Core Shell Model

   P. Yin🇨🇳 · A. M. Shirokov🇷🇺 · H. Li🇨🇳 · B. Zhou🇨🇳 · X. Zhao🇨🇳 · S. Bacca🇩🇪 · J. P. Vary🇺🇸

   The state-of-the-art ab initio nuclear many-body approaches with modern nuclear forces are challenged by the recent experimental measurement of the monopole form factor of the $0_1^{+}\to 0_2^{+}$ transition in the $\alpha$ particle [Kegel et al., Phys. Rev. Lett. 130, 152502 (2023)]. We investigate the elastic and inelastic $0_1^{+}\to 0_2^{+}$ transition form factors using the ab initio no-core shell model (NCSM). We observe a good convergence of both form factors with respect to the basis size employing the Daejeon16 nucleon-nucleon ($NN$) interaction. Our NCSM results are very close to the effective interaction hyperspherical harmonic calculations using $NN$ plus three-nucleon interactions based on the chiral effective field theory which take into account the continuum effects via the Lorentz integral transform. The significant difference between the ab initio results with various modern nuclear interactions and of some of them with the recent experimental data provides motivations for deeper investigation of this observable.

   ↳ nucl-thnucl-exPRC(2025)·3 citations
5. 05*

   Low-Energy Neutrino-Nucleus Scattering and New Physics

   S. Carey🇺🇸 · V. Pandey🇺🇸

   The interactions of low-energy neutrinos with nuclei provide a unique window to explore various Standard Model (SM) and Beyond the Standard Model (BSM) processes. In particular, the recent observation of coherent elastic neutrino-nucleus scattering (CEvNS), predicted over five decades ago, has generated significant interest across disciplines. With its high cross section and suitability for compact detectors, particularly with stopped pion neutrinos, CEvNS offers a powerful probe for light, weakly coupled new physics. Ongoing global experimental efforts now aim to leverage CEvNS to test SM predictions and search for BSM signals, where deviations in event rates or spectra could reveal new physics. We present here an estimate of the number of recoil events obtained from CEvNS using the current and upcoming liquid argon based experiments. Furthermore, the event rate due to the inclusion of neutrino magnetic moment is also discussed.

   ↳ hep-phhep-exnucl-exnucl-th1 citation
6. 06*

   Chirality in $(\vec{p},2p)$ reactions induced by proton helicity

   Tomoatsu Edagawa🇯🇵 · Kazuki Yoshida🇯🇵 · Shoichiro Kawase🇯🇵 · Kazuyuki Ogata🇯🇵 · Masaki Sasano🇯🇵

   It is shown that longitudinally polarized protons can be used to induce chirality in the final states of the $(\vec{p},pN)$ reaction at intermediate energies, when there exist three final-state particles with non-coplanar momentum vectors. The analyzing power $A_z$ is proposed as a measure of this effect. Theoretical descriptions to obtain $A_z$ based on an intuitive picture as well as a distorted wave impulse approximation are presented, showing that the helicity of incident protons is coupled to the chirality of the orbital motion of a single-particle wave function, resulting in the chirality of the final states and a large $A_z$ value.

   ↳ nucl-thnucl-exPRC(2026)·0 citations
7. 07*

   Fermionic equations of motion in strongly-correlated media: applications to the nuclear many-body problem

   Elena Litvinova🇺🇸

   These notes summarise the lectures given at the International School of Physics "Enrico Fermi" in Summer 2024 in Varenna (Italy) about the strongly coupled quantum many-body theory and its applications to nuclear structure. The lectures present a rather short overview of the subject with an emphasis on the analytical aspects of the nuclear many-body problem, aiming at a deep understanding of the complexity of strongly coupled nucleonic states and emergent collective phenomena. The major pedagogical focus is recognizing how all the models describing nuclear dynamics follow from a unified model-independent framework formulated in the universal language of quantum field theory. In particular, connections between the classes of ab initio, density functional theory, and beyond mean-field approaches are made accessible. Approximations of varying complexity are discussed in applications to excited states of medium-heavy nuclei.

   ↳ nucl-thnucl-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.