Tue·Mar 5, 2024Tuesday·March 5, 2024

1. 01*

   Recent Findings from Heavy-Flavor Angular Correlation Measurements in Hadronic Collisions

   Deepa Thomas🇺🇸 · Fabio Colamaria🇮🇹

   The study of angular correlations of heavy-flavor particles in hadronic collisions can provide crucial insight into the heavy quark production, showering, and hadronization processes. The comparison with model predictions allows us to discriminate among different approaches for heavy quark production and hadronization, as well as different treatments of the underlying event employed by the models to reproduce correlation observables. In ultra-relativistic heavy-ion collisions, where a deconfined state of matter, the quark--gluon plasma (QGP), is created, heavy-flavor correlations can shed light on the modification of the heavy quark fragmentation due to the interaction between charm and beauty quarks with the QGP constituents, as well as characterize their energy loss processes while traversing the medium. Insight into the possible emergence of collective-like mechanisms in smaller systems, resembling those observed in heavy-ion collisions, can also be obtained by performing correlation studies in high-multiplicity proton--proton and proton--nucleus collisions. In this review, the most recent and relevant measurements of heavy-flavor correlations performed in all collision systems at the LHC and RHIC will be presented, and the new understandings that they provide will be discussed.

   nucl-exUniverse(2024)·3 citations
2. 02*

   Electroproduction of the Lambda/Sigma^0 hyperons at Q^2~0.5 (GeV/c)^2 at forward angles

   K. Okuyama🇯🇵 · K. Itabashi🇯🇵 · S. Nagao🇯🇵 · S.N. Nakamura🇯🇵 · K.N. Suzuki🇯🇵 · T. Gogami🇯🇵 · B. Pandey🇺🇸 · L. Tang🇺🇸 · P. Bydžovský🇨🇿 · D. Skoupil🇨🇿 · T. Mart🇮🇩 · D. Abrams🇺🇸 and 74 other authors

   In 2018, the E12-17-003 experiment was conducted at the Thomas Jefferson National Accelerator Facility (JLab) to explore the possible existence of an nnLambda state in the reconstructed missing mass distribution from a tritium gas target [K. N. Suzuki et al., Prog. Theor. Exp. Phys. 2022, 013D01 (2022), B. Pandey et al., Phys. Rev. C 105, L051001 (2022)]. As part of this investigation, data was also collected using a gaseous hydrogen target, not only for a precise absolute mass scale calibration but also for the study of Lambda/Sigma^0 electroproduction. This dataset was acquired at Q^2~0.5 (GeV/c)^2, W=2.14 GeV, and theta_{gamma K}^{c.m.}~8 deg. It covers forward angles where photoproduction data is scarce and a low-Q^2 region that is of interest for hypernuclear experiments. On the other hand, this kinematic region is at a slightly higher Q^2 than previous hypernuclear experiments, thus providing crucial information for understanding the Q^2 dependence of the differential cross sections for Lambda/Sigma^0 hyperon electroproduction. This paper reports on the Q^2 dependence of the differential cross section for the e + p -> e' + K^+ + Lambda/Sigma^0 reaction in the 0.2-0.8 (GeV/c)^2, and provides comparisons with the currently available theoretical models.

   nucl-exPRC(2024)·3 citations
3. 03*

   Formation of bound dineutrons in the ${}^{175}Lu(n,{}^{2}n){}^{174g}Lu$ nuclear reaction and its cross section

   Ihor Kadenko🇺🇦 · Barna Biró · Mihály Braun🇷🇺 · András Fenyvesi · Kateryna Okopna · Nadiia Sakhno · Loránd Zakàny

   The dineutron as a bound chargeless nucleus of two identical nucleons has been attracting attention for many decades. In addition to the study of the formation of a bound dineutron in the outgoing channel of some specific nuclear reactions, cross section estimates have been gaining interest as research target. We used a traditional neutron activation technique to irradiate Lu samples followed by measurements of the induced activity with HPGe spectrometer in order to detect gamma-peaks of the ${}^{175}Lu(n,2n{)}^{174g}Lu$ reaction product when this reaction channel is not open for incident neutron energies. Based on two measurements of the instrumental gamma ray spectra of Lu samples we reliably identified the presence of the ${}^{174g}Lu$ isotope in the outgoing channel of the ${}^{175}Lu(n,{}^{2}n{)}^{174g}Lu$ nuclear reaction. Also, the cross section for this nuclear reaction was obtained and to be equal $33.5\pm 5.9$ mb. For the first time, the dineutron as a nuclear reaction product was indirectly detected via statistically significant observation of the induced activity of ${}^{174g}Lu$ with corresponding cross-section estimate.

   nucl-exPLB(2024)·2 citations
4. 04*

   Abatement of Ionizing Radiation for Superconducting Quantum Devices

   B. Loer (1)🇺🇸 · P. M. Harrington (2)🇺🇸 · B. Archambault (1)🇺🇸 · E. Fuller (1)🇺🇸 · B. Pierson (1)🇺🇸 · I. Arnquist (1)🇺🇸 · K. Harouaka (1)🇺🇸 · T. D. Schlieder (1)🇺🇸 · D. K. Kim (c)🇵🇰 · A. J. Melville (c)🇵🇰 · B. M. Niedzielski (3)🇺🇸 · J. K. Yoder (3)🇺🇸 and 6 other authors

   Ionizing radiation has been shown to reduce the performance of superconducting quantum circuits. In this report, we evaluate the expected contributions of different sources of ambient radioactivity for typical superconducting qubit experiment platforms. Our assessment of radioactivity inside a typical cryostat highlights the importance of selecting appropriate materials for the experiment components nearest to qubit devices, such as packaging and electrical interconnects. We present a shallow underground facility (30-meter water equivalent) to reduce the flux of cosmic rays and a lead shielded cryostat to abate the naturally occurring radiogenic gamma-ray flux in the laboratory environment. We predict that superconducting qubit devices operated in this facility could experience a reduced rate of correlated multi-qubit errors by a factor of approximately 20 relative to the rate in a typical above-ground, unshielded facility. Finally, we outline overall design improvements that would be required to further reduce the residual ionizing radiation rate, down to the limit of current generation direct detection dark matter experiments.

   ↳ quant-phnucl-exJINST(2024)·23 citations
5. 05*

   Quantum-number projected generator coordinate method for ${}^{21}$Ne with a chiral two-nucleon-plus-three-nucleon interaction

   W. Lin🇨🇳 · E. F. Zhou · J. M. Yao🇨🇳 · H. Hergert🇺🇸

   We report a study of the low-lying states of deformed ${}^{21}$Ne within the framework of quantum-number projected generator coordinate method (PGCM), starting from a chiral two-nucleon-plus-three-nucleon (NN+3N) interaction. The wave functions of states are constructed as a linear combination of a set of axially-deformed Hartree-Fock-Bogliubov (HFB) wave functions with different quadrupole deformations. These HFB wave functions are projected onto different angular momenta and the correct neutron and proton numbers for ${}^{21}$Ne. The results of calculations based on the effective Hamiltonians derived by normal-ordering the 3N interaction with respect to three different reference states, including the quantum-number projected HFB wave functions for ${}^{20}$Ne, ${}^{22}$Ne, and an ensemble of them with equal weights, are compared. This study serves as a key step towards ab initio calculations of odd-mass deformed nuclei with the in-medium GCM.

   ↳ nucl-thnucl-exSymmetry(2024)·8 citations
6. 06*

   Strangeness plus-one ($S=+1$) resonance-state $P_0^{+\ast }$ via $K^{+}n\to K^{\ast 0}p$

   Dayoung Lee🇰🇷 · Seung-il Nam🇰🇷

   In our current study, we delve into the peak-like structure observed during the reaction process of $K^{+}n\to K^{0}p$ at approximately $\sqrt{s}\sim 2.5$ GeV. Our focus centers on exploring the potential $S=+1$ resonance $P_0^{+\ast }\equiv P_0^{\ast }$ as an excited state within the extended vector-meson and baryon ($VB$) antidecuplet. To achieve this aim, we employ the effective Lagrangian method in conjunction with the $(u,t)$-channel Regge approach, operating within the tree-level Born approximation. We thoroughly examine various spin-parity quantum numbers for the resonance, resulting in a compelling description of the data, where $M_{P_0^{\ast }}\approx 2.5$ GeV and ${\Gamma }_{P_0^{\ast }}\approx 100$ MeV. Furthermore, we propose an experimental technique to amplify the signal-to-noise ratio ($S/N$) for accurately measuring the resonance. Notably, our findings reveal that background interference diminishes significantly within the $K^{\ast }$ forward-scattering region in the center-of-mass frame when the $K^{\ast }$ is perpendicularly polarized to the reaction plane. Additionally, we explore the recoil-proton spin asymmetry to definitively determine the spin and parity of the resonance. This study stands to serve as a valuable reference for designing experimental setups aimed at investigating and comprehending exotic phenomena in QCD. Specifically, our insights will inform future J-PARC experiments, particularly those employing higher kaon beam energies.

   ↳ hep-phnucl-exnucl-thPRC(2024)·2 citations
7. 07*

   Study of forbidden $\beta$ decays within the realistic shell model

   G. De Gregorio🇮🇹 · R. Mancino🇨🇿 · L. Coraggio🇮🇹 · N. Itaco🇮🇹

   For the first time, half-lives and energy spectra of forbidden $\beta$ decays are calculated within the realistic shell model. Namely, we approach this issue starting from a realistic nucleon-nucleon potential and deriving effective Hamiltonians and decay operators. Our goal is to explore the sensitivity of the shape of calculated energy spectra to the renormalization of forbidden $\beta$ -decay operators, an operation that allows to take into account those configurations that are not explicitly included in the chosen model space. The region that has been considered for this investigation are nuclei outside the ${}^{78}$Ni core, more precisely we have studied the second-forbidden $\beta$ decays of ${}^{94}$Nb and ${}^{99}$Tc, and fourth-forbidden $\beta$ decays of ${}^{113}$Cd and ${}^{115}$In, that are currently of a renewed experimental interest in terms of novel spectroscopic techniques. Our results evidence that the introduction of a renormalized $\beta$-decay operator leads to a marked improvement of the reproduction of experimental half-lives. As regards the spectra of both second-forbidden and fourth-forbidden decays, we have found that their calculated shapes are in good agreement with the observed ones, even if scarcely responsive to the renormalization of the decay operator. We carry out also a detailed inspection of the different components of the calculated spectra for a deeper insight about their role in reproducing the experimental shapes.

   ↳ nucl-thhep-exnucl-exPRC(2024)·11 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.