Tue·Feb 8, 2022Tuesday·February 8, 2022

1. 01*

   A First Glimpse at the Shell Structure beyond ${}^{54}$Ca: Spectroscopy of ${}^{55}$K, ${}^{55}$Ca, and ${}^{57}$Ca

   T. Koiwai🇯🇵 · K. Wimmer🇯🇵 · P. Doornenbal🇯🇵 · A. Obertelli🇫🇷 · C. Barbieri🇮🇹 · T. Duguet🇫🇷 · J. D. Holt🇨🇦 · T. Miyagi🇨🇦 · P. Navrátil🇨🇦 · K. Ogata🇯🇵 · N. Shimizu🇯🇵 · V. Somà🇫🇷 and 71 other authors

   States in the $N=35$ and 37 isotopes ${}^{55,57}$Ca have been populated by direct proton-induced nucleon removal reactions from ${}^{56,58}$Sc and ${}^{56}$Ca beams at the RIBF. In addition, the $(p,2p)$ quasi-free single-proton removal reaction from ${}^{56}$Ca was studied. Excited states in ${}^{55}$K, ${}^{55}$Ca, and ${}^{57}$Ca were established for the first time via in-beam $\gamma$-ray spectroscopy. Results for the proton and neutron removal reactions from ${}^{56}$Ca to states in ${}^{55}$K and ${}^{55}$Ca for the level energies, excited state lifetimes, and exclusive cross sections agree well with state-of-the-art theoretical calculations using different approaches. The observation of a short-lived state in ${}^{57}$Ca suggests a transition in the calcium isotopic chain from single-particle dominated states at $N=35$ to collective excitations at $N=37$.

   nucl-exPLB(2022)·14 citations
2. 02*

   Beam-Recoil Transferred Polarization in $K^{+}Y$ Electroproduction in the Nucleon Resonance Region with CLAS12

   D.S. Carman🇺🇸 · A. D'Angelo🇮🇹 · L. Lanza🇮🇹 · V.I. Mokeev🇺🇸 · K.P. Adhikari🇺🇸 · M.J. Amaryan🇺🇸 · W.R. Armstrong🇺🇸 · H. Atac🇺🇸 · H. Avakian🇺🇸 · C. Ayerbe Gayoso🇺🇸 · N.A. Baltzell🇺🇸 · L. Barion🇮🇹 and 129 other authors

   Beam-recoil transferred polarizations for the exclusive electroproduction of $K^{+}\Lambda$ and $K^{+}{\Sigma }^0$ final states from an unpolarized proton target have been measured using the CLAS12 spectrometer at Jefferson Laboratory. The measurements at beam energies of 6.535~GeV and 7.546~GeV span the range of four-momentum transfer $Q^2$ from 0.3 to 4.5~GeV${}^2$ and invariant energy $W$ from 1.6 to 2.4~GeV, while covering the full center-of-mass angular range of the $K^{+}$. These new data extend the existing hyperon polarization data from CLAS in a similar kinematic range but from a significantly larger dataset. They represent an important addition to the world data, allowing for better exploration of the reaction mechanism in strangeness production processes, for further understanding of the spectrum and structure of excited nucleon states, and for improved insight into the strong interaction in the regime of non-perturbative dynamics.

   nucl-exPRC(2022)·13 citations
3. 03*

   Entanglement entropy and flow in two dimensional QCD: parton and string duality

   Yizhuang Liu🇵🇱 · Maciej A. Nowak🇵🇱 · Ismail Zahed🇺🇸

   We discuss quantum entanglement between fast and slow degrees of freedom, in a two dimensional (2D) large $N_c$ gauge theory with Dirac quarks, quantized on the light front. Using the 't Hooft wave functions, we construct the reduced density matrix for an interval in the momentum fraction $x$-space, and calculate its von Neumann entropy in terms of structure functions, that are measured by DIS on mesons (hadrons in general). We found that the entropy is bounded by an area law with logarithmic divergences, proportional to the rapidity of the meson. The evolution of the entanglement entropy with rapidity, is fixed by the cumulative singlet PDF, and bounded from above by a Kolmogorov-Sinai entropy of 1. At low-$x$, the entanglement exhibits an asymptotic expansion, similar to the forward meson-meson scattering amplitude in the Regge limit. The evolution of the entanglement entropy in parton-$x$ per unit rapidity, measures the meson singlet PDF. The re-summed entanglement entropy along the single meson Regge trajectory, is string-like. We suggest that its extension to multi-meson states, models DIS scattering on a large 2D ${}^{\prime }$nucleus${}^{\prime }$. The result, is a large rate of change of the entanglement entropy with rapidity, that matches the current Bekenstein-Bremermann bound for maximum quantum information flow. This mechanism may be at the origin of the large entropy deposition and rapid thermalization, reported in current heavy ion colliders, and may extend to future electron-ion colliders.

   ↳ hep-phhep-thnucl-exnucl-thPRD(2022)·23 citations
4. 04*

   Quantification of 242Pu with a Microcalorimeter Gamma Spectrometer

   David J. Mercer🇺🇸 · Ryan Winkler · Katrina E. Koehler🇺🇸 · Daniel T. Becker🇺🇸 · Douglas A. Bennett · Matthew H. Carpenter🇺🇸 · Mark P. Croce🇺🇸 · Krystal I. de Castro · Eric A. Feissle · Joseph W. Fowler · Johnathon D. Gard · John A. B. Mates and 9 other authors

   We report measurements of the 103-keV and 159-keV gamma ray signatures of 242Pu using microcalorimetry. This is the first observation of these gamma rays in a non-destructive measurement of an unprepared sample, and so represents an important advance in nuclear material accountancy. The measurement campaign also serves as the first demonstration of a field campaign with a portable microcalorimeter gamma-ray spectrometer. For the 103-keV gamma ray we report an improved centroid energy and emission probability.

   ↳ physics.ins-detnucl-ex1 citation
5. 05*

   Dynamics of rotation in chiral nuclei

   Z. X. Ren🇨🇳 · P. W. Zhao🇨🇳 · J. Meng🇨🇳

   The dynamics of chiral nuclei is investigated for the first time with the time-dependent and tilted axis cranking covariant density functional theories on a three-dimensional space lattice in a microscopic and self-consistent way. The experimental energies of the two pairs of the chiral doublet bands in ${}^{135}$Nd are well reproduced without any adjustable parameters beyond the well-defined density functional. A novel mechanism, i.e., chiral precession, is revealed from the microscopic dynamics of the total angular momentum in the body-fixed frame, whose harmonicity is associated with a transition from the planar into aplanar rotations with the increasing spin. This provides a fully microscopic and dynamical view to understand the chiral excitations in nuclei.

   ↳ nucl-thnucl-exPRC(2022)·33 citations
6. 06*

   Heavy quarks at finite temperature

   Johannes Heinrich Weber🇩🇪

   New incarnations of heavy-ion collision experiments are turning our attention to hard processes and a more fine-grained resolution of the QGP. In this endeavor quarkonia or open heavy flavors turn out to be versatile probes, which are usually described through models based on perturbative QCD, AdS, and effective field theories. The lattice provides nonperturbative input and constraints to such models.\newline In-medium bottomonia, the complex static quark-antiquark potential, and the heavy-quark momentum diffusion coefficient are key quantities where lattice gauge theory has recently achieved significant progress with impact for heavy-ion phenomenology. We review these lattice results, relate them to phenomenological applications, and close with an outlook.

   ↳ hep-lathep-phnucl-exnucl-thPoS(2022)·1 citation
7. 07*

   Flexible scenario for heavy element research

   D.Ibadullayev · A.N.Polyakov · Yu.S.Tsyganov · A.A.Voinov🇺🇸

   Detection system and software package coded in Builder C ++ are developed for the new analog spectrometer of the DGFRS-2 setup installed on the new DC-280 cyclotron. This software allows providing data acquisition using a 48x128 DSSSD (Double Side Silicon Strip Detector) detector and a multi-wire gaseous detector. The main feature of this software package is the use of flexible real-time algorithms to provide deep suppression of the background in reactions for the synthesis of superheavy elements, using the detection of correlations ER-{\alpha} (Recoil-alpha particle). The block-diagram of analog spectrometer is presented.

   ↳ physics.ins-detnucl-ex0 citations
8. 08*

   Streaming readout for next generation electron scattering experiment

   Fabrizio Ameli🇮🇹 · Marco Battaglieri🇮🇹 · Vladimir V. Berdnikov🇺🇸 · Mariangela Bondì🇮🇹 · Sergey Boyarinov🇺🇸 · Nathan Brei🇺🇸 · Laura Cappelli🇮🇹 · Andrea Celentano🇮🇹 · Tommaso Chiarusi🇮🇹 · Raffaella De Vita🇮🇹 · Cristiano Fanelli🇺🇸 · Vardan Gyurjyan🇺🇸 and 9 other authors

   Current and future experiments at the high intensity frontier are expected to produce an enormous amount of data that needs to be collected and stored for offline analysis. Thanks to the continuous progress in computing and networking technology, it is now possible to replace the standard `triggered' data acquisition systems with a new, simplified and outperforming scheme. `Streaming readout' (SRO) DAQ aims to replace the hardware-based trigger with a much more powerful and flexible software-based one, that considers the whole detector information for efficient real-time data tagging and selection. Considering the crucial role of DAQ in an experiment, validation with on-field tests is required to demonstrate SRO performance. In this paper we report results of the on-beam validation of the Jefferson Lab SRO framework. We exposed different detectors (PbWO-based electromagnetic calorimeters and a plastic scintillator hodoscope) to the Hall-D electron-positron secondary beam and to the Hall-B production electron beam, with increasingly complex experimental conditions. By comparing the data collected with the SRO system against the traditional DAQ, we demonstrate that the SRO performs as expected. Furthermore, we provide evidence of its superiority in implementing sophisticated AI-supported algorithms for real-time data analysis and reconstruction.

   ↳ physics.ins-detnucl-exEur.Phys.J.Plus(2022)·15 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.