Thu·Aug 19, 2021Thursday·August 19, 2021

1. 01*

   Sensitivity analysis towards trace-uranium detection with $\gamma$-$\gamma$ coincidence NAA

   Raymond Hei Man Tsang🇺🇸 · Omar Nusair · Andreas Piepke🇺🇸

   We present an improved approach for detection of trace amounts of ${}^{238}$U by means of neutron activation analysis (NAA). The analysis enhancement is obtained by utilizing $\gamma$-$\gamma$ coincidence counting. An empirical method for evaluating the sensitivity gain in the presence of a large source-related background is presented. A comparison of detection limits is made between two counting schemes; namely, counting single gammas using one HPGe detector versus counting coincident gammas using two HPGe detectors placed face-to-face. A data-validated radiation transport model, created in GEANT4 for a single HPGe detector, is extended to handle the two-detector setup. In this counting scheme, a ${}^{238}$U-detection sensitivity enhancement of about a factor of 8 is predicted for a sample of Saint-Gobain G3 Sapphire when compared to the simpler singles counting approach.

   ↳ physics.ins-detnucl-exJINST(2021)·5 citations
2. 02*

   CUORE Opens the Door to Tonne-scale Cryogenics Experiments

   CUORE Collaboration: D. Q. Adams🇺🇸 · C. Alduino🇺🇸 · F. Alessandria🇮🇹 · K. Alfonso🇺🇸 · E. Andreotti🇮🇹 · F. T. Avignone III🇺🇸 · O. Azzolini🇮🇹 · M. Balata🇮🇹 · I. Bandac🇺🇸 · T. I. Banks🇺🇸 · G. Bari🇮🇹 · M. Barucci🇮🇹 and 196 other authors

   The past few decades have seen major developments in the design and operation of cryogenic particle detectors. This technology offers an extremely good energy resolution - comparable to semiconductor detectors - and a wide choice of target materials, making low temperature calorimetric detectors ideal for a variety of particle physics applications. Rare event searches have continued to require ever greater exposures, which has driven them to ever larger cryogenic detectors, with the CUORE experiment being the first to reach a tonne-scale, mK-cooled, experimental mass. CUORE, designed to search for neutrinoless double beta decay, has been operational since 2017 at a temperature of about 10 mK. This result has been attained by the use of an unprecedentedly large cryogenic infrastructure called the CUORE cryostat: conceived, designed and commissioned for this purpose. In this article the main characteristics and features of the cryogenic facility developed for the CUORE experiment are highlighted. A brief introduction of the evolution of the field and of the past cryogenic facilities are given. The motivation behind the design and development of the CUORE cryogenic facility is detailed as are the steps taken toward realization, commissioning, and operation of the CUORE cryostat. The major challenges overcome by the collaboration and the solutions implemented throughout the building of the cryogenic facility will be discussed along with the potential improvements for future facilities. The success of CUORE has opened the door to a new generation of large-scale cryogenic facilities in numerous fields of science. Broader implications of the incredible feat achieved by the CUORE collaboration on the future cryogenic facilities in various fields ranging from neutrino and dark matter experiments to quantum computing will be examined.

   ↳ physics.ins-detnucl-exPPNP(2022)·48 citations
3. 03*

   Interplay between core and corona components in high-energy nuclear collisions

   Yuuka Kanakubo🇯🇵 · Yasuki Tachibana🇯🇵 · Tetsufumi Hirano🇯🇵

   We establish the updated version of dynamical core--corona initialization framework (DCCI2) as a unified description from small to large colliding systems and from low to high transverse momentum ($p_T$) regions. Using DCCI2, we investigate effects of interplay between locally equilibrated and non-equilibrated systems, in other words, core and corona components in high-energy nuclear collisions. Given experimental multiplicity distributions and yield ratios of $\Omega$ baryons to charged pions as inputs, we extract the fraction of core and corona components in p+p collisions at $\sqrt{s}=7$ TeV and Pb+Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV. We find core contribution overtakes corona contribution as increasing multiplicity above $⟨d{N}_{\mathrm{ch}}/d\eta {⟩}_{|\eta |<0.5}\sim 18$ regardless of the collision system or energy. We also see that the core contribution exceeds the corona contribution only in 0.0-0.95\% multiplicity class in p+p collisions. Notably, there is a small enhancement of corona contribution with $\sim 20$\% below $p_T\sim 1$ GeV even in minimum bias Pb+Pb collisions. We find that the corona contribution at low $p_T$ gives $\sim 15$-$38$ $\%$ correction on $v_2\{2\}$ at $N_{\mathrm{ch}}\lesssim 370$. This raises a problem in conventional hydrodynamic analyses in which low $p_T$ soft hadrons originate solely from core components. We finally scrutinize the roles of string fragmentation and the longitudinal expansion in the transverse energy per unit rapidity, which is crucial in initial conditions for hydrodynamics from event generators based on string models.

   ↳ nucl-thhep-phnucl-exPRC(2022)·45 citations
4. 04*

   Nucleon-nucleon correlations in the extreme oxygen isotopes

   S. M. Wang🇨🇳 · W. Nazarewicz🇺🇸 · R. J. Charity🇺🇸 · L. G. Sobotka

   There has been an upsurge of interest in two-nucleon decays thanks to the studies of nucleon-nucleon correlations. In our previous work, based on a novel time-dependent three-body approach, we demonstrated that the energy and angular correlations of the emitted nucleons can shed light on the structure of nucleonic pairs formed inside the nucleus. In this work, we apply the new framework to study the decay dynamics and properties of some extreme proton-rich and neutron-rich oxygen isotopes, including two-proton ($2p$) decays of ${}^{11,12}$O and two-neutron ($2n$) decay of ${}^{26}$O. Here we show that the low-$\ell$ components of ${}^{11,12}$O wave functions, which are affected by continuum and configuration-interaction effects, strongly impact decay dynamics and asymptotic correlations. In the calculated wave functions of ${}^{11,12}$O, diproton and cigarlike structures merge together during the tunneling process and the resulting energy- and angular correlations are very consistent with the experimental data. The asymptotic correlations of the $2n$ decay of ${}^{26}$O dramatically change as the two-neutron decay energy approaches the zero-energy threshold. The small reported value of $Q_{2n}$ suggests that the $2n$ decay of this nucleus can be understood in terms of the universal phase-space limit.

   ↳ nucl-thnucl-exJ.Phys.G(2022)·20 citations
5. 05*

   Mining for Gluon Saturation at Colliders

   Astrid Morreale🇺🇸 · Farid Salazar🇺🇸

   Quantum chromodynamics (QCD) is the theory of strong interactions of quarks and gluons collectively called partons, the basic constituents of all nuclear matter. Its non-abelian character manifests in nature in the form of two remarkable properties: color confinement and asymptotic freedom. At high energies, perturbation theory can result in the growth and dominance of very gluon densities at small-x. If left uncontrolled, this growth can result in gluons eternally growing violating a number of mathematical bounds. The resolution to this problem lies by balancing gluon emissions by recombinating gluons at high energies : phenomena of gluon saturation. High energy nuclear and particle physics experiments have spent the past decades quantifying the structure of protons and nuclei in terms of their fundamental constituents confirming predicted extraordinary behavior of matter at extreme density and pressure conditions. In the process they have also measured seemingly unexpected phenomena. We will give a state of the art review of the underlying theoretical and experimental tools and measurements pertinent to gluon saturation physics. We will argue for the need of high energy electron-proton/ion colliders such as the proposed EIC (USA) and LHeC (Europe) to consolidate our knowledge of QCD in the small x kinematic domains.

   ↳ hep-phhep-exnucl-exnucl-thUniverse(2021)·168 citations
6. 06*

   Toward emulating nuclear reactions using eigenvector continuation

   C. Drischler🇺🇸 · M. Quinonez🇺🇸 · P. G. Giuliani🇺🇸 · A. E. Lovell🇺🇸 · F. M. Nunes🇺🇸

   We construct an efficient emulator for two-body scattering observables using the general (complex) Kohn variational principle and trial wave functions derived from eigenvector continuation. The emulator simultaneously evaluates an array of Kohn variational principles associated with different boundary conditions, which allows for the detection and removal of spurious singularities known as Kohn anomalies. When applied to the $K$-matrix only, our emulator resembles the one constructed by Furnstahl et al. [Phys. Lett. B 809, 135719] although with reduced numerical noise. After a few applications to real potentials, we emulate differential cross sections for ${}^{40}$Ca$(n,n)$ scattering based on a realistic optical potential and quantify the model uncertainties using Bayesian methods. These calculations serve as a proof of principle for future studies aimed at improving optical models.

   ↳ nucl-thhep-lathep-phnucl-exPLB(2021)·69 citations
7. 07*

   Deep-inelastic electron-deuteron scattering with spectator nucleon tagging at the electron-ion collider. Extracting free nucleon structure

   Alexander Jentsch🇺🇸 · Zhoudunming Tu🇺🇸 · Christian Weiss🇺🇸

   Background: Deep-inelastic scattering (DIS) on the deuteron with spectator nucleon tagging represents a unique method for extracting the free neutron structure functions and exploring the nuclear modifications of bound protons and neutrons. The detection of the spectator (with typical momenta $\lesssim$ 100 MeV/c in the deuteron rest frame) controls the nuclear configuration during the DIS process and enables a differential analysis of nuclear effects. At the future electron-ion collider (EIC) such measurements will be performed using far-forward detectors. Purpose: Simulate deuteron DIS with proton or neutron tagging with the baseline EIC far-forward detector design. Quantify detector acceptance and resolution effects. Study feasibility of free nucleon structure extraction using pole extrapolation in the spectator momentum. Methods: DIS events with proton and neutron spectators are generated using the BeAGLE Monte Carlo generator. The spectator nucleon momentum is reconstructed including effects of detector acceptance and resolution. Pole extrapolation is performed under realistic conditions. The free nucleon structure extraction is validated by comparing with the input model. Results: Proton and neutron spectator detection is possible over the full transverse momentum range $0<p_T<100$ MeV/c needed for pole extrapolation. Resolution effects on the distributions before corrections are ~10% for proton and ~30 for neutron spectators. The overall accuracy of nucleon structure extraction is expected to be at the few-percent level. Conclusions: Free neutron structure extraction through proton tagging and pole extrapolation is feasible with the baseline EIC far-forward detector design. The corresponding extraction of free proton structure through neutron tagging provides a reference point for future studies of nuclear modifications.

   ↳ hep-phhep-exnucl-exPRC(2021)·24 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.