Thu·Nov 28, 2019Thursday·November 28, 2019

1. 01*

   Measurement of D${}^0$-meson + hadron two-dimensional angular correlations in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}=$ 200 GeV

   STAR Collaboration: J. Adam · L. Adamczyk · J. R. Adams · J. K. Adkins · G. Agakishiev · M. M. Aggarwal · Z. Ahammed · I. Alekseev · D. M. Anderson · A. Aparin · E. C. Aschenauer · M. U. Ashraf and 345 other authors

   Open heavy flavor hadrons provide unique probes of the medium produced in ultra-relativistic heavy-ion collisions. Due to their increased mass relative to light-flavor hadrons, long lifetime, and early production in hard-scattering interactions, they provide access to the full evolution of the partonic medium formed in heavy-ion collisions. This paper reports two-dimensional (2D) angular correlations between neutral $D$-mesons and unidentified charged particles produced in minimum-bias Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV. $D^0$ and ${\bar{D}}^0$ mesons are reconstructed via their weak decay to $K^{\mp }{\pi }^{\pm }$ using the Heavy Flavor Tracker (HFT) in the Solenoidal Tracker at RHIC (STAR) experiment. Correlations on relative pseudorapidity and azimuth $(\Delta \eta ,\Delta \varphi )$ are presented for peripheral, mid-central and central collisions with $D^0$ transverse momentum from 2 to 10 GeV/$c$. Attention is focused on the 2D peaked correlation structure near the triggered $D^0$-meson, the {\em near-side} (NS) peak, which serves as a proxy for a charm-quark containing jet. The correlated NS yield of charged particles per $D^0$-meson and the 2D widths of the NS peak increase significantly from peripheral to central collisions. These results are compared with similar correlations using unidentified charged particles, consisting primarily of light-flavor hadrons, at similar trigger particle momenta. Similar per-trigger yields and widths of the NS correlation peak are observed. The present results provide additional evidence that $D^0$-mesons undergo significant interactions with the medium formed in heavy-ion collision and show, for the first time, significant centrality evolution of the NS 2D peak in the correlations of particles associated with a heavy-flavor hadron produced in these collisions.

   nucl-exPRC(2020)·17 citations
2. 02*

   High-precision nuclear forces from chiral EFT: State-of-the-art, challenges and outlook

   E. Epelbaum🇩🇪 · H. Krebs🇩🇪 · P. Reinert🇩🇪

   We review a new generation of nuclear forces derived in chiral effective field theory using the recently proposed semilocal regularization method. We outline the conceptual foundations of nuclear chiral effective field theory, discuss all steps needed to compute nuclear observables starting from the effective chiral Lagrangian and consider selected applications in the two- and few-nucleon sectors. We highlight key challenges in developing high-precision tree-body forces, such as the need to maintain consistency between two- and many-body interactions and constraints placed by the chiral and gauge symmetries after regularization.

   ↳ nucl-thhep-phnucl-exFront.in Phys.(2020)·178 citations
3. 03*

   Comparison of Practical Expressions for E1 Photon Strength Functions

   Oleksandr Gorbachenko · Igor Kadenko🇺🇦 · Vladimir Plujko🇺🇦 · Kateryna Solodovnyk

   The closed-form expressions for the photon strength functions (PSF) are tested using the gamma-decay data of OSLO group. The theoretical calculations are performed for the Lorentzian models of PSF for electric and magnetic dipole gamma-rays. The criteria of minimum of least-square value as well as the root-mean-square deviation factor are used. It is shown that a rather good agreement is obtained within the Simple Modified Lorentzian model for E1 PSF modelling.

   ↳ nucl-thnucl-ex0 citations
4. 04*

   Description of nuclear photoexcitation by Lorentzian expressions for electric dipole photon strength function

   Vladimir Plujko🇺🇦 · Oleksandr Gorbachenko · Kateryna Solodovnyk

   The description of photoabsorption cross-sections of cold nuclei by closed-form Lorentzian models of photon strength functions for photoexcitation by electric dipole gamma-rays is considered. Systematics of the GDR parameters are given and input parameters of different analytical models are discussed The experimental data are compared with theoretical calculations for even-even nuclei using criteria of minimum of both least-square value and root-mean-square deviation factor. Simple extensions of the models with energy-dependent widths to high gamma-ray energies $\gtrsim$ 30MeV which hold the energy-weighted sum rule for E1 gamma-transitions in good approximation are proposed and tested.

   ↳ nucl-thnucl-exEPJA(2019)·8 citations
5. 05*

   Multiple Monoenergetic Gamma Radiography (MMGR) with a compact superconducting cyclotron

   Hin Y. Lee · Brian S. Henderson🇺🇸 · Roberts G. Nelson · Areg Danagoulian

   Smuggling of special nuclear materials (SNM) and nuclear devices through borders and ports of entry constitutes a major risk to global security. Technologies are needed to reliably screen the flow of commerce for the presence of high-$Z$ materials such as uranium and plutonium. Here we present an experimental proof-of-concept of a technique which uses inelastic ($p,p^{\prime }$) nuclear reactions to generate monoenergetic photons, which provide means to measure the areal density and the effective-$Z$ ($Z_{\text{eff}}$) of an object with an accuracy which surpasses that achieved by current methods. We use an ION-12${}^{\text{SC}}$ superconducting 12~MeV proton cyclotron to produce 4.4, 6.1, 6.9, and 7.1~MeV photons from a variety of nuclear reactions. Using these photons in a transmission mode we show that we are able to accurately reconstruct the areal densities and $Z_{\text{eff}}$ of a test object. This methodology could enable mobile applications to screen commercial cargoes with high material specificity, providing a means of distinguishing common cargo materials from high-Z materials that include uranium and plutonium.

   ↳ physics.app-phnucl-exphysics.soc-phJ.Appl.Phys.(2020)·1 citation
6. 06*

   Na-based crystal scintillators for next-generation rare event searches

   S. Nagorny · C. Rusconi · S. Sorbino · J.W. Beeman · F. Bellini · L. Cardani · V.D. Grigorieva · L. Pagnanini · S. Nisi · S. Pirro · K. Schäffner · V.N. Shlegel

   The growing interest in clarifying the controversial situation in the Dark Matter sector has driven the experimental efforts towards new ways to investigate the long-standing DAMA/LIBRA result. Among them, low-temperature calorimeters based on Na-containing scintillating crystals offer the possibility to clarify the nature of the measured signal via particle identification. Here we report the first measurement of Na-containing crystals, based on material different from NaI, i.e. Na${}_2$Mo${}_2$O${}_7$ and Na${}_2$W${}_2$O${}_7$, pointing out their excellent performance in term of energy resolution, light yield, and particle identification.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2020)·6 citations
7. 07*

   Timing performances of a Time-of-Flight detection system for the FRACAS large acceptance mass spectrometer

   S. Salvador🇫🇷 · E. Barlerin🇫🇷 · J. Perronnel🇫🇷 · C. Vandamme🇫🇷

   In this work, we report on the timing performances of the Time-Of-Flight (TOF) apparatus of the FRACAS large acceptance mass spectrometer designed to measure the fragmentation cross sections of a ${}^{12}$C beam in hadrontherapy. The TOF system is composed of a Parallel Plate Avalanche Counter and scintillating detectors to create so-called $\Delta$E---TOF maps used in the fragment charge identification process. From tests with an alpha source and a ${}^{12}$C beam experiment, we measured a coincidence resolving time for the apparatus below 300 ps. Those results should lead in the final design to the identification of all the fragments produced by the interaction of ${}^{12}$C ions with thin targets for energies up to 400 MeV/nucleon.

   ↳ physics.ins-detnucl-exJINST(2020)·2 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.