Wed·Mar 20, 2019Wednesday·March 20, 2019

1. 01*

   Open Heavy-Flavor Production in Heavy-Ion Collisions

   Xin Dong🇺🇸 · Yen-jie Lee🇺🇸 · Ralf Rapp🇺🇸

   The ultra-relativistic heavy-ion programs at the Relativistic Heavy Ion Collider and the Large Hadron Collider have evolved into a phase of quantitative studies of Quantum Chromodynamics at very high temperatures. The charm and bottom hadron production offer unique insights into the remarkable transport properties and the microscopic structure of the Quark-Gluon Plasma (QGP) created in these collisions. Heavy quarks, due to their large masses, undergo Brownian motion at low momentum, provide a window on hadronization mechanisms at intermediate momenta, and are expected to merge into a radiative-energy loss regime at high momentum. We review recent experimental and theoretical achievements on measuring a variety of heavy-flavor observables, characterizing the different regimes in momentum, extracting pertinent transport coefficients and deducing implications for the "inner workings" of the QGP medium.

   nucl-exhep-exhep-thnucl-thAnn.Rev.Nucl.Part.Sci.(2019)·179 citations
2. 02*

   Detailed studies of ${}^{100}$Mo two-neutrino double beta decay in NEMO-3

   NEMO-3 Collaboration: R. Arnold (1)🇫🇷 · C. Augier (2)🇫🇷 · A.S. Barabash (3)🇷🇺 · A. Basharina-Freshville (4)🇬🇧 · S. Blondel (2)🇫🇷 · S. Blot (5)🇬🇧 · M. Bongrand (2)🇫🇷 · D. Boursette (2)🇫🇷 · V. Brudanin (6,7)🇷🇺 · J. Busto (8)🇫🇷 · A.J. Caffrey (9)🇺🇸 · S. Calvez (2)🇫🇷 and 93 other authors

   The full data set of the NEMO-3 experiment has been used to measure the half-life of the two-neutrino double beta decay of ${}^{100}$Mo to the ground state of ${}^{100}$Ru, $T_{1/2}=\left[6.81\pm 0.01{\left(\text{mbox}stat\right)}_{-0.40}^{+0.38}\left(\text{mbox}syst\right)\right]\times 10^{18}$ y. The two-electron energy sum, single electron energy spectra and distribution of the angle between the electrons are presented with an unprecedented statistics of $5\times 10^5$ events and a signal-to-background ratio of ~80. Clear evidence for the Single State Dominance model is found for this nuclear transition. Limits on Majoron emitting neutrinoless double beta decay modes with spectral indices of n=2,3,7, as well as constraints on Lorentz invariance violation and on the bosonic neutrino contribution to the two-neutrino double beta decay mode are obtained.

   nucl-exEPJC(2019)·82 citations
3. 03*

   The JETSCAPE framework

   J. H. Putschke🇺🇸 · K. Kauder🇺🇸 · E. Khalaj🇺🇸 · A. Angerami🇺🇸 · S. A. Bass🇺🇸 · S. Cao🇺🇸 · J. Coleman🇺🇸 · L. Cunqueiro🇺🇸 · T. Dai🇺🇸 · L. Du🇺🇸 · H. Elfner🇩🇪 · D. Everett🇺🇸 and 33 other authors

   The JETSCAPE simulation framework is an overarching computational envelope for developing complete event generators for heavy-ion collisions. It allows for modular incorporation of a wide variety of existing and future software that simulates different aspects of a heavy-ion collision. The default JETSCAPE package contains both the framework, and an entire set of indigenous and third party routines that can be used to directly compare with experimental data. In this article, we outline the algorithmic design of the JETSCAPE framework, define the interfaces and describe the default modules required to carry out full simulations of heavy-ion collisions within this package. We begin with a description of the various physics elements required to simulate an entire event in a heavy-ion collision, and distribute these within a flowchart representing the event generator and statistical routines for comparison with data. This is followed by a description of the abstract class structure, with associated members and functions required for this flowchart to work. We then define the interface that will be required for external users of JETSCAPE to incorporate their code within this framework and to modify existing elements within the default distribution. We conclude with a discussion of some of the physics output for both $p$-$p$ and $A$-$A$ collisions from the default distribution, and an outlook towards future releases. In the appendix, we discuss various architectures on which this code can be run and outline our benchmarks on similar hardware.

   ↳ nucl-thhep-phnucl-ex193 citations
4. 04*

   Proton scalar dipole polarizabilities from real Compton scattering data, using fixed-t subtracted dispersion relations and the bootstrap method

   B. Pasquini (Pavia U. & INFN, Pavia)🇮🇹 · P. Pedroni (INFN, Pavia)🇮🇹 · S. Sconfietti (Pavia U. & INFN, Pavia)🇮🇹

   We perform a fit of the real Compton scattering (RCS) data below pion-production threshold to extract the electric (${\alpha }_{E1}$) and magnetic (${\beta }_{M1}$) static scalar dipole polarizabilities of the proton, using fixed-$t$ subtracted dispersion relations and a bootstrap-based fitting technique. The bootstrap method provides a convenient tool to include the effects of the systematic errors on the best values of ${\alpha }_{E1}$ and ${\beta }_{M1}$ and to propagate the statistical errors of the model parameters fixed by other measurements. We also implement various statistical tests to investigate the consistency of the available RCS data sets below pion-production threshold and we conclude that there are not strong motivations to exclude any data point from the global set. Our analysis yields ${\alpha }_{E1}=(12.03_{-0.54}^{+0.48})\times 10^{-4}{\text{fm}}^3$ and ${\beta }_{M1}=(1.77_{-0.54}^{+0.52})\times 10^{-4}{\text{fm}}^3$, with p-value $=12\%$.

   ↳ hep-phnucl-exnucl-thJ.Phys.G(2019)·29 citations
5. 05*

   Toward a First-Principles Calculation of Electroweak Box Diagrams

   Chien-Yeah Seng🇩🇪 · Ulf-G. Meißner🇩🇪

   We derive a Feynman-Hellmann theorem relating the second-order nucleon energy shift resulting from the introduction of periodic source terms of electromagnetic and isovector axial currents to the parity-odd nucleon structure function $F_3^N$. It is a crucial ingredient in the theoretical study of the $\gamma W$ and $\gamma Z$ box diagrams that are known to suffer from large hadronic uncertainties. We demonstrate that for a given $Q^2$, one only needs to compute a small number of energy shifts in order to obtain the required inputs for the box diagrams. Future lattice calculations based on this approach may shed new light on various topics in precision physics including the refined determination of the Cabibbo-Kobayashi-Maskawa matrix elements and the weak mixing angle.

   ↳ hep-phhep-exhep-latnucl-ex+1PRL(2019)·36 citations
6. 06*

   Muon capture in nuclei: an ab initio approach based on quantum Monte Carlo methods

   A. Lovato🇺🇸 · N. Rocco🇺🇸 · R. Schiavilla🇺🇸

   An ab initio quantum Monte Carlo method is introduced for calculating total rates of muon weak capture in light nuclei with mass number $A\le 12$. As a first application of the method, we perform a calculation of the rate in ${}^4$He in a dynamical framework based on realistic two- and three-nucleon interactions and realistic nuclear charge-changing weak currents. The currents include one- and two-body terms induced by $\pi$- and $\rho$-meson exchange, and $N$-to-$\Delta$ excitation, and are constrained to reproduce the empirical value of the Gamow-Teller matrix element in tritium. We investigate the sensitivity of theoretical predictions to current parametrizations of the nucleon axial and induced pseudoscalar form factors as well as to two-body contributions in the weak currents. The large uncertainties in the measured values obtained from bubble-chamber experiments (carried out over 50 years ago) prevent us from drawing any definite conclusions.

   ↳ nucl-thnucl-exPRC(2019)·19 citations
7. 07*

   Particle-Set Identification method to study multiplicity fluctuations

   M. Gazdzicki🇵🇱 · M. I. Gorenstein🇺🇦 · M. Mackowiak-Pawlowska🇵🇱 · A. Rustamov🇦🇿

   In this paper a new method of experimental data analysis, the Particle-Set Identification method, is presented. The method allows to reconstruct moments of multiplicity distribution of identified particles. The difficulty the method copes with is due to incomplete particle identification -- a particle mass is frequently determined with a resolution which does not allow for a unique determination of the particle type. Within this method the moments of order $k$ are calculated from mean multiplicities of $k$-particle sets of a given type. The Particle-Set Identification method remains valid even in the case of correlations between mass measurements for different particles. This distinguishes it from the Identity method introduced by us previously to solve the problem of incomplete particle identification in studies of particle fluctuations.

   ↳ nucl-thhep-phnucl-exNPA(2020)·4 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.