Wed·Oct 3, 2018Wednesday·October 3, 2018

1. 01*

   Measurement of the neutron lifetime using a magneto-gravitational trap

   Nathan Callahan🇺🇸

   Precision measurements of the free neutron lifetime ${\tau }_n$, when combined with measurements of the axial vector form factor, can be used to test unitarity of the CKM matrix. Non-unitarity is a signal for physics Beyond the Standard Model (BSM). Sensitivity to BSM physics requires measurements of ${\tau }_n$ to a precision of 0.1~s. However, the two dominant techniques to measure ${\tau }_n$ (colloquially beam and bottle measurements) disagree by nearly 10~s. UCN$\tau$ is a neutron lifetime experiment using a magneto-gravitational trap and an in-situ neutron detector. Neutrons in this trap are not susceptible to loss on material walls as in previous bottle measurements. Additionally, the in-situ detector allows spectral monitoring of the trapped Ultracold Neutrons. In this talk, I will present our most recent result - ${\tau }_n=877.7\pm 0.7_{\text{(stat.)}}+0.4/-0.2_{\text{(sys.)}}$~s. I will also present Monte Carlo simulations of systematic effects in the experiment including heating and spectral cleaning.

   nucl-exphysics.ins-det0 citations
2. 02*

   Probing BSM and High-x Physics with SoLID at JLab

   P. A. Souder🇺🇸

   The program of parity violation with the proposed new SoLID spectrometer at JLab is presented. Physics topics include searched for physics beyond the Standard Model, studies of charge symmetry violation at the quark level, searched for quark-quark correlations, and a measurement of the ratio of up and down PDF's in the proton.

   nucl-exnucl-th1 citation
3. 03*

   Recent Results on Heavy Quark Production in High Energy Nucleus Collisions

   Xin Dong🇺🇸

   The goal of the ultra-relativistic heavy ion program is to study Quantum Chromodynamics under finite temperature and density conditions. After a couple of decades of experiment, the focus at the top RHIC and the LHC energy has evolved to quantitative understanding of properties of the hot and dense medium, namely the strongly-coupled Quark Gluon Plasma (sQGP) created in these heavy-ion collisions, and to constrain transport parameters of the sQGP medium. Heavy quarks offer unique insights towards detailed understanding of the sQGP properties due to their large masses. Recent collider and detector advances have enabled precision measurements of heavy quark hadron production in heavy-ion collisions. In this talk, I will review recent results from heavy quark production measurements at RHIC and the LHC. These high quality data will offer stringent constraints on theoretical model calculations and help precision determination of QGP medium transport parameters. Finally, I look forward to a more prospective future of the heavy quark program with further improved detectors at both RHIC and the LHC.

   nucl-exnucl-th4 citations
4. 04*

   Probing the Strange Sea Quarks with Kaon SIDIS

   F. Benmokhtar🇺🇸 · M. Muhoza🇺🇸 · C. McCauley🇺🇸

   It is well known that protons and neutrons are made from constituents, called quarks and gluons, which give substructure to these particles. The goal of this project is to make measurements of the spatial distributions and the momenta of the quarks that provide a three-dimensional map of quarks in the nuclear medium. This knowledge provides the basis of our understanding of nuclear matter in terms of the dynamics of their internal constituents. This abstract focuses on the study of the contribution of the sea quarks and in particular of the strange sea to the proton spin structure. This study is feasible with semi-inclusive deep inelastic scattering of electrons off proton and deuteron targets in Hall B at Jefferson Lab. To achieve the desired precision, a Ring Imaging CHerenkov (RICH) detector was built so pion, kaon and proton identification is well performed in the momentum range of 3 to 8 GeV/c. The experimental method and projected precision of the measurements of the parton distributions using Kaon SIDIS will be discussed and the status of the recently built Hybrid RICH detector will be presented.

   nucl-exhep-ex0 citations
5. 05*

   Impacts of the New Carbon Fusion Cross Sections on Type Ia Supernovae

   Kanji Mori🇯🇵 · Michael A. Famiano🇺🇸 · Toshitaka Kajino🇯🇵 · Motohiko Kusakabe🇨🇳 · Xiaodong Tang🇨🇳

   Type Ia supernovae (SNe Ia) are thought to be thermonuclear explosion of white dwarfs (WDs). Their progenitors are not well understood. One popular scenario is the double-degenerate (DD) scenario, which attributes SNe Ia to WD-WD binary mergers. The fates of the WD mergers depend on the rate of ${}^{12}$C+${}^{12}$C reaction. Recently, the ${}^{12}$C+${}^{12}$C cross sections have been measured and the analysis of the data using the Trojan Horse Method suggested that the astrophysical reaction rate is larger than conventional rates at astrophysical temperatures due to possible resonances. The resonance contribution results in a decrease of the carbon burning ignition temperature. Therefore accretion induced collapse occurs more easily and increases the birthrate of Galactic neutron stars with the contribution of the DD scenario to the SNe Ia rate becoming even smaller.

   ↳ astro-ph.HEastro-ph.SRnucl-exMNRAS(2019)·31 citations
6. 06*

   Simulating the Chiral Magnetic Wave in a Box System

   Wen-Hao Zhou🇨🇳 · Jun Xu🇨🇳

   The chiral magnetic wave from the interplay between the chiral magnetic effect and the chiral separation effect is simulated in a box system with the periodic boundary condition based on the chiral kinetic equations of motion. Simulation results are compared with available limits from theoretical derivations, and effects of the temperature, the magnetic field, and the specific shear viscosity on the key properties of the chiral magnetic wave are discussed. Our study serves as a baseline for further simulations of chiral anomalies in relativistic heavy-ion collisions.

   ↳ nucl-thhep-exnucl-exPRC(2018)·22 citations
7. 07*

   Event by event fluctuations of the source shape: implications for the Levy shape, and Event Shape Sorting

   Boris Tomasik🇸🇰 · Jakub Cimerman🇨🇿

   In the first part of this contribution we show that the Levy stable shape of the correlation function can be caused by averaging of the measured correlation functions over a large number of events. In the second part it is demonstrated how a sample of events sorted by Event Shape Sorting technique exhibits different azimuthal dependence of correlation radii in each event class.

   ↳ nucl-thhep-phnucl-ex0 citations
8. 08*

   Topology optimization in the framework of the linear Boltzmann equation -- a method for designing optimal nuclear equipment and particle optics

   Sébastien Chabod🇫🇷

   In this study, we describe a procedure of topology optimization in the framework of the linear Boltzmann equation, implemented using a reference Monte-Carlo particle transport code. This procedure can design complex structures that optimize the transport of particles, according to preset objectives and constraints. Although simple and perfectible, this procedure was successfully tested on a series of difficult problems, with results outperforming human capabilities. Improved, it could be used to assist or automate the design of particle optics or nuclear devices.

   ↳ physics.ins-detnucl-exphysics.app-phNucl.Instrum.Meth.A(2019)·1 citation

* 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.