Nuclear Theory·nucl-th

Thursday·April 28, 2016

8 papers—5 primary·3 cross-listed

06
Protophobic Fifth Force Interpretation of the Observed Anomaly in $^{8}$ Be Nuclear Transitions
Jonathan L. Feng🇺🇸 · Bartosz Fornal🇺🇸 · Iftah Galon🇺🇸 · Susan Gardner🇺🇸 · Jordan Smolinsky🇺🇸 · Tim M. P. Tait🇺🇸 · Philip Tanedo🇺🇸
Recently a 6.8 $σ$ anomaly has been reported in the opening angle and invariant mass distributions of $e^{+} e^{-}$ pairs produced in $^{8} Be$ nuclear transitions. The data are explained by a 17 MeV vector gauge boson $X$ that is produced in the decay of an excited state to the ground state, $^{8} Be^{*} \to^{8} Be X$ , and then decays through $X \to e^{+} e^{-}$ . The $X$ boson mediates a fifth force with a characteristic range of 12 fm and has milli-charged couplings to up and down quarks and electrons, and a proton coupling that is suppressed relative to neutrons. The protophobic $X$ boson may also alleviate the current 3.6 $σ$ discrepancy between the predicted and measured values of the muon's anomalous magnetic moment.
↳ hep-phhep-exnucl-exnucl-thPRL(2016)·301 citations
07
Helicity and nuclear $β$ decay correlations
Ran Hong🇺🇸 · Matthew G. Sternberg🇺🇸 · Alejandro García🇺🇸
We present simple derivations of nuclear $β$ -decay correlations with an emphasis on the special role of helicity. This provides a good opportunity to teach students about helicity and chirality in particle physics through exercises using simple aspects of quantum mechanics. In addition, this paper serves as an introduction to nuclear $β$ -decay correlations from both a theoretical and experimental vantage. This article can be used to introduce students to ongoing experiments searching for hints of new physics in the low-energy precision frontier.
↳ physics.ed-phnucl-thAm.J.Phys.(2017)·6 citations
08
An implementation of hybrid parallel CUDA code for the hyperonic nuclear forces
Hidekatsu Nemura · for HAL QCD Collaboration
We present our recent effort to develop a GPGPU program to calculate 52 channels of the Nambu-Bethe-Salpeter (NBS) wave functions in order to study the baryon interactions, from nucleon-nucleon to $Ξ - Ξ$ , from lattice QCD. We adopt CUDA programming to perform the multi-GPU execution on a hybrid parallel programming with MPI and OpenMP. Effective baryon block algorithm is briefly outlined, which calculates efficaciously a large number of NBS wave functions at a time, and three CUDA kernel programs are implemented to materialize the effective baryon block algorithm using GPUs on the single-program multiple-data (SPMD) programming model. In order to parallelize multiple GPUs, we take both two approaches by dividing the time dimension and by dividing the spatial dimensions. Performances are measured using HA-PACS supercomputer in University of Tsukuba, which includes NVIDIA M2090 and NVIDIA K20X GPUs. Strong scaling and weak scaling measured by using both M2090 and K20X GPUs are presented. We find distinct difference between the M2090 and the K20X in the sustained performance measurement of particular kernel executions which utilize the cudaStream objects.
↳ hep-latnucl-thPoS(2016)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Protophobic Fifth Force Interpretation of the Observed Anomaly in 8Be Nuclear Transitions

Helicity and nuclear β decay correlations

An implementation of hybrid parallel CUDA code for the hyperonic nuclear forces

Affiliations

Protophobic Fifth Force Interpretation of the Observed Anomaly in $^{8}$ Be Nuclear Transitions

Helicity and nuclear $β$ decay correlations