Wed·Jul 16, 2014Wednesday·July 16, 2014

1. 01*

   Tensor-polarized structure functions: Tensor structure of deuteron in 2020's

   S. Kumano🇯🇵

   We explain spin structure for a spin-one hadron, in which there are new structure functions, in addition to the ones ($F_1$, $F_2$, $g_1$, $g_2$) which exist for the spin-1/2 nucleon, associated with its tensor structure. The new structure functions are $b_1$, $b_2$, $b_3$, and $b_4$ in deep inelastic scattering of a charged-lepton from a spin-one hadron such as the deuteron. Among them, twist-two functions are related by the Callan-Gross type relation $b_2=2x{b}_1$ in the Bjorken scaling limit. First, these new structure functions are introduced, and useful formulae are derived for projection operators of $b_{1-4}$ from a hadron tensor $W_{\mu \nu }$. Second, a sum rule is explained for $b_1$, and possible tensor-polarized distributions are discussed by using HERMES data in order to propose future experimental measurements and to compare them with theoretical models. A proposal was approved to measure $b_1$ at the Thomas Jefferson National Accelerator Facility (JLab), so that much progress is expected for $b_1$ in the near future. Third, formalisms of polarized proton-deuteron Drell-Yan processes are explained for probing especially tensor-polarized antiquark distributions, which were suggested by the HERMES data. The studies of the tensor-polarized structure functions will open a new era in 2020's for tensor-structure studies in terms of quark and gluon degrees of freedom, which is much different from ordinary descriptions in terms of nucleons and mesons.

   ↳ hep-phhep-exhep-latnucl-ex+1J.Phys.Conf.Ser.(2014)·14 citations
2. 02*

   Mean-field potential effects on particle and antiparticle elliptic flows in the beam-energy scan program at RHIC

   Jun Xu · Che Ming Ko · Feng Li · Taesoo Song · He Liu

   The elliptic flow splitting between particles and their antiparticles has recently been observed by the STAR Collaboration in the beam-energy scan program at the Relativistic Heavy Ion Collider. In studies based on transport models, we have found that this splitting can be explained by the different mean-field potentials acting on particles and their antiparticles in the produced baryon-rich matter. In particular, we have shown that the experimentally measured relative elliptic flow difference can help constrain the vector coupling constant in the Nambu-Jona-Lasinio model used in describing the partonic stage of heavy-ion collisions. This information is useful for locating the critical point in the QCD phase diagram and thus understanding the phase structure of QCD.

   ↳ nucl-thhep-exnucl-exNucl.Phys.Rev32:146,2015·2 citations
3. 03*

   Bootstrapping the statistical uncertainties of NN scattering data

   R. Navarro Perez🇪🇸 · J. E. Amaro🇪🇸 · E. Ruiz Arriola🇪🇸

   We use the Monte Carlo bootstrap as a method to simulate pp and np scattering data below pion production threshold from an initial set of over 6700 experimental mutually $3\sigma$ consistent data. We compare the results of the bootstrap, with 1020 statistically generated samples of the full database, with the standard covariance matrix method of error propagation. No significant differences in scattering observables and phase shifts are found. This suggests alternative strategies for propagating errors of nuclear forces in nuclear structure calculations.

   ↳ nucl-thhep-phnucl-exPLB(2014)·31 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.