Fri·Mar 15, 2019Friday·March 15, 2019

1. 01*

   Experimental studies at low $Q^2$ of the spin structure of the nucleon at Jefferson Lab

   A. Deur🇺🇸

   We summarize the experimental program of Jefferson Lab that studies the nucleon spin structure at low $Q^2$. This program completes the precise experimental mapping of the nucleon spin structure functions $g_1(\nu ,Q^2)$ and $g_2(\nu ,Q^2)$ and their moments started at SLAC, CERN and DESY at high $Q^2$, and continued at Jefferson Lab at intermediate $Q^2$. The results presented cover the domain where Chiral Effective Field Theory ($\chi$EFT) should describe the strong interaction. They provide a comprehensive set of benchmark measurements for $\chi$EFT. The preliminary conclusion is that nucleon spin structure data are still challenging for $\chi$EFT in spite of the notable improvements in these calculations.

   nucl-exPoS(2019)·2 citations
2. 02*

   Measurement of strange baryon-antibaryon interactions with femtoscopic correlations

   ALICE Collaboration

   Two-particle correlation functions were measured for $\mathrm{p}\overline{\mathrm{p}}$, $\mathrm{p}\overline{\mathrm{\Lambda }}$, $\overline{\mathrm{p}}\mathrm{\Lambda }$, and $\Lambda \overline{\Lambda }$ pairs in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV and $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV recorded by the ALICE detector. From a simultaneous fit to all obtained correlation functions, real and imaginary components of the scattering lengths, as well as the effective ranges, were extracted for combined $\mathrm{p}\overline{\mathrm{\Lambda }}$ and $\overline{\mathrm{p}}\mathrm{\Lambda }$ pairs and, for the first time, for $\Lambda \overline{\Lambda }$ pairs. Effective averaged scattering parameters for heavier baryon-antibaryon pairs, not measured directly, are also provided. The results reveal similarly strong interaction between measured baryon-antibaryon pairs, suggesting that they all annihilate in the same manner at the same pair relative momentum $k^{\ast }$. Moreover, the reported significant non-zero imaginary part and negative real part of the scattering length provide motivation for future baryon-antibaryon bound state searches.

   nucl-exhep-exPLB(2020)·40 citations
3. 03*

   All the Fun of the FAIR: Fundamental physics at the Facility for Antiproton and Ion Research

   M. Durante🇮🇹 · P. Indelicato🇫🇷 · B. Jonson🇸🇪 · V. Koch🇺🇸 · K. Langanke🇩🇪 · Ulf-G. Meißner🇩🇪 · E. Nappi🇮🇹 · T. Nilsson🇸🇪 · Th. Stöhlker🇩🇪 · E. Widmann🇦🇹 · M. Wiescher🇺🇸

   The Facility for Antiproton and Ion Research (FAIR) will be the accelerator-based flagship research facility in many basic sciences and their applications in Europe for the coming decades. FAIR will open up unprecedented research opportunities in hadron and nuclear physics, in atomic physics and nuclear astrophysics as well as in applied sciences like materials research, plasma physics and radiation biophysics with applications towards novel medical treatments and space science. FAIR is currently under construction as an international facility at the campus of the GSI Helmholtzzentrum for Heavy-Ion Research in Darmstadt, Germany. While the full science potential of FAIR can only be harvested once the new suite of accelerators and storage rings is completed and operational, some of the experimental detectors and instrumentation are already available and will be used starting in summer 2018 in a dedicated research program at GSI, exploiting also the significantly upgraded GSI accelerator chain. The current manuscript summarizes how FAIR will advance our knowledge in various research fields ranging from a deeper understanding of the fundamental interactions and symmetries in Nature to a better understanding of the evolution of the Universe and the objects within.

   ↳ nucl-thhep-exhep-phnucl-ex+1Phys.Scripta(2019)·111 citations
4. 04*

   Discovery potential of multi-ton xenon detectors in neutrino electromagnetic properties

   Chung-Chun Hsieh🇹🇼 · Lakhwinder Singh🇹🇼 · Chih-Pan Wu🇹🇼 · Jiunn-Wei Chen🇹🇼 · Hsin-Chang Chi🇹🇼 · C.-P. Liu🇹🇼 · Mukesh K. Pandey🇹🇼 · Henry T. Wong🇹🇼

   Next-generation xenon detectors with multi-ton-year exposure are powerful direct probes of dark matter candidates, in particular the favorite weakly-interacting massive particles. Coupled with the features of low thresholds and backgrounds, they are also excellent telescopes of solar neutrinos. In this paper, we study the discovery potential of ton-scale xenon detectors in electromagnetic moments of solar neutrinos. Relevant neutrino-atom scattering processes are calculated by applying a state-of-the-arts atomic many-body method--relativistic random phase approximation (RRPA). Limits on these moments are derived from existing data and estimated with future experiment specifications. With one ton-year exposure, XENON-1T can improve the effective milli-charge constraint by a factor two. With LZ and DARWIN, the projected improvement on the solar neutrino effective milli-charge(magnetic moment) is around 7(2) times smaller than the current bound. If LZ can keep the same background level and push the electron recoil threshold to 0.5 keV, the projected improvement on milli-charge(magnetic moment) is about 10(3) times smaller than the current bound.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2019)·35 citations
5. 05*

   Extension of Intra-Nuclear Cascade Model to Neutron Induced Nonelastic Cross-Sections in Low Energy Region

   Masahiro Nakano🇯🇵 · Yusuke Uozumi🇯🇵

   Two features, a slow slope and a sharp drop, in neutron induced total nonelastic cross-sections are analyzed within the framework of an intra-nuclear cascade (INC) model. First, to reproduce the slow slope from 100MeV to 10 MeV, the original INC is generalized in two points; a method to construct the ground state of the target nucleus, and a method of taking the effective two body cross-sections between two nucleons. Secondly, to analyze the origin of the sharp drop from 10MeV to nearly 1 MeV, the INC is extended to include quantum effects which are originated from the existence of the discrete states in the nuclear potential. It is shown that this extension leads to the sharp drops in the very low energy below around 10MeV. It is concluded that the INC model can be extended to explain the sharp drops in addition to the slow slope in neutron induced nonelastic cross-sections in the energy region from 100MeV down to 1 MeV.

   ↳ nucl-thnucl-exPRC(2019)·8 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.