Fri·Oct 31, 2014Friday·October 31, 2014

1. 01*

   Partial Wave Analysis of the Reaction $p(3.5GeV)+p\to p{K}^{+}\Lambda$ to Search for the "$pp{K}^{-}$" Bound State

   G. Agakishiev🇷🇺 · O. Arnold🇩🇪 · D. Belver🇪🇸 · A. Belyaev🇷🇺 · J.C. Berger-Chen🇩🇪 · A. Blanco🇵🇹 · M. Böhmer🇩🇪 · J. L. Boyard🇫🇷 · P. Cabanelas🇪🇸 · S. Chernenko🇷🇺 · A. Dybczak🇵🇱 · E. Epple🇩🇪 and 84 other authors

   Employing the Bonn-Gatchina partial wave analysis framework (PWA), we have analyzed HADES data of the reaction $p(3.5GeV)+p\to p{K}^{+}\Lambda$. This reaction might contain information about the kaonic cluster "$pp{K}^{-}$" via its decay into $p\Lambda$. Due to interference effects in our coherent description of the data, a hypothetical $\overline{K}NN$ (or, specifically "$pp{K}^{-}$") cluster signal must not necessarily show up as a pronounced feature (e.g. a peak) in an invariant mass spectra like $p\Lambda$. Our PWA analysis includes a variety of resonant and non-resonant intermediate states and delivers a good description of our data (various angular distributions and two-hadron invariant mass spectra) without a contribution of a $\overline{K}NN$ cluster. At a confidence level of CL${}_s$=95\% such a cluster can not contribute more than 2-12\% to the total cross section with a $p{K}^{+}\Lambda$ final state, which translates into a production cross-section between 0.7 $\mu b$ and 4.2 $\mu b$, respectively. The range of the upper limit depends on the assumed cluster mass, width and production process.

   nucl-exPLB(2015)·95 citations
2. 02*

   ALICE results on vector meson photoproduction in ultra-peripheral p-Pb and Pb-Pb collisions

   E. L. Kryshen (for the ALICE Collaboration)🇨🇭

   Lead nuclei, accelerated at the LHC, are sources of strong electromagnetic fields that can be used to measure photon-induced interactions in a new kinematic regime. These interactions can be studied in ultra-peripheral p-Pb and Pb-Pb collisions where impact parameters are larger than the sum of the nuclear radii and hadronic interactions are strongly suppressed. Heavy quarkonium photoproduction is of particular interest since it is sensitive to the gluon distribution in the target. The ALICE Collaboration has studied J/psi and psi(2S) photoproduction in ultra-peripheral Pb-Pb collisions and exclusive J/psi photoproduction off protons in ultra-peripheral p-Pb collisions at the LHC. Implications for the study of gluon density distributions and nuclear gluon shadowing are discussed. Recent ALICE results on rho photoproduction are also presented.

   nucl-ex3 citations
3. 03*

   A measurement of the neutron to 199Hg magnetic moment ratio

   S. Afach🇨🇭 · C.A. Baker🇬🇧 · G. Ban🇫🇷 · G. Bison🇨🇭 · K. Bodek🇵🇱 · M. Burghoff🇩🇪 · Z. Chowdhuri🇨🇭 · M. Daum🇨🇭 · M. Fertl🇨🇭 · B. Franke🇨🇭 · P. Geltenbort🇫🇷 · K. Green🇬🇧 and 42 other authors

   The neutron gyromagnetic ratio has been measured relative to that of the 199Hg atom with an uncertainty of 0.8 ppm. We employed an apparatus where ultracold neutrons and mercury atoms are stored in the same volume and report the result ${\gamma }_{\mathrm{n}}/{\gamma }_{\mathrm{Hg}}=3.8424574(30)$.

   nucl-exphysics.atom-phphysics.ins-detPLB(2014)·43 citations
4. 04*

   Recent Highlights from the PHENIX Heavy-Ion Program at RHIC

   Baldo Sahlmueller (for the PHENIX collaboration)🇩🇪

   Over the last decade it has been established that a quark-gluon plasma (QGP) is formed in ultrarelativistic A+A collisions at RHIC energies. In recent years, detector upgrades have enabled the detailed study of this hot and dense matter. Important probes, among others, are direct photons and heavy flavor observables. Although the RHIC d+Au program was originally undertaken to study initial state and cold nuclear matter effects, recent measurements at both RHIC (d+Au) and the LHC (p+Pb) have found evidence for collective phenomena in these small systems.

   nucl-ex0 citations
5. 05*

   The Low energy structure of the Nucleon-Nucleon interaction: Statistical vs Systematic Uncertainties

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

   We analyze the low energy NN interaction by confronting statistical vs systematic uncertainties. This is carried out with the help of model potentials fitted to the Granada-2013 database where a statistically meaningful partial wave analysis comprising a total of $6713$ np and pp published scattering data from 1950 till 2013 below $350\mathrm{MeV}$ has been made. We extract threshold parameters uncertainties from the coupled channel effective range expansion up to $j\le 5$. We find that for threshold parameters systematic uncertainties are generally at least an order of magnitude larger than statistical uncertainties. Similar results are found for np phase-shifts and amplitude parameters.

   ↳ nucl-thnucl-exJ.Phys.G(2016)·42 citations
6. 06*

   QCD and nuclear physics. How to explain the coincidence between the action radius of nuclear forces and the characteristic scale of the neutron-neutron electrostatic interaction?

   A.A. Godizov🇷🇺

   An attempt is made to interpret, in the framework of QCD, the likeness between the shapes of the neutron-neutron strong and electrostatic interactions at the distances $\sim 1÷3$ fm.

   ↳ hep-phnucl-exnucl-thInt.J.Theor.Phys.(2016)·0 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.