Thu·Aug 31, 2017Thursday·August 31, 2017

1. 01*

   Rapid fluctuation of the tensor polarization of deuteron beams behind carbon foils and their relation to the resonances in the isospin-breaking ${}^{12}\mathrm{C}(d,{\alpha }_2{)}^{10}{\mathrm{B}}^{\ast }$ reaction

   H. Seyfarth🇩🇪 · A. Rouba · V. Baryshevsky🇧🇾 · R. Engels🇩🇪 · K. Grigoryev🇩🇪 · F. Rathmann🇩🇪 · H. Ströher🇩🇪

   Rapid fluctuations are observed in the tensor-polarization $p_{zz}$ of deuteron beams forward-transmitted through graphite targets. Unpolarized 9.50 to 18.60\,MeV beams from the Köln tandem accelerator were utilized, and the polarization behind seven 36 to 188\,mg/cm${}^2$ targets was measured with a polarimeter based on the ${}^3\mathrm{He}(\vec{d},p{)}^4\mathrm{He}$ reaction. Due to the chosen relation between the areal target densities and the initial beam energies $E_{\mathrm{in}}$, the seven sets of $p_{zz}(E_{\mathrm{in}})$ can be combined in a common plot as a function of $E_{\mathrm{in}}$. This allows one to understand $p_{zz}$, measured behind the 188\,mg/cm${}^2$ target at $E_{\mathrm{in}}$=18.6\,MeV, as resulting from the sequence of differential polarization production $\Delta p_{zz}(E)/\Delta E$ during energy degradation in the target from $E$=18.60 to 9.50\,MeV. The rapid fluctuations of $\Delta p_{zz}(E)/\Delta E$$p_{zz}$ are described by 51 Gaussian-distributed cross-sections removing deuterons either in the $m=0$ or in the $m=\pm 1$ state from the beam. The 51 fitted central energies $E_0$ with a single exception agree with the energies of the narrow peaks in the excitation functions of the weak, isospin-breaking ${}^{12}\mathrm{C}(d,{\alpha }_2{)}^{10}{\mathrm{B}}^{\ast }(1.74\mathrm{MeV},J^{\pi }=0^{+},T=1)$ reaction with population of the second excited ${}^{10}\mathrm{B}$ state via intermediate excited ${}^{14}$N states. Strong evidence is found that removal of deuterons in the $m=0$ ($m=\pm 1$) state from the beam leads to the formation of ${}^{14}$N states of established positive (negative) parity. As an application, the removal cross-section functions allow to calculate $p_{zz}$ achievable with carbon targets for initial beam energies $E_{\mathrm{in}}$ between 18.60 and 9.50\,MeV and $E_{\mathrm{out}}$ given by the areal target density. Carbon layers in a sandwich technique would enable $p_{zz}$ between -0.4 and +0.3.

   nucl-ex0 citations
2. 02*

   Exploring GPDs through the photoproduction of a $\gamma \rho$ pair

   R. Boussarie🇵🇱 · B. Pire🇫🇷 · L. Szymanowski🇵🇱 · S. Wallon🇫🇷

   We describe the process $\gamma N\to \gamma \rho N^{\prime }$ in the generalized Bjorken regime where the $\gamma \rho$ pair has a large invariant mass. In the collinear QCD factorization framework, the amplitude gives access to both chiral-even and chiral-odd quark generalized parton distributions (GPDs), and is insensitive to gluon GPDs. The separation of longitudinally and transversely polarized $\rho$ meson production allows to distinguish chiral-even and chiral-odd contributions. Production rates are estimated in the kinematics of the near-future JLab~12-GeV experiments.

   ↳ hep-phhep-exnucl-exnucl-thPoS(2018)·3 citations
3. 03*

   Interferometry correlations in central p+Pb collisions

   Piotr Bozek🇵🇱 · Sebastian Bysiak

   We present results on interferometry correlations for pions emitted in central p+Pb collisions at 5.02TeV in a 3+1 dimensional viscous hydrodynamic model with initial conditions from the Glauber Monte Carlo model. The correlation function is calculated as a function of the pion pair rapidity. The extracted interferometry radii show a weak rapidity dependence, reflecting the lack of boost invariance of the pion distribution. A cross-term between the $out$ and $long$ directions is found to be nonzero. The results obtained in the hydrodynamic model are in fair agreement with recent data of the ATLAS Collaboration.

   ↳ nucl-thnucl-exEPJC(2018)·1 citation
4. 04*

   Radiopure tungstate and molybdate crystal scintillators for double beta decay experiments

   F.A. Danevich🇺🇦

   Crystal scintillators are very promising detectors to investigate double beta decay of atomic nuclei. Recent achievements in development and application of tungstate and molybdate crystal scintillators as well as prospects for the next generation double beta decay experiments are discussed.

   ↳ physics.ins-detnucl-exInt.J.Mod.Phys.A(2017)·7 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.