Tue·Jun 20, 2017Tuesday·June 20, 2017

1. 01*

   Analysis of various projectile interactions with Nuclear Emulsion Detector nuclei at ~ 1 GeV per nucleon using Coulomb modified Glauber model

   N. Marimuthu🇮🇳 · V. Singh🇮🇳 · S. S. R. Inbanathan🇮🇳

   The total nuclear reaction cross-section is calculated considering with and without medium effect by employing Coulomb Modified Glauber Model (CMGM) for interactions of projectiles 56^Fe_26, 84^Kr_36, 132^Xe_54, 197^Au_79 and 238^U_92 with nuclear emulsion detector (NED) nuclei at around 1 GeV per nucleon incident kinetic energy. These calculated reaction cross-sections are correlated with the different target groups of the NED nuclei. The average value of various parameters are also calculated and compared with the corresponding experimental results. The number of shower particles emitted in an interaction is also calculated and showed good agreement with the experimental result. We observed that the total reaction cross-section increases with increasing the target mass number in case of all the considered projectiles. In addition, it shows that the average value of reaction cross-section with nuclear medium effect is in good agreement with the experimental results for projectiles 56^Fe, 84^Kr, 132^Xe, although results of projectiles 197^Au and 238^U are not in agreement with the experimental observations. This study sheds some light on the energy dependence of the nuclear reaction cross-section.

   nucl-exhep-exAdv.High Energy Phys.(2017)·14 citations
2. 02*

   Analytic parametrizations of the ${\gamma }^{\ast }N\to N(1440)$ form factors inspired by Light-Front holography

   G. Ramalho🇧🇷

   We present analytic parametrizations for the ${\gamma }^{\ast }N\to N(1440)$ form factors derived from light-front holography in leading twist approximation. The new parametrizations describe the electromagnetic form factors using analytic functions dependent on the masses of the $\rho$ meson and respective radial excitations, as well as the masses of the nucleon and the resonance $N(1440)$. The free parameters of the model, associated with three independent couplings, are interpreted as bare couplings, and are fixed by the nucleon data for large $Q^2$. The proposed parametrizations compare remarkably well with the empirical data for $Q^2>2$ GeV${}^2$, corroborating the dominant role of the valence quark degrees of freedom in the ${\gamma }^{\ast }N\to N(1440)$ transition.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2017)·19 citations
3. 03*

   Suppression of excited ${\rm Y}$ states relative to the ground state in PbPb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV

   CMS Collaboration

   The relative yields of ${\rm Y}$ mesons produced in pp and PbPb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV and reconstructed via the dimuon decay channel are measured using data collected by the CMS experiment. Double ratios are formed by comparing the yields of the excited states, ${\rm Y}$(2S) and ${\rm Y}$(3S), to the ground state, ${\rm Y}$(1S), in both PbPb and pp collisions at the same center-of-mass energy. The double ratios, [${\rm Y}$(nS)/${\rm Y}$(1S)]${}_{\mathrm{PbPb}}$ / [${\rm Y}$(nS)/${\rm Y}$(1S)]${}_{\mathrm{pp}}$, are measured to be 0.308 $\pm$ 0.055 (stat) $\pm$ 0.019 (syst) for the ${\rm Y}$(2S) and less than 0.26 at 95% confidence level for the ${\rm Y}$(3S). No significant ${\rm Y}$(3S) signal is found in the PbPb data. The double ratios are studied as a function of collision centrality, as well as dimuon transverse momentum and rapidity. No significant dependencies are observed.

   ↳ hep-exnucl-exPRL(2018)·100 citations
4. 04*

   Radiopurity assessment of the energy readout for the NEXT double beta decay experiment

   S. Cebrián🇪🇸 · J. Pérez🇪🇸 · I. Bandac🇪🇸 · L. Labarga🇪🇸 · V. Álvarez🇪🇸 · C.D.R. Azevedo🇵🇹 · J.M. Benlloch-Rodríguez🇪🇸 · F.I.G.M. Borges🇵🇹 · A. Botas🇪🇸 · S. Cárcel🇪🇸 · J.V. Carrión🇪🇸 · C.A.N. Conde🇵🇹 and 58 other authors

   The Neutrino Experiment with a Xenon Time-Projection Chamber (NEXT) experiment intends to investigate the neutrinoless double beta decay of 136Xe, and therefore requires a severe suppression of potential backgrounds. An extensive material screening and selection process was undertaken to quantify the radioactivity of the materials used in the experiment. Separate energy and tracking readout planes using different sensors allow us to combine the measurement of the topological signature of the event for background discrimination with the energy resolution optimization. The design of radiopure readout planes, in direct contact with the gas detector medium, was especially challenging since the required components typically have activities too large for experiments demanding ultra-low background conditions. After studying the tracking plane, here the radiopurity control of the energy plane is presented, mainly based on gamma-ray spectroscopy using ultra-low background germanium detectors at the Laboratorio Subterráneo de Canfranc (Spain). All the available units of the selected model of photomultiplier have been screened together with most of the components for the bases, enclosures and windows. According to these results for the activity of the relevant radioisotopes, the selected components of the energy plane would give a contribution to the overall background level in the region of interest of at most 2.4 x 10-4 counts keV-1 kg-1 y-1, satisfying the sensitivity requirements of the NEXT experiment.

   ↳ physics.ins-dethep-exnucl-exJINST(2017)·29 citations
5. 05*

   Correlation Energy of Proton-Neutron Subsystem in Valence Orbit

   Tomohiro Oishi🇮🇹 · Lorenzo Fortunato🇮🇹

   Deuteron correlation energy (DCE) of the valence proton-neutron subsystem is evaluated by utilizing a simple three-body model. We focus on the ${}^6$Li and ${}^{18}$F nuclei assuming the doubly-closed core and the valence proton and neutron. Two interaction models, schematic density-dependent contact (SDDC) and Minnesota potentials, are utilized to describe the proton-neutron interaction. Evaluating DCE, we conclude that the proton-neutron binding in ${}^6$Li can be stronger than its counterpart of a deuteron in vacuum. On the other hand, in ${}^{18}$F, the energetic correlation is remarkably weak, and does not favor the bound, deuteron-like configuration. This significant difference between two systems can be understood from a competition between the proton-neutron kinetic and pairing energies, which are sensitive to the spatial extension of the wave function. This result indicates a remarkable dependence of the deuteron correlation to its environment and the valence orbits.

   ↳ nucl-thnucl-exphysics.atm-clus0 citations
6. 06*

   Onset of $\eta$-meson binding in the He isotopes

   N. Barnea🇮🇱 · E. Friedman🇺🇸 · A. Gal🇮🇱

   The onset of binding $\eta$(548) mesons in nuclei is studied in the He isotopes by doing precise $\eta NNN$ and $\eta NNNN$ few-body stochastic variational method calculations for two semi-realistic $NN$ potentials and two energy dependent $\eta N$ potentials derived from coupled-channel models of the $N^{\ast }(1535)$ nucleon resonance. The energy dependence of the $\eta N$ subthreshold input is treated self consistently. It is found that a minimal value of the real part of the $\eta N$ scattering length $a_{\eta N}$ close to 1 fm is required to bind $\eta$ mesons in ${}^3$He, yielding then a few MeV $\eta$ binding in ${}^4$He. The onset of $\eta$-meson binding in ${}^4$He requires that Re$a_{\eta N}$ exceeds 0.7 fm approximately. These results compare well with results of recent $\eta NNN$ and $\eta NNNN$ pionless effective field theory calculations. Related optical-model calculations are also discussed.

   ↳ nucl-thhep-phnucl-exNPA(2017)·34 citations
7. 07*

   Decuplet to octet baryon transitions in chiral perturbation theory

   Hao-Song Li🇨🇳 · Zhan-Wei Liu🇨🇳 · Xiao-Lin Chen🇨🇳 · Wei-Zhen Deng🇨🇳 · Shi-Lin Zhu🇨🇳

   We have systematically investigated the decuplet (T) to octet (B) baryon ($T\to B\gamma$) transition magnetic moments to the next-to-next-to-leading order and electric quadruple moments to the next-to-leading order in the framework of the heavy baryon chiral perturbation theory. Our calculation includes the contributions from both the intermediate decuplet and octet baryon states in the loops. Our results show reasonably good convergence of the chiral expansion and agreement with the experimental data. The analytical expressions may be useful to the chiral extrapolation of the lattice simulations of the decuplet electromagnetic properties.

   ↳ hep-phhep-exhep-latnucl-ex+1EPJC(2019)·19 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.