Tue·Mar 14, 2017Tuesday·March 14, 2017

1. 01*

   Two-photon exchange in elastic electron-proton scattering

   A. Afanasev🇺🇸 · P. G. Blunden🇨🇦 · D. Hasell🇺🇸 · B. A. Raue🇺🇸

   We review recent theoretical and experimental progress on the role of two-photon exchange (TPE) in electron-proton scattering at low to moderate momentum transfers. We make a detailed comparison and analysis of the results of competing experiments on the ratio of e+p to e-p elastic scattering cross sections, and of the theoretical calculations describing them. A summary of the current experimental situation is provided, along with an outlook for future experiments.

   nucl-exnucl-thPPNP(2017)·113 citations
2. 02*

   First elastic electron scattering from ${}^{132}$Xe at the SCRIT facility

   K. Tsukada🇯🇵 · A. Enokizono🇯🇵 · T. Ohnishi · K. Adachi · T. Fujita🇯🇵 · M. Hara · M. Hori · T. Hori · S. Ichihara · K. Kurita🇯🇵 · M. Matsuda🇯🇵 · T. Suda🇯🇵 and 5 other authors

   The first elastic electron scattering has been successfully performed at the self-confining RI ion target (SCRIT) facility, the world's first electron scattering facility for exotic nuclei. The SCRIT technique achieved high luminosity (over 10${}^{27}$~cm${}^{-2}$s${}^{-1}$, sufficient for determining the nuclear shape) with only 10${}^8$ target ions. While ${}^{132}$Xe used in this time as a target is stable isotope, the charge density distribution was firstly extracted from the momentum transfer distributions of the scattered electrons by comparing the results with those calculated by a phase shift calculation.

   nucl-exPRL(2017)·75 citations
3. 03*

   Valence quark contributions for the ${\gamma }^{\ast }N\to N(1440)$ form factors from Light-Front holography

   G. Ramalho🇧🇷 · D. Melnikov🇧🇷

   The structure of the nucleon and the first radial excitation of the nucleon, the Roper, $N(1440)$, is studied within the formalism of Light-Front holography. The nucleon elastic form factors and ${\gamma }^{\ast }N\to N(1440)$ transition form factors are calculated under the assumption of the dominance of the valence quark degrees of freedom. Contrary to the previous studies, the bare parameters of the model associated with the valence quark are fixed by the empirical data for large momentum transfer ($Q^2$) assuming that the corrections to the three-quark picture (meson cloud contributions) are suppressed. The ${\gamma }^{\ast }N\to N(1440)$ transition form factors are then calculated without any adjustable parameters. Our estimates are compared with results from models based on valence quarks and others. The model compares well with the ${\gamma }^{\ast }N\to N(1440)$ transition form factor data, suggesting that meson cloud effects are not large, except in the region $Q^2<1.5$ GeV${}^2$. In particular, the meson cloud contributions for the Pauli form factor are small.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2018)·28 citations
4. 04*

   Differential flow correlations in relativistic heavy-ion collisions

   Jing Qian🇨🇳 · Ulrich Heinz🇺🇸 · Ronghua He🇨🇳 · Lei Huo🇨🇳

   A systematic analysis of correlations between different orders of $p_T$-differential flow is presented, including mode coupling effects in flow vectors, correlations between flow angles (a.k.a. event-plane correlations), and correlations between flow magnitudes, all of which were previously studied with integrated flows. We find that the mode coupling effects among differential flows largely mirror those among the corresponding integrated flows, except at small transverse momenta where mode coupling contributions are small. For the fourth- and fifth-order flow vectors $V_4$ and $V_5$ we argue that the event plane correlations can be understood as the ratio between the mode coupling contributions to these flows and and the flow magnitudes. We also find that for $V_4$ and $V_5$ the linear response contribution scales linearly with the corresponding cumulant-defined eccentricities but not with the standard eccentricities.

   ↳ nucl-thnucl-exPRC(2017)·21 citations
5. 05*

   Global constraints on absolute neutrino masses and their ordering

   Francesco Capozzi · Eleonora Di Valentino · Eligio Lisi · Antonio Marrone · Alessandro Melchiorri · Antonio Palazzo

   Within the standard three-neutrino framework, the absolute neutrino masses and their ordering (either normal, NO, or inverted, IO) are currently unknown. However, the combination of current data coming from oscillation experiments, neutrinoless double beta decay searches, and cosmological surveys, can provide interesting constraints for such unknowns in the sub-eV mass range, down to O(0.1) eV in some cases. We discuss current limits on absolute neutrino mass observables by performing a global data analysis, that includes the latest results from oscillation experiments, neutrinoless double beta decay bounds from the KamLAND-Zen experiment, and constraints from representative combinations of Planck measurements and other cosmological data sets. In general, NO appears to be somewhat favored with respect to IO at the level of ~2 sigma, mainly by neutrino oscillation data (especially atmospheric), corroborated by cosmological data in some cases. Detailed constraints are obtained via the chi^2 method, by expanding the parameter space either around separate minima in NO and IO, or around the absolute minimum in any ordering. Implications for upcoming oscillation and non-oscillation neutrino experiments, including beta-decay searches, are also discussed.

   ↳ hep-phastro-ph.COhep-exnucl-exPhys. Rev. D 95, 096014 (2017)

* 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.