Nuclear Theory·nucl-th

Thursday·November 5, 2015

9 papers—4 primary·5 cross-listed

05
[Submitted on 4 Nov 2015] (cross-list from hep-ph)
Neutrino-induced meson productions
Satoshi X. Nakamura (Osaka University)🇯🇵
We develop a dynamical coupled-channels (DCC) model for neutrino-nucleon reactions in the resonance region, by extending the DCC model that we have previously developed through an analysis of $π N, γ N \to π N, η N, K Λ, K Σ$ reaction data for $W \leq 2.1$ GeV. We analyze electron-induced reaction data for both proton and neutron targets to determine the vector current form factors up to $Q^{2} \leq$ 3.0 (GeV/ $c$ ) $^{2}$ . Axial-current matrix elements are derived in accordance with the Partially Conserved Axial Current (PCAC) relation to the $π N$ interactions of the DCC model. As a result, we can uniquely determine the interference pattern between resonant and non-resonant amplitudes. Our calculated cross sections for neutrino-induced single-pion productions are compared with available data, and are found to be in reasonable agreement with the data. We also calculate the double-pion production cross sections in the resonance region, for the first time, with relevant resonance contributions and channel couplings. The result is compared with the double-pion production data. For a future development of a neutrino-nucleus reaction model and/or a neutrino event generator for analyses of neutrino experiments, the DCC model presented here can give a useful input.
Comments:
8 pages, 12 figures, Contribution to the proceedings of 10th International Workshop on the Physics of Excited Nucleons (NSTAR2015), May 25-28 2015, Osaka, Japan
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1511.01187 [pdf]
JPS Conf.Proc.(2016)·1 citation
06
[Submitted on 4 Nov 2015] (cross-list from hep-ph)
Compositeness of baryonic resonances: Applications to the Delta(1232), N(1535), and N(1650) resonances
Takayasu Sekihara (Osaka U., Res. Ctr. Nucl. Phys.)🇯🇵 · Takashi Arai (KEK, Tsukuba)🇯🇵 · Junko Yamagata-Sekihara (Nat. Inst. Tech., Oshima Coll.)🇯🇵 · Shigehiro Yasui (Tokyo Inst. Tech.)🇯🇵
We present a formulation of the compositeness for baryonic resonances in order to discuss the meson-baryon molecular structure inside the resonances. For this purpose, we derive a relation between the residue of the scattering amplitude at the resonance pole position and the two-body wave function of the resonance in a sophisticated way, and we define the compositeness as the norm of the two-body wave functions. As applications, we investigate the compositeness of the $Δ (1232)$ , $N (1535)$ , and $N (1650)$ resonances from precise $π N$ scattering amplitudes in a unitarized chiral framework with the interaction up to the next-to-leading order in chiral perturbation theory. The $π N$ compositeness for the $Δ (1232)$ resonance is evaluated in the $π N$ single-channel scattering, and we find that the $π N$ component inside $Δ (1232)$ in the present framework is nonnegligible, which supports the previous work. On the other hand, the compositeness for the $N (1535)$ and $N (1650)$ resonances is evaluated in a coupled-channels approach, resulting that the $π N$ , $η N$ , $K Λ$ and $K Σ$ components are negligible for these resonances.
Comments:
23 pages, 7 eps figures, version accepted for publication in PRC, discussions improved
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1511.01200 [pdf]
PRC(2016)·46 citations
07
[Submitted on 4 Nov 2015] (cross-list from physics.atom-ph)
Level-resolved quantum statistical theory of electron capture into many-electron compound resonances in highly charged ions
J. C. Berengut · C. Harabati · V. A. Dzuba · V. V. Flambaum · G. F. Gribakin
The strong mixing of many-electron basis states in excited atoms and ions with open $f$ shells results in very large numbers of complex, chaotic eigenstates that cannot be computed to any degree of accuracy. Describing the processes which involve such states requires the use of a statistical theory. Electron capture into these 'compound resonances' leads to electron-ion recombination rates that are orders of magnitude greater than those of direct, radiative recombination, and cannot be described by standard theories of dielectronic recombination. Previous statistical theories considered this as a two-electron capture process which populates a pair of single-particle orbitals, followed by 'spreading' of the two-electron states into chaotically mixed eigenstates. This method is similar to a configuration-average approach, as it neglects potentially important effects of spectator electrons and conservation of total angular momentum. In this work we develop a statistical theory which considers electron capture into 'doorway' states with definite angular momentum obtained by the configuration interaction method. We apply this approach to electron recombination with W $^{20 +}$ , considering 2 million doorway states. Despite strong effects from the spectator electrons, we find that the results of the earlier theories largely hold. Finally, we extract the fluorescence yield (the probability of photoemission and hence recombination) by comparison with experiment.
Comments:
11 pages, 5 figures
Subjects:
Atomic Physics (physics.atom-ph); Nuclear Theory (nucl-th)
arXiv:
1511.01221 [pdf]
PRA(2015)·2 citations
08
[Submitted on 4 Nov 2015] (cross-list from nucl-ex)
First measurement of several $β$ -delayed neutron emitting isotopes beyond N=126
R. Caballero-Folch · C. Domingo-Pardo · J. Agramunt · A. Algora · F. Ameil · A. Arcones · Y. Ayyad · J. Benlliure · I.N. Borzov · M. Bowry · F. Calvino · D. Cano-Ott and 53 other authors
The $β$ -delayed neutron emission probabilities of neutron rich Hg and Tl nuclei have been measured together with $β$ -decay half-lives for 20 isotopes of Au, Hg, Tl, Pb and Bi in the mass region N $≳$ 126. These are the heaviest species where neutron emission has been observed so far. These measurements provide key information to evaluate the performance of nuclear microscopic and phenomenological models in reproducing the high-energy part of the $β$ -decay strength distribution. In doing so, it provides important constraints to global theoretical models currently used in $r$ -process nucleosynthesis.
Comments:
Submitted to Phys. Rev. Lett
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1511.01296 [pdf]
PRL(2016)·60 citations
09
[Submitted on 4 Nov 2015] (cross-list from hep-ph)
Glueball decay patterns in top-down holographic QCD
Frederic Brünner🇦🇹 · Denis Parganlija🇦🇹 · Anton Rebhan🇦🇹
We discuss our results on scalar glueball decay in the top-down holographic Witten-Sakai-Sugimoto model for low-energy QCD and compare with available experimental data, which appear to disfavor the glueball candidate $f_{0} (1500)$ but seem to be perfectly consistent with interpreting $f_{0} (1710)$ as a nearly unmixed glueball. The holographic model moreover makes definite predictions for future experiments.
Comments:
6 pages. To appear in the Proceedings of the EPS-HEP Conference 22-29 July 2015, Vienna, Austria
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1511.01391 [pdf]
PoS(2015)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

Neutrino-induced meson productions

Compositeness of baryonic resonances: Applications to the Delta(1232), N(1535), and N(1650) resonances

Level-resolved quantum statistical theory of electron capture into many-electron compound resonances in highly charged ions

First measurement of several β-delayed neutron emitting isotopes beyond N=126

Glueball decay patterns in top-down holographic QCD

Affiliations

First measurement of several $β$ -delayed neutron emitting isotopes beyond N=126