Wed·Oct 9, 2019Wednesday·October 9, 2019

1. 01*

   20Ne + 76Ge elastic and inelastic scattering at 306 MeV

   A. Spatafora🇮🇹 · F. Cappuzzello🇮🇹 · D. Carbone🇮🇹 · M. Cavallaro🇮🇹 · J. A. Lay🇪🇸 · L. Acosta🇲🇽 · C. Agodi🇮🇹 · D. Bonanno🇮🇹 · D. Bongiovanni🇮🇹 · I. Boztosun🇹🇷 · G. A. Brischetto🇮🇹 · S. Burrello🇮🇹 and 37 other authors

   Background: Double charge exchange (DCE) nuclear reactions have recently attracted much interest as tools to provide experimentally driven information about nuclear matrix elements of interest in the context of neutrinoless double-beta decay. In this framework, a good description of the reaction mechanism and a complete knowledge of the initial and final-state interactions are mandatory. Presently, not enough is known about the details of the optical potentials and nuclear response to isospin operators for many of the projectile-target systems proposed for future DCE studies. Among these, the 20Ne + 76Ge DCE reaction is particularly relevant due to its connection with 76Ge double-beta decay. Purpose: We intend to characterize the initial-state interaction for the 20Ne + 76Ge reactions at 306 MeV bombarding energy and determine the optical potential and the role of the couplings between elastic channel and inelastic transitions to the first low-lying excited states. Methods: We determine the experimental elastic and inelastic scattering cross-section angular distributions, compare the theoretical predictions by adopting different models of optical potentials with the experimental data, and evaluate the coupling effect through the comparison of the distorted-wave Born approximation calculations with the coupled channels ones. Results: Optical models fail to describe the elastic angular distribution above the grazing angle (9.4{\deg}). A correction in the geometry to effectively account for deformation of the involved nuclear systems improves the agreement up to about 14{\deg}. Coupled channels effects are crucial to obtain good agreement at large angles in the elastic scattering cross section.

   nucl-exnucl-thPRC(2019)·49 citations
2. 02*

   Elastic and inelastic scattering of ${}^{16}$O on ${}^{27}$Al and ${}^{28}$Si at 240 MeV

   L. M. Fonseca · R. Linares · V. A. B. Zagatto🇧🇷 · F. Cappuzzello🇮🇹 · D. Carbone🇮🇹 · M. Cavallaro🇮🇹 · C. Agodi🇮🇹 · J. Lubian🇧🇷 · J. R. B. Oliveira🇧🇷

   The nuclear scattering at energies well above the Coulomb barrier allows for a fairly sensitive examination of the parameters of the optical potential when the relevant couplings are included into the calculations. In this work we present experimental angular distribution data for the elastic and inelastic scatterings of ${}^{16}$O impinging on ${}^{27}$Al and ${}^{28}$Si target nuclei at \textit{E}${}_{lab}=240$ MeV. The experimental data were measured at $7°<{\theta }_{c.m.}<16°$ with good angular resolution. Experimental data are compared with coupled channel calculations with the inclusion of couplings to excited states in the target and projectile. We show that the shape of angular distributions are sensitive to the mass diffuseness parameter and the best agreement is achieved for $a=0.62$ fm.

   nucl-exnucl-thPRC(2019)·19 citations
3. 03*

   Analysis of the one-neutron transfer to ${}^{16}$O, ${}^{28}$Si and ${}^{64}$Ni induced by (${}^{18}$O, ${}^{17}$O) reaction at 84 MeV

   R. Linares · M. J. Ermamatov🇺🇿 · J. Lubian🇧🇷 · F. Cappuzzello🇮🇹 · D. Carbone🇮🇹 · E. N. Cardozo🇧🇷 · M. Cavallaro🇮🇹 · J. L. Ferreira🇧🇷 · A. Foti🇮🇹 · A. Gargano🇮🇹 · B. Paes · G. Santagati🇮🇹 · V. A. B. Zagatto🇧🇷

   Background: Recently, a systematic exploration of two-neutron transfer induced by the (${}^{18}$O, ${}^{16}$O) reaction on different targets has been performed. The high resolution data have been collected at the MAGNEX magnetic spectrometer of the INFN-LNS laboratory in Catania and analyzed with the coupled reaction channel (CRC) approach. The simultaneous and sequential transfers of the two neutrons have been considered under the same theoretical framework without the need of adjustable factors in the calculations. Purpose: A detailed analysis of the one-neutron transfer cross sections is important to study the sequential two-neutron transfer. Here, we examine the (${}^{18}$O, ${}^{17}$O) reaction on ${}^{16}$O, ${}^{28}$Si and ${}^{64}$Ni targets. These even-even nuclei allow for investigation of one-neutron transfer in distinct nuclear shell spaces. Method: The MAGNEX spectrometer was used to measure mass spectra of ejectiles and extract differential cross sections of one-neutron transfer to low-lying states. We adopted the same CRC formalism used in the sequential two-neutron transfer, including relevant channels and using spectroscopic amplitudes obtained from shell model calculations. We also compare with one-step distorted wave Born approximation (DWBA). Results: For the ${}^{18}$O + ${}^{16}$O and the ${}^{18}$O + ${}^{28}$O systems we used two interactions in the shell model. The experimental angular distributions are reasonably well reproduced by the CRC calculations. In the ${}^{18}$O + ${}^{64}$Ni system, we considered only one interaction and the theoretical curve describes the shape and order of magnitude observed in the experimental data. Conclusions: Comparisons between experimental, DWBA and CRC angle-integrated cross sections suggest that excitations before or after the transfer of neutron is relevant in the ${}^{18}$O + ${}^{16}$O and ${}^{18}$O + ${}^{64}$Ni systems.

   nucl-exnucl-thPRC(2018)·24 citations
4. 04*

   Measurements of differential and angle-integrated cross sections for the ${}^{10}$B($n,\alpha$)${}^7$Li reaction in the neutron energy range from 1.0 eV to 2.5 MeV

   Haoyu Jiang🇨🇳 · Wei Jiang🇨🇳 · Huaiyong Bai🇨🇳 · Zengqi Cui🇨🇳 · Guohui Zhang🇨🇳 · Ruirui Fan🇨🇳 · Han Yi🇨🇳 · Changjun Ning🇨🇳 · Liang Zhou🇨🇳 · Jingyu Tang🇨🇳 · Qi An🇨🇳 · Jie Bao🇨🇳 and 76 other authors

   Differential and angle-integrated cross sections for the ${}^{10}$B($n,\alpha$)${}^7$Li, ${}^{10}$B($n,\alpha$${}_0$)${}^7$Li and ${}^{10}$B($n,\alpha$${}_1$)${}^7$Li${}^{\ast }$ reactions have been measured at CSNS Back-n white neutron source. Two enriched (90%) ${}^{10}$B samples 5.0 cm in diameter and ~85.0 $\mu$g/cm${}^2$ in thickness each with an aluminum backing were prepared, and back-to-back mounted at the sample holder. The charged particles were detected using the silicon-detector array of the Light-charged Particle Detector Array (LPDA) system. The neutron energy E${}_n$ was determined by TOF (time-of-flight) method, and the valid $\alpha$ events were extracted from the E${}_n$-Amplitude two-dimensional spectrum. With 15 silicon detectors, the differential cross sections of $\alpha$-particles were measured from 19.2{\deg} to 160.8{\deg}. Fitted with the Legendre polynomial series, the ($n,\alpha$) cross sections were obtained through integration. The absolute cross sections were normalized using the standard cross sections of the ${}^{10}$B($n,\alpha$)${}^7$Li reaction in the 0.3 - 0.5 MeV neutron energy region. The measurement neutron energy range for the ${}^{10}$B($n,\alpha$)${}^7$Li reaction is 1.0 eV $\le$ En < 2.5 MeV (67 energy points), and for the ${}^{10}$B($n,\alpha$${}_0$)${}^7$Li and ${}^{10}$B($n,\alpha$${}_1$)${}^7$Li${}^{\ast }$ reactions is 1.0 eV $\le$ En < 1.0 MeV (59 energy points). The present results have been analyzed by the resonance reaction mechanism and the level structure of the ${}^{11}$B compound system, and compared with existing measurements and evaluations.

   nucl-exCPC(2019)·8 citations
5. 05*

   Hadronic resonances production with ALICE at the LHC

   Sushanta Tripathy (for the ALICE Collaboration)🇮🇳

   Measurements of the production of short-lived hadronic resonances are used to probe the properties of the late hadronic phase in ultra-relativistic heavy-ion collisions. Since these resonances have lifetimes comparable to that of the fireball, they are sensitive to the competing effects of particle re-scattering and regeneration in the hadronic gas, which modify the observed particle momentum distributions and yields after hadronisation. Having different masses, quantum numbers and quark content, hadronic resonances carry a wealth of information on different aspects of ion-ion collisions, including the processes that determine the shapes of particle momentum spectra, insight into strangeness production and collective effects in small collision systems. We present the most recent ALICE results on $\rho (770{)}^0$, K*(892)${}^0$, $\varphi (1020)$, $\Sigma (1385{)}^{\pm }$, $\Lambda (1520)$, $\Xi (1530{)}^0$ and $\Xi (1820)$ production at the LHC. They include measurements performed in pp, p--Pb and Pb--Pb collisions at different energies, as well as the latest results from the LHC Run 2 with Xe--Xe collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.44 TeV and with Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV. Collision energy, centrality and multiplicity differential measurements integrated yields and particle ratios are discussed in detail. A critical overview of these results are given through comparisons to measurements from other experiments and theoretical models.

   ↳ hep-exhep-phnucl-exSpringer Proc.Phys.(2020)·1 citation
6. 06*

   Lifetime estimations and a non-monotonic initial energy density in heavy ion collisions at RHIC and LHC

   G. Kasza🇭🇺 · T. Csorgo🇭🇺

   We highlight some connections between the final state hadronic observables and the initial conditions using a recently found new exact family of solutions of relativistic hydrodynamics. These relations provide explicit examples of the scaling behaviour in relativistic hydrodynamics and may provide an advanced estimate of the lifetime and the initial energy density in $\sqrt{s_{NN}}=62.4$, $130$, and $200$ GeV Au+Au collisions at RHIC and $\sqrt{s_{NN}}=5.0$ TeV Pb+Pb and $5.44$ TeV Xe+Xe as well as $\sqrt{s}=7$, $8$ and $13$ TeV p+p collisions at LHC energies. A surprising result is that these advanced estimates yield a non-monotonic increase of the initial energy density with increasing collision energy at the RHIC energy range.

   ↳ nucl-thhep-exhep-phnucl-exPhys.Part.Nucl.(2020)·0 citations
7. 07*

   Triangular symmetry in cluster nuclei

   R. Bijker🇲🇽 · A.H. Santana-Valdés

   In this contribution, we present evidence for the occurrence of triangular symmetry in cluster nuclei. We discuss the structure of rotational bands for 3-alpha and 3-alpha+1 configurations with triangular D(3h) symmetry by exploiting the double group D'(3h), and study the application to 12C and 13C. The structure of rotational bands can be used as a fingerprint of the underlying geometric configuration of alpha-particles.

   ↳ nucl-thnucl-exJ.Phys.Conf.Ser.(2020)·1 citation

* 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.