Superscaling analysis of the Coulomb Sum Rule in quasielastic electron-nucleus scattering

The Coulomb sum rule for inclusive quasielastic electron scattering in $^{12}$C, $^{40}$Ca and $^{56}$Fe is analyzed based on scaling and superscaling properties. Results obtained in the relativistic impulse approximation with various descriptions of the final state interactions are shown. A comparison with experimental data measured at Bates and Saclay is provided. The theoretical description based on strong scalar and vector terms present in the relativistic mean field, which has been shown to reproduce the experimental asymmetric superscaling function, leads to results that are in fair agreement with Bates data while it sizeably overestimates Saclay data. We find that the Coulomb sum rule for a momentum transfer $q\geq 500$ $MeV/c$ saturates to a value close to 0.9, being very similar for the three nuclear systems considered. This is in accordance with Bates data, which indicates that these show no significative quenching in the longitudinal response.Comment: 22 pages, 6 figures. To be published in Phys. Lett.

Final state interaction effects in neutrino-nucleus quasielastic scattering

We consider the charged-current quasielastic scattering of muon neutrinos on an Oxygen 16 target, described within a relativistic shell model and, for comparison, the relativistic Fermi gas. Final state interactions are described in the distorted wave impulse approximation, using both a relativistic mean field potential and a relativistic optical potential, with and without imaginary part. We present results for inclusive cross sections at fixed neutrino energies in the range $E_\nu =$ 200 MeV - 1 GeV, showing that final state interaction effects can remain sizable even at large energies.Comment: 4 pages, 4 figures; poster session of the Third International Workshop on Neutrino-Nucleus Interactions in the Few GeV Region (NuInt04), Gran Sasso (Italy), March 17-21, 2004; to appear in the proceeding

Scaling and isospin effects in quasielastic lepton-nucleus scattering in the Relativistic Mean Field Approach

The role of isospin in quasielastic electron scattering and charge-changing neutrino reactions is investigated in the relativistic impulse approximation. We analyze proton and neutron scaling functions making use of various theoretical descriptions for the final-state interactions, focusing on the effects introduced by the presence of strong scalar and vector terms in the relativistic mean field approach. An explanation for the differences observed in the scaling functions evaluated from $(e,e')$ and $(\nu,\mu)$ reactions is provided by invoking the differences in isoscalar and isovector contributions.Comment: 10 pages, 5 figures, submitted to Phys. Lett.

Relativistic description of 3He(e,e'p)2H

The Relativistic Distorted-Wave Impulse Approximation is used to describe the $^3$He($e,e^\prime p$)$^2$H process. We describe the $^3$He nucleus within the adiabatic hyperspherical expansion method with realistic nucleon-nucleon interactions. The overlap between the $^3$He and the deuteron wave functions can be accurately computed from a three-body calculation. The nucleons are described by solutions of the Dirac equation with scalar and vector (S-V) potentials. The wave function of the outgoing proton is obtained by solving the Dirac equation with a S-V optical potential fitted to elastic proton scattering data on the residual nucleus. Within this theoretical framework, we compute the cross section of the reaction and other observables like the transverse-longitudinal asymmetry, and compare them with the available experimental data measured at JLab.Comment: 4 pages, 3 figures. Proceedings of the 21st European Few Body Conference held in Salamanca (Spain) in August-September 201

Jesuits and the Natural Sciences in Modern Times, 1814–2014

From 1814, linked to their educational work, Jesuits made significant contributions to the natural sciences, especially in the fields of astronomy, meteorology, seismology, terrestrial magnetism, mathematics, and biology in a worldwide network of universities, secondary schools and observatories.; Readership: All interested in the history of Jesuits and their contribution to the natural sciences, in science and religion and in general in the history of science

Nuclear effects in electron- and neutrino-nucleus scattering within a relativistic quantum mechanical framework

We study the impact of the description of the knockout nucleon wave function on electron- and neutrino-induced quasielastic and single-pion production cross sections. We work in a fully relativistic and quantum mechanical framework, where the relativistic mean-field model is used to describe the target nucleus. The focus is on Pauli blocking and the distortion of the final nucleon, these two nuclear effects are separated and analyzed in detail. We find that a proper quantum mechanical treatment of these effects is crucial to provide the correct magnitude and shape of the inclusive cross section. Also, this seems to be key to predict the right ratio of muon- to electron-neutrino cross sections at very forward scattering angles.Comment: 14 pages, 14 figure

Jesuits and the Natural Sciences in Modern Times, 1814–2014

From 1814, linked to their educational work, Jesuits made significant contributions to the natural sciences, especially in the fields of astronomy, meteorology, seismology, terrestrial magnetism, mathematics, and biology in a worldwide network of universities, secondary schools and observatories.; Readership: All interested in the history of Jesuits and their contribution to the natural sciences, in science and religion and in general in the history of science

Strange form factors of the proton: a new analysis of the neutrino (antineutrino) data of the BNL-734 experiment

We consider ratios of elastic neutrino(antineutrino)-proton cross sections measured by the Brookhaven BNL-734 experiment and use them to obtain the neutral current (NC) over charged current (CC) neutrino-antineutrino asymmetry. We discuss the sensitivity of these ratios and of the asymmetry to the electric, magnetic and axial strange form factors of the nucleon and to the axial cutoff mass M_A. We show that the effects of the nuclear structure and interactions on the asymmetry and, in general, on ratios of cross sections are negligible. We find some restrictions on the possible values of the parameters characterizing the strange form factors. We show that a precise measurement of the neutrino-antineutrino asymmetry would allow the extraction of the axial and vector magnetic strange form factors in a model independent way. The neutrino-antineutrino asymmetry turns out to be almost independent on the electric strange form factor and on the axial cutoff mass.Comment: 12 page

The Gulf of Cádiz: thrusting or strike-slip motion?

In the Gulf of Cádiz (SW Iberian Peninsula) the boundary between Eurasia and Nubia plates corresponds to a narrow band well defined by the seismicity, where large earthquakes (M>7.0) may be associated to N-S to NNW-SSE horizontal compression due to the convergence between the two plates. Most of these earthquakes are at shallow depth (less than 40 km), with some foci at intermediate-depth, showing E-W distribution and limited by a narrow band less than 20 km wide that broadens as we move to the Strait of Gibraltar. In this area the lithospheric material is relatively rigid and the stresses are released by larger earthquakes. General tectonic models proposed for the Azores-Tunisia plate boundary explain fairly well the nature of its seismicity and tectonic motions; however, details of some of its aspects are still poorly understood and controversial. Zittelini et al. (2009) has recently proposed for the Gulf of Cádiz, transcurrent-transpressional motion along a long strike slip fault based on multichannel seismic reflection surveys. However, this contradicts the compressional motion and reverse faulting of large 1755 Lisbon earthquake (~Mw9), which generate a large tsunami and the recent moderate (Mw>6.0) in 1964, 2007 and 2009 and large (Mw= 8.0) in 1969 earthquakes occurred in the region. These earthquakes show thrusting motion along E-W faults with the southern block going under, corresponding to horizontal NW-SE compression, and they can be related directly to the plate convergence between Nubia and Iberia. References Zitellini et al., 2009. The quest for the Africa–Eurasia plate boundary west of the Strait of Gibraltar. Earth and Planetary Science Letters 280 (2009) 13–50

Probing for high-momentum protons in He-4 via the He-4(e, e ' p)X reactions

©2022 American Physical Society. Artículo firmado por 110 autores. Special thanks to Silviu Covrig for providing the CFD calculations as a possibility to understanding the target vertex spectra for the SRC target. Special thanks to Or Hen for valuable discussions and inputs on the paper. The research presented in this paper is partially supported by the U.S. National Science Foundation under Grants No. PHY-2012413 (F.B.), No. PHY 16-15067 (F.B.), and No. PHY 09-69380 (K.A.). This work was supported by the U.S. Department of Energy under Contract No. DE-AC05-06OR23177 under which Jefferson Science Associates operates the Thomas Jefferson National Accelerator Facility.Experimental cross sections for the He-4(e, e'p)X reactions in the missing energy range from 0.017 to 0.022 GeV and up to a missing momentum of 0.632 GeV/c at x(B) = 1.24 and Q(2) = 2 (GeV/c)(2) are reported. The data are compared to relativistic distorted-wave impulse approximation calculations for the He-4(e, e'p)H-3 channel. Significantly more events are observed for p(m) >= 0.45 GeV/c than are predicted by the theoretical model, and striking fluctuations in the ratio of data to the theoretical model around p(m) = 0.3 GeV/c are possible signals of initial-state multinucleon correlations.U.S. National Science FoundationU.S. Department of EnergyDepto. de Estructura de la Materia, Física Térmica y ElectrónicaFac. de Ciencias FísicasTRUEpu