1,721,030 research outputs found
Nuclear electromagnetic processes in ChEFT
Get PDFWe review our recent work on the derivation of the nuclear electromagnetic charge and current operators in chiral perturbation theory, based on time-ordered perturbation theory. We then discuss the strategies for fixing the relevant low-energy constants, and compare the resulting predictions for the electric and magnetic form factors of the deuteron and trinucleons with experimental data, using as input accurate nuclear wave functions derived with realistic potentials
Effect of Three Nucleon Forces in p − 3He Scattering
Get PDFThe effect of the inclusion of different models of three nucleon (3N) forces in p − 3He elastic scattering at low energies is studied. Two models have been considered: one derived from effective field theory at next-to-next-to-leading order and one derived from a more phenomenological point of view—the so-called Illinois model. The four nucleon scattering observables are calculated using the Kohn variational principle and the hyperspherical harmonic technique and the results are compared with available experimental data. We have found that with the inclusion of both 3N force models the agreement with the experimental data is improved, in particular for the proton vector analyzing power A y
Effect of Three-Nucleon Interactions in p-^{3}He Elastic Scattering
Get PDFWe present a detailed study of the effect of different three-nucleon interactions in p-3He elastic scattering at low energies. In particular, two interactions have been considered: one derived from effective
field theory at next-to-next-to-leading order and one derived from a more phenomenological point of view—the so-called Illinois model. The four-nucleon scattering observables are calculated by using the Kohn variational principle and the hyperspherical harmonics technique, and the results are compared with available experimental data. We have found that the inclusion of both interactions improves the agreement with the experimental data, in particular, for the proton vector analyzing power
Recent Progress in Ab-initio Four-Body Scattering Calculations
Get PDFIn the first part of the contribution, we discuss the results of a recent benchmark calculation of n − 3H and p − 3He phase-shifts below the trinucleon disintegration thresholds. Three different methods—
Alt, Grassberger and Sandhas, Hyperspherical Harmonics, and Faddeev–Yakubovsky—have been used and their results are compared. For both n − 3H and p − 3He we observe a rather good agreement between the three different theoretical methods. In the second part of the contribution, we study the longitudinal asymmetry
An3He z in the 3He(n, p)3H reaction in order to obtain information about the parity-violating components of the nucleon–nucleon interaction
Study of nucleonic matter with a consistent two- and three-body perturbative chiral interaction
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Hadronic parity violation in few-body systems
No full textRecent interest, both from experimental and theoretical point of view, on hadronic parity violation is reviewed, with particular emphasis on an eective theory description. After discussing the minimal form of the parity-violating NN contact eective Lagrangian, we concentrate on the calculation of the neutron spin rotation in n(polarized) - d scattering at zero energy.
We find that this observable is sensitive to the long-range component of the parity-violating NN pontential due to the pion exchange, and that it is expected to be one order of magnitude
larger than in n(polarized) - p scattering
Neutron-Triton Elastic Scattering
No full textThe Kohn variational principle and the hyperspherical harmonics technique are applied to study the n-H-3 elastic scattering at low energies. In this contribution the first results obtained using a non-local realistic interaction derived from the chiral perturbation theory are reported. They are found to be in good agreement with those obtained solving the Faddeev-Yakubovsky equations. The calculated total and differential cross sections are compared with the available experimental data. The effect of including a three-nucleon interaction is also discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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