129 research outputs found
Muon Capture on A=2 and 3 Nuclei
No full textAbstractWe present the results of a recent simultaneous study of the muon capture reactions 2H(μ-,vμ)nn and 3He(μ-,vμ)3H. The initial and final A=2 and 3 nuclear wave functions are obtained from the Argonne v18 or chiral N3LO twonucleon potential, in combination with, respectively, the Urbana IX or chiral N2LO three-nucleon potential in the case of A=3. The weak current consists of polar- and axial-vector components. The former are related to the isovector piece of the electromagnetic current via the conserved-vector-current hypothesis. These and the axial currents are derived either in a meson-exchange or in a chiral e_ective field theory (xEFT) framework. In the first case, the only parameter is in the axial-vector current and is fixed by reproducing the experimental Gamow-Teller matrix element in tritium _-decay (GTEXP). In the second case, the low-energy constants, two in the polar and one in the axial-vector current, are fixed, respectively, by reproducing the A=3 magnetic moments and GTEXP. The total rates are found to be 392.0±2.3s-1 for A=2, and 1484±13s-1 for A=3, where the spread accounts for the model dependence relative to the adopted interactions and currents and to cuto_ sensitivity in the xEFT currents. These values are compared with available experimental data and results of previous calculations
The hep reaction and the solar neutrino problem
No full textThe results of a new calculation of the astrophysical S-factor for the proton weak capture on He-3 are reviewed. The method used to obtain very accurate initial and final state wave functions and to construct the nuclear weak current operator is described. Finally, the implications of these results for the Super-Kamiokande solar neutrino data are discussed
Domestication process of two Solanum (section Lasiocarpa) species among Amerindians in the Upper Orinoco, Venezuela with special focus on Piaroa indians
No full textVolpato, Gabriele, Rossella Marcucci, Noemi Tornadore, and Maurizio G. Paoletti (Department
of Biology, University of Padua, 325100 Padova, Italy; email corresponding author:
[email protected]). DOMESTICATION PROCESS OF TWO SOLANUM SECTION LASIOCARPA SPECIES
AMONG AMERINDIANS IN THE UPPER ORINOCO, VENEZUELA, WITH SPECIAL FOCUS ON PIAROA
INDIANS. Economic Botany 58(2):000–000, 2004. Two semi-cultivated Solanum species (S. sessiliflorum
Dunal and S. stramonifolium Jacq.) are utilized by the Amazonian Indians of the
Upper Orinoco Basin in Venezuela. The manner by which they have become partially domesticated
by the Piaroas and other native tribes of this rain forest region is elucidated in the
following text. Both species have two varieties, with and without prickles, the latter the result
of human selection. Patterns of indigenous utilization of these species by the selection of morphologic
forms and to the differentiation of karyotypes of varieties, and exploitation of the
species reflects also in the perception of them among users. S. sessiliflorum is cultivated in
swiddens and has an economic role, whereas S. stramonifolium is grown in dooryards. This
difference is detectable to the Piaroas, as they recognize in their folk taxonomy three different
varieties of the S. sessiliflorum and one of S. stramonifolium, this according to the stage of
domestication of the species and the way in which they are utilized
Vincoli intertestuali-intersemiotici in Naked People di A. Astvacaturov. Analisi, percezione, scelte traduttive
No full textThis study aims to continue research on cinema “intexts” (Torop 1995, It. Transl. 2010, also known as crossmedial relations (Fateeva 2007)) in Russian contemporary literture, focusing on their translation and underlining the primary importance of their analysis and function in the source text. The current research develops from previous work centered on cinema intertextuality in M. Elizarov’s novel Cartoons (Marcucci 2015a) and, secondarily, in E. Popov’s Internet novel Arbeit. A broad canvas (Marcucci 2015b). The current study follows up on this research by investigating Andrey Astvatsaturov’s novel Naked People (translated by the author) and pursuing three aims. 1. Analyze the types of intexts (which films does the author refer to? From which period? Of wich genres?) and the strategies used by the author to insert in his text references to other texts belonging to the cinema semiotic system, in which iconic signs have a primary role. 2. Explore the functions of these intexts. 3. Reflect on the operations to carry out when such texts are translated into a different linguacultural universe, specifically the Italian one. Here, the main focus will shift onto the translator’s role and task.
Progress in the quest for a realistic three-nucleon force
No full textWe investigate whether the subleading three nucleon contac t interaction, depending on 10 low- energy constants (LECs), may provide enough flexibility to s olve existing discrepancies between theory and experiment in A = 3 scattering observables. To this aim we choose a realistic t wo- nucleon interaction (AV18) supplemented with the leading a nd subleading three-nucleon contact interaction, and fit the LECs to very precise data on polariza tion observables in elastic p − d scattering at 3 MeV proton energy
Ponzio, Orazio Censore, Montano, Rainaldi per la cappella Colonna in S. Giovanni in Laterano
No full textLa cappella del coro d'inverno venne costruita nell'ambito della ristrutturazione della "nave trasversa" di S. Giovanni in Laterano patrocinata da Clemente VIII (Aldobrandini, 1592-1605), intrapresa appena dopo l'elezione al pontificato. Introdotta, dal deambulatorio – poi demolito – attraverso la sagrestia dei Beneficiati, già costruita nel 1594, anche la cappella del coro d'inverno, poi anche dei Colonna, deve risalire a quegli anni. E' attribuita, in base alle parole di antichi biografi e all'analisi critica di F. Fasolo, a Girolamo Rainaldi e l'esecuzione viene ricondotta agli anni del gran contestabile del Regno di Napoli Filippo Colonna che la ebbe nuovamente in assegnazione nel 1623 per costruirvi il monumento funebre della moglie Lucrezia Tomacelli, morta l'anno prima.
La documentazione edita e quella inedita rintracciata ha dimostrato che le vicende costruttive e decorative della cappella sono state lunghe e complesse, vedendo impegnati più artisti; lo "stile" di Rainaldi riconosciuto da Fasolo è in realtà comune anche ad altri artisti attivi negli stessi anni o poco prima, come Flaminio Ponzio, ricordato quale architetto della basilica nel 1597 in una annotazione di G. Zander e redattore di una stima sui lavori eseguiti nella cappella del 1613, dalla quale si sa che l'opera architettonica e decorativa era in quell’anno in gran parte eseguita.
Alla cultura di maestranze dell’entourage di Montano si è attribuito il progetto del coro ligneo per i canonici, di cui si è scritto nel commento al saggio precedente; Orazio Censore, noto fonditore di metalli, è richiamato da Baglione come autore della cappella – ma probabilmente solo per le numerose opere bronzee che la decorano -; Girolamo Rainaldi fu probabilmente solo l'autore della fase finale di completamento di opere impostate da altri, ma che hanno indotto la storiografia ad individuare e ricercare uno "stile" rainaldesco in più architetture del periodo.
The winter choir chapel was built within restoration of the “transverse nave" of the Basilica of St. John Lateran sponsored by Clement VIII (Aldobrandini, 1592-1605), which he started as soon as he became Pope. Connected through the ambulatory – then demolished – to the Sacristy of the Beneficiaries, already built in 1594, the winter choir chapel – named also the Colonna chapel later on – must date back to those years, too. In accordance with old biographers and the critical analysis of F. Fasolo, it was ascribed to Girolamo Rainaldi while the erection was related to the years of the Grand Constable of the Kingdom of Naples Filippo Colonna, to whom it was assigned again in 1623 for building in there a memorial of his wife Lucrezia Tomacelli, dying the year before.
Pursuant to both the published and unpublished documentation found, the construction and decoration aspects of the chapel were long and complex, with several artists at work; the "style" of Rainaldi, recognised by Fasolo, was in fact shared by other artists operating in those years or a little earlier, too, such as Flaminio Ponzio, mentioned as architect of the Basilica in 1597 in a note by G. Zander, and author of a survey on the works carried out at the chapel in 1613, through which it is known that the architectonic and decorative work was almost finished in that year.
The project of the wooden choir for canons was assigned to the workers from the Montano entourage; that project was mentioned in the commentary to the previous essay; Orazio Censore, well-known caster of metals is recalled by Baglione as the creator of the chapel, probably just for the numerous bronze works decorating it; Girolamo Rainaldi is likely to have carried out just the final phase, the completion of works planned by others, nevertheless inducing historiographers to identify or look for the Rainaldi style in several architectures of the period
Electromagnetic structure of trinucleons
No full textThe electromagnetic form factors of the trinucleons H-3 and He-3 are calculated with wave functions obtained with the Argonne vis two-nucleon and Urbana IX three-nucleon interactions. Full account is taken of the two-body currents required by current conservation with the upsilon(18) interaction as well as those associated with Na transition currents and the currents of Delta resonance components in the wave functions. Explicit three-nucleon current operators associated with the two-pion exchange three-nucleon interaction arising from irreducible S-wave pion-nucleon scattering are constructed and shown to have very little effect on the calculated magnetic form factors. The calculated magnetic form factor of H-3, and charge form factors of both H-3 and He-3 are in satisfactory agreement with the experimental data. However, the position of the zero in the magnetic form factor of He-3 is slightly underpredicted. [S0556-2813(98)06312-2]
How well does the chiral expansion converge in nuclear and neutron matter
No full textThe equations of state of nuclear and neutron matter (and, more generally, neutron-rich matter) play a fundamental role towards the understanding of a broad spectrum of systems, ranging from the skins of neutron-rich nuclei to the structure of compact stars. After a brief review of different approaches to predict the properties of nuclear and neutron matter, we will focus on error quantification in effective field theory. The various sources of uncertainty and their impact in infinite matter will be explored. We will then report on recent calculations of the nuclear and neutron matter equations of state at different orders of the chiral expansion as well as changing resolution scale. We will discuss the significance of such predictions as a foundation for future studies of convergence of the chiral perturbation series
Isospin Mixing in the 4He Bound State and the Nucleon Strange Form Factor
No full textThe contribution of isospin admixtures in the ground state of the He-4 nucleus is studied using wave functions derived from the most modern nuclear interactions, including isospin symmetry breaking terms. The present calculations show that this contribution is larger than previous estimates had indicated. Its effect on parity violating elastic scattering of polarized electrons from He-4 is investigated. In particular, a simple analysis of the recently measured left-right asymmetry at low Q^2 shows that the contribution of these isospin admixtures is of comparable magnitude to that associated with strangeness components in the nucleon electric form factor
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