1,239 research outputs found
Final-state interactions in the response of nuclear matter
Final-state interactions in the response of a many-body system to an external
probe delivering large momentum are normally described using the eikonal
approximation, for the trajectory of the struck particle, and the frozen
approximation, for the positions of the spectators. We propose a generalization
of this scheme, in which the initial momentum of the struck particle is
explicitly taken into account. Numerical calculations of the nuclear matter
response at 1 2 GeV/c show that the inclusion of this momentum
dependence leads to a sizable effect in the low energy tail. Possible
implications for the analysis of existing electron-nucleus scattering data are
discussed.Comment: 21 pages, 4 figure
The imprint of the equation of state on the axial w-modes of oscillating neutron stars
We discuss the dependence of the pulsation frequencies of the axial
quasi-normal modes of a nonrotating neutron star upon the equation of state
describing the star interior. The continued fraction method has been used to
compute the complex frequencies for a set of equations of state based on
different physical assumptions and spanning a wide range of stiffness. The
numerical results show that the detection of axial gravitational waves would
allow to discriminate between the models underlying the different equation of
states, thus providing relevant information on both the structure of neutron
star matter and the nature of the hadronic interactions.Comment: 9 pages, 7 figures, mn.st
Nuclear effects in neutrino-nucleus interactions
An accurate description of the nuclear response functions for neutrino
scattering in the Gev region is essential for the interpretation of present and
future neutrino oscillation experiments. Due to the close similarity of
electromagnetic and weak scattering processes, we will review the status of the
scaling approach and of relativistic modeling for the inclusive electron
scattering response functions in the quasielastic and -resonance
regions. In particular, recent studies have been focused on scaling violations
and the degree to which these imply modifications of existing predictions for
neutrino reactions. We will discuss sources and magnitude of such violations,
emphasizing similarities and differences between electron and neutrino
reactions.Comment: 7 pages, 5 figures, Proceeding of the XVIII International School on
Nuclear Physics, Neutron Physics and Applications, September 21 - 27, 2009
Varna, Bulgari
Many-Body Theory of the Electroweak Nuclear Response
After a brief review of the theoretical description of nuclei based on
nonrelativistic many-body theory and realistic hamiltonians, these lectures
focus on its application to the analysis of the electroweak response. Special
emphasis is given to electron-nucleus scattering, whose experimental study has
provided a wealth of information on nuclear structure and dynamics, exposing
the limitations of the shell model. The extension of the formalism to the case
of neutrino-nucleus interactions, whose quantitative understanding is required
to reduce the systematic uncertainty of neutrino oscillation experiments, is
also discussed.Comment: Lectures delivered at the DAE-BRNS Workshop on Hadron Physics.
Aligarh Muslim University, Aligarh (India), February 18-23, 200
Scaling in many-body systems and proton structure function
The observation of scaling in processes in which a weakly interacting probe
delivers large momentum to a many-body system simply reflects the
dominance of incoherent scattering off target constituents. While a suitably
defined scaling function may provide rich information on the internal dynamics
of the target, in general its extraction from the measured cross section
requires careful consideration of the nature of the interaction driving the
scattering process. The analysis of deep inelastic electron-proton scattering
in the target rest frame within standard many-body theory naturally leads to
the emergence of a scaling function that, unlike the commonly used structure
functions and , can be directly identified with the intrinsic proton
response.Comment: 11 pages, 4 figures. Proceedings of the 11th Conference on Recent
Progress in Many-Body Theories, Manchester, UK, July 9-13 200
A linked cluster expansion for the calculation of the semi-inclusive A(e,e'p)X processes using correlated Glauber wave functions
The distorted one-body mixed density matrix, which is the basic nuclear
quantity appearing in the definition of the cross section for the
semi-inclusive A(e,e'p)X processes, is calculated within a linked-cluster
expansion based upon correlated wave functions and the Glauber multiple
scattering theory to take into account the final state interaction of the
ejected nucleon. The nuclear transparency for 16O and 40Ca is calculated using
realistic central and non-central correlations and the important role played by
the latter is illustrated.Comment: 18 pages, RevTeX, 3 ps figures. Final version, to appear in Phys.
Rev.
Comparative study of three-nucleon potentials in nuclear matter
A new generation of local three-body potentials providing an excellent
description of the properties of light nuclei, as well as of the
neutron-deuteron doublet scattering length, has been recently derived. We have
performed a comparative analysis of the equations of state of both pure neutron
matter and symmetric nuclear matter obtained using these models of
three-nucleon forces. None of the considered potentials simultaneously explains
the empirical equilibrium density and binding energy of symmetric nuclear
matter. However, two of them provide reasonable values of the saturation
density. The ambiguity concerning the treatment of the contact term of the
chiral inspired potentials is discussed.Comment: 14 pages, 8 figure
Inclusive quasi-elastic electron-nucleus scattering
This article presents a review of the field of inclusive quasi-elastic
electron-nucleus scattering. It discusses the approach used to measure the data
and includes a compilation of data available in numerical form. The theoretical
approaches used to interpret the data are presented. A number of results
obtained from the comparison between experiment and calculation are then
reviewed. The analogies and differences to other fields of physics exploiting
quasi-elastic scattering from composite systems are pointed out.Comment: Accepted for publication in Reviews of Modern Physic
Neutron star matter equation of state and gravitational wave emission
The EOS of strongly interacting matter at densities ten to fifteen orders of
magnitude larger than the typical density of terrestrial macroscopic objects
determines a number of neutron star properties, including the pattern of
gravitational waves emitted following the excitation of nonradial oscillation
modes. This paper reviews some of the approaches employed to model neutron star
matter, as well as the prospects for obtaining new insights from the
experimental study of gravitational waves emitted by neutron stars.Comment: 15 pages, 8 figures. To be published as a Brief Review in Modern
Physics Letters
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