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Title: Isoscalar short-range current in the deuteron induced by an intermediate dibaryon

Abstract

A new model for short-range isoscalar currents in the deuteron and in the NN system is developed. The model is based on the generation of an intermediate dressed dibaryon, which is the basic ingredient for the medium- and short-range NN interaction proposed recently by the present authors. The new current model has only one free parameter, which has a clear physical meaning. Our calculations have demonstrated that this new current model can very well describe the experimental data for three basic deuteron observables of isoscalar magnetic type: the magnetic moment, the circular polarization of the photon in the n-vectorp{yields}d{gamma}-vector process at thermal neutron energies, and the structure function B(Q{sup 2}) up to Q{sup 2}{approx_equal}2 GeV{sup 2}/c{sup 2}.

Authors:
; ; ;  [1];  [2];  [2]
  1. Institute of Nuclear Physics, Moscow State University, RU-119899 Moscow (Russian Federation)
  2. (Germany)
Publication Date:
OSTI Identifier:
20864187
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 74; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevC.74.064005; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ALGEBRAIC CURRENTS; DEUTERONS; FOUR MOMENTUM TRANSFER; MAGNETIC MOMENTS; NUCLEON-NUCLEON INTERACTIONS; PHOTONS; POLARIZATION; STRUCTURE FUNCTIONS; THERMAL NEUTRONS; VECTORS

Citation Formats

Kukulin, V. I., Obukhovsky, I. T., Grabmayr, Peter, Faessler, Amand, Physikalisches Institut, Universitaet Tuebingen, D-72076 Tuebingen, and Institut fuer Theoretische Physik, Universitaet Tuebingen, D-72076 Tuebingen. Isoscalar short-range current in the deuteron induced by an intermediate dibaryon. United States: N. p., 2006. Web. doi:10.1103/PHYSREVC.74.064005.
Kukulin, V. I., Obukhovsky, I. T., Grabmayr, Peter, Faessler, Amand, Physikalisches Institut, Universitaet Tuebingen, D-72076 Tuebingen, & Institut fuer Theoretische Physik, Universitaet Tuebingen, D-72076 Tuebingen. Isoscalar short-range current in the deuteron induced by an intermediate dibaryon. United States. doi:10.1103/PHYSREVC.74.064005.
Kukulin, V. I., Obukhovsky, I. T., Grabmayr, Peter, Faessler, Amand, Physikalisches Institut, Universitaet Tuebingen, D-72076 Tuebingen, and Institut fuer Theoretische Physik, Universitaet Tuebingen, D-72076 Tuebingen. Fri . "Isoscalar short-range current in the deuteron induced by an intermediate dibaryon". United States. doi:10.1103/PHYSREVC.74.064005.
@article{osti_20864187,
title = {Isoscalar short-range current in the deuteron induced by an intermediate dibaryon},
author = {Kukulin, V. I. and Obukhovsky, I. T. and Grabmayr, Peter and Faessler, Amand and Physikalisches Institut, Universitaet Tuebingen, D-72076 Tuebingen and Institut fuer Theoretische Physik, Universitaet Tuebingen, D-72076 Tuebingen},
abstractNote = {A new model for short-range isoscalar currents in the deuteron and in the NN system is developed. The model is based on the generation of an intermediate dressed dibaryon, which is the basic ingredient for the medium- and short-range NN interaction proposed recently by the present authors. The new current model has only one free parameter, which has a clear physical meaning. Our calculations have demonstrated that this new current model can very well describe the experimental data for three basic deuteron observables of isoscalar magnetic type: the magnetic moment, the circular polarization of the photon in the n-vectorp{yields}d{gamma}-vector process at thermal neutron energies, and the structure function B(Q{sup 2}) up to Q{sup 2}{approx_equal}2 GeV{sup 2}/c{sup 2}.},
doi = {10.1103/PHYSREVC.74.064005},
journal = {Physical Review. C, Nuclear Physics},
number = 6,
volume = 74,
place = {United States},
year = {Fri Dec 15 00:00:00 EST 2006},
month = {Fri Dec 15 00:00:00 EST 2006}
}
  • A calculation of the deuteron polarization observables A{sub y}{sup d}, A{sub yy}, A{sub xx}, A{sub xz} and the differential cross section for elastic nucleon-deuteron scattering at incident deuteron energies 270 and 880 MeV in lab is presented. A comparison of the calculations with two different deuteron wave functions derived from the Bonn-CD NN-potential model and the dressed-quark-bag model is carried out. A model-independent approach, based on an optical-potential framework, is used in which a nucleon-nucleon T matrix is assumed to be local and taken on the energy shell, but still depends on the internal nucleon momentum in a deuteron.
  • We study the pionic decay of a possible dibaryon d{sup {prime}}{r_arrow}N+N+{pi} in the microscopic quark shell model. The initial d{sup {prime}} dibaryon wave function (J{sup P}=0{sup {minus}}, T=0) consists of one 1{h_bar}{omega} six-quark shell-model s{sup 5}p[51]{sub X} configuration. The most important final six-quark configurations s{sup 6}[6]{sub X}, s{sup 4}p{sup 2}[42]{sub X}, and (s{sup 4}p{sup 2}{minus}s{sup 5}2s)[6]{sub X} are properly projected onto the NN channel. The final state NN interaction is investigated by means of two phase-equivalent{emdash}but off-shell different{emdash}potential models. We demonstrate that the decay width {Gamma}{sub d{sup {prime}}} depends strongly on the short-range behavior of the NN wave function. Inmore » addition, the width {Gamma}{sub d{sup {prime}}} is very sensitive to the mass and size of the d{sup {prime}} dibaryon. For dibaryon masses slightly above the experimentally suggested value M{sub d{sup {prime}}}=2.065GeV, we obtain a pionic decay width of {Gamma}{sub d{sup {prime}}}{approx}0.18{endash}0.32MeV close to the experimental value {Gamma}{sub d{sup {prime}}}{approx}0.5MeV. {copyright} {ital 1997} {ital The American Physical Society}« less
  • Six-quark dibaryon model for fundamental NN- and 3N-forces at intermediate and short ranges are discussed briefly. The structure of the intermediate dibaryon dressed with {sigma}-meson field is similar to those of Roper resonance where the {sigma}-meson field plays a very important role. The t-channel {sigma}-exchange between dibaryon and third nucleon is shown to result in new strong scalar attractive 3N force which contributes at least a half of nuclear binding in 3N system. This dibaryon induced {sigma}-exchange leads also to a new spin-orbit attractive 3N-force.
  • We calculate the neutrino and antineutrino elastic scattering cross section on unpolarized deuterons at energies from a few MeV to several GeV and squared momentum transfers up to 5 GeV{sup 2}. These cross sections can be used to deduce the unknown weak SU(2) isoscalar and SU(3) flavor-scalar axial-vector coupling to nucleons. This observable can be related to the strangeness axial-vector matrix element in the absence of QCD radiative or isospin-violating corrections. We show that the unknown weak magnetic vector coupling may also be gleaned from these measurements. We use different techniques at different energies, including light-cone impulse approximation at themore » highest energies, and show that they connect smoothly to each other.« less
  • A model for the NN force, which is induced by the formation of an intermediate dibaryon dressed with {sigma}- and other meson fields, has been developed by the present authors in previous years. This model is applied to the deuteron photodisintegration processes with the main focus on the {gamma}-induced polarization P{sub y}{sup '} of the neutron at energies below E{sub {gamma}} < or approx. 30 MeV. The inclusion of the intermediate dibaryon leads to a model of the NN force completely different to the conventional NN potential models at short distances. Here the model is tested on the nucleonic levelmore » through comparison to rather similar predictions from the conventional NN potential model both for the total and differential cross sections and also for the spin polarization of the ejected neutrons. The predictions of the present model are at least of the same quality than those for the Nijmegen potential; the visible differences with experimental data for P{sub y}{sup '} still remain. However, in combination with the previous results a consistent description can be achieved simultaneously for many observables.« less