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Title: Description of intermediate- and short-range NN nuclear force within a covariant effective field theory

Abstract

The present paper is aimed to developing an effective field theory in the GeV region to describe consistently both elastic and inelastic NN scattering in a fully covariant way. In this development we employ our novel s-channel mechanism of NN interaction at intermediate and short ranges assuming a formation of the six-quark bag dressed with basic meson fields such as {pi}, {sigma}, {rho}, and {omega} in the intermediate state. The peripheral part of the interaction is governed by t-channel one- and two-pion exchanges described fairly well by chiral perturbation theory. The {sigma}-meson dressing should be especially important for the stabilization of the bag due to a high coupling constant of the {sigma}-meson with the bag and also a strong interaction between the {sigma}-field and space symmetric quark core |s{sup 6}[6]>. This stabilization of the intermediate dressed bag (which shifts the mass of the bag downward to NN threshold) will be crucially important for the description of {pi}, 2{pi}, {rho}, and {omega}-meson production in NN collisions, and, in particular, for the correct description of {pi} {sup 0} production near threshold. So that, we expect that the results of the present work will lead to a deeper understanding the short- and intermediate-rangemore » nuclear forces and internucleon correlations in nuclei.« less

Authors:
 [1];  [2];  [3]
  1. Institut fuer Theoretische Physik, Universitaet Tuebingen, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany)
  2. Institute of Nuclear Physics, Moscow State University, 119899 Moscow (Russian Federation). E-mail: kukulin@nucl-th.sinp.msu.ru
  3. Joint Institute for Nuclear Research, Moscow Region, 141980 Dubna (Russian Federation)
Publication Date:
OSTI Identifier:
20690203
Resource Type:
Journal Article
Resource Relation:
Journal Name: Annals of Physics (New York); Journal Volume: 320; Journal Issue: 1; Other Information: DOI: 10.1016/j.aop.2005.05.008; PII: S0003-4916(05)00091-6; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CHIRALITY; COUPLING CONSTANTS; GEV RANGE; INELASTIC SCATTERING; INTERMEDIATE STATE; NUCLEAR FORCES; NUCLEON-NUCLEON INTERACTIONS; NUCLEON-NUCLEON POTENTIAL; OMEGA BARYONS; PARTICLE PRODUCTION; PERTURBATION THEORY; PIONS NEUTRAL; QUANTUM FIELD THEORY; QUARKS; S CHANNEL; STABILIZATION; STRONG INTERACTIONS; T CHANNEL; TENSOR MESONS; VECTOR MESONS

Citation Formats

Faessler, Amand, Kukulin, V.I., and Shikhalev, M.A. Description of intermediate- and short-range NN nuclear force within a covariant effective field theory. United States: N. p., 2005. Web. doi:10.1016/j.aop.2005.05.008.
Faessler, Amand, Kukulin, V.I., & Shikhalev, M.A. Description of intermediate- and short-range NN nuclear force within a covariant effective field theory. United States. doi:10.1016/j.aop.2005.05.008.
Faessler, Amand, Kukulin, V.I., and Shikhalev, M.A. Tue . "Description of intermediate- and short-range NN nuclear force within a covariant effective field theory". United States. doi:10.1016/j.aop.2005.05.008.
@article{osti_20690203,
title = {Description of intermediate- and short-range NN nuclear force within a covariant effective field theory},
author = {Faessler, Amand and Kukulin, V.I. and Shikhalev, M.A.},
abstractNote = {The present paper is aimed to developing an effective field theory in the GeV region to describe consistently both elastic and inelastic NN scattering in a fully covariant way. In this development we employ our novel s-channel mechanism of NN interaction at intermediate and short ranges assuming a formation of the six-quark bag dressed with basic meson fields such as {pi}, {sigma}, {rho}, and {omega} in the intermediate state. The peripheral part of the interaction is governed by t-channel one- and two-pion exchanges described fairly well by chiral perturbation theory. The {sigma}-meson dressing should be especially important for the stabilization of the bag due to a high coupling constant of the {sigma}-meson with the bag and also a strong interaction between the {sigma}-field and space symmetric quark core |s{sup 6}[6]>. This stabilization of the intermediate dressed bag (which shifts the mass of the bag downward to NN threshold) will be crucially important for the description of {pi}, 2{pi}, {rho}, and {omega}-meson production in NN collisions, and, in particular, for the correct description of {pi} {sup 0} production near threshold. So that, we expect that the results of the present work will lead to a deeper understanding the short- and intermediate-range nuclear forces and internucleon correlations in nuclei.},
doi = {10.1016/j.aop.2005.05.008},
journal = {Annals of Physics (New York)},
number = 1,
volume = 320,
place = {United States},
year = {Tue Nov 01 00:00:00 EST 2005},
month = {Tue Nov 01 00:00:00 EST 2005}
}
  • We examine the role of the {Delta}{Delta} intermediate state in NN scattering in the {sup 1}S{sub 0} channel. The computation is performed at lowest order in an effective-field theory involving local four-fermion operators and one-pion exchange using dimensional regularization with minimal subtraction ({ovr MS}). As first discussed by Weinberg, in the theory with only nucleons, the large-scattering length in this channel requires a small scale for the local N{sup 4} operators. When {Delta}{close_quote}s are included (but without pions) a large-scattering length can be obtained from operators with a scale {radical}(2M{sub N}(M{sub {Delta}}{minus}M{sub N})), but fine-tuning is required. The coefficients ofmore » the contact terms involving the {Delta} fields are not uniquely determined but for reasonable values one finds that, in general, NN scattering computed in the theory with {Delta}{close_quote}s looks like that computed in the theory without {Delta}{close_quote}s. The leading effect of the {Delta}{close_quote}s is to change the coefficients of the four-nucleon contact terms between the theories with and without {Delta}{close_quote}s. Further, the decoupling of the {Delta}{close_quote}s in the limit of large mass and strong coupling is clearly demonstrated. When pions are included, the typical scale for the contact terms is {approximately}100MeV, both with and without {Delta}{close_quote}s and is not set by {radical}(2M{sub N}(M{sub {Delta}}{minus}M{sub N})). For reasonable values of contact terms that reproduce the scattering length and effective range (at lowest order) the phase shift is not well reproduced over a larger momentum range as is found in the theory without {Delta}{close_quote}s at lowest order. {copyright} {ital 1997} {ital The American Physical Society}« 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
  • We investigate in detail the effect of making the range of the {open_quotes}contact{close_quotes} interaction used in effective field theory (EFT) calculations of NN scattering finite. This is done in both an effective field theory with explicit pions, and one where the pions have been integrated out. In both cases we calculate NN scattering in the {sup 1}S{sub 0} channel using potentials which are second order in the EFT expansion. The contact interactions present in the EFT Lagrangian are made finite by use of a square-well regulator. We find that there is an optimal radius for this regulator, at which second-ordermore » corrections to the EFT are identically zero; for radii near optimal these second-order corrections are small. The cutoff EFT{close_quote}s which result from this procedure appear to be valid for momenta up to about 100{endash}150MeV/c. We also find that the radius of the square well cannot be reduced to zero if the theory is to reproduce both the experimental scattering length and effective range. Indeed, we show that, if the NN potential is the sum of a one-pion-exchange piece and a short-range interaction, then the short-range piece must extend out beyond 1.05 fm, regardless of its particular form. {copyright} {ital 1997} {ital The American Physical Society}« less