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2.
J.M. Pearson S. Goriely M. Samyn 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):13-16
We recall the main features of the recently published mass formula, HFBCS-1, based on the Hartree-Fock-BCS method, and compare
its extrapolations out to the neutron drip line with those given by the fine-range droplet model. A new Hartree-Fock-Bogolyubov
mass formula, HFB-1, is described: the rms error of the fit to 1888 masses is 0.766 MeV, compared with 0 .738 MeV for HFBCS-1,
but there are no substantial changes in the predictions relevant to the r-process. After a critical examination of various
questions relating to the effective nucleon mass and to the requirements of the relativistic mean-field theory, we conclude
that the greatest remaining ambiguity concerns the nature of the pairing force.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: pearson@lps.umontreal.ca 相似文献
3.
R. Fiore A. Flachi L.L. Jenkovszky A.I. Lengyel V.K. Magas 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):505-515
An explicit model realizing parton-hadron duality and fitting the data is suggested. Complex nonlinear Regge trajectories
are important ingredients of the model. The inclusion of Δ and N* trajectories should account for all resonances in the direct channel. The exotic trajectory is responsible for the smooth
background.
Received: 7 June 2002 / Accepted: 3 July 2002 / Published online: 10 December 2002
RID="a"
ID="a"e-mail: fiore@cs.infn.it
RID="b"
ID="b"e-mail: flachi@ifae.es
RID="c"
ID="c"e-mail: jenk@gluk.org
RID="d"
ID="d"e-mail: sasha@len.uzhgorod.ua
RID="e"
ID="e"e-mail: vladimir@cfif.ist.utl.pt
Communicated by V.V. Anisovich 相似文献
4.
We study the static scalar susceptibility of the nuclear medium, i.e., the change of the quark condensate for a small modification of the quark mass. In the linear sigma model it is linked to
the in-medium sigma propagator and its magnitude increases due to the mixing with the softer modes of the nucleon-hole excitations.
We show that the pseudoscalar susceptibility, which is large in the vacuum, owing to the smallness of the pion mass, follows
the density evolution of the quark condensate and thus decreases. At normal nuclear matter density the two susceptibilities
become much closer, a partial chiral symmetry restoration effect as they become equal when the full restoration is achieved.
Received: 20 July 2002 / Accepted: 14 September 2002 / Published online: 21 January 2003
RID="a"
ID="a"e-mail: chanfray@ipnl.in2p3.fr
Communicated by A. Molinari 相似文献
5.
W.M. Alberico F. Giacosa M. Nardi C. Ratti 《The European Physical Journal A - Hadrons and Nuclei》2003,16(2):221-228
We employ the Nambu-Jona-Lasinio model to determine the vacuum pressure on the quarks in a baryon and hence their density
inside. Then we estimate the baryonic masses by implementing the local density approximation for the mean-field quark energies
obtained in a uniform and isotropic system. We obtain a fair agreement with the experimental masses.
Received: 27 September 2002 / Accepted: 4 October 2002 / Published online: 4 February 2003
RID="a"
ID="a"e-mail: giacosa@tphys.physik.uni-tuebingen.de
Communicated by A. Molinari 相似文献
6.
E. Mergel C.M. Petrache G. Lo Bianco H. Hübel J. Domscheit D. Roßbach G. Schönwaßer N. Nenoff A. Neußer A. Görgen F. Becker E. Bouchez M. Houry A. Hürstel Y. Le Coz R. Lucas Ch. Theisen W. Korten A. Bracco N. Blasi F. Camera S. Leoni F. Hannachi A. Lopez-Martens M. Rejmund D. Gassmann P. Reiter P.G. Thirolf A. Astier N. Buforn M. Meyer N. Redon O. Stezowski 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):417-420
The even-even nucleus 136Nd was studied via in-beam γ-ray spectroscopy using the 16O + 125Te reaction at 100 MeV and the EUROBALL array. One new dipole band was observed. Together with a previously identified dipole
band, whose position in the level scheme is revised, the new band forms a doublet structure similar to the recently observed
chiral bands in the odd-odd neighboring nuclei. This would be the first case of a chiral doublet in an even-even nucleus.
Received: 23 May 2002 / Accepted: 30 September 2002 / Published online: 27 November 2002
RID="a"
ID="a"e-mail: costel.petrache@unicam.it
RID="b"
ID="b"Present address: Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
RID="c"
ID="c"Present address: Gesellschaft für Schwerionenforschung D-64291 Darmstadt, Germany.
Communicated by C. Signorini 相似文献
7.
In treating the relativistic 3-quark problem, a dressed-quark propagator parameterization is used which is compatible with
recent lattice data and pion observables. Furthermore 2-quark correlations are modeled as a series of quark loops in the scalar
and axialvector channel. The resulting reduced Faddeev equations are solved for nucleon and delta. Nucleon electromagnetic
form factors are calculated in a fully covariant and gauge-invariant scheme. Whereas the proton electric form factor G
E and the nucleon magnetic moments are described correctly, the neutron electric form factor and the ratio G
E/G
M for the proton appear to be quenched. The influence of vector mesons on the form factors is investigated which amounts to
a 25% modification of the electromagnetic proton radii within this framework.
Received: 16 April 2002 / Accepted: 29 August 2002 / Published online: 17 January 2003
RID="a"
ID="a"Supported by a Feodor-Lynen fellowship of the Alexander-von-Humboldt foundation and the Australian Research Council.
RID="b"
ID="b"Address after April 30: MPI für Metallforschung, Heisenbergstr. 1, 70569 Stuttgart, Germany.
RID="c"
ID="c"e-mail: Reinhard.Alkofer@uni-tuebingen.de
Communicated by A. Sch?fer 相似文献
8.
A. Borah S. Ghosh S. Nandy 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(2):221-225
The novel inelastic collision properties of two-soliton interaction for an n-component coupled higher order nonlinear Schr?dinger equation are studied. Some interesting features of three soliton interactions,
related to the integrability of the n-component coupled higher order nonlinear Schr?dinger equation are also discussed.
Received 17 April 2002 Published online 2 October 2002
RID="a"
ID="a"e-mail: abhijit@iitg.ernet.in
RID="b"
ID="b"e-mail: sasanka@iitg.ernet.in
RID="c"
ID="c"e-mail: sudipta@iitg.ernet.in 相似文献
9.
R.-D. Herzberg N. Amzal J.E. Bastin F. Becker P.M.T. Brew P.A. Butler A.J.C. Chewter J.F.C. Cocks O. Dorvaux K. Eskola J. Gerl P.T. Greenlees N.J. Hammond K. Hauschild K. Helariutta F. Heßberger M. Houry A. Hürstel R.D. Humphreys G.D. Jones P.M. Jones R. Julin S. Juutinen H. Kankaanpää H. Kettunen T.L. Khoo W. Korten P. Kuusiniemi Y. Le Coz M. Leino A.P. Leppänen C.J. Lister R. Lucas M. Muikku P. Nieminen R.D. Page T. Page P. Rahkila P. Reiter Ch. Schlegel C. Scholey G. Sletten O. Stezowski Ch. Theisen W.H. Trzaska J. Uusitalo H.J. Wollersheim 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):205-208
In-beam conversion electron spectroscopy experiments have been performed on the transfermium nuclei 253, 254No using the conversion electron spectrometer SACRED in nearly collinear geometry in conjunction with the gas-filled separator
RITU at the University of Jyv?skyl?. The experimental setup is discussed and the spectra are compared to Monte Carlo simulations.
The implications for the ground-state configuration of 253No are discussed.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: rdh@ns.ph.liv.ac.uk
RID="b"
ID="b"Present address: GANIL, F-14021 Caen, France.
RID="c"
ID="c"Permanent address: IReS Strasbourg, IN2P3-CNRS, F-67037-Strasbourg, France.
RID="d"
ID="d"Present address: CEA/DIF DCRE/SDE/LDN F-91680 Bruyeres-le-Chatel.
RID="e"
ID="e"Present address: Daresbury Laboratory, Daresbury WA4 4AD, UK.
RID="f"
ID="f"Permanent address: IPN Lyon, IN2P3-CNRS, F-69037 Lyon, France. 相似文献
10.
Progress is reviewed of available data for evaluation of atomic masses since the 1995 one. Many more direct mass measurements
have become available, especially in the region of proton-rich nuclides. The number of alpha- and, especially, proton-decay
data increased considerably. In the region of superhigh mass numbers, many very interesting new observations were made.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: wapstra@nikhef.nl 相似文献
11.
U.T. Yakhshiev U.-G. Meißner A. Wirzba 《The European Physical Journal A - Hadrons and Nuclei》2003,16(4):569-574
We investigate the possible modifications of the nucleons' electromagnetic form factors in the framework of a modified Skyrme
model allowing for nucleon deformation and using realistic nuclear mass distributions. We show that such effects are small
in light nuclei
Received: 19 November 2002 / Accepted: 3 December 2002 / Published online: 18 March 2003
RID="a"
ID="a"Address after January 1st, 2003: Helmholtz Institut für Strahlen- und Kernphysik (Theorie), Universit?t Bonn, Nu?allee
14-16, D-53115 Bonn, Germany; e-mail: meissner@itkp.uni-bonn.de
RID="b"
ID="b"Present address: Helmholtz Institut für Strahlen- und Kernphysik (Theorie), Universit?t Bonn, D-53115 Bonn, Germany.
Communicated by V. Vento 相似文献
12.
M. Terraneo B. Georgeot D.L. Shepelyansky 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(1):127-130
We show that dissipative classical dynamics converging to a strange attractor can be simulated on a quantum computer. Such
quantum computations allow to investigate efficiently the small scale structure of strange attractors, yielding new information
inaccessible to classical computers. This opens new possibilities for quantum simulations of various dissipative processes
in nature.
Received 10 August 2002 Published online 29 October 2002
RID="a"
ID="a"e-mail: dima@irsamc.ups-tlse.fr
RID="b"
ID="b"UMR 5626 du CNRS 相似文献
13.
C.H. Raymond Ooi K.-P. Marzlin J. Audretsch 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(2):259-267
A general scheme for reducing the center-of-mass entropy is proposed. It is based on the repetition of a cycle, composed of
three concepts: velocity selection, deceleration and irreversible accumulation. Well-known laser techniques are used to represent
these concepts: Raman π-pulse for velocity selection, STIRAP for deceleration, and a single spontaneous emission for irreversible
accumulation. No closed pumping cycle nor repeated spontaneous emissions are required, so the scheme is applicable to cool
a molecular gas. The quantum dynamics are analytically modelled using the density matrix. It is shown that during the coherent
processes the gas is translationally cooled. The internal states serve as an entropy sink, in addition to spontaneous emission.
This scheme provides new possibilities to translationally laser-cool molecules for high precision molecular spectroscopy and
interferometry.
Received 25 June 2002 / Received in final form 28 September 2002 Published online 12 November 2002
RID="a"
ID="a"e-mail: ooi@spock.physik.uni-konstanz.de
RID="b"
ID="b"e-mail: Peter.Marzlin@uni-konstanz.de
RID="c"
ID="c"e-mail: Juergen.Audretsch@uni-konstanz.de 相似文献
14.
A. Hürstel M. Rejmund E. Bouchez P.T. Greenlees K. Hauschild S. Juutinen H. Kettunen W. Korten Y. Le Coz P. Nieminen Ch. Theisen A.N. Andreyev F. Becker T. Enqvist P.M. Jones R. Julin H. Kankaanpää A. Keenan P. Kuusiniemi M. Leino A.-P. Leppänen M. Muikku J. Pakarinen P. Rahkila J. Uusitalo 《The European Physical Journal A - Hadrons and Nuclei》2002,15(3):329-334
Prompt and delayed gamma-ray spectroscopy of very neutron-deficient bismuth isotopes 187, 189Bi has been performed using the Recoil Decay Tagging (RTD) method. The isomeric i
13/2 states have been identified and their lifetimes have been measured. The systematics of these long-lived M2 isomers has been extended to the proton-unbound isotopes. The general behaviour of single-proton states is discussed within
the systematics and interpreted within the shell-model framework.
Received: 2 May 2002 / Accepted: 3 June 2002 / Published online: 19 November 2002
RID="a"
ID="a"e-mail: wkorten@cea.fr
RID="b"
ID="b"Present address: GANIL, Caen, France.
RID="c"
ID="c"Present address: Radiation and Nuclear Safety Authority, P.O. Box 14, FIN-00881 Helsinki.
Communicated by D. Schwalm 相似文献
15.
D. Bucurescu A. Gadea Ghe. Căta-Danil I. Căta-Danil M. Ivaşcu N. Mărginean C. Rusu L. Stroe C.A. Ur 《The European Physical Journal A - Hadrons and Nuclei》2003,16(4):469-474
High-spin states in the 97Tc nucleus have been studied by in-beam γ-ray spectroscopy with the reaction 82Se(19F,4nγ) at 68 MeV incident energy. Excited states have been observed up to about 8 MeV excitation and spin 43/2. The observed
level scheme is compared with results of shell model calculations.
Received: 22 November 2002 / Accepted: 23 December 2002 / Published online: 18 March 2003
RID="a"
ID="a"e-mail: bucurescu@tandem.nipne.ro
RID="b"
ID="b"Present address: INFN, Laboratori Nazionali di Legnaro, Legnaro, Italy.
RID="b"
ID="b"Present address: INFN, Laboratori Nazionali di Legnaro, Legnaro, Italy.
RID="b"
ID="b"Present address: INFN, Laboratori Nazionali di Legnaro, Legnaro, Italy.
RID="c"
ID="c"Present address: Università di Padova, Padova, Italy.
Communicated by C. Signorini 相似文献
16.
I. Lubashevsky P. Wagner R. Mahnke 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,32(2):243-247
This paper introduces a car following model where the driving scheme takes into account the deficiencies of human decision
making in a general way. Additionally, it improves certain shortcomings of most of the models currently in use: it is stochastic
but has a continuous acceleration. This is achieved at the cost of formulating the model in terms of the time derivative of
the acceleration, making it non-Newtonian. However, the recipe for construction of bounded rational driver models proposed
in this paper seems to be very general and can be applied to most, if not all of the traditional car-following models.
Received 18 November 2002 / Received in final form 6 February 2003 Published online 1st April 2003
RID="a"
ID="a"e-mail: ialub@fpl.gpi.ru
RID="b"
ID="b"e-mail: peter.wagner@dlr.de
RID="c"
ID="c"e-mail: reinhard.mahnke@physik.uni-rostock.de 相似文献
17.
18.
Bo-Wen Xiao Xin Qian Bo-Qiang Ma 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):523-527
The electromagnetic form factor of the kaon meson is calculated in the light-cone formalism of the relativistic constituent
quark model. The calculated K+ form factor is consistent with almost all of the available experimental data at low-energy scale, while other properties
of the kaon could also be interrelated in this representation with reasonable parameters. Predictions of the form factors
for the charged and neutral kaons at a higher-energy scale are also given, and we find the non-zero K0 form factor at Q
2≠ 0 due to the mass difference between the strange and down quarks inside K0.
Received: 21 June 2002 / Accepted: 29 July 2002 / Published online: 3 December 2002
RID="a"
ID="a"e-mail: mabq@phy.pku.edu.cn
Communicated by A. Sch?fer 相似文献
19.
S. Zschocke O.P. Pavlenko B. Kämpfer 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):529-537
QCD sum rules are evaluated at finite nucleon densities and temperatures to determine the change of mass parameters for the
lightest vector mesons ρ, ω and φ in a strongly interacting medium. For conditions relevant for the starting experiments at
HADES we find that the in-medium mass shifts of the ρ- and ω-mesons are governed, within the Borel QCD sum rule approach,
by the density and temperature dependence of the four-quark condensate. In particular, the variation of the strength of the
density dependence of the four-quark condensate reflects directly the decreasing mass of the ρ-meson and can lead to a change
of the sign of the ω-meson mass shift as a function of the density. In contrast, the in-medium mass of the φ-meson is directly
related to the chiral strange quark condensate which seems correspondingly accessible.
Received: 15 May 2002 / Accepted: 31 July 2002 / Published online: 10 December 2002
RID="a"
ID="a"e-mail: Kaempfer@fz.rossendorf.de
Communicated by A. Sch?fer 相似文献
20.
J. Bordes Chan Hong-Mo Tsou Sheung Tsun 《The European Physical Journal C - Particles and Fields》2003,27(2):189-200
It is shown that existing data on the mixing between up and down fermion states and on the hierarchical mass ratios between
fermion generations, as far as can be so analyzed at present, are all consistent with the two phenomena being both consequences
of a mass matrix rotating in generation space with changing energy scale. As a result, the rotating mass matrix can be traced
over some 14 orders of magnitude in energy from the mass scale of the t quark at 175 GeV to below that of the atmospheric neutrino at 0.05 eV.
Received: 27 August 2002 / Published online: 24 January 2003
RID="a"
ID="a" e-mail: jose.m.bordes@uv.es
RID="b"
ID="b" e-mail: h.m.chan@rl.ac.uk
RID="c"
ID="c" e-mail: tsou@maths.ox.ac.uk 相似文献