共查询到20条相似文献,搜索用时 31 毫秒
1.
G. Degrassi S. Heinemeyer W. Hollik P. Slavich G. Weiglein 《The European Physical Journal C - Particles and Fields》2003,28(1):133-143
The status of the evaluation of the MSSM Higgs sector is reviewed. The phenomenological impact of recently obtained corrections
is discussed. In particular it is shown that the upper bound on mh within the MSSM is shifted upwards. Consequently, lower limits on obtained by confronting the upper bound as function of with the lower bound on mh from Higgs searches are significantly weakened. Furthermore, th
e region in the MA--plane where the coupling of the lightest Higgs boson to down-type fermions is suppressed is modified. The presently not calculated
higher-order corrections to the Higgs-boson mass matrix are estimated to shift the mass of the lightest Higgs boson by up
to 3 GeV.
Received: 12 December 2002 / Published online: 3 March 2003
RID="a"
ID="a" e-mail: giuseppe.degrassi@roma3.infn.it
RID="b"
ID="b" e-mail: Sven.Heinemeyer@physik.uni-muenchen.de
RID="c"
ID="c" e-mail: hollik@mppmu.mpg.de
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ID="d" e-mail: slavich@mppmu.mpg.de
RID="e"
ID="e" e-mail: Georg.Weiglein@durham.ac.uk 相似文献
2.
3.
We use the transverse-momentum dependence of the cross section for the diffractive dissociation of high energy pions to two
jets to study some non-perturbative light-cone wave functions of the pion. We compare the predictions for this distribution
by Gaussian and Coulomb wave functions as well as the wave function derived from a solution of the light-cone Hamiltonian
in the singlet model. We conclude that this experimentally measured information provides a powerful tool for these studies.
Received: 15 January 2003 / Published online: 14 April 2003
RID="a"
ID="a" e-mail: ashery@tauphy.tau.ac.il
RID="b"
ID="b" e-mail: pauli@mpi-hd.mpg.de 相似文献
4.
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
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ID="c"e-mail: reinhard.mahnke@physik.uni-rostock.de 相似文献
5.
F. Deppisch H. Päs A. Redelbach R. Rückl Y. Shimizu 《The European Physical Journal C - Particles and Fields》2003,28(3):365-374
We discuss the perspectives of testing the right-handed Majorana mass scale MR of the SUSY see-saw model in the mSUGRA framework. Lepton-flavor violating low energy processes are analyzed in recently
proposed post-LEP benchmark scenarios, taking into account present uncertainties and future developments in the neutrino sector.
Non-observation of in the next-generation PSI experiment will provide upper bounds on MR of the order of GeV, while on the other hand, a positive signal for at SUPERKEKB or the LHC may determine MR for a given mSUGRA scenario with an accuracy of a factor of 2.
Received: 14 June 2002 / Revised version: 7 January 2003 / Published online: 14 April 2003
RID="a"
ID="a" e-mail: deppisch@physik.uni-wuerzburg.de
RID="b"
ID="b" e-mail: paes@physik.uni-wuerzburg.de
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ID="c" e-mail: asredelb@physik.uni-wuerzburg.de
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ID="d" e-mail: rueckl@physik.uni-wuerzburg.de
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ID="e" e-mail: shimizu@eken.phys.nagoya-u.ac.jp 相似文献
6.
R.P. Duperray K.V. Protasov A.Yu. Voronin 《The European Physical Journal A - Hadrons and Nuclei》2003,16(1):27-34
The experimental data of the antideuteron production in proton-proton and proton-nucleus collisions are analyzed within a
simple model based on the diagrammatic approach to the coalescence model. This model is shown to be able to reproduce most
of the existing data without any additional parameter.
Received: 18 April 2002 / Accepted: 30 August 2002 / Published online: 17 January 2003
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ID="a"e-mail: duperray@isn.in2p3.fr
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ID="b"e-mail: protasov@isn.in2p3.fr
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ID="c"e-mail: avoronin@aha.ru
Communicated by A. Molinari 相似文献
7.
Recent experiments on unzipping of RNA helix-loop structures by force have shown that ≈40-base molecules can undergo kinetic
transitions between two well-defined “open” and “closed” states, on a timescale ≈1 sec [Liphardt et al., Science 297, 733-737 (2001)]. Using a simple dynamical model, we show that these phenomena result from the slow kinetics
of crossing large free energy barriers which separate the open and closed conformations. The dependence of barriers on sequence
along the helix, and on the size of the loop(s) is analyzed. Some DNA and RNA sequences that could show dynamics on different
time scales, or three(or more)-state unzipping, are proposed. Our dynamical model is also applied to the unzipping of long
(kilo-basepair) DNA molecules at constant force.
Received 29 July 2002 / Received in final form 5 February 2003 Published online: 16 April 2003
RID="a"
ID="a"e-mail: cocco@ldfc.u-strasbg.fr
RID="b"
ID="b"e-mail: jmarko@uic.edu
RID="c"
ID="c"e-mail: monasson@lpt.ens.fr 相似文献
8.
C. Dams R. Kleiss P. Draggiotis E.N. Argyres A. van Hameren C.G. Papadopoulos 《The European Physical Journal C - Particles and Fields》2003,28(4):561-571
We introduce a class of self-interacting scalar theories in which the various coupling constants obey a recursive relation.
These imply a particularly simple form for the generating function of the Feynman amplitudes with vanishing external momenta,
as well as for the effective potential. In addition we discuss an interesting duality inherent in these models. Specializing
to the case of zero spacetime dimensions we find intriguing nullification properties for the amplitudes.
Received: 19 December 2001 / Published online: 5 May 2003
RID="a"
ID="a" e-mail: chrisd@sci.kun.nl
RID="b"
ID="b" e-mail: kleiss@sci.kun.nl
RID="c"
ID="c" e-mail: petros@sci.kun.nl
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ID="d" e-mail: andrevh@sci.kun.nl
RID="e"
ID="e" e-mail: papadopo@alice.nuclear.demokritos.gr 相似文献
9.
Equilibrium phase coexistence between two chemical species implies the equality of the chemical potentials and of the osmotic
pressures. We study this problem on a deformable membrane when one type of the molecules serves as anchor for polymeric chains
immersed in the surrounding medium (considered as a good solvent). We derive the general conditions for phase coexistence
when both the curvature of the membrane and the density field of the anchor molecule are free to adjust themselves. We show
that curvature favors phase segregation. Our model predicts that membranes decorated with polymeric chains exhibit new shape
bifurcations without equivalent in fixed density systems.
Received: 26 November 2002 / Accepted: 2 April 2003 / Published online: 12 May 2003
RID="a"
ID="a"e-mail: nicolas@drfmc.ceng.cea.fr
RID="b"
ID="b"e-mail: bfourcade@cea.fr 相似文献
10.
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
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ID="b"e-mail: flachi@ifae.es
RID="c"
ID="c"e-mail: jenk@gluk.org
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ID="d"e-mail: sasha@len.uzhgorod.ua
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ID="e"e-mail: vladimir@cfif.ist.utl.pt
Communicated by V.V. Anisovich 相似文献
11.
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
12.
D. Klabucar K. Kumericki D. Mekterovic B. Podobnik 《The European Physical Journal C - Particles and Fields》2003,29(1):71-78
If instantons are introduced into the MIT bag model in such a way that the bag radii are allowed to vary, the MIT bag interior
can accommodate an instanton density which is by an order of magnitude larger than in the case when the radii are fixed (although
it is still significantly smaller than in the non-perturbative QCD vacuum). The instanton contribution to the baryon mass
shifts is also correspondingly larger. The instanton-induced part of the scalar strangeness of the nucleon MIT bag is an order
of magnitude larger than found previously, within the linearized approximation. The decrease of the model radii (which is
associated with the increase of the instanton density) is very favorable from the standpoint of nuclear physics.
Received: 7 February 2003 / Revised version: 1 April 2003 / Published online: 23 May 2003
RID="a"
ID="a" e-mail: klabucar@phy.hr
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ID="b" e-mail: kkumer@phy.hr
RID="c"
ID="c" e-mail: dmekter@rudjer.irb.hr
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ID="d" e-mail: bp@phy.hr. Present address: Faculty of Civil Engineering, University of Rijeka, HR-51000 Rijeka, Croatia 相似文献
13.
14.
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
15.
16.
N. Kan K. Sakamoto K. Shiraishi 《The European Physical Journal C - Particles and Fields》2003,28(3):425-430
We calculate the effective potential for the WLPNGB in a world with a circular latticized extra dimension. The mass of the
Wilson line pseudo-Nambu-Goldstone boson (WLPNGB) is calculated from the one-loop quantum effect of scalar fields at zero
and finite temperature. We show that a series expansion by the modified Bessel functions is useful to calculate the one-loop
effective potentials.
Received: 24 January 2003 / Published online: 14 April 2003
RID="a"
ID="a" e-mail: b1834@sty.cc.yamaguchi-u.ac.jp
RID="b"
ID="b" e-mail: b1795@sty.cc.yamaguchi-u.ac.jp
RID="c"
ID="c" e-mail: shiraish@po.cc.yamaguchi-u.ac.jp 相似文献
17.
Karanikas A.I. Ktorides C.N. Stefanis N.G. 《The European Physical Journal C - Particles and Fields》2003,26(3):445-455
We employ the Polyakov world-line path-integral version of QCD to identify and resum at leading perturbative order enhanced
radiative gluon contributions to the Drell-Yan type ( pair annihilation) cross-sections. We emphasize that this is the first time that world-line techniques are applied to cross-section
calculations.
Received: 10 June 2002 / Published online: 31 October 2002
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ID="a" e-mail: akaranik@cc.uoa.gr
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ID="b" e-mail: cktorid@cc.uoa.gr
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ID="c" e-mail: stefanis@tp2.ruhr-uni-bochum.de 相似文献
18.
19.
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
20.
S. Kagiyama S. Kumamoto A. Minaka A. Nakamura K. Ohkura S. Yamaguchi 《The European Physical Journal C - Particles and Fields》2002,25(3):453-458
The phase structure of hadrons and the quark-gluon plasma is investigated by two types of equation of state of the hadrons,
namely the ideal hadron gas model and the compressible bag model. It is pointed out that, while the ideal gas model produces
an unrealistic extra hadron phase, the compressible bag model gives the expected and reasonable phase diagram even if the
rich hadron spectrum is taken into account.
Received: 22 February 2002 / Revised version: 28 June 2002 / Published online: 20 September 2002
RID="a"
ID="a" e-mail: kagiyama@sci.kagoshima-u.ac.jp
RID="b"
ID="b" e-mail: kumamoto@cosmos01.cla.kagoshima-u.ac.jp
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ID="c" e-mail: minaka@edu.kagoshima-u.ac.jp
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ID="d" e-mail: nakamura@sci.kagoshima-u.ac.jp
RID="e"
ID="e" e-mail: ohkura@cosmos01.cla.kagoshima-u.ac.jp
RID="f"
ID="f" e-mail: yamaguchi@cosmos01.cla.kagoshima-u.ac.jp 相似文献