65,105 research outputs found
Probing the QCD Critical Point with Higher Moments of Net-proton Multiplicity Distributions
Higher moments of event-by-event net-proton multiplicity distributions are
applied to search for the QCD critical point in the heavy ion collisions. It
has been demonstrated that higher moments as well as moment products are
sensitive to the correlation length and directly connected to the thermodynamic
susceptibilities computed in the Lattice QCD and Hadron Resonance Gas (HRG)
model. In this paper, we will present measurements for kurtosis (),
skewness () and variance () of net-proton multiplicity
distributions at the mid-rapidity () and GeV/ for
Au+Au collisions at =19.6, 39, 62.4, 130 and 200 GeV, Cu+Cu
collisions at =22.4, 62.4 and 200 GeV, d+Au collisions at
=200 GeV and p+p collisions at =62.4 and 200 GeV.
The moment products and of net-proton
distributions, which are related to volume independent baryon number
susceptibility ratio, are compared to the Lattice QCD and HRG model
calculations. The and of net-proton
distributions are consistent with Lattice QCD and HRG model calculations at
high energy, which support the thermalization of the colliding system.
Deviations of and for the Au+Au collisions at
low energies from HRG model calculations are also observed.Comment: 10 pages, 8 figures, Proceedings of 27th Winter Workshon on Nuclear
Dynamics. Feb. 6-13 (2011
A Tri-band-notched UWB Antenna with Low Mutual Coupling between the Band-notched Structures
A compact printed U-shape ultra-wideband (UWB) antenna with triple band-notched characteristics is presented. The proposed antenna, with compact size of 24×33 mm2, yields an impedance bandwidth of 2.8-12GHz for VSWR<2, except the notched bands. The notched bands are realized by introducing two different types of slots. Two C-shape half-wavelength slots are etched on the radiating patch to obtain two notched bands in 3.3-3.7GHz for WiMAX and 7.25-7.75GHz for downlink of X-band satellite communication systems. In order to minimize the mutual coupling between the band-notched structures, the middle notched band in 5-6GHz for WLAN is achieved by using a U-slot defected ground structure. The parametric study is carried out to understand the mutual coupling. Surface current distributions and equivalent circuit are used to illustrate the notched mechanism. The performance of this antenna both by simulation and by experiment indicates that the proposed antenna is suitable and a good candidate for UWB applications
Two-loop Renormalization Group Equations in General Gauge Field Theories
The complete set of two-loop renormalization group equations in general gauge
field theories is presented. This includes the \beta functions of parameters
with and without a mass dimension
Simple model of bouncing ball dynamics: displacement of the table assumed as quadratic function of time
Nonlinear dynamics of a bouncing ball moving in gravitational field and
colliding with a moving limiter is considered. Displacement of the limiter is a
quadratic function of time. Several dynamical modes, such as fixed points, 2 -
cycles and chaotic bands are studied analytically and numerically. It is shown
that chaotic bands appear due to homoclinic structures created from unstable 2
- cycles in a corner-type bifurcation.Comment: 11 pages, 6 figure
Nonlinear Realization of Spontaneously Broken N=1 Supersymmetry Revisited
This paper revisits the nonlinear realization of spontaneously broken N=1
supersymmetry. It is shown that the constrained superfield formalism can be
reinterpreted in the language of standard realization of nonlinear
supersymmetry via a new and simpler route. Explicit formulas of actions are
presented for general renormalizable theories with or without gauge
interactions. The nonlinear Wess-Zumino gauge is discussed and relations are
pointed out for different definitions of gauge fields. In addition, a general
procedure is provided to deal with theories of arbitrary Kahler potentials.Comment: 1+18 pages, LaTe
Linear and Non Linear Effects on the Newtonian Gravitational Constant as deduced from the Torsion Balance
The Newtonian gravitational constant has still 150 parts per million of
uncertainty. This paper examines the linear and nonlinear equations governing
the rotational dynamics of the torsion gravitational balance. A nonlinear
effect modifying the oscillation period of the torsion gravitational balance is
carefully explored.Comment: 11 pages, 2 figure
Constrained Superfields and Standard Realization of Nonlinear Supersymmetry
A constrained superfield formalism has been proposed recently to analyze the
low energy physics related to Goldstinos. We prove that this formalism can be
reformulated in the language of standard realization of nonlinear
supersymmetry. New relations have been uncovered in the standard realization of
nonlinear supersymmetry.Comment: 8+1 pages, Latex, expanded discussions on scalar and vector field
Simple model of bouncing ball dynamics. Displacement of the limiter assumed as a cubic function of time
Nonlinear dynamics of a bouncing ball moving vertically in a gravitational
field and colliding with a moving limiter is considered and the Poincare map,
describing evolution from an impact to the next impact, is described.
Displacement of the limiter is assumed as periodic, cubic function of time. Due
to simplicity of this function analytical computations are possible. Several
dynamical modes, such as fixed points, 2 - cycles and chaotic bands are studied
analytically and numerically. It is shown that chaotic bands are created from
fixed points after first period doubling in a corner-type bifurcation. Equation
for the time of the next impact is solved exactly for the case of two
subsequent impacts occurring in the same period of limiter's motion making
analysis of chattering possible.Comment: 8 pages, 1 figure, presented at the DSTA 2011 conference, Lodz,
Polan
Black Holes in the Presence of Cosmological Constant and Large N Brane World
Analytic form has been obtained for four-dimensional black holes with a
minimal Hawking temperature in a theory with cosmological constant, dilaton and
gauge fields. In general dimensions, black hole solutions are shown to exist
and their asymptotic behaviors are obtained. In theories of ten dimension, N
coincident D3-branes as the boundary of an space are constructed by
embedding black D3-branes, with a five-dimensional compactified space of
negligible size if N is large, which provide natural realizations of the
Randall-Sundrum scenario. For this background, the cosmological
constant is a higher order perturbation and its effect on the spectra of
standard model fields on the branes can be calculated.Comment: 12 pages, no figure
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