1,370 research outputs found
Fluxes of Atmospheric Leptons at 600 GeV - 60 TeV
The atmospheric muon flux is generated with CORSIKA 6.030 (using QGSJET
high-energy interaction model) and fitted with the formula from Gaisser (1990).
Spectra and mass distribution of primaries were taken according to the
poli-gonato model of Horandel (2003). A convenient parameterization of the
cos(th)->cos(th*) correction, originally tabulated in Volkova (1969), is
presented. This correction, together with muon energy losses and decay, is
shown to significantly improve the fit to the simulated data.Comment: routines with corrections are available at
http://amanda.berkeley.edu/~dima/work/CORSIKA
Propagating leptons through matter with Muon Monte Carlo (MMC)
An accurate simulation of the propagation of muons through matter is needed
for the analysis of data produced by muon/neutrino underground experiments. A
muon may sustain hundreds of interactions before it is detected by the
experiment. Since a small systematic uncertainty repeated hundreds of times may
lead to sizable errors, requirements on the precision of the muon propagation
code are very stringent. A new tool for propagating muon and tau charged
leptons through matter that is believed to meet these requirements is presented
here. An overview of the program is given and some results of its application
are discussed.Comment: MMC can be downloaded at http://icecube.wisc.edu/~dima/work/MUONPR
Quantum theory of self-action of ultrashort light pulses in an inertial nonlinear medium
The systematic theory of the formation of the short light pulses in the
squeezed state during the propagation in a medium with inertial Kerr
nonlinearity is developed. The algebra of time-dependent Bose-operators is
elaborated and the normal-ordering theorem for them is formulated. It is
established that the spectral region where the quadrature fluctuations are
weaker than the shot-noise, depends on both the relaxation time of the
nonlinearity and the magnitude of the nonlinear phase shift. It is also shown
that the frequency at which suppression of the fluctuation is greatest can be
controlled by adjusting the phase of the initial coherent light pulse. The
spectral correlation function of photons is introduced and photon antibunching
is found.Comment: 10 pages (RevTex), 5 .eps figures, typos corrected and some
cosmetical changes made in formulae on pages. 2, 3, acknowledgments added;
submitted to Phys.Rev.
Formation of ultrashort pulses with sub-Poissonian photon statistics
A simple method for the production of ultrashort light pulses (USPs) with
suppressed photon fluctuations is considered. The method is based on self-phase
modulation (SPM) of an USP in a nonlinear medium (optical fibre) and subsequent
transmission of pulse through a dispersive optical element.Comment: 4 pages, LaTeX, 3 .eps figure
Self- and cross-phase modulation of ultrashort light pulses in an inertial Kerr medium: spectral control of squeezed light
Quantum theory of self-phase and cross-phase modulation of ultrashort light
pulses in the Kerr medium is developed with taking into account the response
time of an electronic nonlinearity. The correspondent algebra of time-dependent
Bose-operators is elaborated. It is established that the spectral region of the
pulse, where the quadrature fluctuations level is lower than the shot-noise
one, depends on the value of the nonlinear phase shift, the intensity of
another pulse, and the relaxation time of the nonlinearity. It is shown that
the frequency of the pulse spectrum at which the suppression of fluctuations is
maximum can be controlled by adjusting the other pulse intensity.Comment: LaTeXe, 19 pages, 7 figures, revised version, to appear in J. Opt. B:
Quantum and Semiclass. Opt. (2002) http://www.iop.org/, style files include
Light Pulse Squeezed State Formation In Medium With The Relaxation Kerr Nonlinearity
The consistent theory of formation of pulsed squeezed states as a result of
self-action of ultrashort light pulse in the medium with relaxation Kerr
nonlinearity has been developed. A simple method to form the ultrashort light
pulse with sub-Poissonian photon statistics is analyzed too.Comment: 5 pages, LaTeX, 2 .eps figures, Talk given at ICSSUR'99, May 1999,
Ital
Control of squeezed light pulse spectrum in the Kerr medium with an inertial nonlinearity
The consistent quantum theory of self-phase modulation (SPM) and cross-phase
modulation (XPM) for ultrashort light pulses (USP) in medium with electronic
Kerr-nonlinearity are developed. The approach makes use of momentum operator of
electrical field which takes account of the inertial behaviour of the
nonlinearity. The spectrum of quantum fluctuations of squeezed-quadrature
component as a function of response time of nonlinearity and values of
nonlinear phase shifts due to the SPM and XPM effects, is investigated.Comment: 8 pages, LaTeX, style file included, 1 .eps figure. Talk given at QCM
& C 2000 (Capri, Italy). To appear in "Quantum Communication, Measurement and
Computing 3" (Kluwer Acad. Plen.Publ. NY). New interpretations of previous
e-print
Improvement of optical image by measurement reduction technique at parametric multiplexing
In the process of parametric optical image amplification, images are formed
at new frequencies in addition to the amplified original image. We show that
the parametric multiplexing of optical images can be used to produce an image
with improved quality. As an example, we study the parametric amplification of
an optical image at low-frequency pumping in which multiplexed optical images
turn out to be quantum-correlated. Additional improvement is made possible by
using the information about the object that is available to the researcher, in
particular, about sparsity of its image. To take the available information into
account, we apply the measurement reduction technique.Comment: 18 pages, 7 figures. arXiv admin note: substantial text overlap with
arXiv:1808.0702
To the theory of quasi-phase-matched parametric amplification in periodically-poled optical nonlinear crystals
Theory of the optical parametric amplification at high-frequency pumping in
crystals with a regular space modulation of the sign of nonlinear coupling
coefficient of interacting waves is developed. By applying the matrix method,
the theory is based on a step-by-step approach. It is shown that, in the case
where the pumping intensity is less than some critical value, the spatial
dynamics of the signal intensity inside a separate layer with the constant
nonlinear coefficient has an oscillatory behavior and the change of the signal
intensity from layer to layer is defined, in general, by the power function.
The same law is valid for the change of variance of signal's quadrature
components. At large number of layers, these dependences can be reduced to the
well-known ones for homogeneous nonlinear optical crystals.Comment: 14 pages, 3 figures, to be published in Journal of Russian Laser
Research 2003, V. 24, No.
Correlations of multiplexed quantum ghost images and improvement of the quality of restored image
The currently used ghost image schemes traditionally involve two-mode
entangled light states or incoherent radiation. Here, application of four-mode
entangled light states is considered. It is shown that multiplexed ghost images
(MGI) formed by four-mode entangled quantum light states have mutual spatial
correlations determined by the 8th order field correlation functions. A special
algorithm to calculate high-order correlations of Bose operators was developed.
We also demonstrate that the accounting of MGI correlations allows us to
improve the quality of the restored image of an object when processing MGI by
measurement reduction method. Computer modelling of recovery of the image from
MGI was carried out. It is established that in the considered example the
signal-to-noise ratio of the reduced ghost image is times higher than the
best signal-to-noise ratio for the ghost images themselves.Comment: 9 pages, 2 figure
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