2,565 research outputs found
GEANT simulation of energy losses of slow hadrons
The algorithm of the simulation of energy losses for hadrons with kinetic energy down to few eV is described. The details of its implementation in Geant4 are discussed. The comparison of the results of simulation with the experimental data is presented
Quantum charge diffusion in underdamped Josephson junctions and superconducting nanowires
The effect of quantum fluctuations on the current-voltage characteristics of
Josephson junctions and superconducting nanowires is studied in the underdamped
limit. Quantum fluctuations induce transitions between a Coulomb--blockade and
a supercurrent branch, and can significantly modify the shape of
current-voltage characteristics in the case of a highly resistive environment.
Owing to the phase-charge duality, our results can be directly extended to the
opposite overdamped limit.Comment: 6 pages, 2 figures, replaced with published versio
Evidence of phi --> pi0 pi0 gamma and phi --> pi0 eta gamma decays in SND experiment at VEPP-2M
Preliminary results on the study of e+e- --> phi(1020) --> pi0 pi0 gamma, eta
pi0 gamma processes from SND experiment at VEPP-2M collider in Novosibirsk are
presented. Branching ratios of rare radiative phi --> pi0 pi0 gamma and phi -->
pi0 eta gamma decays are measured:
B(phi --> pi0 pi0 gamma ) = (1.1 +- 0.2) * 10^-4
(invariant mass (pi0 pi0) < 800 MeV),
B(phi --> eta pi0 gamma ) = (1.3 +- 0.5) * 10^-4.Comment: Talk at the HADRON97 conference, BNL, Aug 24-30 1997; LaTeX, 4 pages,
4 eps figure
Exact analytical solution of the problem of current-carrying states of the Josephson junction in external magnetic fields
The classical problem of the Josephson junction of arbitrary length W in the
presence of externally applied magnetic fields (H) and transport currents (J)
is reconsidered from the point of view of stability theory. In particular, we
derive the complete infinite set of exact analytical solutions for the phase
difference that describe the current-carrying states of the junction with
arbitrary W and an arbitrary mode of the injection of J. These solutions are
parameterized by two natural parameters: the constants of integration. The
boundaries of their stability regions in the parametric plane are determined by
a corresponding infinite set of exact functional equations. Being mapped to the
physical plane (H,J), these boundaries yield the dependence of the critical
transport current Jc on H. Contrary to a wide-spread belief, the exact
analytical dependence Jc=Jc(H) proves to be multivalued even for arbitrarily
small W. What is more, the exact solution reveals the existence of unquantized
Josephson vortices carrying fractional flux and located near one of the
junction edges, provided that J is sufficiently close to Jc for certain finite
values of H. This conclusion (as well as other exact analytical results) is
illustrated by a graphical analysis of typical cases.Comment: 21 pages, 9 figures, to be published in Phys. Rev.
Study of isobar electroproduction at VEPP-2M collider
Results from the Spherical Nonmagnetic Detector (SND) on
isobar electroproduction in the collisions of beam electrons (positrons) and
residual gas nuclei in the VEPP-2M collider are presented. On the
basis of the obtained data the expected counting rate of this process in future
high luminosity colliders (~-, -- and -factories)
was estimated.Comment: 7 pages LATEX and 3 figure
Study of the , , Decays with an SND Detector on a VEPP-2M Collider
The process was studied in the energy range
MeV with an SND detector on a VEPP-2M collider. The
decay branching ratios , , and
were measured.Comment: 5 pages, 4 figure
Spectroscopy at B-factories Using Hard Photon Emission
The process of hard photon emission by initial electrons (positrons) at
B-factories is discussed. It is shown that studies of the bottomonium
spectroscopy will be feasible for the planned integrated luminosity of the
B-factory experiments.Comment: 9 pages, Latex, 1 fugure, Submitted to Int.Jour.Mod.Phys.
- …