4,861 research outputs found
Suspension of objects in magnetic and electric fields
Device has improved suspension efficiency by simulating characteristics of diamagnetic materials. Pseudodiamagnetic device suspended magnet in magnetic field at rate of 232 Kg/W. Suspension in magnetic field can be produced in two ways: magnetic source can be stationary and pseudodiamagnetic device suspended or vice versa
On the possibility of q-scaling in high energy production processes
It has been noticed recently that transverse momenta (p_T) distributions
observed in high energy production processes exhibit remarkably universal
scaling behaviour. This is the case when a suitable variable replaces the usual
p_T. On the other hand, it is also widely known that transverse momentum
distributions in general follow a power-like Tsallis distribution, rather than
an exponential Boltzmann-Gibbs, with a (generally energy dependent)
nonextensivity parameter q. Here we show that it is possible to choose a
suitable variable such that all the data can be fitted by the same Tsallis
distribution (with the same, energy independent value of the q-parameter). Thus
they exhibit q-scaling.Comment: Final version, accepted by J.Phys.
Possible Implication of a Single Nonextensive Distribution for Hadron Production in High-Energy Collisions
Multiparticle production processes in collisions at the central rapidity
region are usually considered to be divided into independent "soft" and "hard"
components. The first is described by exponential (thermal-like) transverse
momentum spectra in the low- region with a scale parameter associated
with the temperature of the hadronizing system. The second is governed by a
power-like distributions of transverse momenta with power index at
high- associated with the hard scattering between partons. We show that
the hard-scattering integral can be approximated as a nonextensive distribution
of a quasi-power-law containing a scale parameter and a power index , where is the nonextensivity parameter. We demonstrate that the whole
region of transverse momenta presently measurable at LHC experiments at central
rapidity (in which the observed cross sections varies by orders of
magnitude down to the low region) can be adequately described by a single
nonextensive distribution. These results suggest the dominance of the
hard-scattering hadron-production process and the approximate validity of a
"no-hair" statistical-mechanical description of the spectra for the whole
region at central rapidity for collisions at high-energies.Comment: 10 pages, 3 figures; presented by G.Wilk at the XLIV International
Symposium on Multiparticle Dynamics; 8 - 12 September 2014 - Bologna, ITAL
Studies of space experiments to measure gravitational constant variations and the Eotvos ratio
Detecting variations of gravitational constant difference between inertial and passive gravitational mas
Entanglement of two individual neutral atoms using Rydberg blockade
We report the generation of entanglement between two individual Rb
atoms in hyperfine ground states and which are held in
two optical tweezers separated by 4 m. Our scheme relies on the Rydberg
blockade effect which prevents the simultaneous excitation of the two atoms to
a Rydberg state. The entangled state is generated in about 200 ns using pulsed
two-photon excitation. We quantify the entanglement by applying global Raman
rotations on both atoms. We measure that 61% of the initial pairs of atoms are
still present at the end of the entangling sequence. These pairs are in the
target entangled state with a fidelity of 0.75.Comment: text revised, with additional reference
Fluctuations of g-factors in metal nanoparticles: Effects of electron-electron interaction and spin-orbit scattering
We investigate the combined effect of spin-orbit scattering and
electron-electron interactions on the probability distribution of -factors
of metal nanoparticles. Using random matrix theory, we find that even a
relatively small interaction strength %(ratio of exchange constant and mean
level %spacing \spacing ) significantly increases -factor
fluctuations for not-too-strong spin-orbit scattering (ratio of spin-orbit rate
and single-electron level spacing 1/\tau_{\rm so} \spacing \lesssim 1), and
leads to the possibility to observe -factors larger than two.Comment: RevTex, 2 figures inserte
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