104,543 research outputs found
The Formation of Classical Defects After a Slow Quantum Phase Transition
Classical defects (monopoles, vortices, etc.) are a characteristic
consequence of many phase transitions of quantum fields. We show a model in
which the onset of classical probability distributions, for the long-wavelength
modes at early times, allows the identification of line-zeroes of the field
with vortex separation. We obtain a refined version of Kibble's causal results
for defect separation, but from a completely different approach. It is apparent
that vortices are not created from thermal fluctuations in the Ginzburg regime.Comment: 10 pages, RevTex file. No figures. To appear in Phys. Lett.
Noise-induced energy excitation by a general environment
We analyze the effects that general environments, namely ohmic and non-ohmic,
at zero and high temperature induce over a quantum Brownian particle. We state
that the evolution of the system can be summarized in terms of two main
environmental induced physical phenomena: decoherence and energy activation. In
this article we show that the latter is a post-decoherence phenomenon. As the
energy is an observable, the excitation process is a direct indication of the
system-environment entanglement particularly useful at zero temperature.Comment: 14 pages; 7 figures. Version to appear in Phys Lett.
Decoherence of domains and defects at phase transitions
In this further letter on the onset of classical behaviour in field theory
due to a phase transition, we show that it can be phrased easily in terms of
the decoherence functional, without having to use the master equation. To
demonstrate this, we consider the decohering effects due to the displacement of
domain boundaries, with implications for the displacement of defects, in
general. We see that decoherence arises so quickly in this event, that it is
negligible in comparison to decoherence due to field fluctuations in the way
defined in our previous papers.Comment: Version published in Phys. Lett.
Hadronic B Decays at BABAR and BELLE
We review recent results of the BABAR and BELLE Collaborations on the the
alpha and gamma angles of the unitary triangle, on the B to K pi pi Dalitz-plot
analyses, and on the searches for baryonic B decays and for B to DD decays.Comment: SLAC-PUB-13240. To appear in the Proceedings of "Rencontres de
Moriond QCD and High Energy Interactions", La Thuile (Italy) March 8-15, 200
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