188 research outputs found
Adventures of the Coupled Yang-Mills Oscillators: II. YM-Higgs Quantum Mechanics
We continue our study of the quantum mechanical motion in the
potentials for , which arise in the spatially homogeneous limit of the
Yang-Mills (YM) equations. In the present paper, we develop a new approach to
the calculation of the partition function beyond the Thomas-Fermi (TF)
approximation by adding a harmonic (Higgs) potential and taking the limit , where is the vacuum expectation value of the Higgs field. Using the
Wigner-Kirkwood method to calculate higher-order corrections in , we
show that the limit leads to power-like singularities of the type
, which reflect the possibility of escape of the particle along the
channels in the classical limit. We show how these singularities can be
eliminated by taking into account the quantum fluctuations dictated by the form
of the potential
Branching Processes and Multi-Particle Production
The general theory of the branching processes is used for establishing the
relation between the parameters and of the negative binomial
distribution. This relation gives the possibility to describe the overall data
on multiplicity distributions in -collisions for energies up to
900 GeV and to make several interesting predictions for higher energies. This
general approach is free from ambiguities associated with the extrapolation of
the parameter to unity.Comment: 13 pages, (8 figures available on request), DUKE-TH-93-5
Adventures of the Coupled Yang-Mills Oscillators: I. Semiclassical Expansion
We study the quantum mechanical motion in the potentials with
, which arise in the spatially homogeneous limit of the Yang-Mills (YM)
equations. These systems show strong stochasticity in the classical limit
() and exhibit a quantum mechanical confinement feature. We
calculate the partition function going beyond the Thomas-Fermi (TF)
approximation by means of the semiclassical expansion using the Wigner-Kirkwood
(WK) method. We derive a novel compact form of the differential equation for
the WK function. After separating the motion in the channels of the
equipotential surface from the motion in the central region, we show that the
leading higher-order corrections to the TF term vanish up to eighth order in
, if we treat the quantum motion in the hyperbolic channels correctly by
adiabatic separation of the degrees of freedom. Finally, we obtain an
asymptotic expansion of the partition function in terms of the parameter
Out of equilibrium dynamics of coherent non-abelian gauge fields
We study out-of-equilibrium dynamics of intense non-abelian gauge fields.
Generalizing the well-known Nielsen-Olesen instabilities for constant initial
color-magnetic fields, we investigate the impact of temporal modulations and
fluctuations in the initial conditions. This leads to a remarkable coexistence
of the original Nielsen-Olesen instability and the subdominant phenomenon of
parametric resonance. Taking into account that the fields may be correlated
only over a limited transverse size, we model characteristic aspects of the
dynamics of color flux tubes relevant in the context of heavy-ion collisions.Comment: 12 pages, 10 figures; PRD version, minor change
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