15,765 research outputs found
Effective Theory Approach to the Skyrme model and Application to Pentaquarks
The Skyrme model is reconsidered from an effective theory point of view. From
the most general chiral Lagrangian up to including terms of order ,
and (), new interactions, which have never
been considered before, appear upon collective coordinate quantization. We
obtain the parameter set best fitted to the observed low-lying baryon masses,
by performing the second order perturbative calculations with respect to
. We calculate the masses and the decay widths of the other members
of (mainly) anti-decuplet pentaquark states. The formula for the decay widths
is reconsidered and its baryon mass dependence is clarified.Comment: 65 pages, 1 figure. Revised version:the complete second order
perturbative calculations performed and two appendices adde
Two loop finiteness of Higgs mass and potential in the gauge-Higgs unification
The zero mode of an extra-dimensional component of gauge potentials serves as
a 4D Higgs field in the gauge-Higgs unification. We examine QED on and determine the mass and potential of a 4D Higgs field (the
component) at the two loop level with gauge invariant reguralization. It is
seen that the mass is free from divergences and independent of the
renormalization scheme.Comment: 18 pages, 1 figur
Exchange and spin Jahn-Teller distortions for a triangular cluster of spin-1/2
We study the effects of magnetoelastic coupling on the degenerate ground
state of the spin-1/2 antiferromagnetic Heisenberg model for the regular
triangular spin cluster. Static displacement of spins spontaneously lifts the
degeneracy of the ground state through the distance dependence of exchange
coupling, i.e., a spin Jahn-Teller mechanism takes place. On the other hand,
dynamical displacement does not lift the degeneracy, though the cluster
distorts spontaneously. The energy decrease obtained by dynamical theory is
twice as large as that obtained by static theory because of quantum
fluctuation.Comment: 4 pages, 1 figure. Accepted by JPSJ. Clarified some setences.
Corrected typo
Charge 4/3 leptons in cosmic rays
A cosmic ray counter telescope has been operated at zenith angles of 0, 40, 44, and 60 degs in order to look for charge 4/3 particles. A few million clean single cosmic rays of each zenith angle are analyzed
The read-out system of spatial distribution of thermoluminescence in meteorites
The thermoluminescence (TL) technique used for dating the terrestrial age of meteorites is based on the TL fading of interior samples. The depth dependence of the TL for Antarctic meteorites with fusion crust is measured. Usually, meteorites are powdered and their TL measured under a photomultiplier. In this case, a TL spatial distribution of a cross section of antarctic meteorites is measured using a read out system of spatial distribution of TL, since a meteorite is made up of inhomogeneous material. Antarctic meteorites MET-78028(L6) and ALH-77278(L13) are used
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