18,906 research outputs found
Fermionic decays of scalar leptoquarks and scalar gluons in the minimal four color symmetry model
Fermionic decays of the scalar leptoquarks
and of the scalar gluons predicted by the four color symmetry
model with the Higgs mechanism of the quark-lepton mass splitting are
investigated. Widths and branching ratios of these decays are calculated and
analysed in dependence on coupling constants and on masses of the decaying
particles. It is shown that the decays are
dominant with the widths of order of a few GeV for TeV and with
the total branching ratios close to 1. In the case of the dominant
scalar leptoquark decays are S_1^{(+)}\to cl_j^+, S_1^{(-)}\to \nu_i\tilde b,
S_m\to b\l_j^+, S_m\to c\tilde \nu_j with the total branching ratios
,
and A
search for such decays at the LHC and Tevatron may be of interest.Comment: 11 pages, 1 figure, 1 table, to be published in Modern Physics
Letters
Explicit computation of Drinfeld associator in the case of the fundamental representation of gl(N)
We solve the regularized Knizhnik-Zamolodchikov equation and find an explicit
expression for the Drinfeld associator. We restrict to the case of the
fundamental representation of . Several tests of the results are
presented. It can be explicitly seen that components of this solution for the
associator coincide with certain components of WZW conformal block for primary
fields. We introduce the symmetrized version of the Drinfeld associator by
dropping the odd terms. The symmetrized associator gives the same knot
invariants, but has a simpler structure and is fully characterized by one
symmetric function which we call the Drinfeld prepotential.Comment: 14 pages, 2 figures; several flaws indicated by referees correcte
Quasi-exactly solvable problems and the dual (q-)Hahn polynomials
A second-order differential (q-difference) eigenvalue equation is constructed
whose solutions are generating functions of the dual (q-)Hahn polynomials. The
fact is noticed that these generating functions are reduced to the (little
q-)Jacobi polynomials, and implications of this for quasi-exactly solvable
problems are studied. A connection with the Azbel-Hofstadter problem is
indicated.Comment: 15 pages, LaTex; final version, presentation improved, title changed,
to appear in J.Math.Phy
Four-dimensional integration by parts with differential renormalization as a method of evaluation of Feynman diagrams
It is shown how strictly four-dimensional integration by parts combined with
differential renormalization and its infrared analogue can be applied for
calculation of Feynman diagrams.Comment: 6 pages, late
Storage and retrieval of light pulses in atomic media with "slow" and "fast" light
We present experimental evidence that light storage, i.e. the controlled
release of a light pulse by an atomic sample dependent on the past presence of
a writing pulse, is not restricted to small group velocity media but can also
occur in a negative group velocity medium. A simple physical picture applicable
to both cases and previous light storage experiments is discussed.Comment: 4 pages, 3 figures, submitted to Physical Review Letter
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