20,310 research outputs found
Form factors for principal chiral field model with Wess-Zumino-Novikov-Witten term
We construct the form factors of the trace of energy-momentum tensor for the
massless model described by principal chiral field model with WZNW tern
on level 1. We explain how this construction can be generalized to a class of
integrable massless models including the flow from tricritical to critical
Ising model.Comment: 9 pages, LATE
Gauge Non-Invariant Higher-Spin Currents in
Conserved currents of any spin built from bosonic symmetric massless
gauge fields of arbitrary integer spins in are found. Analogously to
the case of Minkowski space, currents considered in this paper are not
gauge invariant but generate gauge invariant conserved charges.Comment: 18 pages; V2: Typos and coefficients corrected, published versio
Gauge Non-Invariant Higher-Spin Currents in Minkowski Space
Conserved currents of any spin built from symmetric massless gauge
fields of any integer spin in {4d} Minkowski space are found. In
particular, stress-energy tensor for a higher-spin field of any spin is
constructed. Analogously to spin-two stress (pseudo)tensor, currents considered
in this paper are not gauge invariant. However, they are shown to generate
gauge invariant conserved charges. Besides expected parity even HS currents, we
found unexpected parity odd currents that generate less symmetries than the
even ones. It is argued that these odd currents unlikely admit a consistent
deformation.Comment: 17 pages; V2: Minor corrections, the version published in the volume
in honor of Andrei Alekseevich Slavno
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
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
Lepton mixing from the hidden sector
Experimental results indicate a possible relation between the lepton and
quark mixing matrices of the form U_PMNS \approx V_CKM^\dagger U_X, where U_X
is a matrix with special structure related to the mechanism of neutrino mass
generation. We propose a framework which can realize such a relation. The main
ingredients of the framework are the double seesaw mechanism, SO(10) Grand
Unification and a hidden sector of theory. The latter is composed of singlets
(fermions and bosons) of the GUT symmetry with masses between the GUT and
Planck scale. The interactions in this sector obey certain symmetries G_hidden.
We explore the conditions under which symmetries G_hidden can produce flavour
structures in the visible sector. Here the key elements are the basis-fixing
symmetry and mediators which communicate information about properties of the
hidden sector to the visible one. The interplay of SO(10) symmetry,
basis-fixing symmetry identified as Z2 x Z2 and G_hidden can lead to the
required form of U_X. A different kind of new physics is responsible for
generation of the CKM mixing. We present the simplest realizations of the
framework which differ by nature of the mediators and by symmetries of the
hidden sector.Comment: 30 pages, 6 figures; typo corrected, one reference added, version for
publication in Phys. Rev.
Solar neutrinos: the SNO salt phase results and physics of conversion
We have performed analysis of the solar neutrino data including results from
the SNO salt phase as well as the combined analysis of the solar and the
KamLAND results. The best fit values of neutrino parameters are Delta m^2 =
7.1e-5 eV^2, tan^2\theta = 0.40 with the boron flux f_B = 1.04. New SNO results
strongly disfavor maximal mixing and the h-LMA region (Delta m^2 > 1e-4 eV^2)
which is accepted now at the 3-sigma level. We find the 3-sigma upper bounds:
Delta m^2 < 1.7e-4$ eV^2 and tan^2\theta < 0.64, and the lower bound Delta m^2
> 4.8e-5 eV^2. Non-zero 13-mixing does not change these results significantly.
The present data determine quantitatively the physical picture of the solar
neutrino conversion. At high energies relevant for SNO and Super-Kamiokande the
deviation of the effective survival probability from the non-oscillatory value
is about 10 - 14%. The oscillation effect contribution to this difference about
10% and the Earth regeneration is about 3 - 4%. At low energies (E < 1 MeV) the
matter corrections to vacuum oscillation effect are below 5%. The predictions
for the forthcoming measurements are given which include the spectral
distortion and CC/NC ratio at SNO, the Day-Night asymmetry, the KamLAND
spectrum and rate.Comment: figures and some numbers corrected, discussion of coherence loss
added, number of pages slightly change
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