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 $SU(2)$ 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 AdS4AdS_4

Conserved currents of any spin $t>0$ built from bosonic symmetric massless gauge fields of arbitrary integer spins in $AdS_4$ are found. Analogously to the case of $4d$ 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 4d4d Minkowski Space

Conserved currents of any spin $t>0$ built from symmetric massless gauge fields of any integer spin $s \geq t$ 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 $AdS$ 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 $gl(N)$. 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 $S=S_1^{(+)}, S_1^{(-)}, S_m$ and of the scalar gluons $F=F_1, F_2$ 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 $S_1^{(+)}\to tl^+_j, S_1^{(-)}\to \nu_i\tilde b, S_m\to t\tilde \nu_j, F_1\to t\tilde b, F_2\to t\tilde t$ are dominant with the widths of order of a few GeV for $m_S, m_F<1$ TeV and with the total branching ratios close to 1. In the case of $m_S < m_t$ 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 $Br(S_1^{(+)}\to cl^+) \approx$ $Br(S_1^{(-)}\to \nu\tilde b) \approx 1$, $Br(S_m\to bl^+) \approx 0.9$ and $Br(S_m\to c\tilde \nu) \approx 0.1.$ 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