LEPTON MASSES IN AN SU(3)L-CIRCLE-TIMES-U(1)N GAUGE-MODEL

The SU(3)cxSU(3)LxU(1)N model of Pisano and Pleitez extends the standard model in a particularly nice way, so that, for example, the anomalies cancel only when the number of generations is divisible by 3. The original version of the model has some problems accounting for the lepton masses. We resolve this problem by modifying the details of the symmetry-breaking sector in the model.

Fundamental fermion masses from deformed SUq(2) triplets

A spectrum-generating q-algebra, within the framework of SUq(2), as firstly suggested by Iachello, is studied in order to describe the mass spectrum of three generations of quarks and leptons. The SUq(2) quantum group is a q-deformed extension of SU(2), where q = e(alpha) (with alpha real) is the deformation parameter. In this work, the essential use of inequivalent representations of SUq(2) is introduced. The inequivalent representations are labelled by (j, nu(0)), where j = 0, 1/2, 1, ... and nu(0) is a positive real number. A formula for the fermion masses M-m(j, nu(0)), with -j less than or equal to m less than or equal to j is derived. As an example, a possible scheme which corresponds to two triplets (j = 1) associated to up and down quarks is presented here in some detail. They are associated to different values of the deformation parameter, indicating a dependence of the charge Q on the parameter alpha. The masses of the charged leptons are treated in a similar way. The current results show that some mass relations for quarks and leptons found in the literature can be considered as approximations of the equations obtained in the j = 1 representations. The breaking of SUq(2) necessary to describe the Cabibbo-Kobayashi-Maskawa (CKM) flavor mixing is briefly discussed.

Multiwavelength visible and white light generation by upconversion emission in Ho/Tm/Yb triply doped fluorogermanate glass-ceramic

Energy transfer excited multiwavelength visible upconversion emission and white light generation is described in a single sample of PbGeO(3)-PbF(2)-CdF(2) glass-ceramic triply doped With Ho/Tm/Yb under single infrared laser excitation. Blue (475 nm), green (540 mn), and red (650 nm), upconversion luminescence signals are generated, and the emissions are assigned, respectively, to thulium ((1)G(4)-(3)H(6)), and holmium ((5)S(2);(5)F(4)) -> (5)I(8), (5)F(5) -> (5)I(8)) ions transitions, both excited via successive energy transfers from ytterbium ions. It is experimentally shown that with a proper combination of the rare earth ions contents, white light may be produced, with the simultaneous generation of fluorescence with controllable intensities at the wavelengths of the three primary colours in a single sample and using a single near-infrared excitation source.

Population genetic structure and dispersal in white-lipped peccaries (Tayassu pecari) from the Brazilian Pantanal

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estimates of genetic parameters, and cluster and principal components analyses of breeding values related to egg production traits in a White Leghorn population

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The use of auxiliary courts by the lek-forming White-bearded Manakin Manacus manacus (Aves, Pipridae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)