Baryon Fields with U_L(3) \times U_R(3) Chiral Symmetry: Axial Currents of Nucleons and Hyperons

We use the conventional F and D octet and decimet generator matrices to reformulate chiral properties of local (non-derivative) and one-derivative non-local fields of baryons consisting of three quarks with flavor SU(3) symmetry that were expressed in SU(3) tensor form in Ref. [12]. We show explicitly the chiral transformations of the [(6,3)\oplus(3,6)] chiral multiplet in the "SU(3) particle basis", for the first time to our knowledge, as well as those of the (3,\bar{3}) \oplus (\bar{3}, 3), (8,1) \oplus (1,8) multiplets, which have been recorded before in Refs. [4,5]. We derive the vector and axial-vector Noether currents, and show explicitly that their zeroth (charge-like) components close the SU_L(3) \times SU_R(3) chiral algebra. We use these results to study the effects of mixing of (three-quark) chiral multiplets on the axial current matrix elements of hyperons and nucleons. We show, in particular, that there is a strong correlation, indeed a definite relation between the flavor-singlet (i.e. the zeroth), the isovector (the third) and the eighth flavor component of the axial current, which is in decent agreement with the measured ones.Comment: one typo correction, and accepted by PR

Renormalization group evolution of neutrino masses and mixing in seesaw models: A review

We consider different extensions of the standard model which can give rise to the small active neutrino masses through seesaw mechanisms, and their mixing. These tiny neutrino masses are generated at some high energy scale by the heavy seesaw fields which then get sequentially decoupled to give an effective dimension-5 operator. The renormalization group evolution of the masses and the mixing parameters of the three active neutrinos in the high energy as well as the low energy effective theory is reviewed in this article.Comment: 54 pages. Invited review submitted to IJMP

Shape complexity and fractality of fracture surfaces of swelled isotactic polypropylene with supercritical carbon dioxide

We have investigated the fractal characteristics and shape complexity of the fracture surfaces of swelled isotactic polypropylene Y1600 in supercritical carbon dioxide fluid through the consideration of the statistics of the islands in binary SEM images. The distributions of area $A$, perimeter $L$, and shape complexity $C$ follow power laws $p(A)\sim A^{-(\mu_A+1)}$, $p(L)\sim L^{-(\mu_L+1)}$, and $p(C)\sim C^{-(\nu+1)}$, with the scaling ranges spanning over two decades. The perimeter and shape complexity scale respectively as $L\sim A^{D/2}$ and $C\sim A^q$ in two scaling regions delimited by $A\approx 10^3$. The fractal dimension and shape complexity increase when the temperature decreases. In addition, the relationships among different power-law scaling exponents $\mu_A$, $\mu_B$, $\nu$, $D$, and $q$ have been derived analytically, assuming that $A$, $L$, and $C$ follow power-law distributions.Comment: RevTex, 6 pages including 7 eps figure

Exceptionally strong magnetism in 4d perovskites RTcO3 (R=Ca,Sr,Ba)

The evolution of the magnetic ordering temperature of the 4d3 perovskites RTcO3 (R=Ca,Sr,Ba) and its relation with its electronic and structural properties has been studied by means of hybrid density functional theory and Monte Carlo simulations. When compared to the most widely studied 3d perovskites the large spatial extent of the 4d shells and their relatively strong hybridization with oxygen weaken the tendency to form Jahn-Teller like orbital ordering. This strengthens the superexchange interaction. The resulting insulating G-type antiferromagnetic ground state is characterized by large superexchange coupling constants (26-35 meV) and Neel temperatures (750-1200 K). These monotonically increase as a function of the R ionic radius due to the progressive enhancement of the volume and the associated decrease of the cooperative rotation of the TcO6 octahedra.Comment: 4 pages, 3 figure

Dirac quasinormal modes of a Schwarzschild black hole surrounded by free static spherically symmetric quintessence

We evaluate the quasinormal modes of massless Dirac perturbation in a Schwarzschild black hole surrounded by the free static spherically symmetric quintessence by using the third-order WKB approximation. The result shows that due to the presence of quintessence, the massless field damps more slowly. The real part of the quasinormal modes increases and the the absolute value of the imaginary part increases when the state parameter $w_q$ increases. In other words, the massless Dirac field decays more rapidly for the larger $w_q$. And the peak value of potential barrier gets higher as $|k|$ increases and the location of peak moves along the right for fixed $w_q$.Comment: 7 pages, 4 figure

A full parametrization of the 6 X 6 flavor mixing matrix in the presence of three light or heavy sterile neutrinos

In addition to three active neutrinos, one or more light sterile neutrinos have been conjectured to account for the LSND, MiniBooNE and reactor antineutrino anomalies (at the sub-eV mass scale) or for warm dark matter in the Universe (at the keV mass scale). Heavy Majorana neutrinos at or above the TeV scale have also been assumed in some seesaw models. Such hypothetical particles can weakly mix with active neutrinos, and thus their existence can be detected at low energies. In the (3+3) scenario with three sterile neutrinos we present a full parametrization of the 6 X 6 flavor mixing matrix in terms of fifteen rotation angles and fifteen phase angles. We show that this standard parametrization allows us to clearly describe the salient features of some problems in neutrino phenomenology, such as (a) possible contributions of light sterile neutrinos to the tritium beta decay and neutrinoless double-beta decay; (b) leptonic CP violation and deformed unitarity triangles of the 3 X 3 flavor mixing matrix of three active neutrinos; (c) a reconstruction of the 6 X 6 neutrino mass matrix in the type-(I+II) seesaw mechanism; and (d) flavored and unflavored leptogenesis scenarios in the type-I seesaw mechanism with three heavy Majorana neutrinos.Comment: RevTex 18 pages, 1 figure. Minor changes, references updated. Accepted for publication in Phys. Rev.

Immobilization of Scandium and Other Chemical Elements in Systems with Aquatic Macrophyte

The possibility of immobilization of scandium and other chemical elements by biogenic materialsderived from an aquatic macrophyte was explored. The concentrations of scandium and some other chemicalelements were measured in the dried biomass (mortmass) of aquatic plants Myriophyllum aquaticum. In theexperiments, the mortmass was incubated in aquatic systems where some chemical elements were added to theaquatic medium. After the incubation, the concentrations of these chemical elements in the mortmass weremeasured using inductively coupled plasma atomic emission spectroscopy (ICP-AES), also referred to asinductively coupled plasma optical emission spectrometry (ICP-OES). Increases in the concentrations ofscandium and some other chemical elements (Ce, In, Se, Ru, Pd, U, and Zr) were observed in the biogenic materia