Special Symmetric Quark Mass Matrices

We give a procedure to construct a special class of symmetric quark mass matrices near the democratic limit of equal Yukawa couplings for each sector. It is shown that within appropriate weak-bases, the requirements of symmetry and arg(det[M])=0 are very strong conditions, that necessarily lead to a Cabibbo angle given by |V_us|=Sqrt[md/ms], and to |V_cb|~ms/mb, in first order. In addition, we prove that the recently classified ansatze, which also reproduce these mixing relations, and which were based on the hypothesis of the Universal Strength for Yukawa couplings, where all Yukawa couplings have equal moduli while the flavour dependence is only in their phases, are, in fact, particular cases of the generalized symmetric quark mass matrix ansatze we construct here. In an excellent numerical example, the experimental values on all quark mixings and masses are accommodated, and the CP violation phase parameter is shown to be crucially dependent on the values of mu and V_us.Comment: 13 pages, LaTe

Beating in electronic transport through quantum dot based devices

Electronic transport through a two-level system driven by external electric field and coupled to (magnetic or non-magnetic) electron reservoirs is considered theoretically. The basic transport characteristics such as current and tunnel magnetoresistance (TMR) are calculated in the weak coupling approximation by the use of rate equation connected with Green function formalism and slave-boson approach. The time dependent phenomenon is considered in the gradient expansion approximation. The results show that coherent beats pattern can be observed both in current and TMR. The proposed system consisting of two quantum dots attached to external leads, in which the dots' levels can be tuned independently, can be realized experimentally to test this well known physical phenomenon. Finally, we also indicate possible practical applications of such device.Comment: 9 pages, 9 figure

The Troubled Evolution of Energy Policy in the EEC: A Discordant Note in the Harmonization Process

This article will explore the troubled evolution of EEC energy policy and the attendant institutional and structural tensions that have militated against a cohesive energy policy and regulatory regime. Certainly, a by-product of such an inquiry is the issue of whether energy-based decision-making has been predicated upon a communitarian vision with Pan-European meaning, or whether nationalism and the pressures of the historical moment have determined the choice of rules to be made irrespective of long- term institutional considerations. While it is recognized that energy encompasses a variety of sources, including petroleum, coal, electricity, geothermal power, and nuclear energy, this article will focus upon the importance of petroleum products for the evolution of Community energy policy

Anemia treatment in chronic kidney disease accompanied by diabetes mellitus or congestive heart failure

Anemia is common in chronic kidney disease (CKD). The CHOIR study found increased risk of a composite cardiovascular outcome when anemia was treated with epoetin-alfa to a target hemoglobin level of 13.5 as compared with 11.3 g/dl. Whether this increase applies to all patient subgroups equally is unclear. We discuss an analysis by Szczech and colleagues of the effects of the higher hemoglobin target in CKD patients with diabetes mellitus or congestive heart failure

Glueball Spin

The spin of a glueball is usually taken as coming from the spin (and possibly the orbital angular momentum) of its constituent gluons. In light of the difficulties in accounting for the spin of the proton from its constituent quarks, the spin of glueballs is reexamined. The starting point is the fundamental QCD field angular momentum operator written in terms of the chromoelectric and chromomagnetic fields. First, we look at the restrictions placed on the structure of glueballs from the requirement that the QCD field angular momentum operator should satisfy the standard commutation relationships. This can be compared to the electromagnetic charge/monopole system, where the quantization of the field angular momentum places restrictions (i.e. the Dirac condition) on the system. Second, we look at the expectation value of this operator under some simplifying assumptions.Comment: 11 pages, 0 figures; added references and some discussio

The Symmetry behind Extended Flavour Democracy and Large Leptonic Mixing

We show that there is a minimal discrete symmetry which leads to the extended flavour democracy scenario constraining the Dirac neutrino, the charged lepton and the Majorana neutrino mass term ($M_R$) to be all proportional to the democratic matrix, with all elements equal. In particular, this discreet symmetry forbids other large contributions to $M_R$, such as a term proportional to the unit matrix, which would normally be allowed by a $S_{3L}\times S_{3R}$ permutation symmetry. This feature is crucial in order to obtain large leptonic mixing, without violating 't Hooft's, naturalness principle.Comment: 11 pages, LaTe