263 research outputs found
On quark-lepton complementarity
Recent measurements of the neutrino solar mixing angle and the Cabibbo angle
satisfy the empirical relation theta_{sol} + theta_{C} ~ 45^{o}. This relation
suggests the existence of a correlation between the mixing matrices of leptons
and quarks, the so called quark-lepton complementarity. Here, we examine the
possibility that this correlation originates in the strong hierarchy in the
mass spectra of quarks and charged leptons, and the seesaw mechanism that gives
mass to the Majorana neutrinos. In a unified treatment of quarks and leptons in
which the mass matrices of all fermions have a similar Fritzsch texture, we
calculate the mixing matrices V_{CKM} and U_{MNSP} as functions of quark and
lepton masses and only two free parameters, in very good agreement with the
latest experimental values on masses and mixings. Three essential ingredients
to explain the quark-lepton complementarity relation are identified: the strong
hierarchy in the mass spectra of quarks and charged leptons, the normal seesaw
mechanism and the assumption of maximal CP violation in the lepton sector.Comment: 6 pages, to appear in "Particles and fields: Xth Mexican Workshop on
Particles and Fields" (Morelia, Mich. Mexico, November 6-12, 2005), Eds. A.
Bashir and L. Villasenor, AIP Conference proceedings (2006
Universal Mass Texture, CP violation and Quark-Lepton Complementarity
The measurements of the neutrino and quark mixing angles satisfy the
empirical relations called Quark-Lepton Complementarity. These empirical
relations suggest the existence of a correlation between the mixing matrices of
leptons and quarks. In this work, we examine the possibility that this
correlation between the mixing angles of quarks and leptons originates in the
similar hierarchy of quarks and charged lepton masses and the seesaw mechanism
type~I, that gives mass to the Majorana neutrinos. We assume that the similar
mass hierarchies of charged lepton and quark masses allows us to represent all
the mass matrices of Dirac fermions in terms of a universal form with four
texture zeroes.Comment: 14 page
Generalized reflection symmetry and leptonic CP violation
We propose a generalized reflection symmetry to constrain the
lepton flavor mixing parameters. We obtain a new correlation between the
atmospheric mixing angle and the "Dirac" CP violation phase
. Only in a specific limit our proposed CP transformation
reduces to standard reflection, for which and
are both maximal. The "Majorana" phases are predicted to lie at
their CP-conserving values with important implications for the neutrinoless
double beta decay rates. We also study the phenomenological implications of our
scheme for present and future neutrino oscillation experiments including T2K,
NOA and DUNE.Comment: 14 pages, 9 figures, latex, Final version to appear in Physics
Letters
Maximum power, ecological function and efficiency of an irreversible Carnot cycle. A cost and effectiveness optimization
In this work we include, for the Carnot cycle, irreversibilities of linear
finite rate of heat transferences between the heat engine and its reservoirs,
heat leak between the reservoirs and internal dissipations of the working
fluid. A first optimization of the power output, the efficiency and ecological
function of an irreversible Carnot cycle, with respect to: internal temperature
ratio, time ratio for the heat exchange and the allocation ratio of the heat
exchangers; is performed. For the second and third optimizations, the optimum
values for the time ratio and internal temperature ratio are substituted into
the equation of power and, then, the optimizations with respect to the cost and
effectiveness ratio of the heat exchangers are performed. Finally, a criterion
of partial optimization for the class of irreversible Carnot engines is herein
presented.Comment: 17 pages, 4 figures. Submitted to Energy Convers. Manag
Hypersurfaces Levi-plates et leur complément dans les surfaces complexes
In this work we study analytic Levi-flat hypersurfaces in complex algebraic surfaces. These are real hypersurfaces that admit a foliation by holomorphic curves, called Cauchy Riemann foliation (CR). First, we show that if this foliation admits chaotic dynamics (i.e. if it doesn't admit an invariant transverse measure), then the connected components of the complement of the hypersurface are Stein. This allows us to extend the CR foliation to a singular algebraic foliation on the ambient complex surface. We apply this result to prove, by contradiction, that analytic Levi-flat hypersurfaces admitting a transverse affine structure in a complex algebraic surface have a transverse invariant measure. This leads us to conjecture that Levi-flat hypersurfaces in complex algebraic surfaces that are diffeomorphic to a hyperbolic tori bundle over the circle are fibrations by algebraic curves.Dans ce mémoire nous étudions les hypersurfaces Levi-plates analytiques dans les surfaces algébriques complexes. Il s'agit des hypersurfaces réelles qui admettent un feuilletage par des courbes holomorphes, appelé le feuilletage de Cauchy Riemann (CR). Dans un premier temps nous montrons que si ce dernier admet une dynamique chaotique (i.e. s'il n'admet pas de mesure transverse invariante) alors les composantes connexes de l'extérieur de l'hypersurface sont des modifications de domaines de Stein. Ceci permet d'étendre le feuilletage CR en un feuilletage algébrique singulier sur la surface complexe ambiante. Nous appliquons ce résultat pour montrer, par l'absurde, qu'une hypersurface Levi-plate analytique qui admet une structure affine transverse dans une surface algébrique complexe possède une mesure transverse invariante. Ceci nous amène à conjecturer que les hypersurfaces Levi-plates dans les surfaces algébriques complexes qui sont difféomorphes à un fibré hyperbolique en tores sur le cercle sont des fibrations par courbes algébriques
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