2,955 research outputs found
Aspects of Neutrino Mass Matrices
After an Introduction briefly describing the rise and fall of the three-zero
texture of the Zee model, we discuss still-allowed two-zero textures for the
Majorana three-neutrino mass matrix. Finally, a model with two right-handed
neutrinos and two Dirac texture zeros is described (FGY model) which can relate
CP violation in leptogenesis to CP violation in long-baseline neutrino
oscillations.Comment: 9 pages latex. Talk at Coral Gables 2003. Added reference
Stability Issues for w < -1 Dark Energy
Precision cosmological data hint that a dark energy with equation of state and hence dubious stability is viable. Here we discuss for any
nucleation from to in a first-order phase
transition. The critical radius is argued to be at least of galactic size and
the corresponding nucleation rate is glacial, thus underwriting the dark
energy's stability and rendering remote any microscopic effect.Comment: 9 pages LaTeX. Significantly rewritten (including abstract
Mersenne Primes, Polygonal Anomalies and String Theory Classification
It is pointed out that the Mersenne primes and associated
perfect numbers play a significant role in string
theory; this observation may suggest a classification of consistent string
theories.Comment: 10 pages LaTe
German social pedagogy and social work: the academic discourses mapping a changing historical relationship
The term ‘social pedagogy’ was coined in Germany, a country which also provided fertile ground for the early development of social work. This article reconstructs the evolution of the two disciplines, which existed alongside one another for much of the twentieth century. It starts with their identities at the time of their early emergence, and then focuses on two formative periods: the early twentieth century, when both disciplines were in the nascent stages of independent development; and the late twentieth century, when they appeared to be in a state of amalgamation. In the course of this examination, Hämäläinen’s recent suggestion that social pedagogy can be regarded as a science, as a profession and in terms of its education is investigated. So too is Lorenz’s framework for considering a nation’s social professions in terms of social policy, civil society and academic discourse elements. Those academic discourses tied to the identity of the two professions offer an opportunity to pin down the slippery German concept of social pedagogy, demarcate it from social work and consider the path dependencies of each profession. This is carried out with particular reference to the early figures who shaped the disciplines, specifically Paul Natorp, Herman Nohl and Alice Salomon. The case of Germany reveals not only few uncontested definitions of the two professions, but also a clear formal separation for much of the twentieth century, which is best understood by considering historical, not contemporary arrangements
Outcome from Spontaneous CP Violation for B Decays
In the aspon model solution of the strong problem, there is a gauged
symmetry, spontaneously broken by the same vacuum expectation value
which breaks , whose massive gauge boson provides an additional mechanism
of weak violation. We calculate the asymmetries in decays for the
aspon model and show that they are typically smaller than those predicted from
the standard model. A linear relation between the asymmetries of different
decay processes is obtained.Comment: REVTEX, 9 pages, IFP-486-UNC, NSF-PT-94-1, and UDHEP-01-9
Aspects of Soft and Spontaneous CP Violation
We study four different models for CP violation: the standard (KM) model, the
aspon model of spontaneous breaking and two models of soft breaking. In all
except the standard model, the strong CP problem is addressed and solved.
Testable predictions for the area of the unitarity triangle and for
(epsilon'/epsilon)_K are emphasized. The issue of CP violation may well become
the first place where the standard model of particle theory is shown
definitively to be deficient. There are two reasons for expecting this to
happen: (1) the strong CP problem is still not understood in the unadorned
standard model and (2) the KM mechanism, although unquestionably present, may
not provide the full explanation of epsilon_K and (epsilon'/epsilon)_K.Comment: 24 pages LaTeX including 4 figures. Minor modification to analysis of
lower bound for d_n, summarized in new Table I
Flavor Symmetry for Quarks and Leptons
Present data on neutrino masses and mixing favor the highly symmetric
tribimaximal neutrino mixing matrix which suggests an underlying flavor
symmetry. A systematic study of non-abelian finite groups of order
reveals that tribimaximal mixing can be derived not only from the well known
tetrahedral flavor symmetry , but also by using the binary
tetrahedral symmetry which does not contain the
tetrahedral group as a subgroup. has the further advantage that it can
also neatly accommodate the quark masses including a heavy top quark.Comment: 12 pages latex. More typos correcte
Constraints on Deflation from the Equation of State of Dark Energy
In cyclic cosmology based on phantom dark energy the requirement that our
universe satisfy a CBE-condition ({\it Comes Back Empty}) imposes a lower bound
on the number of causal patches which separate just prior to
turnaround. This bound depends on the dark energy equation of state with . More accurate measurement of will
constrain . The critical density in the model has a lower
bound or
when the smallest bound state has size m, or m,
respectively.Comment: 23 pages, 3 figures, typos fixe
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