20 research outputs found
The Non-Trivial Effective Potential of the `Trivial' lambda Phi^4 Theory: A Lattice Test
The strong evidence for the `triviality' of (lambda Phi^4)_4 theory is not
incompatible with spontaneous symmetry breaking. Indeed, for a `trivial' theory
the effective potential should be given exactly by the classical potential plus
the free-field zero-point energy of the shifted field; i.e., by the one-loop
effective potential. When this is renormalized in a simple, but nonperturbative
way, one finds, self-consistently, that the shifted field does become
non-interacting in the continuum limit. For a classically scale-invariant (CSI)
lambda Phi^4 theory one finds m_h^2 = 8 pi^2 v^2, predicting a 2.2 TeV Higgs
boson. Here we extend our earlier work in three ways: (i) we discuss the
analogy with the hard-sphere Bose gas; (ii) we extend the analysis from the CSI
case to the general case; and (iii) we propose a test of the predicted shape of
the effective potential that could be tested in a lattice simulation.Comment: 22 pages, LaTeX, DE-FG05-92ER40717-
The Weak-Magnetic Moment of Heavy Quarks
With initial and final particles on-shell, the anomalous weak-magnetic dipole
moments of b and c quarks are electroweak gauge invariant quantities of the
effective couplings Zb\bar{b} and Zc\bar{c}, respectively, and good candidates
to test the Standard Model and/or new physics. Here we present a complete
computation of these quantities within the Standard Model. We show that
decoupling properties with respect to heavy particles do take place in the weak
magnetic moment. The obtained values, a_b(M_Z^2)=(2.98-1.56i)x10^(-4) and
a_c(M_Z^2)=(-2.80+1.09i)x10^(-5) are dominated by one-gluon exchange diagrams.
The electroweak corrections are less than 1% of the total magnitude.Comment: 12 pages, 1 Postscript figure, LaTeX. 1 reference corrected.
Published in Phys. Lett.
A Phenomenological Analysis of Gluon Mass Effects in Inclusive Radiative Decays of the and $\Upsilon
The shapes of the inclusive photon spectra in the processes \Jp \to \gamma
X and \Up \to \gamma X have been analysed using all available experimental
data.
Relativistic, higher order QCD and gluon mass corrections were taken into
account in the fitted functions. Only on including the gluon mass corrections,
were consistent and acceptable fits obtained. Values of
GeV and GeV were found for the
effective gluon masses (corresponding to Born level diagrams) for the \Jp and
\Up respectively. The width ratios \Gamma(V \to {\rm hadrons})/\Gamma(V \to
\gamma+ {\rm hadrons}) V=\Jp, \Up were used to determine and . Values consistent with the current world
average were obtained only when gluon mass correction factors,
calculated using the fitted values of the effective gluon mass, were applied. A
gluon mass GeV, as suggested with these results, is consistent with
previous analytical theoretical calculations and independent phenomenological
estimates, as well as with a recent, more accurate, lattice calculation of the
gluon propagator in the infra-red region.Comment: 50 pages, 11 figures, 15 table
Screening for LXR target genes involved in the maintenance of mouse caput epididymis structure and function
The maturation of murine spermatozoa membranes within the epididymis, a computational biology perspective
Lattice (? 4)4 effective potential giving spontaneous symmetry breaking and the role of the Higgs mass
Interaction of Non-Aggregated Boar AWN-1 and AQN-3 with Phospholipid Matrices. A Model for Coating of Spermadhesins to the Sperm Surface
Does it Matter that we do not Agree on the Definition of Poverty? A Comparison of Four Approaches
While there is world-wide agreement on poverty reduction as an overriding goal of development policy, there is little agreement on the definition of poverty. Four approaches to the definition and measurement of poverty are reviewed in this paper: the monetary, capability, social exclusion and participatory approaches. The theoretical underpinnings of the various measures and problems of operationalizing them are pointed out. It is argued that each is a construction of reality, involving numerous judgements, which are often not transparent. The different methods have different implications for policy, and also, to the extent that they point to different people as being poor, for targeting. Empirical work in Peru and India shows that there is significant lack of overlap between the methods with, for example, nearly half the population identified as in poverty according to monetary poverty but not in capability poverty, and conversely. This confirms similar findings elsewhere. Hence, the definition of poverty does matter for poverty eradication strategies.