30,518 research outputs found
Measuring and interpreting current permanent and transitory earnings and dividends : methods and applications / BEBR No. 815
Bibliography: p. 21-22
Residual theory, partial adjustment, and information content on dividend payments decisions : an integration and extension / BEBR No. 760
Bibliography: p. 31-32
Dark matter and dark gauge fields
Following the unexpected theoretical discovery of a mass dimension one
fermionic quantum field of spin one half, we now present first results on two
_local_ versions. The Dirac and Majorana fields of the standard model of
particle physics are supplemented by their natural counterparts in the dark
matter sector. The possibility that a mass dimension transmuting symmetry may
underlie a new standard model of particle physics is briefly suggested.Comment: This manuscript combines a plenary talk (by DVA) and an invited talk
(by DS) at "Dark 2007 - Sixth International Heidelberg Conference on Dark
Matter in Astro and Particle Physics (Sydney, Australia, 24th-28th September
2007)." 11 pages. v2: minor typos correcte
Fama's hypotheses of the relationship between inflation and nominal interest rates : an international comparison
Includes bibliographical references (p. 21)
Some effects of utility regulation on firm operating and financial strategies / BEBR No. 421
Includes bibliographical references (leaves 21-22).This paper shows that different degrees of regulation affect electric utility firm's operating and financial strategies. The analysis also provides a potential approach for testing the Averch-Johnson effect using financial information which has been neglected until this time
Physical Parameters and Renormalization of U(1)_a x U(1)_b Models
We analize the structure of models with unbroken and spontaneously broken
U(1)_a x U(1)_b gauge symmetry. We show that the quantum corrections to the 2N
gauge charges, with N = #fermions + #scalars, can be absorbed in the
redefinition of three independent gauge couplings (g_a,g_b and g_ab). We
establish the (one-loop) conditions on the matter cotent for g_ab= = 0 (a value
usually assumed in the literature) and we show that in the minimal extensions
of the Standard Model with an extra U(1) symmetry the choice g_ab = 0 is not
stable under radiative corrections induced by the standard Higgs fields.
Moreover, g_ab = 0 to all orders seems to require an exact symmetry. The
spontaneous breaking of the gauge symmetry induces further mixing between the
two gauge bosons and introduces a fourth independent physical parameter. A
consequence of our analysis is that the usual tree-level description with only
three physical parameters (i.e., two gauge couplings and one gauge boson mixing
angle) is not in general a justified zero order limit of the treatment
including radiative corrections.Comment: 24 pages, tex, 1 figur
Singlet fermionic dark matter
We propose a renormalizable model of a fermionic dark matter by introducing a
gauge singlet Dirac fermion and a real singlet scalar. The bridges between the
singlet sector and the standard model sector are only the singlet scalar
interaction terms with the standard model Higgs field. The singlet fermion
couples to the standard model particles through the mixing between the standard
model Higgs and singlet scalar and is naturally a weakly interacting massive
particle (WIMP). The measured relic abundance can be explained by the singlet
fermionic dark matter as the WIMP within this model. Collider implication of
the singlet fermionic dark matter is also discussed. Predicted is the elastic
scattering cross section of the singlet fermion into target nuclei for a direct
detection of the dark matter. Search of the direct detection of the dark matter
provides severe constraints on the parameters of our model.Comment: 12 pages, 7 figure
Flavor symmetry breaking and scaling for improved staggered actions in quenched QCD
We present a study of the flavor symmetry breaking in the pion spectrum for
various improved staggered fermion actions. To study the effects of link
fattening and tadpole improvement, we use three different variants of the p4
action - p4fat3, p4fat7, and p4fat7tad. These are compared to Asqtad and also
to naive staggered. To study the pattern of symmetry breaking, we measure all
15 meson masses in the 4-flavor staggered theory. The measurements are done on
a quenched gauge background, generated using a one-loop improved Symanzik
action with and 8.00, corresponding to lattice
spacings of approximately a = .31 fm., .21 fm., and .14 fm. We also study how
the lattice scale set by the mass on each of these ensembles compares to
one set by the static quark potential.Comment: 18 pages, 6 figure
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