One-loop Regularization of Supergravity II: The Dilaton and the Superfield Formulation

The on-shell regularization of the one-loop divergences of supergravity theories is generalized to include a dilaton of the type occurring in effective field theories derived from superstring theory, and the superfield structure of the one-loop corrections is given. Field theory anomalies and quantum contributions to soft supersymmetry breaking are discussed. The latter are sensitive to the precise choice of couplings that generate Pauli-Villars masses, which in turn reflect the details of the underlying theory above the scale of the effective cut-off. With a view to the implementation the Green-Schwarz and other mechanisms for canceling field theory anomalies under a U(1) gauge transformation and under the T-duality group of modular transformations, we show that the K\"ahler potential renormalization for the untwisted sector of orbifold compactification can be made invariant under these groups.Comment: 46 pages, full postscript also available from http://phyweb.lbl.gov/theorygroup/papers/43259.p

One-Loop Pauli-Villars Regularization of Supergravity I: Canonical Gauge Kinetic Energy

It is shown that the one-loop coefficients of on-shell operators of standard supergravity with canonical gauge kinetic energy can be regulated by the introduction of Pauli-Villars chiral and abelian gauge multiplets, subject to a condition on the matter representations of the gauge group. Aspects of the anomaly structure of these theories under global nonlinear symmetries and an anomalous gauge symmetry are discussed.Comment: 46 pages, full postscript also available from http://phyweb.lbl.gov/theorygroup/papers/preprints.html/41981.ps . Misprints and errors in equations present in the original version have been correcte

Suplementação de vitamina C associada à densidade de criação no desempenho de frangos de corte

Avaliou-se o efeito da suplementação da vitamina C (75 e 150 mg/kg) na alimentação de frangos de corte machos sob condições de estresse de calor e superlotação. As aves foram criadas sobre "cama" de cavaco de madeira nas lotações de 10 e 14 aves/m². O delineamento experimental foi o inteiramente casualizado em esquema fatorial (3 níveis de vitamina C na ração e 2 lotações), com 5 repetições. Os resultados indicaram que o aumento da lotação de criação prejudicou (PThe effect of vitamin C supplementation (75 and 150 mg/kg) was evaluated in male broiler feeding under heat stress, crowding and normal floor space conditions. The results showed that crowding conditions (10 vs. 14 birds/m²) affected negatively (

Independent Component Separation from incomplete spherical data using wavelets. Application to CMB data analysis

Spectral matching ICA (SMICA) is a source separation method based on covariance matching in Fourier space that was designed to address in a flexible way some of the general problems raised by Cosmic Microwave Background data analysis. However, a common issue in astronomical data analysis is that the observations are unevenly sampled or incomplete maps with missing patches or intentionally masked parts. In addition, many astrophysical emissions are not well modeled as stationary processes over the sky. These effects impair data processing techniques in the spherical harmonics representation. This paper describes a new wavelet transform for spherical maps and proposes an extension of SMICA in this space-scale representation

One-loop Correction and the Dilaton Runaway Problem

We examine the one-loop vacuum structure of an effective theory of gaugino condensation coupled to the dilaton for string models in which the gauge coupling constant does not receive string threshold corrections. The new ingredients in our treatment are that we take into account the one-loop correction to the dilaton K\"ahler potential and we use a formulation which includes a chiral field $H$ corresponding to the gaugino bilinear. We find through explicit calculation that supersymmetry in the Yang-Mills sector is broken by gaugino condensation. The dilaton and $H$ field have masses on the order of the gaugino condensation scale independently of the dilaton VEV. Although the calculation performed here is at best a model of the full gaugino condensation dynamics, the result shows that the one-loop correction to the dilaton K\"ahler potential as well as the detailed dynamics at the gaugino condensation scale may play an important role in solving the dilaton runaway problem.Comment: 19 page

Theory-Motivated Benchmark Models and Superpartners at the Tevatron

Recently published benchmark models have contained rather heavy superpartners. To test the robustness of this result, several benchmark models have been constructed based on theoretically well-motivated approaches, particularly string-based ones. These include variations on anomaly and gauge-mediated models, as well as gravity mediation. The resulting spectra often have light gauginos that are produced in significant quantities at the Tevatron collider, or will be at a 500 GeV linear collider. The signatures also provide interesting challenges for the LHC. In addition, these models usually account for electroweak symmetry breaking with relatively less fine-tuning than previous benchmark models.Comment: 44 pages, 4 figures; some typos corrected. Revisions reflect published versio

Supersymmetry and Superstring Phenomenology

We briefly cover the early history of supersymmetry, describe the relation of SUSY quantum field theories to superstring theories and explain why they are considered a likely tool to describe the phenomenology of high energy particle theory beyond the Standard Model.Comment: 18 pages. To be published in ``Supersymmetry on the Eve of the LHC'', a special volume of the European Physical Journal C (EPJC) dedicated to the memory of Julius Wes

New D=4 gauged supergravities from N=4 orientifolds with fluxes

We consider classes of T_6 orientifolds, where the orientifold projection contains an inversion I_{9-p} on 9-p coordinates, transverse to a Dp-brane. In absence of fluxes, the massless sector of these models corresponds to diverse forms of N=4 supergravity, with six bulk vector multiplets coupled to N=4 Yang--Mills theory on the branes. They all differ in the choice of the duality symmetry corresponding to different embeddings of SU(1,1)\times SO(6,6+n) in Sp(24+2n,R), the latter being the full group of duality rotations. Hence, these Lagrangians are not related by local field redefinitions. When fluxes are turned on one can construct new gaugings of N=4 supergravity, where the twelve bulk vectors gauge some nilpotent algebra which, in turn, depends on the choice of fluxes.Comment: 51 pages, 1 figure. Latex. Reference added. Typos corrected. Discussion on gaugings expande

Parikh-Wilczek Tunneling from Noncommutative Higher Dimensional Black Holes

We study tunneling of massless and massive particles through the smeared quantum horizon of the extra-dimensional Schwarzschild black holes. The emission rate of the particles' tunneling is modified by noncommutativity effects in a bulk spacetime of dimension $d$. The issues of information loss and possible correlations between emitted particles are discussed. We show that even by considering both noncommutativity and braneworld effects, there is no correlation between different modes of evaporation at least at late-time and within approximations used in the calculations. However, incorporation of quantum gravity effects such as modification of the standard dispersion relation or generalization of the Heisenberg uncertainty principle, leads to the correlation between emitted particles. Although time-evolution of these correlations is not trivial, a part of information coming out of the black hole can be preserved in these correlations. On the other hand, as a well-known result of spacetime noncommutativity, a part of information may be preserved in a stable black hole remnant.Comment: 23 pages, 1 figure, Accepted for publication in JHE