118951198
Neutrino constraints on spontaneous Lorentz violation
We study the effect of spontaneous Lorentz violation on neutrinos. We consider two kinds of effects: static effects, where the neutrino acquires a Lorentz-violating dispersion relation, and dynamic effects, which arise from the interactions of the neutrino with the Goldstone boson of spontaneous Lorentz violation. Static effects are well detailed in the literature. Here, special emphasis is given to the novel dynamic effect of Goldstone-Cerenkov radiation, where neutrinos moving with respect to a preferred rest frame can spontaneously emit Goldstone bosons. We calculate the observable consequences of this process and use them to derive experimental bounds from SN1987A and the CMBR. The bounds derived from dynamic effects are complementary to - and in many cases much stronger than - those obtained from static effects.
14189365
Supergravity computations without gravity complications
The conformal compensator formalism is a convenient and versatile representation of supergravity (SUGRA) obtained by gauge-fixing conformal SUGRA. Unfortunately, practical calculations often require cumbersome manipulations of component field terms involving the full gravity multiplet. In this paper, we derive an alternative gauge fixing for conformal SUGRA which decouples these gravity complications from SUGRA computations. This yields a simplified tree-level action for the matter fields in SUGRA which can be expressed compactly in terms of superfields and a modified conformal compensator. Phenomenologically relevant quantities such as the scalar potential and fermion mass matrix are then straightforwardly obtained by expanding the action in superspace.
119104051
Prospects for Mirage Mediation
Mirage mediation reduces the fine-tuning in the minimal supersymmetric standard model by dynamically arranging a cancellation between anomaly-mediated and modulus-mediated supersymmetry breaking. We explore the conditions under which a mirage ``messenger scale'' is generated near the weak scale and the little hierarchy problem is solved. We do this by explicitly including the dynamics of the SUSY-breaking sector needed to cancel the cosmological constant. The most plausible scenario for generating a low mirage scale does not readily admit an extra-dimensional interpretation. We also review the possibilities for solving the μ/Bμ problem in such theories, a potential hidden source of fine-tuning.
119243170
Hadron Mass Effects in Power Corrections to Event Shapes
We study the effect of hadron masses on the leading power correction of dijet event-shape distributions. We define the transverse velocity operator, that describes the effects of hadron masses. It depends on the "transverse velocity" r, which is different from one only for non-vanishing hadron masses. We find that hadron-mass effects in general break universality. However we provide a simple method to identify universality classes of event shapes with a common power correction. We also compute the anomalous dimension of the power correction and the structure of the corresponding Wilson coefficient, finding a nontrivial result.
966872
Auxiliary gauge mediation: a new route to mini-split supersymmetry
A bstractThe discovery of a standard-model-like Higgs at 126 GeV and the absence of squark signals thus far at the LHC both point towards a mini-split spectrum for supersymmetry. Within standard paradigms, it is non-trivial to realize a mini-split spectrum with heavier sfermions but lighter gauginos while simultaneously generating Higgs sector soft terms of the correct magnitude, suggesting the need for new models of supersymmetry breaking and mediation. In this paper, we present a new approach to mini-split model building based on gauge mediation by “auxiliary groups”, which are the anomaly-free continuous symmetries of the standard model in the limit of vanishing Yukawa couplings. In addition to the well-known flavor SU(3)F and baryon-minus-lepton U(1)B−L groups, we find that an additional U(1)H acting on the Higgs doublets alone can be used to generate Higgs soft masses and B-terms necessary for a complete model of mini-split. Auxiliary gauge mediation is a special case of Higgsed gauge mediation, and we review the resulting two-loop scalar soft terms as well as three-loop gaugino masses. Along the way, we present a complete two-loop calculation of A-terms and B-terms in gauge mediation, which — contrary to a common misconception — includes a non-zero contribution at the messenger threshold which can be sizable in models with light gauginos. We present several phenomenologically acceptable mini-split spectra arising from auxiliary gauge mediation and highlight a complete minimal model which realizes the required spectrum and Higgs sector soft terms with a single U(1)X auxiliary gauge symmetry. We discuss possible experimental consequences.
118395989
Anomaly mediation from unbroken supergravity
A bstractWhen supergravity (SUGRA) is spontaneously broken, it is well known that anomaly mediation generates sparticle soft masses proportional to the gravitino mass. Recently, we showed that one-loop anomaly-mediated gaugino masses should be associated with unbroken supersymmetry (SUSY). This counterintuitive result arises because the underlying symmetry structure of (broken) SUGRA in flat space is in fact (unbroken) SUSY in anti-de Sitter (AdS) space. When quantum corrections are regulated in a way that preserves SUGRA, the underlying AdS curvature (proportional to the gravitino mass) necessarily appears in the regulated action, yielding soft masses without corresponding goldstino couplings. In this paper, we extend our analysis of anomaly mediation to sfermion soft masses. Already at tree-level we encounter a number of surprises, including the fact that zero soft masses correspond to broken (AdS) SUSY. At one-loop, we explain how anomaly mediation appears when regulating SUGRA in a way that preserves super-Weyl invariance. We find that recent claims in the literature about the non-existence of anomaly mediation were based on a Wilsonian effective action with residual gauge dependence, and the gauge-invariant 1PI effective action contains the expected anomaly-mediated spectrum. Finally, we calculate the sfermion spectrum to all orders, and use supertrace relations to derive the familiar two-loop soft masses from minimal anomaly mediation, as well as unfamiliar tree-level and one-loop goldstino couplings consistent with renormalization group invariance.
124645739
Experimental Measurement of K0(L) --> mu+ mu-
18123417
BINGO : A Set of Object Oriented Tools for Hierarchical Pattern Recognition and Track Fitting
We describe an object oriented set of tools for carrying out integrated hierarchical pattern recognition in a tracking system composed of an arbitrary set of tracking devices. Two fundamental components are part of the method, a LayerSet object for pattern recognition operations and a TrackFilter object for manipulation of track candidates. The other major components in the package are: a management object that controls the package’s overall operation; a generic input data object capable of holding information from any type of tracking element; and a track candidate object that can receive output from a LayerSet or TrackFilter algorithm. We have implemented a dictionary-based pattern recognition algorithm in this framework.
33624256
LARGE SYNOPTIC SURVEY TELESCOPE: FROM SCIENCE DRIVERS TO REFERENCE DESIGN
In the history of astronomy, major advances in our understanding of the Universe have come from dramatic improvements in our ability to accurately measure astronomical quantities. Aided by rapid progress in information technology, current sky surveys are changing the way we view and study the Universe. Next-generation surveys will maintain this revolutionary progress. We focus here on the most ambitious survey currently planned in the visible band, the Large Synoptic Survey Telescope (LSST). LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: constraining dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. It will be a large, wide-field ground-based system designed to obtain multiple images covering the sky that is visible from Cerro Pachon in Northern Chile. The current baseline design, with an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg{sup 2} field of view, and a 3,200 Megapixel camera, will allow about 10,000 square degrees of sky to be covered using pairs of 15-second exposures in two photometric bands every three nights on average. The system is designed to yield high image quality, as well as superb astrometric and photometric accuracy. The survey area will include 30,000 deg{sup 2} with {delta} < +34.5{sup o}, and will be imaged multiple times in six bands, ugrizy, covering the wavelength range 320-1050 nm. About 90% of the observing time will be devoted to a deep-wide-fast survey mode which will observe a 20,000 deg{sup 2} region about 1000 times in the six bands during the anticipated 10 years of operation. These data will result in databases including 10 billion galaxies and a similar number of stars, and will serve the majority of science programs. The remaining 10% of the observing time will be allocated to special programs such as Very Deep and Very Fast time domain surveys. We describe how the LSST science drivers led to these choices of system parameters.
120057201
Testing the Dark Energy Camera on a telescope simulator
The Dark Energy Camera is a new prime-focus instrument to be delivered to the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory (CTIO) in 2011. Construction is in-progress at this time at Fermilab. In order to verify that the camera meets technical specifications for the Dark Energy Survey and to reduce the time required to commission the instrument while it is on the telescope, we are constructing a "Telescope Simulator" and performing full system testing prior to shipping to CTIO. This presentation will describe the Telescope Simulator and how we use it to verify some of the technical specifications.
195840216
Modeling and Simulation of the SDC Data Collection Chip