Covariant Description of Flavor Conversion in the LHC Era

A simple covariant formalism to describe flavor and CP violation in the left-handed quark sector in a model independent way is provided. The introduction of a covariant basis, which makes the standard model approximate symmetry structure manifest, leads to a physical and transparent picture of flavor conversion processes. Our method is particularly useful to derive robust bounds on models with arbitrary mechanisms of alignment. Known constraints on flavor violation in the K and D systems are reproduced in a straightforward manner. Assumptions-free limits, based on top flavor violation at the LHC, are then obtained. In the absence of signal, with 100 fb^{-1} of data, the LHC will exclude weakly coupled (strongly coupled) new physics up to a scale of 0.6 TeV (7.6 TeV), while at present no general constraint can be set related to Delta t=1 processes. LHC data will constrain Delta F=2 contributions via same-sign tops signal, with a model independent exclusion region of 0.08 TeV (1.0 TeV). However, in this case, stronger bounds are found from the study of CP violation in D-bar D mixing with a scale of 0.57 TeV (7.2 TeV). In addition, we apply our analysis to models of supersymmetry and warped extra dimension. The minimal flavor violation framework is also discussed, where the formalism allows to distinguish between the linear and generic non-linear limits within this class of models.Comment: 24 pages, 6 figures. Some corrections and clarifications; references added. Matches published versio

Model Independent Predictions for Rare Top Decays with Weak Coupling

Measurements at B factories have provided important constraints on new physics in several rare processes involving the B meson. New Physics, if present in the b quark sector may also affect the top sector. In an effective Lagrangian approach, we write down operators where effects in the bottom and the top sector are related. Assuming the couplings of the operators to be of the same size as the weak coupling g of the Standard Model and taking into account constraints on new physics from the bottom sector as well as top branching ratios, we make predictions for the rare top decays t -> cV where V = \gamma, Z. We find branching fractions for these decays within possible reach of the LHC. Predictions are also made for t -> sW.Comment: 14 pages, 4 figures. Accepted in PR

Monitoring Processes in Visual Search Enhanced by Professional Experience: The Case of Orange Quality-Control Workers

Visual search tasks have often been used to investigate how cognitive processes change with expertise. Several studies have shown visual experts' advantages in detecting objects related to their expertise. Here, we tried to extend these findings by investigating whether professional search experience could boost top-down monitoring processes involved in visual search, independently of advantages specific to objects of expertise. To this aim, we recruited a group of quality-control workers employed in citrus farms. Given the specific features of this type of job, we expected that the extensive employment of monitoring mechanisms during orange selection could enhance these mechanisms even in search situations in which orange-related expertise is not suitable. To test this hypothesis, we compared performance of our experimental group and of a well-matched control group on a computerized visual search task. In one block the target was an orange (expertise target) while in the other block the target was a Smurfette doll (neutral target). The a priori hypothesis was to find an advantage for quality-controllers in those situations in which monitoring was especially involved, that is, when deciding the presence/absence of the target required a more extensive inspection of the search array. Results were consistent with our hypothesis. Quality-controllers were faster in those conditions that extensively required monitoring processes, specifically, the Smurfette-present and both target-absent conditions. No differences emerged in the orange-present condition, which resulted to mainly rely on bottom-up processes. These results suggest that top-down processes in visual search can be enhanced through immersive real-life experience beyond visual expertise advantages

Australian Sheep Industry CRC: Economic Evaluations of Scientific Research Programs

By the end of its seven-year term in 2007-08, the Australian Sheep Industry CRC (Sheep CRC) will have received total funds of about $90 million, that comprises Commonwealth and industry funding of$30 million, and in-kind contributions valued at $60 million. This level of public and private funding emphasises the need for the Sheep CRC to demonstrate that its research programs will generate sound economic returns to all stakeholders. This paper reports an evaluation of the potential economic value of the achievements of the Sheep CRC at the midpoint of its term of operations at which it has some completed research and a large volume of research in progress. The main question that has been addressed in this evaluation concerns the nature and likely magnitude of the potential benefits relative to the costs of their realisation. The economic methods and other procedures that were used to answer this question, the evaluation scenarios and the results obtained are described. Based on the defined with- and without-Sheep CRC evaluation scenarios, the ‘bottom-line’ result was that the Sheep CRC’s scientific research programs have the potential to deliver a total incremental benefit with a 20-year net present value (NPV) of$191.3 million, and a total benefit-cost ratio (BCR) of 8.1:1 (both at a 5% real rate of discount), indicating that the Sheep CRC’s total research investment over all programs has the potential to return about $8 for every$1 of research investment funds.sheep research, economic evaluations, economic-surplus- benefit-cost analysis., Agribusiness, Farm Management, Livestock Production/Industries, Production Economics, Research and Development/Tech Change/Emerging Technologies, Q160,

Soft peer review: social software and distributed scientific evaluation

The debate on the prospects of peer-review in the Internet age and the increasing criticism leveled against the dominant role of impact factor indicators are calling for new measurable criteria to assess scientific quality. Usage-based metrics offer a new avenue to scientific quality assessment but face the same risks as first generation search engines that used unreliable metrics (such as raw traffic data) to estimate content quality. In this article I analyze the contribution that social bookmarking systems can provide to the problem of usage-based metrics for scientific evaluation. I suggest that collaboratively aggregated metadata may help fill the gap between traditional citation-based criteria and raw usage factors. I submit that bottom-up, distributed evaluation models such as those afforded by social bookmarking will challenge more traditional quality assessment models in terms of coverage, efficiency and scalability. Services aggregating user-related quality indicators for online scientific content will come to occupy a key function in the scholarly communication system

Implementing collaborative improvement, top-down, bottom-up, or both?

The research presented in this paper was aimed at increasing the current understanding of the process of developing collaborative improvement in Extended Manufacturing Enterprises (EME). Based on action research and action learning of three EMEs involving a total of thirteen companies from five European countries, the present study identifies three different approaches to collaborative improvement (CoI), that is, inter-organisational continuous improvement. One approach to CoI focuses on learning at a practical level, developing this knowledge into strategic and theoretical knowledge. We call this the bottom-up learning-bydoing approach. Another approach focuses on goal alignment and assessment to provide a foundation for improvement before actually improving. We call this the top-down directive approach. Yet another approach focuses on shared goals/vision and meeting on equal terms, and joint work in a non-directive matter. This is the laissez-faire approach. The different approaches influence the collaborative improvement results achieved, and how and why they do so is the question addressed this article

Dissecting the Wjj Anomaly: Diagnostic Tests of a Leptophobic Z'

We examine the scenario where a leptophobic Z' boson accounts for the excess of events in the Wjj channel as observed by CDF. We assume generation independent couplings for the Z' and obtain allowed regions for the four hadronic couplings using the cross section range quoted by CDF as well as constraints from dijet production at UA2. These coupling regions translate into well-determined rates for the associated production of Z/\gamma+Z' at the Tevatron and LHC, as well as W+Z' at the LHC,that are directly correlated with the Wjj rate observed at the Tevatron. The Wjj rate at the LHC is large and this channel should be observed soon once the SM backgrounds are under control. The rates for Z/\gamma+Z' associated production are smaller, and these processes should not yet have been observed at the Tevatron given the expected SM backgrounds. In addition, we also show that valuable coupling information is obtainable from the distributions of other kinematic variables, e.g., M_{WZ'}, p_T^W, and \cos \theta_W^*. Once detected, these associated production processes and the corresponding kinematic distributions examined here will provide further valuable information on the Z' boson couplings.Comment: 20 pages, 10 figures. Analysis and discussion update