Directional detection as a strategy to discover Galactic Dark Matter

Directional detection of Galactic Dark Matter is a promising search strategy for discriminating genuine WIMP events from background ones. Technical progress on gaseous detectors and read-outs has permitted the design and construction of competitive experiments. However, to take full advantage of this powerful detection method, one need to be able to extract information from an observed recoil map to identify a WIMP signal. We present a comprehensive formalism, using a map-based likelihood method allowing to recover the main incoming direction of the signal and its significance, thus proving its galactic origin. This is a blind analysis intended to be used on any directional data. Constraints are deduced in the ($\sigma_n, m_\chi$) plane and systematic studies are presented in order to show that, using this analysis tool, unambiguous dark matter detection can be achieved on a large range of exposures and background levels.Comment: 20 pages, 5 figures Final version to appear in Phys. Lett.

Kinetic models for optimal control of wealth inequalities

We introduce and discuss optimal control strategies for kinetic models for wealth distribution in a simple market economy, acting to minimize the variance of the wealth density among the population. Our analysis is based on a finite time horizon approximation, or model predictive control, of the corresponding control problem for the microscopic agents' dynamic and results in an alternative theoretical approach to the taxation and redistribution policy at a global level. It is shown that in general the control is able to modify the Pareto index of the stationary solution of the corresponding Boltzmann kinetic equation, and that this modification can be exactly quantified. Connections between previous Fokker-Planck based models and taxation-redistribution policies and the present approach are also discussed

Resolution of dark matter problem in f(T) gravity

In this paper, we attempt to resolve the dark matter problem in f(T) gravity. Specifically, from our model we successfully obtain the flat rotation curves of galaxies containing dark matter. Further, we obtain the density profile of dark matter in galaxies. Comparison of our analytical results shows that our torsion-based toy model for dark matter is in good agreement with empirical data-based models. It shows that we can address the dark matter as an effect of torsion of the space.Comment: 14 pages, 3 figure

Measurement of the scintillation time spectra and pulse-shape discrimination of low-energy beta and nuclear recoils in liquid argon with DEAP-1

The DEAP-1 low-background liquid argon detector was used to measure scintillation pulse shapes of electron and nuclear recoil events and to demonstrate the feasibility of pulse-shape discrimination (PSD) down to an electron-equivalent energy of 20 keV. In the surface dataset using a triple-coincidence tag we found the fraction of beta events that are misidentified as nuclear recoils to be $<1.4\times 10^{-7}$ (90% C.L.) for energies between 43-86 keVee and for a nuclear recoil acceptance of at least 90%, with 4% systematic uncertainty on the absolute energy scale. The discrimination measurement on surface was limited by nuclear recoils induced by cosmic-ray generated neutrons. This was improved by moving the detector to the SNOLAB underground laboratory, where the reduced background rate allowed the same measurement with only a double-coincidence tag. The combined data set contains $1.23\times10^8$ events. One of those, in the underground data set, is in the nuclear-recoil region of interest. Taking into account the expected background of 0.48 events coming from random pileup, the resulting upper limit on the electronic recoil contamination is $<2.7\times10^{-8}$ (90% C.L.) between 44-89 keVee and for a nuclear recoil acceptance of at least 90%, with 6% systematic uncertainty on the absolute energy scale. We developed a general mathematical framework to describe PSD parameter distributions and used it to build an analytical model of the distributions observed in DEAP-1. Using this model, we project a misidentification fraction of approx. $10^{-10}$ for an electron-equivalent energy threshold of 15 keV for a detector with 8 PE/keVee light yield. This reduction enables a search for spin-independent scattering of WIMPs from 1000 kg of liquid argon with a WIMP-nucleon cross-section sensitivity of $10^{-46}$ cm$^2$, assuming negligible contribution from nuclear recoil backgrounds.Comment: Accepted for publication in Astroparticle Physic

Colliders and Cosmology

Dark matter in variations of constrained minimal supersymmetric standard models will be discussed. Particular attention will be given to the comparison between accelerator and direct detection constraints.Comment: Submitted for the SUSY07 proceedings, 15 pages, LaTex, 26 eps figure

Predictors of false lumen thrombosis in type B aortic dissection treated with TEVAR

BACKGROUND: Thoracic endovascular aortic repair (TEVAR) offers a less invasive treatment option in type B aortic dissection (TBAD) patients and its value has been demonstrated in acute and chronic dissection patients. Total false lumen thrombosis (FLT) is associated with better long-term outcome in these patients, however, this is not obtained in all patients. The purpose of this study was to investigate predictors of FLT. METHODS: We retrospectively investigated patients who underwent TEVAR for a type B dissection in a large referral center between 2005 and 2012. All patients with a CT angiogram (CTA) obtained preoperatively, postoperatively and after one year of follow-up were selected for analysis. Volume measurements and several morphologic characteristics were analyzed for all scans using Aquarius iNtuition software (TeraRecon, San Mateo, Calif, USA). Multivariate logistic regression analyses were used to study the influence of these characteristics on FLT. RESULTS: Of 132 patients that received TEVAR for an aortic dissection, 43 patients (mean age, 60.3\ub114.2; 30 male) met our inclusion criteria, of whom 16 (37%) developed full FLT after 1 yr of follow-up. Multivariate logistic regression showed that side branch involvement [odds ratio (OR), 0.03; 95% confidence interval (CI), 0.00-0.92; P=0.045] and a total patent false lumen (FL) at presentation (OR, 0.01; 95% CI, 0.00-0.58; P=0.027) were associated with decreased complete FLT. Volumetric data showed significantly more reduction of the thoracic false lumen in FLT patients compared with non-FLT (-52.3% vs. -32.4%; P=0.043) and also a tendency of less volume increase in the abdominal segment (-5.0\ub137.5 vs. 21.8\ub144.3; P=0.052). CONCLUSIONS: Patients admitted with type B dissection and branch vessel involvement or a patent entry tear after TEVAR are less likely to develop FLT and aortic remodeling during follow-up. These findings suggest that these patients may require a more extensive procedure and more intensive follow-up to prevent long-term complications