The Center for Medicare and Medicaid Innovation: Activity on Many Fronts

Provides an overview of the Innovation Center's organization, differences from CMS's traditional demonstration authority, payment and delivery reform initiatives, and first-year efforts to solicit and promote new ideas and collaborate with other payers

Searching for Extra Dimensions in High Energy Cosmic Rays

We present a study of the decay of an intermediate mini black hole at the first impact of a cosmic ray particle with the atmosphere, in the context of D-brane world scenarios with TeV scale gravity and large extra dimensions. We model the decay of the black hole using the semiclassical approximation and include the corrections coming from energy loss into the bulk. Extensive simulations show that mini black hole events are characterized by essentially different multiplicities and wider lateral distributions of the air showers as a function of the energy of the incoming primary, as compared to standard events. Implications for their detection and some open issues on their possible discovery are also briefly addressed.Comment: 4 pages, 4 figures, Presented by C. Coriano' at the XIII Intl. Symp. on High Energy Cosmic Rays Interactions, Pylos, Greece, 6-12 Sept. 200

Parton Distributions, Logarithmic Expansions and Kinetic Evolution

Aspects of the QCD parton densities are briefly reviewed, drawing some parallels to the density matrix formulation of quantum mechanics, exemplified by Wigner functions. We elaborate on the solution of their evolution equations using logarithmic expansions and overview their kinetic interpretation. We illustrate how a Fokker-Planck equation can be derived using the master formulation of the same equations and its construction in the case of the transverse spin distributions. A simple connection of the leading order DGLAP equation to fractional diffusion using fractional calculus is also briefly outlined.Comment: Review article to appear in Lecture Notes of SIM (S. Dragomir ed.) 32 pages, 1 figur

Link-Prediction Enhanced Consensus Clustering for Complex Networks

Many real networks that are inferred or collected from data are incomplete due to missing edges. Missing edges can be inherent to the dataset (Facebook friend links will never be complete) or the result of sampling (one may only have access to a portion of the data). The consequence is that downstream analyses that consume the network will often yield less accurate results than if the edges were complete. Community detection algorithms, in particular, often suffer when critical intra-community edges are missing. We propose a novel consensus clustering algorithm to enhance community detection on incomplete networks. Our framework utilizes existing community detection algorithms that process networks imputed by our link prediction based algorithm. The framework then merges their multiple outputs into a final consensus output. On average our method boosts performance of existing algorithms by 7% on artificial data and 17% on ego networks collected from Facebook

Ultra High Energy Cosmic Rays and Air Shower Simulations: a top-bottom view

Stable Superstring Relics (SSR) provide some of the candidates for the possible origin of the Ultra High Energy Cosmic Rays (UHECR). After a brief overview of the motivations for introducing such relics, we address the question whether statistical fluctuations in the formation of the air showers generated by the primary spectrum of protons can be separated from a possible signal of new physics hidden in the first impact with the atmosphere. Our results are generated by using minimal modifications in the cross section of the primaries, and using available simulation codes used by the experimental collaborations. The results indicate that substantial increases in the cross section of the first impact, possibly due to new interactions, are unlikely to be detected in geometrical and/or variations of multiplicities in the cascade.Comment: 6 pages. 2 figures. Standard Latex. Typos corrected. To appear in the proceedings of the XV Incontri sulla Fisica delle Alte Energie (IFAE), Lecce, Italy, 23-26 April 200

Numerical analysis of the one-mode solutions in the Fermi-Pasta-Ulam system

The stability of the one-mode nonlinear solutions of the Fermi-Pasta-Ulam - $\beta$ system is numerically investigated. No external perturbation is considered for the one-mode exact analytical solutions, the only perturbation being that introduced by computational errors in numerical integration of motion equations. The threshold energy for the excitation of the other normal modes and the dynamics of this excitation are studied as a function of the parameter $\mu$ characterizing the nonlinearity, the energy density $\epsilon$ and the number N of particles of the system. The achieved results confirm in part previous results, obtained with a linear analysis of the problem of the stability, and clarify the dynamics by which the one-mode exchanges energy with the other modes with increasing energy density. In a range of energy density near the threshold value and for various values of the number of particles N, the nonlinear one-mode exchanges energy with the other linear modes for a very short time, immediately recovering all its initial energy. This sort of recurrence is very similar to Fermi recurrences, even if in the Fermi recurrences the energy of the initially excited mode changes continuously and only periodically recovers its initial value. A tentative explanation of this intermittent behaviour, in terms of Floquet's theorem, is proposed.Comment: 37 pages, 41 figure

Superstring Relics, Supersymmetric Fragmentation and UHECR

Superstring theory predicts the existence of relic metastable particles whose average lifetime is longer than the age of the universe and which could, in principle, be good dark matter candidates. At the same time, these states would be responsible for the Ultra High Energy Cosmic Rays (UHECR) events which will be searched for by various experimental collaborations in the near future. We describe a possible phenomenological path which could be followed in order to search for new physics in their detection.Comment: 7 pages 4 Figs. Plenary Talk presented by Claudio Coriano' at the 1st Intl. Conf. on String Phenomenology, Oxford, UK, July 6-11, 200

NNLO Logarithmic Expansions and Exact Solutions of the DGLAP Equations from x-Space: New Algorithms for Precision Studies at the LHC

A NNLO analysis of certain logarithmic expansions, developed for precision studies of the evolution of the QCD parton distributions (pdf) at the Large Hadron Collider, is presented. We elaborate on their relations to all the solutions of the DGLAP equations that have been hitherto obtained from Mellin space, to which are equivalent. Exact expansions, equivalent to exact solutions of the equations, are constructed in the non-singlet sector. The algorithmic features of our approach are also emphasized, since this method allows to obtain numerical solutions of the evolution equations with the same accuracy of other methods, based on Mellin space, and of brute force methods, which solve the equations by finite differences. The implementation of our analysis allows to compare with existing benchmarks for the evolution of the pdf's, useful for applications at the LHC, and to extend them significantly in a systematic fashion, especially when solutions that retain logarithmic corrections only of a certain accuracy are searched for.Comment: 56 pages, no figure

Training in the suburban newsroom

Suburban newspapers have traditionally relied on a junior workforce, which means they have a significant influence in training cadets and shaping the journalists of the future. These cadets may find themselves comprising 50 per cent of the editorial staff of the newspaper they are assigned to, producing up to 16 stories a week on anything from complex planning issues to golden wedding anniversaries. Lack of staff and resources mean that the loftier ideals of journalism often give way for the more practical issues of finding enough stories and dealing with pushy advertising representatives. This paper discusses the challenges facing suburban journalists and trainers in this environment