Signatures for flow effects in s**(1/2) = 200 GeV proton-proton collisions

A simple model based on relativistic geometry and final-state hadronic rescattering is used to predict pion source parameters extracted in two-pion femtoscopy studies of proton-proton collisions at s**(1/2) = 200 GeV. From studying the momentum and particle multiplicity dependences of these parameters in the context of this model and assuming a very short hadronization time, flow-like behavior is seen which resembles the flow behavior commonly observed in relativistic heavy-ion collisions.Comment: 10 pages, 3 figures, submitted to Physical Revie

Hadron Chemistry at High-PT with Identified Particles

We discuss mechanisms that change the hadron chemistry for high momentum particles emitted in high energy nuclear collisions. We argue that particle ratios naturally tend to be different from jets in the vacuum. We show results of computations in a model that propagates leading particles through a quark gluon plasma and permits elastic flavor changing processes. We predict less suppression for kaons compared to pions in central collision. We also discuss elliptic flow resulting from flavor changing processes.Comment: Report for CIPANP 2009; 4 pages, 4 figures, AIP style files include

B+ and Ds+ Decay Constants from Belle and Babar

The Belle and Babar experiments have measured the branching fractions for B+ -> tau+ nu and Ds+ -> mu+ nu decays. From these measurements one can extract the B+ and Ds+ decay constants, which can be compared to lattice QCD calculations. For the Ds+ decay constant, there is currently a 2.1 sigma difference between the calculated value and the measured value.Comment: 10 pages, 8 figures, 1 table, contribution to the Tenth Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2009), San Diego, Californi

The measurement of alpha from the B-factories

Significant progress toward measuring the CKM angle alpha has been made by the B-factories over the past decade. This work has culminated in a constraint on alpha with a precision of less than 4 degrees.Comment: Proceedings of the Tenth Conference on the Intersections of Particle and Nuclear Physics, San Diego, California, May 2009 (4 pages

Fundamental Symmetries of the Early Universe and the Precision Frontier

The search for the next Standard Model of fundamental interactions is being carried out at two frontiers: the high energy frontier involving the Tevatron and Large Hadron Collider, and the high precision frontier where the focus is largely on low energy experiments. I discuss the unique and powerful window on new physics provided by the precision frontier and its complementarity to the information we hope to gain from present and future colliders.Comment: Proceedings of CIPANP 2009; 9 pages, 1 figur

The effect of surface heterogeneity on cloud absorption estimates

This study presents a systematic and quantitative analysis of the effect of inhomogeneous surface albedo on shortwave cloud absorption estimates. We used 3D radiative transfer modeling over a checkerboard surface albedo to calculate cloud absorption. We have found that accounting for surface heterogeneity enhances cloud absorption. However, the enhancement is not sufficient to explain the reported difference between measured and modeled cloud absorption

Spectrally-invariant behavior of zenith radiance around cloud edges simulated by radiative transfer

In a previous paper, we discovered a surprising spectrally-invariant relationship in shortwave spectrometer observations taken by the Atmospheric Radiation Measurement (ARM) program. The relationship suggests that the shortwave spectrum near cloud edges can be determined by a linear combination of zenith radiance spectra of the cloudy and clear regions. Here, using radiative transfer simulations, we study the sensitivity of this relationship to the properties of aerosols and clouds, to the underlying surface type, and to the finite field-of-view (FOV) of the spectrometer. Overall, the relationship is mostly sensitive to cloud properties and has little sensitivity to other factors. At visible wavelengths, the relationship primarily depends on cloud optical depth regardless of cloud phase function, thermodynamic phase and drop size. At water-absorbing wavelengths, the slope of the relationship depends primarily on cloud optical depth; the intercept, by contrast, depends primarily on cloud absorbing and scattering properties, suggesting a new retrieval method for cloud drop effective radius. These results suggest that the spectrally-invariant relationship can be used to infer cloud properties near cloud edges even with insufficient or no knowledge about spectral surface albedo and aerosol properties

The relevance of positivity in spin physics

Positivity reduces substantially the allowed domain for spin observables. We briefly recall some methods used to determine these domains and give some typical examples for exclusive and inclusive spin-dependent reactions.Comment: 7 pages, 3 figures, Talk presented at CIPANP 2009, San Diego California, USA, May 26-31, 2009 To be published in AIP Conference Proceeding

Regge-model predictions for K+Sigma photoproduction from the nucleon

We present Regge-model predictions for the p(gamma,K+)Sigma0 and n(gamma,K+)Sigma- differential cross sections and photon-beam asymmetries in the resonance region. The reaction amplitude encompasses the exchange of K+(494) and K*+(892) Regge-trajectories, introducing a mere three free parameters. These are fitted to the available p(gamma,K+)Sigma0 data beyond the resonance region. The n(gamma,K+)Sigma- amplitude is obtained from the p(gamma,K+)Sigma0 one through SU(2) isospin symmetry considerations.Comment: 4 pages, 2 figures; Proceedings Tenth Conference on the Intersections of Particle and Nuclear Physics, San Diego, 200

Transforming Leadership

The complex challenges of today’s organizations are calling for a new kind of heroic leader. The unquestioned assumption that vision is a pre-requisite for successful change, and that leaders need to be visionaries who can show us the way, presumes the future is predictable, organizations are controllable, and that plans can be implemented.  We argue these assumptions are responsible for the abysmal failure rate of organization change programs. In this paper we will describe how our  ongoing study of newer change practices (Bushe & Marshak, 2009, 2014, 2015) leads us to argue that successful leadership in situations of volatility, uncertainty, complexity and ambiguity (VUCA), which describe most transformational change scenarios, will require very different assumptions about organizing and leading from the prevailing “Performance Mindset” that emphasizes instrumental and measurable goal setting and achievement.  Rather than identifying what the change will be, leaders need to identify and lead processes for  ngaging the necessary stakeholders in emergent change processes.  To do that successfully requires a Generative Leader Mindset that acknowledges and works with the social construction of organizations.  We identify seven assumptions we think underlie successful leadership practice in a VUCA world. The continuing emphasis on being a solitary, strategic thinker who can envision viable futures and the path to those futures does little to prepare today’s leaders for the complex, ever-changing challenges they face. Instead, leaders need to be able to hold the space of complexity and uncertainty in ways that encourage and enable emergent and generative transformational change