Measurement of the Positive Muon Lifetime and Determination of the Fermi Constant to Part-per-Million Precision

We report a measurement of the positive muon lifetime to a precision of 1.0 parts per million (ppm); it is the most precise particle lifetime ever measured. The experiment used a time-structured, low-energy muon beam and a segmented plastic scintillator array to record more than 2 x 10^{12} decays. Two different stopping target configurations were employed in independent data-taking periods. The combined results give tau_{mu^+}(MuLan) = 2196980.3(2.2) ps, more than 15 times as precise as any previous experiment. The muon lifetime gives the most precise value for the Fermi constant: G_F(MuLan) = 1.1663788 (7) x 10^-5 GeV^-2 (0.6 ppm). It is also used to extract the mu^-p singlet capture rate, which determines the proton's weak induced pseudoscalar coupling g_P.Comment: Accepted for publication in Phys. Rev. Let

Improved Measurement of the Positive Muon Lifetime and Determination of the Fermi Constant

The mean life of the positive muon has been measured to a precision of 11 ppm using a low-energy, pulsed muon beam stopped in a ferromagnetic target, which was surrounded by a scintillator detector array. The result, tau_mu = 2.197013(24) us, is in excellent agreement with the previous world average. The new world average tau_mu = 2.197019(21) us determines the Fermi constant G_F = 1.166371(6) x 10^-5 GeV^-2 (5 ppm). Additionally, the precision measurement of the positive muon lifetime is needed to determine the nucleon pseudoscalar coupling g_P.Comment: As published version (PRL, July 2007

Irrigation and the Origins of the Southern Moche State on the North Coast of Peru

In this paper, I examine the role that irrigation played in the formation of the Southern Moche state in the Moche Valley, Peru. Specifically, I attempt to test Wittfogel and Steward's hydraulic model, which postulates that in certain arid environments, the managerial requirements of construction and maintenance of irrigation systems played a crucial role in the formation of centralized polities. I formulate and evaluate four hypotheses concerning the role of irrigation systems in the Moche Valley. Those hypotheses are then evaluated using settlement pattern data drawn from two surveys that cover the entire coastal section of the valley and provide information on 910 archaeological sites. Based on those data, I present a sequence of political development for the valley from the formation of the first autonomous village in the Late Preceramic period (2500–1800 B. C.) to the zenith of the Southern Moche state. Evaluation of the four hypotheses indicates that the managerial requirements of irrigation were relatively unimportant; rather, warfare, highland-coastal interaction, and political control of irrigation systems created opportunities for leaders to form a highly centralized, territorially expansive state sometime between A. D. 200 and 700

Millimeter-wave emissivity as a metric for the non-contact diagnosis of human skin conditions.

A half-space electromagnetic model of human skin over the band 30-300 GHz was constructed and used to model radiometric emissivity. The model showed that the radiometric emissivity rose from 0.4 to 0.8 over this band, with emission being localized to a layer approximately one millimeter deep in the skin. Simulations of skin with differing water contents associated with psoriasis, eczema, malignancy, and thermal burn wounds indicated radiometry could be used as a non-contact technique to detect and monitor these conditions. The skin emissivity of a sample of 30 healthy volunteers, measured using a 95 GHz radiometer, was found to range from 0.2 to 0.7, and the experimental measurement uncertainty was ±0.002. Men on average were found to have an emissivity 0.046 higher than those of women, a measurement consistent with men having thicker skin than women. The regions of outer wrist and dorsal forearm, where skin is thicker, had emissivities 0.06-0.08 higher than the inner wrist and volar forearms where skin is generally thinner. Recommendations are made to develop a more sophisticated model of the skin and to collect larger data sets to obtain a deeper understanding of the signatures of human skin in the millimeter wave band. Bioelectromagnetics. 2017;9999:XX-XX. © 2017 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc

How trust and emotions influence policy acceptance: The case of the Irish water charges

The introduction of new policies can evoke strong emotional reactions by the public. Yet, social‐psychological research has paid little attention to affective determinants of individual‐level policy acceptance. Building on recent theoretical and empirical advances around emotions and decision‐making, we evaluate how people's trust and integral emotions function as important antecedents of cognitive evaluations, and subsequent acceptance of policies. We test our hypotheses within a sample of Irish citizens (n = 505), who were subject to the introduction of water charges in 2015. In line with our hypotheses, results show that general trust in government shapes emotions regarding water charges, which in turn, directly and via expected costs and benefits, influence policy acceptance. Additionally, we find that negative emotions have a larger direct effect on policy acceptance than positive emotions. Specifically, ‘anger’ was the main negative emotion that influenced the acceptance of the water charge. We conclude by discussing directions for future research around emotions and policy acceptance