Regional food trade and policy in West Africa in relation to structural adjustment

Drell-Yan lepton pairs are produced in the process $p\bar{p} \rightarrow e^+e^- + X$ through an intermediate $\gamma^*/Z$ boson. The lepton angular distributions are used to provide information on the electroweak-mixing parameter $sin^2\theta_W$ via its observable effective-leptonic $sin^2\theta_W$, or $sin^2\theta^{lept}_{eff}$. A new method to infer $sin^2\theta_W$, or equivalently, the W-boson mass M_W, is developed and tested using a previous CDF Run II measurement of angular distributions from electron pairs in a sample corresponding to 2.1 fb-1 of integrated luminosity from $p\bar{p}$ collisions at a center-of-momentum energy of 1.96 TeV. The value of $sin^2\theta^{lept}_{eff}$ is found to be 0.2328 +- 0.0011. Within a specified context of the standard model, this results in $sin^2\theta_W$ = 0.2246 +- 0.0011 which corresponds to a W-boson mass of 80.297 +- 0.055 GeV/c^2, in agreement with previous determinations in electron-position collisions and at the Tevatron collider

First measurement of the forward-backward asymmetry in bottom-quark pair production at high mass

This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; the Swiss National Science Foundation; the A. P. Sloan Foundation; the Bundesministerium für Bildung und Forschung, Germany; the Korean World Class University Program, the National Research Foundation of Korea; the Science and Technology Facilities Council and the Royal Society, United Kingdom; the Russian Foundation for Basic Research; the Ministerio de Ciencia e Innovación, and Programa Consolider-Ingenio 2010, Spain; the Slovak R&D Agency; the Academy of Finland; the Australian Research Council; and the EU community Marie Curie Fellowship Contract No. 302103

Third-Party Effects

Most theories about effects of social embeddedness on trust define mechanisms that assume someone’s decision to trust is based on the reputation of the person to be trusted or on other available information. However, there is little empirical evidence about how subjects use the information that is available to them. In this chapter, we derive hypotheses about the effects of reputation and other information on trust from a range of theories and we devise an experiment that allows for testing these hypotheses simultaneously. We focus on the following mechanisms: learning, imitation, social comparison, and control. The results show that actors learn particularly from their own past experiences. Considering third-party information, imitation seems to be especially important

Measurement of the forward-backward asymmetry of top-quark and antiquark pairs using the full CDF Run II data set

Citation: Aaltonen, T., Amerio, S., Amidei, D., Anastassov, A., Annovi, A., Antos, J., . . . Zucchelli, S. (2016). Measurement of the forward-backward asymmetry of top-quark and antiquark pairs using the full CDF Run II data set. Physical Review D - Particles, Fields, Gravitation and Cosmology, 93(11). doi:10.1103/PhysRevD.93.112005We measure the forward-backward asymmetry of the production of top-quark and antiquark pairs in proton-antiproton collisions at center-of-mass energy s=1.96 TeV using the full data set collected by the Collider Detector at Fermilab (CDF) in Tevatron Run II corresponding to an integrated luminosity of 9.1 fb-1. The asymmetry is characterized by the rapidity difference between top quarks and antiquarks (?y) and measured in the final state with two charged leptons (electrons and muons). The inclusive asymmetry, corrected to the entire phase space at parton level, is measured to be AFBtt=0.12±0.13, consistent with the expectations from the standard model (SM) and previous CDF results in the final state with a single charged lepton. The combination of the CDF measurements of the inclusive AFBtt in both final states yields AFBtt=0.160±0.045, which is consistent with the SM predictions. We also measure the differential asymmetry as a function of ?y. A linear fit to AFBtt(|?y|), assuming zero asymmetry at ?y=0, yields a slope of ?=0.14±0.15, consistent with the SM prediction and the previous CDF determination in the final state with a single charged lepton. The combined slope of AFBtt(|?y|) in the two final states is ?=0.227±0.057, which is 2.0? larger than the SM prediction. © 2016 American Physical Society

Structural change, land use and the state in China

Rapid economic growth involves significant changes in land use patterns. The paper uses the recent history of Chinese economic growth to highlight and interrogate the implication of such changes within the context of structural transformation. It argues that though land use change is an important underlying dimension of the massive structural transformation accompanying China’s explosive economic growth, the dominant theoreti

Measurement of sin2?lepteff using e+e? pairs from ??/Z bosons produced in p¯p collisions at a center-of-momentum energy of 1.96 TeV

Citation: Aaltonen, T., Amerio, S., Amidei, D., Anastassov, A., Annovi, A., Antos, J., . . . Zucchelli, S. (2016). Measurement of sin2 ?eff lept using e+e- pairs from ??/Z bosons produced in pp collisions at a center-of-momentum energy of 1.96 TeV. Physical Review D - Particles, Fields, Gravitation and Cosmology, 93(11). doi:10.1103/PhysRevD.93.112016At the Fermilab Tevatron proton-antiproton (pp) collider, Drell-Yan lepton pairs are produced in the process pp?e+e-+X through an intermediate ??/Z boson. The forward-backward asymmetry in the polar-angle distribution of the e- as a function of the e+e - pair mass is used to obtain sin2?efflept, the effective leptonic determination of the electroweak-mixing parameter sin2?W. The measurement sample, recorded by the Collider Detector at Fermilab (CDF), corresponds to 9.4 fb-1 of integrated luminosity from pp collisions at a center-of-momentum energy of 1.96 TeV, and is the full CDF Run II data set. The value of sin2?efflept is found to be 0.23248±0.00053. The combination with the previous CDF measurement based on ?+?- pairs yields sin2?efflept=0.23221±0.00046. This result, when interpreted within the specified context of the standard model assuming sin2?W=1-MW2/MZ2 and that the W- and Z-boson masses are on-shell, yields sin2?W=0.22400±0.00045, or equivalently a W-boson mass of 80.328±0.024 GeV/c2. © 2016 American Physical Society

Search for a low-mass neutral Higgs boson with suppressed couplings to fermions using events with multiphoton final states

Citation: Aaltonen, T., Amerio, S., Amidei, D., Anastassov, A., Annovi, A., Antos, J., . . . Zucchelli, S. (2016). Search for a low-mass neutral Higgs boson with suppressed couplings to fermions using events with multiphoton final states. Physical Review D - Particles, Fields, Gravitation and Cosmology, 93(11). doi:10.1103/PhysRevD.93.112010A search for a Higgs boson with suppressed couplings to fermions, hf, assumed to be the neutral, lower-mass partner of the Higgs boson discovered at the Large Hadron Collider, is reported. Such a Higgs boson could exist in extensions of the standard model with two Higgs doublets, and could be produced via pp?H±hf?W?hfhf?4?+X, where H± is a charged Higgs boson. This analysis uses all events with at least three photons in the final state from proton-antiproton collisions at a center-of-mass energy of 1.96 TeV collected by the Collider Detector at Fermilab, corresponding to an integrated luminosity of 9.2 fb-1. No evidence of a signal is observed in the data. Values of Higgs-boson masses between 10 and 100 GeV/c2 are excluded at 95% Bayesian credibility. © 2016 American Physical Society

Molecular dynamics simulation of aqueous solutions of 26-unit segments of p(NIPAAm) and of p(NIPAAm) "doped" with amino acid based comonomers

We have performed 75-ns molecular dynamics (MD) simulations of aqueous solutions of a 26-unit NIPAAm oligomer at two temperatures, 302 and 315 K, below and above the experimentally determined lower critical solution temperature (LCST) of p(NIPAAm). We have been able to show that at 315 K the oligomer assumes a compact form, while it keeps a more extended form at 302 K. A similar behavior has been demonstrated for a similar NIPAAm oligomer, where two units had been substituted by methacryloyl-l-valine (MAVA) comonomers, one of them being charged and one neutral. For another analogous oligomer, where the same units had been substituted by methacryloyl-l-leucine (MALEU) comonomers, no transition from the extended to the more compact conformation has been found within the same simulation time. Statistical analysis of the trajectories indicates that this transition is related to the dynamics of the oligomer backbone, and to the formation of intramolecular hydrogen bonds and water-bridges between distant units of the solute. In the MAVA case, we have also evidenced an important role of the neutral MAVA comonomer in stabilizing the compact coiled structure. In the MALEU case, the corresponding comonomer is not equally efficacious and, possibly, is even hindering the readjustment of the oligomer backbone. Finally the self-diffusion coefficient of water molecules surrounding the oligomers at the two temperatures for selected relevant times is observed to characteristically depend on the distance from the solute molecules