15,849 research outputs found
Determination of the strong coupling alpha_s from the QCD static energy
We obtain a determination of the strong coupling alpha_s in quantum
chromodynamics, by comparing perturbative calculations for the short-distance
part of the static energy with lattice computations. Our result reads
alpha_s(1.5GeV)=0.326\pm0.019, and when evolved to the scale M_Z (the Z-boson
mass) it corresponds to alpha_s(M_Z)=0.1156^{+0.0021}_{-0.0022}.Comment: 8 pages, 2 figures. Contribution to the proceedings of Quark
Confinement and the Hadron Spectrum
Factorization and resummation for transverse thrust
We analyze transverse thrust in the framework of Soft Collinear Effective
Theory and obtain a factorized expression for the cross section that permits
resummation of terms enhanced in the dijet limit to arbitrary accuracy. The
factorization theorem for this hadron-collider event-shape variable involves
collinear emissions at different virtualities and suffers from a collinear
anomaly. We compute all its ingredients at the one-loop order, and show that
the two-loop input for next-to-next-to-leading logarithmic accuracy can be
extracted numerically, from existing fixed-order codes.Comment: 47 pages, 12 figures. v2: journal versio
15 Years of New Growth Economics: What Have We Learnt?
Paul Romer’s paper Increasing Returns and Long Run Growth, now 15 years old, led to resurgence in the research on economic growth. Since then, growth literature has expanded dramatically and has shifted the research focus of many generations of macroeconomists. The new line of work has emphasized the role of human capital, social and political variables, as well as the importance of institutions as driving forces of long-run economic growth. This paper presents an insight into the theoretical and empirical literature of the past fifteen years, highlighting the most significant contributions for our understanding of economics.
15 years of new growth economics: What have we learnt?
This paper evaluates the empirical and theoretical contributions of the Economic Growth Literature since the publication of Paul Romer’s seminal paper in 1986.Economic gowth, technological progress, empirics of growth
I just ran four million regressions
In this paper I try to move away from the Extreme Bounds method of identifying ``robust'' empirical relations in the economic growth literature. Instead of analyzing the extreme bounds of the estimates of the coefficient of a particular variable, I analyze the entire distribution. My claim in this paper is that, if we do this, the picture emerging from the empirical growth literature is not the pessimistic ``Nothing is Robust'' that we get with the extreme bound analysis. Instead, we find that a substantial number of variables can be found to be strongly related to growth.Economic growth, growth regressions, empirical determinants of economic growth
Electroweak Sudakov effects in W, Z and gamma production at large transverse momentum
We study electroweak Sudakov effects in single W, Z and gamma production at
large transverse momentum using Soft Collinear Effective Theory. We present a
factorized form of the cross section near the partonic threshold with both QCD
and electroweak effects included and compute the electroweak corrections
arising at different scales. We analyze their size relative to the QCD
corrections as well as the impact of strong-electroweak mixing terms. Numerical
results for the vector-boson cross sections at the Large Hadron Collider are
presented.Comment: 14 pages, 5 figures. v2: Minor changes, references added. Journal
versio
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