ETH Zurich

About: ETH Zurich is a education organization based out in Zurich, Switzerland. It is known for research contribution in the topics: Population & Computer science. The organization has 48393 authors who have published 122408 publications receiving 5111383 citations. The organization is also known as: Swiss Federal Institute of Technology in Zurich & Eidgenössische Technische Hochschule Zürich.

Three-jet cross sections to next-to-leading order

Abstract: One- and two-jet inclusive quantities in hadron collisions have already been calculated to next-to-leading order accuracy, using both the subtraction and the cone method Since the one-loop corrections have recently been obtained for all five-parton amplitudes, three-jet inclusive quantities can also be predicted to next-to-leading order The subtraction method presented in the literature is based on a systematic use of boost-invariant kinematical variables, and therefore its application to three-jet production is quite cumbersome In this paper we re-analyze the subtraction method and point out the advantage of using angle and energy variables This leads to simpler results and it has complete generality, extending its validity to $n$-jet production The formalism is also applicable to $n$-jet production in $e^+e^-$ annihilation and in photon-hadron collisions All the analytical results necessary to construct an efficient numerical program for next-to-leading order three-jet inclusive quantities in hadroproduction are given explicitly As new analytical result, we also report the collinear limits of all the two-to-four processes

Radio emission from solar flares

Abstract: Radio emission from solar flares offers a number of unique diagnostic tools to address long-standing questions about energy release, plasma heating, particle acceleration, and particle transport in magnetized plasmas. At millimeter and centimeter wavelengths, incoherent gyrosynchrotron emission from electrons with energies of tens of kilo electron volts to several mega electron volts plays a dominant role. These electrons carry a significant fraction of the energy released during the impulsive phase of flares. At decimeter and meter wavelengths, coherent plasma radiation can play a dominant role. Particularly important are type III and type III‐like radio bursts, which are due to upward- and downwarddirected beams of nonthermal electrons, presumed to originate in the energy release site. With the launch of Yohkohand the Compton Gamma-Ray Observatory , the relationship between radio emission and energetic photon emissions has been clarified. In this review, recent progress on our understanding of radio emission from impulsive flares and its relation to X-ray emission is discussed, as well as energy release in flare-like phenomena (microflares, nanoflares) and their bearing on coronal heating.