New method for calculating helicity amplitudes of jet--like QED processes for high--energy colliders I. Bremsstrahlung processes - IN2P3 - Institut national de physique nucléaire et de physique des particules Access content directly
Journal Articles European Physical Journal C: Particles and Fields Year : 2002

New method for calculating helicity amplitudes of jet--like QED processes for high--energy colliders I. Bremsstrahlung processes

Abstract

Inelastic QED processes, the cross sections of which do not drop with increasing energy, play an important role at high-energy colliders. Such reactions have the form of two-jet processes with the exchange of a virtual photon in the t-channel. We consider them in the region of small scattering angles $m/E \lesssim \theta \ll 1$, which yields the dominant contribution to their total cross sections. A new effective method is presented and applied to QED processes with emission of real photons to calculate the helicity amplitudes of these processes. Its basic idea is similar to the well-known equivalent-lepton method. Compact analytical expressions for those amplitudes up to $e^8$ are derived omitting only terms of the order of $m^2/E^2, \theta^2$, $\theta m/E$ and higher order. The helicity amplitudes are presented in a compact form in which large compensating terms are already cancelled. Some common properties for all jet-like processes are found and we discuss their origin.

Dates and versions

in2p3-00193433 , version 1 (03-12-2007)

Identifiers

Cite

C. Carimalo, A. Schiller, V. G. Serbo. New method for calculating helicity amplitudes of jet--like QED processes for high--energy colliders I. Bremsstrahlung processes. European Physical Journal C: Particles and Fields, 2002, 23, pp.633-649. ⟨10.1007/s100520200905⟩. ⟨in2p3-00193433⟩
8 View
0 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More