Electron mass renormalization and absorption of hard photons

A NUMERICAL RENORMALIZATION GROUP APPROACH FOR AN ELECTRON-PHONON INTERACTION

A finite chain calculation in terms of Hubbard X-operators is explored by setting up a vibronic Harniltonian. The model conveniently transformed into a form so that in the case of strong coupling a numerical renormalization group approach is applicable. To test the technique, a one particle Green function is calculated for the model Harniltonian

Exponentiation of soft photons in a process involving hard photons.

We present a simple method of removing the singularities associated with soft photon emission to all orders in perturbation theory through exponentiation, while keeping a consistent description of hard photon emission. We apply this method to the process e + e ? ! + ? + n where we include both Z 0 and exchange and retain the muon mass dependence. The photonic radiation is allowed to be radiated...

Photon Emitting, Absorption and Reconstruction of Photons

Hard - Soft Renormalization and the Exact Renormalization Group ∗

In gauge theories, after integrating over the hard modes, the Wilsonian functional depending on the soft fields satisfies effective Ward identities. We observe that, enlarging the Wilsonian functional in order to include hard fields, the effective Ward identities arise from a non-local symmetry between the hard and soft fields. Using the flow equation technique, we outline a proof in perturbati...

L in hard collisions of virtual photons

We explore the relevance of extending the concept of the structure to the longitudinally polarized virtual photon involved in hard collisions. We show that for moderate photon virtualities and in the kinematical region accessible in current experiments at HERA and LEP, the contributions of its longitudinal polarization to hard collisions are sizable and should be taken into account as part of t...