Investigation of anomalous four-boson couplings in photon-photon collisions at high energies
- PDF / 612,223 Bytes
- 4 Pages / 612 x 792 pts (letter) Page_size
- 1 Downloads / 171 Views
ENTARY PARTICLES AND FIELDS Theory
Investigation of Anomalous Four-Boson Couplings in Photon–Photon Collisions at High Energies I. B. Marfin* and T. V. Shishkina** Department of Theoretical Physics, Faculty of Physics, Belarussian State University, ul. M. Bogdanovicha 153, Minsk, 240040 Belarus National Research Center for Particle and High-Energy Physics, Belarussian State University, ul. M. Bogdanovicha 153, Minsk, 240040 Belarus Received August 16, 2005
Abstract—Anomalous four-boson couplings can be studied in the production of two or three bosons in γγ collisions at high energies. The dependence of the√cross section for W + W − production on three anomalous couplings is studied at the TESLA energies ( s ∼ 1 TeV). A comprehensive analysis of anomalous contributions to the cross section and angular distributions for the process under consideration is presented. PACS numbers : 12.20.–m DOI: 10.1134/S1063778806040120
1. INTRODUCTION High-energy e+ e− colliders that are currently under construction [1] will make it possible to study collisions of photons whose energy will be close to the energy of colliding electrons and positrons the expected luminosity being about 100 fb−1 per year [1]. In turn, this will permit observing about 106 events of W + W − production in γγ collisions. Investigation into the production of chargedboson pairs in γγ collisions would provide a crucial test of the Standard Model, because the coupling constants for three- and four-boson interactions are determined by SU (2) U (1) gauge invariance. The possible anomalous behavior of three- and fourboson vertices can also be studied in such processes. Any anomalous deviation of three- and four-boson couplings from the predictions of the Standard Model leads to a significant increase in the cross sections for the reactions γγ → W + W − (Z, γ) with increasing primary-photon energy. For this reason, it is important to estimate the coupling constants for boson interactions both in the Standard Model and in various nonminimal gauge models. Values of the three- and four-boson coupling constants affect various aspects of electroweakinteraction theory. For example, investigation of three-boson interactions may reveal deviations in non-Abelian structures of the Standard Model [2, 3], * **
whereas investigation of four-boson interactions is of importance in searches for electroweak-symmetry breaking in the sector of scalar and vector bosons and, hence, for new physics of electroweak gauge bosons. Since Higgs bosons have not yet been discovered, anomalous four-boson vertices may provide the main alternative in explaining a spontaneous breakdown of SU (2) U (1) symmetry in the Standard Model. For gauge theories of electroweak interactions, we consider here Lagrangians that do not generate threeboson vertices, involving only four-boson vertices [4]. 2. CONTRIBUTION OF ANOMALOUS FOUR-BOSON INTERACTIONS TO THE CROSS SECTION FOR THE PROCESS γγ → W + W − Here, we restrict our consideration to anomalous four-boson vertices involving at least one photon. For thi
Data Loading...
