Model-independent limits on four-fermion contact interactions at LC with polarization

Abstract

Fermion compositeness, and other types of new physics that can be described by the exchange of very massive particles, can manifest themselves as the result of an effective four-fermion contact interaction. In the case of the processes $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-},{\tau }^{+}{\tau }^{-},\bar{b}b$ and $\bar{c}c$ at future $e^{+}{e}^{-}$ colliders with $\sqrt{s}=0.5-1$ TeV, we examine the sensitivity to four-fermion contact interactions of two new integrated observables, ${\sigma }_{+}$ and ${\sigma }_{-}$, conveniently defined for such kind of analysis. We find that, if longitudinal polarization of the electron beam were available, these observables would offer the opportunity to separate the helicity cross sections and, in this way, to derive model-independent bounds on the relevant parameters.

13 pages, LaTex

References in corpus (5)

• Leptoquark/Squark Interpretation of HERA Events: Virtual Effects in e+e- Annihilation to Hadrons
• Global Study of Electron-Quark Contact Interactions
• Comments on the high-$Q^2$ HERA anomaly
• Four-Fermion Effective Interactions and Recent Data at HERA
• Z' and anomalous gauge coupling effects at LEP2 and their separation

Cited by in corpus (4)

• Renormalizability and the model independent observables for abelian Z' search
• New physics signatures at a Linear Collider: model-independent analysis from `conventional' polarized observables
• Optimal polarized observables for model-independent new-physics search at e+e- colliders
• Polarized observables to probe Z' at the e+e- linear collider