Testing the Goldstone boson equivalence theorem in hadron colliders.

Abstract

We test the validity of the Goldstone boson equivalence theorem by calculating the cross sections for the real hadronic processes $\mathrm{pp}\ensuremath{\rightarrow}{X}_{L}{X}_{L}+\mathrm{anything} ({X}_{L}={W}_{L}^{\ifmmode\pm\else\textpm\fi{}} or {Z}_{L})$ in hadron colliders. For the subprocesses, we use the exact amplitudes, and also the amplitudes given by the equivalence theorem. For the low ${M}_{{X}_{L}{X}_{L}}$ region (200-400 GeV), there are substantial discrepancies between the two cross sections. In addition to $\frac{{M}_{W}^{2}}{\stackrel{^}{s}}$ terms, there are significant contributions from the $\frac{{M}_{H}^{2}}{\stackrel{^}{s}}$ terms present in the difference between the exact and equivalence amplitude for the subprocesses. In particular, $\frac{{M}_{H}^{2}}{\stackrel{^}{s}}$ terms are very important for ${M}_{H}\ensuremath{\sim}\sqrt{\stackrel{^}{s}}$.