Effects of the mixing of scalar and pseudoscalar Higgs bosons in the process $$e^ + e^ - \to e^ + e^ - b\bar b$$ at a future linear electron-positron collider

Abstract

The sensitivity of data on the process \(e^ + e^ - \to e^ + e^ - b\bar b\) at a future linear electron-positron collider to the deviation of the coupling of the Higgs boson to b quarks from the Standard Model predictions owing to the presence of a pseudoscalar Higgs boson state is analyzed for a collision energy of \(\sqrt s = 500 Gev\). The admixture of a new hypothetical pseudoscalar Higgs boson state in the \(Hb\bar b\) vertex is parametrized in the form mb/v(a + iγ5b). On the basis of an analysis of data on the process \(e^ + e^ - \to e^ + e^ - b\bar b\), it is shown that experiments at the future linear collider TESLA will make it possible to constrain the parameters Δa = a − 1 and b as −0.056 ≤ Δa ≤ 0.055 and −0.32 ≤ b ≤ 0.32, respectively.