Effects of heavy Majorana neutrinos at lepton-proton colliders

Abstract

We discuss the prospects of detecting the processes $e^{+}p\to {\bar{\nu }}_e{\ell }^{+}{\ell }^{\prime +}X$ and ${\nu }_{e}p\to e{\ell }^{+}{\ell }^{\prime +}X$ ($\ell ,{\ell }^{\prime }=e,\mu ,\tau$) under the conditions of the present $ep$ collider HERA and of future colliders. These high-energy processes are assumed to be mediated by the exchange of heavy Majorana neutrinos (HMN). We consider two simple scenarios for the HMN mass spectrum: the effective singlet ($m_1\ll m_2<m_3...$) and the effective doublet ($m_1<m_2\ll m_3...$). For the latter case, the cross section includes information about CP-violating phases.

Comments: 5pages, 2 figures; published in conference proceedings: Particle Physics in Laboratory, Space and Universe, 11th. Lomonosov Conf. on Elementary Particle Physics (Moscow, 21-27 August 2003) (Singapore, World Scientific, 2005)