Eur. Phys. J. C (2011) 71: 1783
https://doi.org/10.1140/epjc/s10052-011-1783-2

Regular Article - Theoretical Physics

Associated production of light gravitinos in e ⁺ e ⁻ and e ⁻ γ collisions

¹ Theoretische Natuurkunde and IIHE/ELEM, International Solvay Institutes, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
² KEK Theory Center and Sokendai, Tsukuba, 305-0801, Japan

^* e-mail: kentarou.mawatari@vub.ac.be

Received: 19 July 2011
Revised: 7 October 2011
Published online: 3 November 2011

Abstract

Light gravitino productions in association with a neutralino (selectron) in e ⁺ e ⁻ (e ⁻ γ) collisions are restudied in a scenario that the lightest supersymmetric particle is a gravitino and the produced neutralino (selectron) promptly decays into a photon (electron) and a gravitino. We explicitly give the helicity amplitudes for the production processes by using the effective goldstino interaction Lagrangian, and present the cross sections with different collision energies and mass spectra. We also examine selection efficiencies by kinematical cuts and beam polarizations for the signal and background processes, and show that the energy and angular distributions of the photon (electron) can explore the mass of the t-channel exchange particle as well as the mass of the decaying particle at a future e ⁺ e ⁻ (e ⁻ γ) collider.