L - R asymmetries and signals for new bosons ∗

Several left-right parity violating asymmetries in lepton-lepton scattering in fixed target and collider experiments are considered as signals for doubly charged vector bosons (bileptons). ∗Presented by M. C. Rodriguez at VIII Mexican School of Particles and Fields, Oaxaca de Juárez, Oax, México, November 20–29, 1998. †e-mail: [email protected] ‡e-mail: [email protected] §e-mails: [email protected] 1 The left-right asymmetry when only one of the lepton is polarized is defined as follows [1] ARL(ll → ll) = dσR − dσL dσR + dσL , (1) where dσR(L) is the differential cross section for one right (left)-handed lepton l scattering on an unpolarized lepton l. That is ARL(ll → ll) = (dσRR + dσRL)− (dσLL + dσLR) (dσRR + dσRL) + (dσLL + dσLR) , (2) where dσij denotes the cross section for incoming leptons with helicity i and j, respectively, and they are given by dσij ∝ ∑ kl |Mij;kl|, i, j; k, l = L, R. (3) Another interesting possibility is the case when both leptons are polarized. We can define an asymmetry AR;RL in which one beam is always in the same polarization state, say righthanded, and the other is either rightor left-handed polarized (similarly we can define AL;LR): AR;RL = dσRR − dσRL dσRR + dσRL , AL;RL = dσLR − dσLL dσLL + dσLR . (4) We can define also an asymmetry when one incident particle is righthanded and the other is left-handed and the final states are rightand left or leftand right-handed: ARL;RL,LR = dσRL;RL − dσRL;LR dσRL;RL + dσRL;LR (5) or similarly, ALR;RL,LR. These asymmetries, in Eqs.(4) and (5), are dominated by QED contributions. However, this will not be the case if a bilepton resonance does exist at typical energies of the NLC. To show this fact is the goal of this paper. These asymmetries can be calculated for both fixed target (FT) and collider (CO) experiments. We can integrate in the scattering angle and define the asymmetry ARL as ARL(ll → ll) = ( ∫ dσRR + ∫ dσRL)− (∫ dσLL + ∫ dσLR) ( ∫ dσRR + ∫ dσRL) + ( ∫ dσLL + ∫ dσLR) , (6)