ZZ gamma and Z gamma gamma couplings at linear e(+)e(-) collider energies with the effects of Z polarization and initial state radiation

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Atag S., Sahin İ.

PHYSICAL REVIEW D, vol.70, no.5, 2004 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 70 Issue: 5
  • Publication Date: 2004
  • Doi Number: 10.1103/physrevd.70.053014
  • Journal Name: PHYSICAL REVIEW D
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED)
  • Ankara University Affiliated: No

Abstract

The constraints on the neutral gauge boson couplings, ZZgamma and Zgammagamma, are investigated at linear e(+)e(-) collider energies through the Zgamma production with longitudinal and transverse polarization states of the final Z boson. Because of high energy of linear electron-positron beams, initial state radiation (ISR) considerably changes the production cross section. We obtain an increase in the cross section by a factor of 2-3 due to ISR for transverse polarization and by a factor of 10-100 for longitudinal polarization states depending on the energy. We find the 95% C.L. limits on the CP conserving form factors h(3)(Z), h(4)(Z), h(3)(gamma), and h(4)(gamma) with integrated luminosity 500 fb(-1) and roots=0.5,1,1.5 TeV energies. It is shown that the longitudinal polarization of the Z boson, together with ISR, can improve sensitivities by factors 2-3.