On the choice of beam polarization in and anomalous triple gauge-boson couplings

Rafiqul Rahaman; Ritesh K. Singh

doi:10.1140/epjc/s10052-017-5093-1

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2024 Impact factor 4.8

Particles and Fields

Open Access

Eur. Phys. J. C (2017) 77: 521
https://doi.org/10.1140/epjc/s10052-017-5093-1

Regular Article - Theoretical Physics

On the choice of beam polarization in $e^+e^-\rightarrow ZZ/Z\gamma$ and anomalous triple gauge-boson couplings

Rafiqul Rahaman and Ritesh K. Singh^*

Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India

^* e-mail: ritesh.singh@iiserkol.ac.in

Received: 3 April 2017
Accepted: 20 July 2017
Published online: 5 August 2017

Abstract

The anomalous trilinear gauge couplings of Z and $\gamma$ are studied in $e^+e^-\rightarrow ZZ/Z\gamma$ with longitudinal beam polarizations using a complete set of polarization asymmetries for the Z boson. We quantify the goodness of the beam polarization in terms of the likelihood and find the best choice of $$e^-$$ and $$e^+$$ polarizations to be ( $$+0.16$$ , $$-0.16$$ ), ( $$+0.09$$ , $$-0.10$$ ) and ( $$+0.12$$ , $$-0.12$$ ) for ZZ, $Z\gamma$ and combined processes, respectively. Simultaneous limits on anomalous couplings are obtained for these choices of beam polarizations using Markov-Chain–Monte-Carlo (MCMC) for an $$e^+e^-$$ collider running at $\sqrt{s}=500$ GeV and $\mathscr {L}=100$ fb $^{-1}$ . We find the simultaneous limits for these beam polarizations to be comparable with each other and also comparable with the unpolarized beam case.