Advances in High Energy Physics

Volume 2017, Article ID 6970587, 8 pages

https://doi.org/10.1155/2017/6970587

## Probe of the Anomalous Quartic Couplings with Beam Polarization at the CLIC

^{1}Department of Physics, Abant Izzet Baysal University, 14280 Bolu, Turkey^{2}Department of Optical Engineering, Cumhuriyet University, 58140 Sivas, Turkey^{3}Department of Physics, Cumhuriyet University, 58140 Sivas, Turkey

Correspondence should be addressed to S. C. İnan; rt.ude.teyiruhmuc@nanimecs

Received 9 September 2016; Revised 30 November 2016; Accepted 21 December 2016; Published 11 January 2017

Academic Editor: Edward Sarkisyan-Grinbaum

Copyright © 2017 A. Senol et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The publication of this article was funded by SCOAP^{3}.

#### Abstract

We have investigated the anomalous quartic couplings defined by the dimension-8 operators in semileptonic decay channel of the process for unpolarized and polarized electron (positron) beam at the Compact Linear Collider. We give the 95% confidence level bounds on the anomalous , , and couplings for various values of the integrated luminosities and center-of-mass energies. The best sensitivities obtained on anomalous , , and couplings through the process with beam polarization at TeV and an integrated luminosity of are , , and , which show improvement over the current bounds.

#### 1. Introduction

The Standard Model (SM) has been proven to be highly successful through many significant experimental tests, in particular the discovery of a new particle consistent with the SM Higgs boson with a mass between 125-126 GeV detected by the ATLAS and the CMS experiments at the LHC [1, 2]. On the other hand, since many important questions such as the origin of mass, the large hierarchy between electroweak and the Planck scale, the strong CP problem, and the matter/antimatter asymmetry remain unanswered in the SM, we need to study physics beyond the SM. One of the ways of probing new physics beyond the SM is to investigate the anomalous gauge boson interactions. Gauge boson self-interactions in the SM are exactly described by the gauge symmetry. The precision measurements of gauge boson self-interactions can further verify the SM. Furthermore, the existence of anomalous gauge boson couplings may be a sign of new physics beyond the SM. The effective Lagrangian approach is one of the common ways for searching new physics beyond the SM in a model independent way. In particular, the anomalous quartic gauge boson couplings can be examined with the aid of the effective Lagrangian approach. Such an approach is parameterized by high-dimensional operators which induce anomalous quartic gauge couplings that modify the interactions between the electroweak gauge bosons.

The LHC is expected to reply some of the fundamental open questions in particle physics. Nevertheless, the analysis of the LHC data is quite difficult due to remnants of the usual proton-proton deep inelastic processes, whereas collisions between electrons and positrons are much simpler to investigate than proton-proton collisions. A linear electron-positron collider with high luminosity and energy is the best option to complement and to expand the LHC physics program. The CLIC is one of the most popular linear colliders, purposed to follow out electron-positron collisions at energies from 0.35 TeV to 3 TeV [3]. To have its high luminosity and energy is quite important with regard to new physics research beyond the SM. Since the anomalous quartic couplings defined through effective Lagrangians have dimension-8, they have very strong energy dependence. Therefore, the anomalous cross section including these vertices has higher energy dependence than the SM cross section. Hence, CLIC will have a great potential to examine the anomalous quartic gauge boson couplings.

High-dimensional effective operators describing the anomalous quartic gauge boson couplings are expressed by either linear or nonlinear effective Lagrangians. Nonlinear effective Lagrangians are considered if there is no Higgs boson in the low energy spectrum. However, linear effective Lagrangians are obtained by using a linear representation of gauge symmetry that is broken by the conventional SM Higgs mechanism. It becomes important to study the anomalous quartic gauge boson couplings based on linear effective Lagrangians due to the discovery of a Higgs boson in the LHC. For these reasons, we only deal with dimension-8 operators in our work.

In this paper, we will analyze the anomalous quartic couplings via process with semileptonic decay including polarized electron (positron) beam effects at the CLIC for the center-of-mass energies of 1.4 and 3 TeV.

#### 2. Dimension-Eight Operators for Quartic Gauge Couplings

There are three classes of operators that describe the anomalous quartic couplings. The first class of operators can be parameterized in terms of only the covariant derivative of the field . This class includes two independent operators [4]: The second class of operators are related to and the field strength. These seven operators are given as follows [4]: The remaining operators contain, solely, the field strength tensors. These operators can be expressed as [4] The complete list of quartic vertices modified by these operators is given in Table 1.