Constraints on anomalous quartic gauge couplings via $Zγjj$ production at the LHC

Abstract

In this paper, we investigate the contributions of anomalous quartic gauge couplings (aQGCs) to Zγjj production at the Large Hadron Collider (LHC) in the context of Standard Model effective theory (SMEFT). When energy scale is large, the validity of SMEFT becomes an important issue.To ensure the validity, the unitarity bound is applied in a model independent approach, which is found to have significant suppressive effects on the signals of O M i operators. The kinematic and polarization features of the aQGC signals are also studied. The polarization effect is useful to highlight the signals of O T i operators. The sensitivity estimates on dimension-8 operators with unitarity bounds at √ s = 14 TeV are obtained.

Measuring the anomalous quartic gauge couplings in the W+W− → W+W− process at muon collider using artificial neural networks

“…The suppression of cross-section when unitarity bounds are considered has been noticed in refs. [41,78,80], and demonstrates the necessity of the unitarity bounds. The effect of unitarity bounds can be estimated in terms of EVA (see appendix.…”

“…In this paper, the unitarity bounds are applied using a matching procedure [108, 109] which has been used in previous studies of aQGCs at the LHC [41,78,80]. We compare the cross-sections with and without aQGCs under a certain energy scale.…”

“…Many NP models can generate effective dimension-8 operators contributing to aQGCs [64][65][66][67][68][69][70][71][72][73]. Although the dimension-6 operators have received most studies, the importance of dimension-8 operators was recently emphasized by many groups [1,[74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91]. As VBS processes receive great attention at the LHC, the above operators in the SMEFT have been investigated intensively.…”

Tri-photon at muon collider: a new process to probe the anomalous quartic gauge couplings

“…[50,51] provided the maximally allowed energy scales when the coefficients are equal to the constraints in table 1. With unitarity taken into account, according to our previous studies [10,12,71], the LHC constraints should become weaker.…”

“…In the SM effective field theory (SMEFT) [1][2][3][4], the gauge interactions can be extended by high-dimensional operators contributing to anomalous triple gauge couplings (aTGCs) and anomalous quartic gauge couplings (aQGCs) [5,6]. Although the SMEFT has been mainly applied to study dimension-6 operators, many groups recently pay much attention to the dimension-8 operators [7][8][9][10][11][12]. The dimension-8 operators are important with respect to the convex geometry perspective to the operator space [13][14][15].…”