In this study, we explore the non-standard νν¯γγ couplings parametrized by dimension-seven operators via e+e−→νν¯γ process at the FCC-ee/CEPC and μ+μ−→νν¯γ process at the Muon Colliders. For the ...detailed Monte Carlo simulation, all signal and relevant background events are produced within the framework of Madgraph where non-standard νν¯γγ couplings are implemented. After passing through Pythia for parton showering and hadronization, detector effects are included via tuned corresponding detector cards for each collider in Delphes. Projected sensitivities on νν¯γγ couplings are obtained at a 5σ confidence level without and with 5% systematic uncertainties for the FCC-ee/CEPC and the Muon Colliders, showcasing the complementarity between lepton colliders. Our best limit on the anomalous νν¯γγ couplings even with 5% systematic uncertainties for muon collider with s=10 TeV and Lint=10 ab−1 are found to be fourteen orders of magnitude stronger than the upper bound obtained from rare decay Z→γγνν¯ analysis using LEP data.
A direct investigation of the self-couplings of gauge bosons, completely described by the non-Abelian gauge symmetry of the Standard Model, is extremely valuable in understanding the gauge structure ...of the SM. Any deviation from the SM predictions on gauge boson self-coupling is to give a hint at the existence of a new physics beyond the SM, which is defined with a modification of the self-interactions using an effective field theory approach. In this paper, we present a detailed Monte Carlo study searching for anomalous quartic gauge dimension-8 couplings related to γγγγ and γγγZ vertices at the future hadron-hadron collider (FCC-hh) via tri-photon production at a 100 TeV center of mass energy with an integrated luminosity Lint =30 ab−1. Events that have been parton showered and include detector effects are analyzed with a Toolkit for Multivariate Data Analysis (TMVA) using a boosted decision tree to help distinguish between signal and background events to achieve the best sensitivities on anomalous quartic gauge couplings. Our obtained results reveal that the limits on anomalous quartic gauge couplings fT8/Λ4 and fT9/Λ4 at 95% C.L. without systematic errors are about three orders of magnitude stronger compared to the best current experimental limits reported by the ATLAS collaboration at the LHC. Considering a realistic systematic uncertainty such as 10% from possible experimental sources, our obtained limits of anomalous quartic couplings get worse by about one order of magnitude compared to those without systematic uncertainty but are still two orders of magnitude better than those recently reported by ATLAS.
The νν¯γγ couplings parametrized with the non-standard dimension-seven operators defined by the Effective Field Theory framework are investigated through the process pp→νν¯γ at the High ...Luminosity-LHC and the Future Circular proton-proton Collider. The effective Lagrangian of νν¯γγ couplings is implemented into FeynRules to generate a UFO module inserted into Madgraph to generate both background and signal events. These events are then passed through Pythia 8 for parton showering and Delphes to include realistic detector effects. The sensitivities on νν¯γγ couplings are obtained at 95% confidence level. We show that the analysis of the signal emerging from the process pp→νν¯γ allows to improve constraints on νν¯γγ couplings given by the LEP collaboration.
We study the CP-conserving and CP-violating dimension-six operators of Higgs-gauge boson couplings via pp→γγ+n-jet signal process in a strongly interacting light Higgs based effective field theory ...framework at the center of mass energy of 100 TeV. In order to perform a simulation which includes realistic detector effects, the signal events in the existence of c¯γ, c˜γ, c¯g and c˜g Wilson coefficients and the relevant SM background events are generated in MadGraph, then passed through Pythia 8 for parton showering and finally run Delphes with FCC-hh detector card. In our analysis, we focus on the kinematic variables of the two photons in the final states of signal and relevant background processes that can reconstruct Higgs boson. We obtain constraints on the four Wilson coefficients of dimension-six operators using the transverse momentum distribution of reconstructed di-photon system with optimized kinematic cuts. The obtained 95% confidence level limits on these four Wilson coefficients including detector effects at s=100TeV with an integrated luminosity of 30 ab−1 without systematic error are at least one order or better than current experimental limits reported by ATLAS experiment. Even with δsys=2% systematic error, we find comparable limits with current experimental results.
We study the sensitivity of anomalous neutral triple gauge couplings (
aNTGC
) via
p
p
→
Z
Z
production in the 4
ℓ
channel at 100 TeV center of mass energy of future circular hadron collider, FCC-hh. ...The analysis including the realistic detector effects is performed in the mode where both Z bosons decay into same-flavor, oppositely charged lepton pairs. The sensitivities to the charge–parity (CP)-conserving couplings
C
B
~
W
/
Λ
4
and CP-violating couplings
C
WW
/
Λ
4
,
C
BW
/
Λ
4
and
C
BB
/
Λ
4
obtained at 95% Confidence Level using the invariant mass distribution of the 4
ℓ
system reconstructing the leading and sub-leading Z boson candidates are
-
0.09
,
+
0.09
,
-
0.21
,
+
0.21
,
-
0.26
,
+
0.26
, and
-
0.10
,
+
0.10
in units of
TeV
-
4
, respectively.
Triple gauge boson production provides a promising opportunity to probe the anomalous quartic gauge couplings in understanding the details of electroweak symmetry breaking at future hadron-hadron ...collider facilities with increasing center of mass energy and luminosity. In this paper, we investigate the sensitivities of dimension-8 anomalous couplings related to the ZZγγ and Zγγγ quartic vertices, defined in the effective field theory framework, via pp→Zγγ signal process with Z-boson decaying to charged leptons at the high luminosity phase of LHC (HL-LHC) and future facilities, namely the High Energy LHC (HE-LHC) and Future Circular hadron-hadron collider (FCC-hh). We analyzed the signal and relevant backgrounds via a cut based method with Monte Carlo event sampling where the detector responses of three hadron collider facilities, the center-of-mass energies of 14, 27 and 100 TeV with integrated luminosities of 3, 15 and 30ab−1 are considered for the HL-LHC, HE-LHC and FCC-hh, respectively. The reconstructed 4-body invariant mass of l+l−γγ system is used to constrain the anomalous quartic gauge coupling parameters under the hypothesis of absence of anomalies in triple gauge couplings. Our results indicate that the sensitivity on anomalous quartic couplings fT8/Λ4 and fT9/Λ4 (fT0/Λ4, fT1/Λ4 and fT2/Λ4) at 95% C.L. for FCC-hh with Lint=30ab−1 without systematic errors is two (one) order better than the current experimental limits. Considering a realistic systematic uncertainty such as 10% from possible experimental sources, the sensitivity of all anomalous quartic couplings gets worsen by about 1.2%, 1.7% and 1.5% compared to those without systematic uncertainty for HL-LHC, HE-LHC and FCC-hh, respectively.
The effects of dimension-eight operators giving rise to anomalous neutral triple gauge boson interactions of Zγγ and ZγZ vertices in pp→l−l+γ and pp→νν¯γ are investigated at 100 TeV center of mass ...energy of future circular hadron collider (FCC-hh). The transverse momentum of photon, invariant mass of l−l+γ and angular distribution of charged lepton in the rest frame of l−l+ and Missing Energy Transverse (MET) are considered in the analysis. The realistic detector effects are also included with Delphes simulation. Sensitivity limits obtained at 95% C.L. for CB˜W/Λ4 and CBB/Λ4 couplings are −0.52;0.52(−0.40;0.40) TeV−4, −0.43;0.43(−0.33;0.33) TeV−4 in the dilepton+photon channel and −0.11;0.11(−0.084;0.084) TeV−4, −0.092;0.092(−0.072;0.072) TeV−4 in the MET+photon channel with Lint=1 (3) ab−1, respectively.
The potential of the e.sup.+e.sup.- right arrow nubar.nuH process in the first stage of CLIC considering center-of-mass energy of 380 GeV and assuming the baseline integrated luminosity of 500 ...fb.sup.-1 is examined to probe CP-conserving dimension-six operators in a model-independent Standard Model effective field theory framework. In the analysis, a detailed fast simulation on e.sup.+e.sup.- right arrow nubar.nuH signal processes and dominant backgrounds is performed including parton showering with PYTHIA and detector simulation based on ILD type detector with DELPHES in MadGraph. The obtained best limits on bar.c.sub.HB, bar.c.sub.W = -bar.c.sub.B, and bar.c.sub.HW are -4.82; 1.53 x 10.sup.-2, -5.11; 4.13 x 10.sup.-3, and -6.58; 5.55 x 10.sup.-3, respectively.
We investigate the sensitivity of the anomalous dimension-8 neutral triple gauge couplings via process pp→ννγ with fast detector simulation including pile-up effects for the post LHC experiments. The ...transverse momentum of the final state photon and missing energy transverse distributions are considered in the analysis. We obtain the sensitivity to the CB˜W/Λ4, CBB/Λ4, CWW/Λ4 and CBW/Λ4 couplings at HL-LHC and HE-LHC with an integrated luminosity of 3 ab−1 and 15 ab−1, respectively. Finally, our numerical results show that one can reach the constraints at 95% confidence level without systematic error on CB˜W/Λ4, CBB/Λ4, CWW/Λ4 and CBW/Λ4 couplings for HL-LHC (HE-LHC) as −0.38;0.38(−0.12;0.12), −0.21;0.21(−0.085;0.085), −1.08;1.08(−0.38;0.38) and −0.48;0.48(−0.25;0.25), respectively. They are better than the experimental limits obtained by LHC.
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