Study of anomalous gauge boson self-couplings and the role of spin-$1$ polarizations

Abstract

The prime goal of this thesis is to study anomalous gauge boson self couplings, triple gauge boson couplings in particular, with the help of spin polarization observables of the gauge bosons $Z$ and $W^{\pm }$ in the presence of beam polarizations where ever possible. The neutral triple gauge boson couplings, i.e., $ZZZ$, $ZZ\gamma$, $Z\gamma \gamma$, are studied in $ZZ/Z\gamma$ ($2lq\bar{q}/2l\gamma$) production at an $e^{+}{e}^{-}$ collider with and without beam polarization. Some of these anomalous couplings are also studied in $ZZ$ ($4l$) production at the LHC. In the charge sector the anomalous gauge boson couplings, i.e., $WWZ$, $WW\gamma$ have been studied at an $e^{+}{e}^{-}$ collider in $W^{+}{W}^{-}$ ($l^{-}\overline{{\nu }_l}{q}^{\prime }\bar{q}$) production. The $WWZ$ anomalous couplings are also studied in $Z{W}^{\pm }$ production at LHC in $3l$ + missing $E_T$ channel. All the analyses at an $e^{+}$-$e^{-}$ collider have been performed for center-of-mass (CM) energy of $500$ GeV and integrated luminosity of $100$ fb${}^{-1}$. The analyses at the LHC are performed at $13$ TeV CM energy of $pp$ collisions. The cross sections and polarization asymmetries, along with other asymmetries (forward-backward, azimuthal), are used to obtain simultaneous limits on the anomalous couplings using Markov-Chain--Monte-Carlo (MCMC) method in each process. The polarization asymmetries can distinguish between $CP$-even and $CP$-odd couplings and help to put tighter constraints on the couplings. The polarization of the initial $e^{-}$ and $e^{+}$ beam, in case of $e^{+}{e}^{-}$ collider, are used to increase the signal to background ratio, putting tighter constraints on the anomalous couplings. The polarization asymmetries are instrumental in the measurement of anomalous couplings should a deviation from the SM be observed.

PhD thesis, 233 pages, 71 figures, 29 tables

References in corpus (18)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• An NNLO subtraction formalism in hadron collisions and its application to Higgs boson production at the LHC
• MadAnalysis 5, a user-friendly framework for collider phenomenology
• Anomalous Triple Gauge Couplings in the Effective Field Theory Approach at the LHC
• Spin Correlation Effects in Top Quark Pair Production at the LHC
• Beyond Standard Model calculations with Sherpa
• An NLO QCD effective field theory analysis of $W_{}^{+}{W}_{}^{-}$ production at the LHC including fermionic operators
• Measurement of the ZZ production cross section and search for anomalous couplings in 2l2l' final states in pp collisions at sqrt(s) = 7 TeV
• Measurement of the Z gamma production cross section in pp collisions at 8 TeV and search for anomalous triple gauge boson couplings
• Study of Triple-Gauge-Boson Couplings ZZZ, ZZgam and Zgamgam at LEP
• Use of transverse beam polarization to probe anomalous VVH interactions at a Linear Collider
• Unravelling the anomalous gauge boson couplings in $Z{W}^{\pm }$ production at the LHC and the role of spin-$1$ polarizations
• CP asymmetries with Longitudinal and Transverse Beam Polarizations in Neutralino Production and Decay into the Z^0 Boson at the ILC
• Probing the anomalous triple gauge boson couplings in $e^{+}{e}^{-}\to W^{+}{W}^{-}$ using $W$ polarizations with polarized beams
• Study of Higgs-gauge boson anomalous couplings through $e^{-}{e}^{+}\to W^{-}{W}^{+}H$ at ILC
• Triple Gauge Couplings at Future Hadron and Lepton Colliders
• Normal tau polarisation as a sensitive probe of CP violation in chargino decay
• Measuring Higgs self couplings in the presence of VVH and VVHH at the ILC

Cited by in corpus (1)

• Vector currents of integer-spin Majorana particles