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We obtain the complete operator bases at mass dimensions 5, 6, 7, 8, 9 for the low energy effective field theory (LEFT), which parametrize various physics effects between the QCD scale and the electroweak scale. The independence of the…
In a way analogous to type IIB supergravity, we give a covariant action for the fermion field supplemented with a constraint which should be imposed on equations of motion, in Berkovits' open superstring field theory. From this action we…
We investigate the possibility of adding a fourth generation of quarks. We also extend the Standard Model gauge group by adding another SU(N) component. In order to cancel the contributions of the fourth generation of quarks to the gauge…
Through an effective field theory approach, we analyze the new physics corrections to muon and beta decays and their effects on the extractions of V_ud and V_us. Assuming nearly flavor blind NP interactions, we find that the only quantity…
We present results for the non-perturbative renormalisation of four-fermion operators with two flavours of dynamical quarks. We consider both fully relativistic left current-left current operators, and a full basis for $\Delta B=2$…
The implications for Higgs decays of potential new physics beyond the Standard Model (BSM) are considered in the context of effective field theory, assuming perturbative decoupling. Using existing data to restrict which dimension-six…
We discuss electroweak precision constraints on dimension-6 operators in the effective theory beyond the standard model. We identify the combinations of these operators that are constrained by the pole observables (the W and Z masses and…
The recent introduction of a deformed non-minimal version of the noncommutative Standard Model in the enveloping-algebra approach, having a one-loop renormalisable gauge sector involving a higher order gauge term, motivates us to consider…
Physics beyond the standard model (SM) can be parameterized with an effective Lagrangian that respects the symmetries of the standard model and contains many operators of dimension six. We consider the subset of these operators that is…
We explore the phenomenology of new R-parity violating operators that can occur in E6 models. The set of allowed operators is found to depend sensitively on the nature of the extension of the standard model gauge group. These new…
We investigate the possibility that four-fermion contact interactions give rise to the observed deviation from the Standard Model prediction for the weak charge of Cesium, through one-loop contributions. We show that the presence of loops…
In a particle theory model whose most readily discovered new particle is the $\sim 1$TeV bilepton resonance in same-sign leptons, currently being sought at CERN's LHC, there exist three quarks ${\cal D, S, T}$ which will be bound by QCD…
A search for new physics in top quark production with additional final-state leptons is performed using data collected by the CMS experiment in proton-proton collisions at $\sqrt{s}$ = 13 TeV at the LHC during 2016-2018. The data set…
Charged lepton flavor violation arises in the Standard Model Effective Field Theory at mass dimension six. The operators that induce neutrinoless muon and tauon decays are among the best constrained and are sensitive to new-physics scales…
The contributions of non-standard four-neutrino contact interactions to electroweak observables are considered at the one-loop level by using the effective quantum field theory. The analysis is done in terms of three unknown parameters: the…
We perform a model-independent analysis of top-philic New Physics scenarios, under the assumption that only effective operators involving top quarks are generated at tree level. Within the SMEFT framework, we derive indirect constraints on…
The possibility that the interactions of the third generation of quarks and leptons may violate universality by a small amount remains an open experimental question. The model of Li and Ma, which naturally accommodates such violations, is…
The early petite unification (PUT) of quarks and leptons at TeV scales with sin^2 theta_W(M^2_Z) used as a constraint, necessitates the introduction of extra quarks and leptons with unconventional electric charges (up to 4/3 for the quarks…
The effective Lagrangian approach allows us to constrain fermion magnetic and electric moments using LEP-I data. We improve some of the previous limits on these moments.
To unify the quantum electrodynamics (QED) under the first principle which brings the renormalization unartificially, we study Feynman diagrams in QED according to the set theory and the category theory. We add the restriction on the…