Related papers: Decoupling Limits in Effective Field Theories via …
Working in the framework of the Standard Model Effective Field Theory, we study chirality-flipping couplings of the top quark to Higgs and gauge bosons. We discuss in detail the renormalization group evolution to lower energies and…
We study the modifications to decay amplitudes in heavy to heavy semileptonic decays with multiple hadrons in the final state due to intermediate heavy hadrons being off-shell or having a finite width. Combining Heavy Hadron Chiral…
We study several issues related to the use of effective field theories in QCD at large baryon density. We show that the power counting is complicated by the appearance of two scales inside loop integrals. Hard dense loops involve the large…
Building upon the Covariant Derivative Expansion, we develop a method to compute effective actions that is able to capture non-perturbative effects induced by strong background fields. We demonstrate the method in scalar QED, by deriving…
The renormalization of higher-dimensional operators in quantum field theory is essential for phenomenological analyses in particle physics, and plays a significant role in the study of critical phenomena. We present a framework for…
We consider a rather minimal extension of the Standard Model involving just one extra particle, namely a single $SU(2)_L$ singlet scalar $S^{++}$ and its antiparticle $S^{--}$. We propose a model independent effective operator, which yields…
We derive model-independent, universal upper bounds on the Operator Product Expansion (OPE) coefficients in unitary 4-dimensional Conformal Field Theories. The method uses the conformal block decomposition and the crossing symmetry…
In effective field theory, the positivity bounds of higher derivative operators are derived from analyticity, causality, and unitarity. We show that the positivity bounds on some operators of the effective field theory, e.g.,…
I discuss the matching relations for the running renormalizable parameters when the heavy particles (top quark, Higgs scalar, Z and W vector bosons) are simultaneously decoupled from the Standard Model. The complete two-loop order matching…
Effective Lagrangians with dimension-six operators are widely used to analyse Higgs and other electroweak data. We show how to build a basis of operators such that each operator corresponds to a coupling which is well measured or will be in…
Using the power of superspace formalism, we investigate the decoupling effects of heavy states in N=1 supersymmetric field theory. We find that "mixed" couplings in the superpotential between the heavy and light fields contribute to the…
In this work we revisit the construction of theories for a massive vector field with derivative self-interactions such that only the 3 desired polarizations corresponding to a Proca field propagate. We start from the decoupling limit by…
Building on an older method used to derive non-decoupling effects of a heavy Higgs boson in the Standard Model, we describe a general procedure to integrate out heavy fields in the path integral. The derivation of the corresponding…
We revise the treatment of fermionic dark matter interacting with photons via dimension-5 and -6 effective operators. We show how the application of the effective operators beyond their validity introduces unphysical, gauge violating…
The effective theory based on combined chiral and heavy quark symmetry, the heavy meson chiral perturbation theory, is applied to studying the role of resonances in various processes of heavy mesons within and beyond the Standard Model.…
The Higgs trilinear coupling $\lambda_{hhh}$ is of great importance to understand the structure of the Higgs sector and allows searching for indirect signs of Beyond-the-Standard-Model (BSM) physics, even if new states are somehow hidden.…
We investigate the possibility of disentangling different new physics contributions to the rare meson decays $K\rightarrow\pi+\displaystyle{\not}E$ and $B\rightarrow K(K^*)+\displaystyle{\not}E$ through kinematic distributions in the…
It is not only conceivable but likely that the spectrum of physics beyond the Standard Model (SM) is non-degenerate. The lightest non-SM particle may reside close enough to the electroweak scale that it can be kinematically probed at…
A scalar potential coupled to other fields of large disparate masses will exhibit power suppression of the quantum loop corrections from these massive fields. Quintessence fields in the dark energy regime and inflaton fields during…
We discuss the limitations of the covariant derivative expansion prescription advocated to compute the one-loop Standard Model (SM) effective lagrangian when the heavy fields couple linearly to the SM. In particular, one-loop contributions…