相关论文: Non-perturbative methods

The possible discovery of proton decay, neutron-antineutron oscillation, neutrinoless beta decay in low energy experiments, and exotic signals related to the violation of the baryon and lepton numbers at collider experiments will change our…

The main elements and methods of chiral perturbation theory, the effective field theory of the Standard Model below the scale of spontaneous chiral symmetry breaking, are summarized. Applications to the interactions of mesons and baryons at…

We interpret anomalies, deviations, from the standard model as being in fact due to effects not given by perturbation, because the top Yukawa coupling is after all so large that not by perturbation effects become important. Most of the…

In systems with a spontaneously broken continuous symmetry, the perturbative loop expansion is plagued with infrared divergences due to the coupling between transverse and longitudinal fluctuations. As a result the longitudinal…

In this report we discuss the main theories to understand the origin of baryon and lepton number violation in physics beyond the Standard Model. We present the theoretical predictions for rare processes such as neutrinoless double beta…

Theoretical as well as experimental progress has been made in the last decade in describing the properties of baryons. In this review I will mostly report on the theoretical issues. Two non-perturbative methods are privileged frameworks for…

This article reviews the current theoretical and experimental status of the field of muon decay and its potential to search for new physics beyond the Standard Model. The importance of rare muon processes with lepton flavor violation is…

We develop a theory of non-relativistic bosons in two spatial dimensions with a weak short range attractive interaction. In the limit as the range of the interaction becomes small, there is an ultra-violet divergence in the problem. We…

It is shown that perturbation theory in $2D$ nonlinear $\sigma$-models as well gauge theories in dimension $D\geq 2$ produces answers that depend on boundary conditions even after the infinite volume limit has been taken. This unphysical…

A class of scalar models with non-polynomial interaction, which naturally admits an analytical resummation of the series of tadpole diagrams is studied in perturbation theory. In particular, we focus on a model containing only one…

Processes with multiparticle final states in weakly coupled theories, both with and without instantons, cannot be studied perturbatively at most interesting energies and multiplicities. Semiclassical approaches to the calculation of their…

Models of hadron structure are associated with a hadronic scale which allows by perturbative evolution to calculate observables in the deep inelastic region. The resolution of Dyson-Schwinger equations leads to the freezing of the QCD…

Baryon number is an accidental symmetry in the standard model, while Peccei-Quinn symmetry is hypothetical symmetry which is introduced to solve the strong CP problem. We study the possible connections between Peccei-Quinn symmetry and…

In realistic supersymmetric models, very small hard supersymmetry breaking terms generally appear. Some of them violate baryon and/or lepton number. We discuss their possible applications to proton decay and generation of neutrino masses.

We compare standard perturbation theory with the polaron transformation for non-linear transport of electrons through a two-level system. For weak electron-phonon coupling and large bias, there is good agreement between both approaches.…

The extraordinary success of the Standard Model asks for a more rigorous control beyond the perturbative approach, which is affected by mathematical problems (interaction picture and canonical quantization, non-convergence of the…

Generally, natural scientific problems are so complicated that one has to establish some effective perturbation or nonperturbation theories with respect to some associated ideal models. In this Letter, a new theory that combines…

We start with a brief presentation of the Standard Model and the weak neutral current, in view of a discussion of parity-violation in electron-hadron electroweak interactions. We then discuss some limitations of this model, motivating the…

A novel perturbative analysis for the 2+1 local supercritical field theory of pomerons is developed. It is based on the PT symmetry of the model which allows to study a similar Hamiltonian with the same real perturbative spectrum. In the…

Simple models are proposed where the baryon and lepton number are gauged and spontaneously broken near the weak scale. The models use a fourth generation that is vector-like with respect to the strong, weak and electromagnetic interactions…