Related papers: Non-perturbative QCD amplitudes in quenched and ei…
About twelve years ago the use of standard functional manipulations was demonstrated to imply an unexpected property satisfied by the fermionic Green's functions of $QCD$. This non-perturbative phenomenon is dubbed Effective Locality. In a…
We define the non-perturbative part of a quantity as the difference between its numerical value and the perturbative series truncated by dropping the order of minimal contribution and the higher orders. For the anharmonic oscillator, the…
A recent QCD formulation that is non-perturbative, finite, gauge-invariant, exact emerged from Schwinger's Generating Functional. A first test of the validity of this formulation is provided here against elastic proton-proton scattering at…
In this paper, we establish the well-posedness in energy space for the quintic energy critical wave inside a cylindrical convex domain $\Omega\subset\mathbb{R}^3$ with smooth boundary $\partial\Omega\neq\emptyset$. The key tools to prove…
We study the spectrum of the even parity excitations of the nucleon in quenched lattice QCD. We extend our earlier analysis by including an expanded basis of nucleon interpolating fields, increasing the physical size of the lattice,…
We study the response to sudden local perturbations of highly excited Quantum Ising Spin Chains. The key quantity encoding this response is the overlap between time-dependent wave functions, which we write as a two-times Loschmidt echo. Its…
We present a comprehensive study of the masses of pseudoscalar and vector mesons, as well as octet and decuplet baryons computed in O(a) improved quenched lattice QCD. Results have been obtained using the non-perturbative definition of the…
We calculate the logarithmic corrections to the matrix elements for $K^+\to\pi^+$ and $K\to$vacuum (which are used on the lattice to determine $K\to\pi\pi$ amplitudes), in one-loop quenched and unquenched Chiral Perturbation Theory. We find…
The past few years have seen remarkable progress in the theory and phenomenology of QCD, bringing perturbative and nonperturbative methods into closer contact with each other and with experiment.
We give an introduction to the special problems encountered in a treatment of HQET beyond perturbation theory in the gauge coupling constant. In particular, we report on a recent test of HQET as an effective theory for QCD and discuss how…
The transformation properties of strong penguin operators under the action of the flavor group change when they are considered as operators in (partially) quenched QCD instead of the unquenched theory. An ambiguity arises, which is…
We present the results from a series of lattice simulations of the charmonium system using a highly-improved NRQCD action, both in the quenched approximation, and with n_f = 2 light dynamical quarks. The spectra show some evidence for…
A dynamical generalisation of the nonlocal coherent-potential approximation is derived based upon the functional integral approach to the interacting electron problem. The free energy is proven to be variational with respect to the…
Associated with the use of conventional integrated parton densities are kinematic approximations on parton momenta which result in unphysical differential distributions for final-state particles. We argue that it is important to reformulate…
The breakthrough of quantum error correction brought with it the picture of quantum information as a sort of combination of two complementary types of classical information, "amplitude" and "phase". Here I show how this intuition can be…
The spin-dependent operators for heavy quarkonium hybrids have been recently obtained in a nonrelativistic effective field theory approach up to next-to-leading order in the heavy-quark mass expansion. In the effective field theory for…
We previously showed that a quantum quench in a one-dimensional translation invariant system produces undamped oscillations of a local observable when the post-quench state includes a single-quasiparticle mode and the observable couples to…
In this paper we discuss effective strong coupling constants. Those are well behaved in the low-Q^2 domain, contrarily to alpha_s from pQCD. We present an extraction of an effective strong coupling constant from Jefferson Lab polarized data…
Various approaches to high energy forward scattering in quantum gravity are compared using the eikonal approximation. The massless limit of the eikonal is shown to be equivalent to other approximations for the same process, specifically the…
We explain how nonperturbative effects can be systematically included when constructing an effective field theory. We concentrate in particular on the matching calculation, by which a low energy theory without a heavy particle degree of…