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Related papers: Chiral Logarithms Tamed

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We study the production amplitude for the reaction NN->NNpi up to next--to--leading order in chiral perturbation theory using a counting scheme that takes into account the large scale introduced by the initial momentum. In particular we…

Nuclear Theory · Physics 2009-11-11 V. Lensky , V. Baru , J. Haidenbauer , C. Hanhart , A. E. Kudryavtsev , U. -G. Meißner

The talk contains a short introduction to mesonic Chiral Perturbation Theory (ChPT). In addition four disparate areas where some progress has been made in recent years are discussed. These are the last fit of the order $p^4$…

High Energy Physics - Phenomenology · Physics 2013-01-30 Johan Bijnens

Linear response (LR) theory is a powerful tool in classic quantum chemistry crucial to understanding photo-induced processes in chemistry and biology. However, performing simulations for large systems and in the case of strong electron…

Chiral perturbation theory is a very general expansion method which can be applied to any dynamical system which has continuous global symmetries and in which the ground state breaks some of these spontaneously. In these lectures we explain…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. Moussallam

The lefthanded Lov\'asz local lemma (LLLL) is a generalization of the Lov\'asz local lemma (LLL), a powerful technique from the probabilistic method. We prove a computable version of the LLLL and use it to effectivize a collection of…

Logic · Mathematics 2024-06-19 Daniel Mourad

We compute the one-loop contributions of the chronological products for massless gravity in the second order of the perturbation theory. We prove that the loop contributions are coboundaries i.e. expressions which give zero when averaged on…

High Energy Physics - Theory · Physics 2019-05-15 Dan-Radu Grigore

We test the one-loop chiral perturbation theory formula on unquenched lattice data of pseudoscalar meson decay constants. The chiral extrapolation including the effect of the chiral logarithm is attempted and its uncertainty is discussed.

Chiral effective field theory complements numerical simulations of quantum chromodynamics (QCD) on a space-time lattice. It provides a model-independent formalism for connecting lattice simulation results at finite volume and a variety of…

High Energy Physics - Lattice · Physics 2015-03-13 J. M. M. Hall , R. D. Young , D. B. Leinweber

We reexamine critically the chiral expansion for the baryon magnetic moments including the contributions from loops which involve intermediate octet and decuplet baryons. We find that, contrary to some claims, the nonanalytic loop…

High Energy Physics - Phenomenology · Physics 2009-10-30 Loyal Durand , Phuoc Ha

These lectures are an attempt to a pedagogical introduction into the elementary concepts of chiral symmetry in nuclear physics. Effective chiral models such as the linear and nonlinear sigma model will be discussed as well as the essential…

Nuclear Theory · Physics 2007-05-23 Volker Koch

Chiral perturbation theory is extended to nonrelativistic systems with spontaneously broken symmetry. In the effective Lagrangian, order parameters associated with the generators of the group manifest themselves as effective coupling…

High Energy Physics - Phenomenology · Physics 2009-10-22 H. Leutwyler

The divergent part of the generating functional of the Resonance Chiral Theory is evaluated up to one loop when one multiplet of scalar an pseudoscalar resonances are included and interaction terms which couple up to two resonances are…

High Energy Physics - Phenomenology · Physics 2011-07-19 I. Rosell

Massive higher spin fields are notoriously difficult to introduce interactions when they are described by symmetric (spin)-tensors. An alternative approach is to use chiral description that does not have unphysical longitudinal modes. For…

High Energy Physics - Theory · Physics 2025-01-28 William Delplanque , Evgeny Skvortsov

We calculate the divergences of the generating functional of quenched Chiral Perturbation Theory at one loop, and renormalize the theory by an appropriate definition of the counterterms. We show that the quenched chiral logarithms can be…

High Energy Physics - Lattice · Physics 2009-10-30 Gilberto Colangelo , Elisabetta Pallante

In cross sections with angular cuts, an intricate pattern of enhanced higher-order corrections known as non-global logarithms arises. The leading logarithmic terms were computed numerically two decades ago, but the resummation of subleading…

High Energy Physics - Phenomenology · Physics 2024-03-21 Thomas Becher , Nicolas Schalch , Xiaofeng Xu

We present a formalism to compute Lagrangian displacement fields for a wide range of cosmologies in the context of perturbation theory up to third order. We emphasize the case of theories with scale dependent gravitational strengths, such…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-16 Alejandro Aviles , Jorge L. Cervantes-Cota

[This version is a minor revision of a previously submitted preprint. Only references have been changed.] We describe a technique for constructing the effective chiral theory for quenched QCD. The effective theory which results is a…

High Energy Physics - Lattice · Physics 2009-10-22 Claude Bernard , Maarten Golterman

Logical relations (LR) have been around for many years, and today they are used in many formal results. However, it can be difficult to LR beginners to find a good place to start to learn. Papers often use highly specialized LRs that use…

Programming Languages · Computer Science 2019-07-26 Lau Skorstengaard

A perturbative approach to quantum field theory involves the computation of loop integrals, as soon as one goes beyond the leading term in the perturbative expansion. First I review standard techniques for the computation of loop integrals.…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stefan Weinzierl

When matter fields are included in chiral perturbation theory, the nonvanishing mass in the chiral limit introduces a new energy scale so that the loop diagrams including such matter field propagators spoil the usual power counting.…

High Energy Physics - Phenomenology · Physics 2016-11-01 Meng-Lin Du , Feng-Kun Guo , Ulf-G. Meißner