Scaling Violations beyond the Leading Order

1981 ◽  
pp. 23-47
Author(s):  
R. Petronzio ◽  
W. Furmanski
Keyword(s):  
Leading Order ◽  
Scaling Violations

Single particle inclusive leptoproduction in quantum chromodynamics

1982 ◽  
Vol 60 (7) ◽  
pp. 939-949 ◽  
Author(s):  
Bruce A. Campbell
Keyword(s):  
Quantum Chromodynamics ◽  
Single Particle ◽  
Particle Production ◽  
Neutral Current ◽  
Asymptotic Freedom ◽  
Charged Current ◽  
Leading Order ◽  
Production Processes ◽  
Scaling Violations

The effects of scaling violations in current induced single particle inclusive lepto-production reactions is examined in the framework of asymptotic freedom. A set of quark fragmention functions is introduced which approximately satisfies the leading order asymptotic freedom constraints of quantum chromodynamics. These are then used to give a consistent leading order treatment of current induced single particle production processes, in particular: e+e− annihilation, charged current neutrino (antineutrino) reactions, electro (muo) production, and neutral current neutrino reactions. We emphasize the consistency of the different reactions with an asymptotically free parton picture.

Membrane theory

2017 ◽  
Author(s):  
David J. Steigmann
Keyword(s):  
Three Dimensional ◽  
Thin Sheets ◽  
Two Dimensional ◽  
Leading Order ◽  
Membrane Theory ◽  
Dimensional Theory ◽  
Small Thickness

This chapter develops two-dimensional membrane theory as a leading order small-thickness approximation to the three-dimensional theory for thin sheets. Applications to axisymmetric equilibria are developed in detail, and applied to describe the phenomenon of bulge propagation in cylinders.

scholarly journals Espalhamento Bhabha: Um Estudo Detalhado

2018 ◽  
Vol 40 (3) ◽  
Author(s):  
Fábio Köpp Nóbrega ◽  
Luiz Fernando Mackedanz
Keyword(s):  
Leading Order ◽  
Para Determinar

Resumo Neste artigo, vamos estudar alguns conceitos fundamentais em física de partículas através do estudo detalhado de um processo específico da Eletrodinâmica Quântica (QED): o espalhamento Bhabha em ordem dominante (Leading Order - LO). Este ocorre na interação entre um elétron e sua antipartícula, o pósitron, sendo um dos processos básicos da QED. Nossa escolha em trabalhar este processo deve-se a riqueza de detalhes proporcionada pelas duas possibilidades (canais) de interação, que servem para ilustrar o cálculo da interferência entre as possibilidades. Além disso, esse processo é utilizado para determinar a luminosidade de um determinado colisor, o que garante maior precisão nas medidas de outras grandezas relevantes para a análise das interações entre partículas. Finalmente, comparamos a predição da QED com os resultados do experimento DESY-PETRA-TASSO.

scholarly journals Complete leading-order standard model corrections to quantum leptogenesis

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Paul Frederik Depta ◽  
Andreas Halsch ◽  
Janine Hütig ◽  
Sebastian Mendizabal ◽  
Owe Philipsen
Keyword(s):  
Standard Model ◽  
Gauge Coupling ◽  
Thermal Bath ◽  
Leading Order ◽  
Boltzmann Equations ◽  
The Standard Model ◽  
Majorana Neutrinos ◽  
Infinite Loop ◽  
First Time ◽  
The Universe

Abstract Thermal leptogenesis, in the framework of the standard model with three additional heavy Majorana neutrinos, provides an attractive scenario to explain the observed baryon asymmetry in the universe. It is based on the out-of-equilibrium decay of Majorana neutrinos in a thermal bath of standard model particles, which in a fully quantum field theoretical formalism is obtained by solving Kadanoff-Baym equations. So far, the leading two-loop contributions from leptons and Higgs particles are included, but not yet gauge corrections. These enter at three-loop level but, in certain kinematical regimes, require a resummation to infinite loop order for a result to leading order in the gauge coupling. In this work, we apply such a resummation to the calculation of the lepton number density. The full result for the simplest “vanilla leptogenesis” scenario is by $$ \mathcal{O} $$ O (1) increased compared to that of quantum Boltzmann equations, and for the first time permits an estimate of all theoretical uncertainties. This step completes the quantum theory of leptogenesis and forms the basis for quantitative evaluations, as well as extensions to other scenarios.

scholarly journals On the three-particle analog of the Lellouch-Lüscher formula

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Fabian Müller ◽  
Akaki Rusetsky
Keyword(s):  
Field Theory ◽  
Finite Volume ◽  
Effective Field Theory ◽  
Effective Field ◽  
Infinite Volume ◽  
Leading Order ◽  
Particle Decay ◽  
Particle Decays

Abstract Using non-relativistic effective field theory, we derive a three-particle analog of the Lellouch-Lüscher formula at the leading order. This formula relates the three-particle decay amplitudes in a finite volume with their infinite-volume counterparts and, hence, can be used to study the three-particle decays on the lattice. The generalization of the approach to higher orders is briefly discussed.

scholarly journals Factorization of e+e− → H X cross section, differential in zh, PT and thrust, in the 2-jet limit

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
M. Boglione ◽  
A. Simonelli
Keyword(s):  
Transverse Momentum ◽  
Cross Section ◽  
Belle Collaboration ◽  
Hadron Production ◽  
Leading Order ◽  
Transverse Momentum Dependent ◽  
Factorization Scheme ◽  
Phenomenological Studies ◽  
Cross Section Differential ◽  
Perturbative Part

Abstract Factorizing the cross section for single hadron production in e+e− annihilations is a highly non trivial task when the transverse momentum of the outgoing hadron with respect to the thrust axis is taken into account. We work in a scheme that allows to factorize the e+e−→ H X cross section as a convolution of a calculable hard coefficient and a Transverse Momentum Dependent (TMD) fragmentation function. The result, differential in zh, PT and thrust, will be given to all orders in perturbation theory and explicitly computed to Next to Leading Order (NLO) and Next to Leading Log (NLL) accuracy. The predictions obtained from our computation, applying the simplest and most natural ansatz to model the non-perturbative part of the TMD, are in exceptional agreement with the experimental measurements of the BELLE Collaboration. The factorization scheme we propose relates the TMD parton densities defined in 1-hadron and 2-hadron processes, restoring the possi- bility to perform global phenomenological studies of TMD physics including experimental data from semi-inclusive deep inelastic scattering, Drell-Yan processes, e+e−→ H1H2X and e+e−→ H X annihilations.

Sign in / Sign up

Export Citation Format

Share Document