scholarly journals A covariant and gauge invariant string fragmentation model

1990 ◽  
Vol 47 (2) ◽  
pp. 215-226 ◽  
Author(s):  
K. Werner ◽  
P. Koch
Keyword(s):  
Fragmentation Model ◽  
Gauge Invariant ◽  
String Fragmentation

scholarly journals Second stage string fragmentation model

1998 ◽  
Vol 58 (1) ◽  
Author(s):  
Thamar Al.-Aithan ◽  
Carl Rosenzweig
Keyword(s):  
Fragmentation Model ◽  
Second Stage ◽  
String Fragmentation

STRING FRAGMENTATION MODEL AND INCLUSIVE PRODUCTION OF K MESONS

1992 ◽  
Vol 07 (16) ◽  
pp. 3665-3690
Author(s):  
MOHAMMAD SALEEM ◽  
MUHAMMAD RAFIQUE
Keyword(s):  
Experimental Data ◽  
Positron Annihilation ◽  
Cross Section ◽  
Inclusive Production ◽  
Fragmentation Model ◽  
Electron Positron Annihilation ◽  
Electron Positron ◽  
The Mean ◽  
K Mesons ◽  
String Fragmentation

An account of the inclusive production of K mesons in electron-positron annihilation is given. The most recent measurements on the cross section are exhibited and compared with the predictions of the Lund model. The model gives a satisfactory agreement with the experimental data. The results from different experiments on cross section, the mean multiplicity per multihadronic event and various other characteristics are found to be consistent.

scholarly journals Photohadronic Processes in Astrophysical Environments

1999 ◽  
Vol 16 (2) ◽  
pp. 160-166 ◽  
Author(s):  
A. Mücke ◽  
J. P. Rachen ◽  
Ralph Engel ◽  
R. J. Protheroe ◽  
Todor Stanev
Keyword(s):  
Cross Section ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
Multiparticle Production ◽  
Monte Carlo Event ◽  
Fragmentation Model ◽  
Event Generator ◽  
Radiation Fields ◽  
Diffractive Scattering ◽  
String Fragmentation

AbstractWe discuss the first applications of our newly developed Monte Carlo event generator SOPHIA to multiparticle photoproduction of relativistic protons with thermal and power-law radiation fields. The measured total cross section is reproduced in terms of excitation and decay of baryon resonances, direct pion production, diffractive scattering, and non-diffractive multiparticle production. Non-diffractive multiparticle production is described using a string fragmentation model. We demonstrate that the widely used ‘Δ-approximation’ for the photoproduction cross section is reasonable only for a restricted set of astrophysical applications. The relevance of this result for cosmic ray propagation through the microwave background and hadronic models of active galactic nuclei and gamma-ray bursts is briefly discussed.

The Standard Theory

2017 ◽  
Author(s):  
John Iliopoulos
Keyword(s):  
Gauge Theory ◽  
Invariant Theory ◽  
Standard Theory ◽  
Strong Interactions ◽  
Gauge Invariant ◽  
Electromagnetic Interactions ◽  
Protons And Neutrons ◽  
Free Particles ◽  
Theoretical Predictions ◽  
Theory And Experiment

All ingredients of the previous chapters are combined in order to build a gauge invariant theory of the interactions among the elementary particles. We start with a unified model of the weak and the electromagnetic interactions. The gauge symmetry is spontaneously broken through the BEH mechanism and we identify the resulting BEH boson. Then we describe the theory known as quantum chromodynamics (QCD), a gauge theory of the strong interactions. We present the property of confinement which explains why the quarks and the gluons cannot be extracted out of the protons and neutrons to form free particles. The last section contains a comparison of the theoretical predictions based on this theory with the experimental results. The agreement between theory and experiment is spectacular.

scholarly journals Time Decay for Nonlinear Dissipative Schrödinger Equations in Optical Fields

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Nakao Hayashi ◽  
Chunhua Li ◽  
Pavel I. Naumkin
Keyword(s):  
Lower Bound ◽  
Positive Root ◽  
Schrodinger Equations ◽  
Schrödinger Equations ◽  
Time Decay ◽  
Large Initial Data ◽  
Initial Value ◽  
Optical Fields ◽  
Gauge Invariant ◽  
Dissipative Condition

We consider the initial value problem for the nonlinear dissipative Schrödinger equations with a gauge invariant nonlinearityλup-1uof orderpn<p≤1+2/nfor arbitrarily large initial data, where the lower boundpnis a positive root ofn+2p2-6p-n=0forn≥2andp1=1+2forn=1.Our purpose is to extend the previous results for higher space dimensions concerningL2-time decay and to improve the lower bound ofpunder the same dissipative condition onλ∈C:Im⁡ λ<0andIm⁡ λ>p-1/2pRe λas in the previous works.

scholarly journals Gauge invariance, polar coordinates and inflation

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Ali Akil ◽  
Xi Tong
Keyword(s):  
Coordinate System ◽  
Effective Potential ◽  
Gauge Invariance ◽  
Polar Coordinates ◽  
Quantum Corrections ◽  
Background Current ◽  
Gauge Invariant ◽  
Gauge Dependence ◽  
Current Term ◽  
Invariant Current

Abstract We point out the necessity of resolving the apparent gauge dependence in the quantum corrections of cosmological observables for Higgs-like inflation models. We highlight the fact that this gauge dependence is due to the use of an asymmetric background current which is specific to a choice of coordinate system in the scalar manifold. Favoring simplicity over complexity, we further propose a practical shortcut to gauge-independent inflationary observables by using effective potential obtained from a polar-like background current choice. We demonstrate this shortcut for several explicit examples and present a gauge-independent prediction of inflationary observables in the Abelian Higgs model. Furthermore, with Nielsen’s gauge dependence identities, we show that for any theory to all orders, a gauge-invariant current term gives a gauge-independent effective potential and thus gauge-invariant inflationary observables.

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