Book contents
- Frontmatter
- Contents
- Acknowledgements
- 1 Introduction
- 2 Relativistic kinematics, electromagnetic fields and the method of virtual quanta
- 3 The harmonic oscillator and the quantum field
- 4 The vacuum as a dielectric medium; renormalisation
- 5 Deep inelastic scattering and the parton model
- 6 The classical motion of the massless relativistic string
- 7 The decay kinematics of the massless relativistic string
- 8 A stochastic process for string decay
- 9 The properties of the Lund model fragmentation formulas; the external-part formulas
- 10 The internal-part fragmentation formulas and their relations to the unitarity equations of a field theory; Regge theory
- 11 The dynamical analogues of the Lund model fragmentation formulas
- 12 Flavor and transverse momentum generation and the vector meson to pseudoscalar meson ratio
- 13 Heavy quark fragmentation and baryon production
- 14 The Hanbury-Brown-Twiss effect and the polarisation effects in the Lund model
- 15 The Lund gluon model, its kinematics and decay properties
- 16 Gluon emission via the bremsstrahlung process
- 17 Multigluon emission, the dipole cascade model and other coherent cascade models
- 18 The λ-measure in the leading-log and modified leading-log approximations of perturbative QCD
- 19 The parton model and QCD
- 20 Inelastic lepto-production in the Lund model, the soft radiation model and the linked dipole chain model
- References
- Index
14 - The Hanbury-Brown-Twiss effect and the polarisation effects in the Lund model
Published online by Cambridge University Press: 23 September 2009
- Frontmatter
- Contents
- Acknowledgements
- 1 Introduction
- 2 Relativistic kinematics, electromagnetic fields and the method of virtual quanta
- 3 The harmonic oscillator and the quantum field
- 4 The vacuum as a dielectric medium; renormalisation
- 5 Deep inelastic scattering and the parton model
- 6 The classical motion of the massless relativistic string
- 7 The decay kinematics of the massless relativistic string
- 8 A stochastic process for string decay
- 9 The properties of the Lund model fragmentation formulas; the external-part formulas
- 10 The internal-part fragmentation formulas and their relations to the unitarity equations of a field theory; Regge theory
- 11 The dynamical analogues of the Lund model fragmentation formulas
- 12 Flavor and transverse momentum generation and the vector meson to pseudoscalar meson ratio
- 13 Heavy quark fragmentation and baryon production
- 14 The Hanbury-Brown-Twiss effect and the polarisation effects in the Lund model
- 15 The Lund gluon model, its kinematics and decay properties
- 16 Gluon emission via the bremsstrahlung process
- 17 Multigluon emission, the dipole cascade model and other coherent cascade models
- 18 The λ-measure in the leading-log and modified leading-log approximations of perturbative QCD
- 19 The parton model and QCD
- 20 Inelastic lepto-production in the Lund model, the soft radiation model and the linked dipole chain model
- References
- Index
Summary
Introduction
In this chapter we consider two different observables, which, within the Lund model, have some bearing upon the confinement properties of QCD.
We start with the Hanbury-Brown-Twiss effect (the HBT effect) or, as it is also called, the Bose-Einstein effect. It originated in astronomical investigations, where one uses the interference pattern of the photons to learn about the size of the photon emission region, i.e. the size of the particular star which is emitting the light.
The Goldhabers, found and used in the same way as HBT a correlation pattern among the produced pions when they investigated proton-antiproton annihilation reactions close to the threshold (i.e. when the annihilation occurs at very low relative velocities, so that the total energy is essentially twice the proton rest mass). Photons and pions have in common that they are bosons, which means that they thrive on being in the same state. The HBT effect can be described as an enhancement of the two-particle correlation function that occurs when the two particles are identical bosons and have very similar values of their energy-momentum.
The size of the emission region obtained from these experiments in hadronic physics seems to be essentially the same in almost any kind of interaction. One obtains a radius of the order of 1 fm, which is a very reasonable size.
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- Chapter
- Information
- The Lund Model , pp. 249 - 268Publisher: Cambridge University PressPrint publication year: 1998