Models for total, elastic and diffractive cross sections.

Area of Science:

• High Energy Physics
• Particle Physics
• Collider Physics

Background:

• The Large Hadron Collider (LHC) provides new data on particle interactions, challenging existing models.
• Current frameworks, such as the Pythia event generator, show discrepancies with LHC measurements for total, elastic, and diffractive cross sections.
• Extrapolations from lower-energy experiments do not always align with LHC observations.

Purpose of the Study:

• To investigate and implement updated models for describing particle interaction cross sections at the LHC.
• To provide more realistic alternatives to the default Pythia framework.
• To extend diffraction models to include double and central diffraction and study rapidity gap phenomena.

Main Methods:

• Study and implementation of two recent theoretical models for particle cross sections.
• Comparison of model predictions with experimental data from the LHC and other colliders.
• Investigation of colour reconnection effects on rapidity gap definitions in diffractive and non-diffractive events.

Main Results:

• The implemented models successfully describe total and elastic cross sections.
• One model accurately incorporates single diffraction, with a proposed variant addressing high-energy issues.
• The variant model is extended to cover double and central diffraction.
• Colour reconnection is analyzed as a potential source of rapidity gaps in non-diffractive events.

Conclusions:

• The studied models offer improved descriptions of particle interaction cross sections compared to default frameworks.
• A refined model addresses limitations at high energies and extends to various diffraction types.
• Understanding rapidity gaps requires considering both diffractive processes and non-diffractive phenomena like colour reconnection.