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Multiplicity and Classification of Final State Particles in Herwig7

Rosenkvist, Carl LU (2021) FYTK02 20211
Theoretical Particle Physics
Abstract
In this work we investigate the hard and soft interactions in the multiple parton interactions (MPI) simulation in Herwig7. The investigation covers how the number of soft and hard interactions in an event is linked to the multiplicity of final state particles. We also present a labeling system for particles produced by different interactions, which we then use to classify the final state particles. We also demonstrate how this labeling system can be used as a tool to disentangle different contributions to a given observable. The observables we investigated are the charged multiplicity and the charged transverse momentum. We observed a large contribution from diffractive events in the high multiplicity region and therefore we produced the... (More)
In this work we investigate the hard and soft interactions in the multiple parton interactions (MPI) simulation in Herwig7. The investigation covers how the number of soft and hard interactions in an event is linked to the multiplicity of final state particles. We also present a labeling system for particles produced by different interactions, which we then use to classify the final state particles. We also demonstrate how this labeling system can be used as a tool to disentangle different contributions to a given observable. The observables we investigated are the charged multiplicity and the charged transverse momentum. We observed a large contribution from diffractive events in the high multiplicity region and therefore we produced the invariant mass distribution of primary clusters. From this distribution, we observed that primary clusters from diffractive events have a long tail towards high invariant mass. (Less)
Popular Abstract
Some particle physicists' job is similar to that of a detective as both use clues to recreate events. The particle physicist's event is the interactions of particles in the particle collider, and the clues are called observables which are physical quantities measured by the detector. The reason for this similarity is that elementary particles like quarks carry color charge but are forced by nature to exist in constellations that are colorless. This restriction is called color-confinement and is the reason why the interaction of two quarks can not be observed directly. This means that particle collisions can be thought to happen inside a box which we cant see into. Theoretical models must thus explain the interactions and through simulating... (More)
Some particle physicists' job is similar to that of a detective as both use clues to recreate events. The particle physicist's event is the interactions of particles in the particle collider, and the clues are called observables which are physical quantities measured by the detector. The reason for this similarity is that elementary particles like quarks carry color charge but are forced by nature to exist in constellations that are colorless. This restriction is called color-confinement and is the reason why the interaction of two quarks can not be observed directly. This means that particle collisions can be thought to happen inside a box which we cant see into. Theoretical models must thus explain the interactions and through simulating events through event generation these models can be compared to real data.
Collisions of composite particles, like e.g protons, are described by their collisions of their constituents called partons. The interactions of partons are the beginnings of the complex processes which eventually result in observable particles in detectors. Due to the proton's composite nature, there is a possibility for several partons to interact in the same proton collision. These additional interactions make it harder to understand which interaction observable particles originate from.
To understand how the different interactions contribute to observable particles we use the event generator Herwig7. We use this event generator to investigate the link between the number of interactions and the number of observable particles. Furthermore we introduce a labeling system which allows us to track particles produced from different interactions. The difference in real data and simulation can be investigated by the labeling system such that we can pinpoint which interaction might be responsible. Therefore the labeling system is a useful tool for model investigation and event generator improvements. (Less)
Please use this url to cite or link to this publication:
author
Rosenkvist, Carl LU
supervisor
organization
course
FYTK02 20211
year
type
M2 - Bachelor Degree
subject
keywords
MPI, multiple parton interactions, multi-parton interactions, event generation, cluster, cluster classification, Herwig7
language
English
id
9055126
date added to LUP
2021-06-24 09:18:40
date last changed
2021-06-24 09:18:40
@misc{9055126,
  abstract     = {{In this work we investigate the hard and soft interactions in the multiple parton interactions (MPI) simulation in Herwig7. The investigation covers how the number of soft and hard interactions in an event is linked to the multiplicity of final state particles. We also present a labeling system for particles produced by different interactions, which we then use to classify the final state particles. We also demonstrate how this labeling system can be used as a tool to disentangle different contributions to a given observable. The observables we investigated are the charged multiplicity and the charged transverse momentum. We observed a large contribution from diffractive events in the high multiplicity region and therefore we produced the invariant mass distribution of primary clusters. From this distribution, we observed that primary clusters from diffractive events have a long tail towards high invariant mass.}},
  author       = {{Rosenkvist, Carl}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Multiplicity and Classification of Final State Particles in Herwig7}},
  year         = {{2021}},
}