On the Energy Dependence of Parameters in PYTHIA8 Heavy-ion Collision Simulations
(2022) FYTK02 20221Theoretical Particle Physics - Has been reorganised
- Abstract
- Particle collisions are an essential component to the research methodology of particle physics. These investigations are not only conducted in experimental laboratories but also through programs such as PYTHIA that simulate a collision or ``event" and then compare its results to known experimental data. This thesis aims to investigate the energy dependence of parameters used in PYTHIA's Angantyr model for heavy-ion collisions. A significant portion of this project was dedicated to collecting the output of simulated collisions within the energy range of 10 GeV - 10 TeV. The focus was mainly on three parameters in the Angantyr model ($k_0$, $\alpha$, and $\sigma_D$) and their parametrizations with respect to the center of mass energy of the... (More)
- Particle collisions are an essential component to the research methodology of particle physics. These investigations are not only conducted in experimental laboratories but also through programs such as PYTHIA that simulate a collision or ``event" and then compare its results to known experimental data. This thesis aims to investigate the energy dependence of parameters used in PYTHIA's Angantyr model for heavy-ion collisions. A significant portion of this project was dedicated to collecting the output of simulated collisions within the energy range of 10 GeV - 10 TeV. The focus was mainly on three parameters in the Angantyr model ($k_0$, $\alpha$, and $\sigma_D$) and their parametrizations with respect to the center of mass energy of the collision. This was performed for two versions of Angantyr that differ in the treatment of the opacity of the colliding particles. In the default version a larger particle radius leads to a more opaque particle, and in the second version a smaller radius implies a more opaque particle. It was found that the second version of Angantyr outperformed the default, especially in the low energy range. Additionally, once the functional forms of the relevant parameters of Angantyr were known, they were used to create a Parameterized Energy Dependence (PED) model. It had good agreement with experimental data and therefore the functional forms of the parameters are deemed useful for a possible implementation into PYTHIA. (Less)
- Popular Abstract
- Particle colliders are the modern ``microscopes" that allow us to peer into the most fundamental particles in the universe. These colliders accelerate small particles to very high speeds before having them collide in an area surrounded by detectors. When particles collide at high energies new particles emerge and these new particles, called \emph{final states}, are detected in laboratories. One can acquire insights into the nature of the original particles by investigating where and how many \emph{final states} are detected.
A powerful ally in these investigations are programs that simulate collisions or ``events", and output an estimate of the \emph{final states}. These programs, sometimes called ``generators", are used by physicists... (More) - Particle colliders are the modern ``microscopes" that allow us to peer into the most fundamental particles in the universe. These colliders accelerate small particles to very high speeds before having them collide in an area surrounded by detectors. When particles collide at high energies new particles emerge and these new particles, called \emph{final states}, are detected in laboratories. One can acquire insights into the nature of the original particles by investigating where and how many \emph{final states} are detected.
A powerful ally in these investigations are programs that simulate collisions or ``events", and output an estimate of the \emph{final states}. These programs, sometimes called ``generators", are used by physicists to test different models of the collision process and then compare simulation results to real-life experimental data collected in large laboratories. An example of such a program is PYTHIA, and one of its models is called Angantyr. This model has the aim of simulating collisions between heavy-ions (charged particles with multiple protons and neutrons). The purpose of this thesis will be to investigate how certain parameters vary depending on the energy of the collision for different versions of the Angantyr model. The two versions investigated differ in the treatment of the ``transparency" of the particle. In the first version a particle, modeled as a disk, becomes more transparent as its size increases. In the second version the opposite is true, with a smaller radius leading to a more transparent disk.
To perform this investigation a large amount of simulations will be run at different energies and their output will be recorded. The acquired information will be used to find suitable equations that describe how the change in energy affects the values of the relevant parameters. Once these dependencies are investigated, comparisons will be made regarding their agreement with experimental data. The final purpose of this thesis is to find equations that model the behaviour of the parameters as simply as possible while maintaining their agreement with real-life data. Finding such a model would prove useful as it could help on deciding which version of Angantyr performs best. It would also serve the purpose of incorporating the parameter equations into PYTHIA, as this would reduce computation time in the simulation. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9096631
- author
- Abedrapo, Felipe LU
- supervisor
- organization
- course
- FYTK02 20221
- year
- 2022
- type
- M2 - Bachelor Degree
- subject
- keywords
- Heavy-ion Collisions, PYTHIA, Angantyr
- report number
- LU-TP 22-33
- language
- English
- id
- 9096631
- date added to LUP
- 2022-08-08 10:16:27
- date last changed
- 2022-08-11 11:43:51
@misc{9096631,
abstract = {{Particle collisions are an essential component to the research methodology of particle physics. These investigations are not only conducted in experimental laboratories but also through programs such as PYTHIA that simulate a collision or ``event" and then compare its results to known experimental data. This thesis aims to investigate the energy dependence of parameters used in PYTHIA's Angantyr model for heavy-ion collisions. A significant portion of this project was dedicated to collecting the output of simulated collisions within the energy range of 10 GeV - 10 TeV. The focus was mainly on three parameters in the Angantyr model ($k_0$, $\alpha$, and $\sigma_D$) and their parametrizations with respect to the center of mass energy of the collision. This was performed for two versions of Angantyr that differ in the treatment of the opacity of the colliding particles. In the default version a larger particle radius leads to a more opaque particle, and in the second version a smaller radius implies a more opaque particle. It was found that the second version of Angantyr outperformed the default, especially in the low energy range. Additionally, once the functional forms of the relevant parameters of Angantyr were known, they were used to create a Parameterized Energy Dependence (PED) model. It had good agreement with experimental data and therefore the functional forms of the parameters are deemed useful for a possible implementation into PYTHIA.}},
author = {{Abedrapo, Felipe}},
language = {{eng}},
note = {{Student Paper}},
title = {{On the Energy Dependence of Parameters in PYTHIA8 Heavy-ion Collision Simulations}},
year = {{2022}},
}