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IKTPLUSS-IKT og digital innovasjon

Modelling of Higher Order Flow Harmonics in Ultra Relativistic Heavy Ion Collisions

Alternative title: Modellering av Anisotropi i Ultra Relativistiske Tung Ion Kollisjoner.

Awarded: NOK 2.0 mill.

The modern day high-energy physics experiments are believed to reproduce the extreme conditions of the early universe, thus reproducing the conditions of hadron formation. Heavy ion collisions in the modern-day state-of-the-art accelerators are thus believed to provide means for the investigations of hadronic phenomena. In the collisions, are the path to observable hadrons believed to go through several phase transitions of the evolving collision-yield. The manifestations of these exotic phases, e.g. "quark gluon plasma", may be observed in the detectors through particle spectra and azimuth. That is: the processes involved in the participant matter evolution are only possible to observe through the abundances and their modulations in the detectors. The dependencies of the observables are commonly investigated in computational models that implements the postulates of front-line theoretical physics, in conjunction with experimental data. In this work are the simulation model HYDJET++ enabling the simulation of particle spectra and azimuthal distributions. By having investigated the lower order observables successfully are the simulation of higher order phenomena the next obvious step when examining manifestations of fundamental physical processes. The addition of realistic fluctuations are providing for a higher order simulation of the evolving fireball, which significantly contribute to the studies of the heavy ion collisions. The simulations appear to display features of deep processes that are believed to be linked to the dynamics of mass-generation.

The students PhD project has been active since the fall of 2016, and is now in its finalizing stage. The student will achieve his PhD degree with some delay. This is due to the University's excessively long application times. During the students time as a PhD student, he has been involved in work for publication in international physics journals, and conferences with his own contribution. Several other publications have been made (4), and several others (2-3) will be made after the finalizing of the project. The student has also developed a new frameworks for computation of complex systems, and also models for data-analysis. The models implements new technology which the student has acquired knowledge of during his time as PhD student. The student will also achieve the degree of philosophy doctor in the field of theoretical physics in a limited time-frame. Given this; is the progress considered as being in line with-, or surpassing the planned progress of the project.

The modern day high-energy physics experiments are believed to reproduce the extreme conditions of the early universe, including hadronization processes. Heavy ion collisions in state-of-the-art accelerators provide means of investigating hadronization and phenomena connected to it. The paths to observable hadrons are believed to go through several phase transitions. The manifestations of these exotic phases, e.g. "quark gluon plasma" may be observed in the detectors through particle spectra and azimuth. The phenomena connected to hadronization are only accessible through particle distributions. This means that the processes involved in the participant matter evolution are only possible to observe through abundances and coherence in the detectors. Thus, the dependencies of the observables have to be investigated in the models and tested against experimental data. In order to investigate these dependencies, a realistic computational model is necessary. The simulation model in use is HYDJET++; which has proven successful in simulating particle spectra and azimuthal distributions. In the model; the superposition of parametrized hydrodynamics and an iterated hard state provides a solid foundation for the investigations of fundamental physics in heavy-ion collisions. Having investigated the lower order harmonics successfully; the need for simulating higher order harmonics (flow) is becoming obvious when examining correlations and interplay. The addition of realistic fluctuations is thus believed to provide for a higher order fireball simulation; and as such believed to make a significant contribution to the already proven simulation model.

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IKTPLUSS-IKT og digital innovasjon