| 研究実績の概要 |
The major goal of this research project is to carry out realistic simulations of proton-nucleus reactions, in which the phi meson (and potentially other mesons) is created in nuclear matter and subsequently decays into di-leptons, which are experimentally measured. In these simulations, several scenarios for the modification of the phi meson in nuclear matter can be tested and it can be studied in what influence these scenarios have on the measured di-lepton spectrum. Therefore, by comparing the simulation results with the experimental di-lepton data, it should be possible to determine in what way the properties of the phi meson have changed in nuclear matter.
During the first year of the project, I first had to learn how to use the simulation code (called PHSD) that is used in the simulation. I did this under the supervision of Elena Bratkovskaya (Goethe University/GSI), who is one of the developers of this code. After having learned how to handle the code, I started to carry out some first simulations of the 12 GeV proton-nucleus reactions that were probed at the E325 experiment at KEK. The used nucleus targets were Carbon and Copper nuclei. By comparing the simulation results with the experimental di-lepton data of the E325 experiment, I found that the data can best reproduced in a scenario of a negative mass shift of about 34 MeV and only a small change in the decay width.
|
| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
As it was planned, I was able to simulate the proton-nucleus reactions probed at the E325 experiment at KEK, which allowed me to successfully analyze the experimental di-lepton data of this experiment and to reach a conclusion about the behavior of the phi meson in nuclear matter based on these experimental data.
After furthermore taking into account the effect of the electro-magnetic interaction on the di-leptons that are the decay-product of the phi meson, I will write a paper about these findings.
|
| 今後の研究の推進方策 |
First, I will need to finish the analysis of the KEK E325 di-lepton data and plan to write a paper about the corresponding results during the first half of the next fiscal year.
After this task is completed, I will start running simulations of the 30 GeV proton-nucleus reactions that are currently measured at the J-PARC E16 experiment. In collaboration with the experimental researchers that perform this experiment, I will then use the results from these simulations to analyze the new experimental data with the goal of determining the behavior of the phi meson in nuclear matter with high precision. This will provide important information about the restoration of chiral symmetry within the strange quark sector in dense matter.
|
