Anastasiia Kirichenko

I graduated a specialization "Elementary particle physics and cosmology" from National Research Nuclear University Moscow Engineering Physics Institute (NRNU MEPhI), Moscow, Russia.
I wanted to get a sense of how our Universe works. What laws govern the Universe and how particles interact with each other. My aim was also to gain practical experience with physical installations and work on a real experiment with real data. 

And already in the 3rd year of my undergraduate studies, I met my future supervisor, Professor Maxim Y. Khlopov (French National Center for Scientific Research Astroparticle and Cosmology Laboratory (CNRS APC), Paris).

At that time, the AMS-02 collaboration had already announced the possibility of detecting antihelium particles in the experiment in the future. AMS-02 is a near-orbit experiment to detect cosmic ray particles. The main focus of the experiment is aimed at detecting antimatter.

The nature of such nuclei can be different, ranging from the dark matter to some astrophysical sources. One of these sources could be the domain of primordial antimatter in the Galaxy in the form of an old globular cluster of antistars. Such objects live in a halo, so the annihilation background will be small, and the only indicator of the presence of such an object is primary antinuclei.

The proof or refutation of the hypothesis of the existence of it would make adjustments to the understanding of the nature of the baryon asymmetry of the Universe.

The bachelor's work on this theory was about estimating the density of antimatter in cosmic rays from a supposed globular cluster of antistars. To do this, it was to apply knowledge of cosmology and work through a large number of articles on the subject of globular clusters. I chose the globular cluster M4 as the prototype of the antimatter domain, since there is a large amount of data on it. 

I studied the composition of the cluster, the rate of injection of the substance and other parameters. At that time, the course of cosmology had not yet been read, and therefore I independently studied the discipline. Genuine interest in the research topic, perseverance, attending the Saturday seminars of my supervisor allowed me to show the results of my work at international conferences.

The obtained value of the antimatter density from the supposed globular cluster of antistars did not contradict the existing restrictions on the detected antimatter in cosmic rays in near-Earth orbit. This result made it possible to continue the analysis already in the magistracy.

In the 3rd and 4th years of work on this topic I studied the distribution of antihelium nuclei in the Galaxy by programming in the MATLAB environment.

It was necessary to know the structure of magnetic fields and the properties of cosmic rays, i studied it in my own. The particle trajectory simulation code is represented by a complex program structure. As part of this, I wrote a code to calculate the initial parameters - the configuration of the galactic magnetic field. The magnetic field configuration was based on the JF12 magnetic field model, which was choosen by my own.

 In two years, I learned how to work with data arrays in large program structures, simulate the movement of particles in a magnetic field, build trajectories of movement and obtain new values based on existing models.

The result of my master's thesis was the first estimated energy of the magnetic cutoff for the penetration of antihelium particles from the halo into the disk. The flow of particles with energies below this value will be largely suppressed. This is due to a process similar to the effect of solar modulation preventing low-energy particles from entering the solar system. I also continued to present my findings at conferences. I received many questions from my scientific colleagues. This inspired me to keep working.

 It is also important to note that my average score in the master's program has increased significantly (bachelor 3.8/5, Master 4.5/5) for one simple reason - there were many more interesting subjects for me. I believe that this fully reflects how I can prioritize and spend time and energy on courses that are important and necessary for my career.

In addition to a high level of independence, I have experience of working in a team. The result of work on the nature of antihelium nuclei was a joint article in the journal Symmetry.

I would like to note that my scientific work was not strictly theoretical. It combined various tasks: from the estimation of physical quantities, the analysis of suitable models, to the programming and modeling of physical processes in the Galaxy. 

I graduated a specialization "Elementary particle physics and cosmology" from National Research Nuclear University Moscow Engineering Physics Institute (NRNU MEPhI), Moscow, Russia.

During my bachelor’s degree studies, I was focusing on courses, which were the foundation of my future specialty. Education began with basic courses in general physics and a course of quantum mechanics. . After that, the elementary particle physics course was held with great interest.

  Also, during my studies, I learned programming in C, C++, MATLAB and Fortran.

During the courses, I independently solved physical problems that were close to real physical experiments. For example, write a code for registering particles on a simplified accelerator.

Then I entered the magistracy, I continued my studies in this specialty.

I began to study cosmology, astrophysics, as well as cosmic microphysics more deeply. 

In the magistracy, I was also intensely interested in experimental physics. 

 I learned  Information Technology for Physical Experiments course, Ultra-high Energy Nuclear Collisions (excellent), Equipment and Facilities in High Energy Physics course. I learned what parts detectors consist of, what physical processes take place there, and what particle acceleration mechanism is currently used. On the disciplines of methods of statistical analysis and Monte Carlo generators in particle physics i learned how to work with arrays of particles, select events and analyze the resulting graphs.

On the Standard Model and its extensions. I learned about how physicists now imagine modern particle models. The Standard Model is imperfect and cannot describe such processes as the baryon asymmetry of the Universe, the existence of dark matter and dark energy, and also the gravitational interaction. Therefore, this subject left in my head more questions than answers.