Focus on Monika Varga-Kofarago

Virginia Greco

Last summer Monika was assigned one of the 2018 ALICE Thesis Awards for her work on “Anomalous Broadening of Jet-Peak Shapes in Pb–Pb Collisions and Characterization of Monolithic Active Pixel Sensors for the ALICE Inner Tracking System Upgrade.” We have talked with her to learn more about her career path and interests.

Monika Varga-Kofaragostudied Physics at the E?tv?s Lor?nd University in Budapest (Hungary), and had her first experience in a heavy-ion experiment towards the end of her Master, when she developed a project in the RHIC's PHENIX experiment. The focus of her work was two- and three-pion femtoscopy, i.e. the study of processes developing in femtosecond time, the final products of which include respectively two or three pions. This allowed her to investigate the Hanbury Brown and Twiss (HBT) correlations of these particles.

During her Master, she had also the occasion to spend a few weeks at CERN as a summer student, working in the ALICE experiment under the supervision of Jan Fiete Grosse-Oetringhaus. “I liked the team, the activities I carried out and the place,” Monika comments, “that is why I decided to join the same group for my PhD.” She enrolled at the University of Utrecht and entered the CERN Doctoral Student Programme. 

During the three years spent at CERN she worked on two topics, getting experience on both physics analysis and detector development. “All the PhD students perform service tasks, which often include hardware activities,” she explains, “but, in my case, the work on the detector was part of my research project and its description actually takes half of my thesis.”

On the detector side, she participated in the ITS upgrade, working on characterizing one of the prototypes.While, on the analysis side, she studied theangular correlation between two unidentified particles in Pb-Pb collisions at 2.76 TeV and compared the results with pp collisions. From this analysis, one can draw conclusions on how jets and mini-jets interact with the quark-gluon plasma in a transverse momentum regime where direct jet reconstruction is not possible.

I am really happy that I could see different aspects of the experiment,” states Monika. “If you have never worked on hardware, somehow you don't really know how data are taken. Therefore, I think it was an excellent experience for me. At the same time, of course, I love studying the products of the collisions and the physics phenomena involved. Indeed, I am more inclined to data analysis; nevertheless, I would prefer to keep a foot in both sides.”

Currently, Monika is working as a postdoctoral fellow at the Wigner Research Centre for Physics, in Hungary, where she is continuing the analysis developed during her PhD, using 5.02 TeV Pb-Pb and p-Pb collision data. She is also still involved, for a small fraction of her time, in the ITS upgrade. “I am actually collaborating with a Norwegian group on the application of the ALPIDE chip, which was developed for the new ITS, to medical physics. I think it is a very important and fascinating project. In addition, I like the fact that hardware activities often imply collaborating more closely with colleagues, while data analysis requires many hours of individual work.

She is also teaching some laboratory classes and supervising two undergraduate students, one working on her analysis topic and the other on the ALPIDE application. “I really enjoy supervising the work of students,” she adds, “I find it rewarding to assign a project or task to them and then to see that they developed it.

Physics-wise, at the moment Monika is really intrigued by phenomena detected in Pb-Pb collisions which are dependent on the centrality of the event and by how these observations change in different collision systems. “In my analysis, I have seen an effect in Pb-Pb collisions, which appears especially in the central ones and gradually disappears in the peripheral ones, that we have not observes in pp collisions. Recently, I have started to look into the p-Pb collisions to know whether this system would fit in the middle of the other two and if there is a collision multiplicity dependence.”

She will focus on developing these research lines over the next year of postdoctoral fellowship. “At the end of this contract, I might get an extension, but I still don't know,” she declares. “I would be happy to continue in the same groups and to remain in Hungary: all my friends and family are there.

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