by Virginia Greco. Published: 12 July 2018

Six young ALICE researchers who presented their work at recent international conferences – Quark Matter 2018 and LHCP 2018 – were awarded a prize for their talk or poster.

Michael Knichel and Barbara Antonina Trzeciak on the stage at Quark Matter 2018.


In the last months, two important physics conferences took place: Quark Matter 2018 – held in Venezia (Italy) between 13 and 19 of May – and LHC Physics 2018 – held in Bologna (Italy), 4-9 June. With high participation from the ALICE collaboration (in particular the first one given its scope), both were also occasions for young researchers to present their work and get visibility. The most promising ones, according to the respective committees, were honoured with a prize.

At Quark Matter, Barbara Antonina Trzeciak, a postdoc at the University of Utrecht, and Michael Knichel, a fellow at CERN, were assigned the Elsevier Nuclear Physics A Young Scientist Award for the best experimental talk, which includes also a monetary prize. 

We talked with them to learn more about their career path and interests: you can find the interview with Barbara and Michael on these pages. 

On the same occasion, three ALICE posters were included in the list of the best 10, out of 430 posters. Their authors, Mike Sas, Sushanta Tripathy and Alessandra Lorenzo, were granted the possibility to give a flash talk on their research.

At the LHCP2018 Conference, Kunal Garg was given the same honour for his poster.

Let’s get to know them.

Mike Sas is a PhD student at the Utrecht University and Nikhef, in the Netherland. His main topics of research are the production and correlations of direct photons and neutral mesons in heavy-ion collisions. During his Master, he started to work on the measurement of the elliptic flow of direct photons in Pb-Pb collisions, performed with the photon conversion method. He also carried out measurements of the invariant yield of neutral pions and etas in p-Pb collisions using the ALICE electromagnetic calorimeter.

I got more and more intrigued by photon measurements, not only for their complexity and the consequent challenge of obtaining a robust and solid result, but also because some of the open questions that we have in heavy-ion physics felt within reach,” Mike explains. “By knowing both the yield and elliptic flow of direct photons, we can gain access to the temperature and space-time evolution of the system. In fact, high direct photon yield implies low direct photon elliptic flow, while a low yield of direct photons would entail a higher direct photon elliptic flow. This means that observing both a high yield and elliptic flow of direct photons would pose a strong question on our current understanding of the physics that governs the evolution of the Quark Gluon Plasma.

While early results of the direct photon elliptic flow with the photon conversion method were already included in his Master thesis, during the following two years he could finalize this work, in very close collaboration with Dmitri Peresunko, who performed the same measurement using the PHOS calorimeter, and Klaus Reygers, who joined them in the effort of combining the measurements and extracting the final results using a Bayesian approach.

In the last months, Mike and his colleagues worked hard to put together a paper on this topic – which was published on arXiv on May 14 – and to be able to present these results at Quark Matter 2018. “Being one of the poster prize winners, and being able to give a flash talk during the closing plenary session, has been an honour for me and a reward for all the work done,” comments Mike. “Now, I’m looking forward to what our future measurements will reveal.

A Ph.D. student at the Indian Institute of Technology Indore working under the supervision of Raghunath Sahoo, Sushanta Tripathy joined the ALICE experiment in January 2016 thanks to the DST-INSPIRE fellowship of the Indian Government. He has been involved since the beginning in the activities of the light flavour working group, focusing in particular on the study of resonances. During this period, he studied the production of the ϕmeson in pp collisions at different beam energies and as a function of charged particle multiplicity.

The measurement of ϕ meson production in small systems is very important and interesting since it gives insight into strangeness production and helps in the search for onset of collectivity in small systems,” explains Sushanta. “Currently, I am looking into the event shape dependence of the ϕ meson production in pp collisions at 5.02 TeV.”

He also carried out some hardware monitoring and maintenance activities, which allowed him to work underground at the experimental site: “It has been a memorable experience!” he states enthusiastically.

Sushanta participated in the Quark Matter conference with a poster about recent results on collision energy and multiplicity dependence of the ϕmeson production at mid-rapidity. “When I was informed that it had been included in the list of the 10 best posters, I was very excited,” Sushanta comments. “It has been a unique and incredible experience for me to deliver a plenary flash talk in front of heavy-ion physics community from all around the world. I am very thankful to my thesis supervisor and to the ALICE collaboration for giving me such an opportunity to work at the research frontiers.”

Alessandra Lorenzo is the youngest of the group, since she has recently concluded her Master studies at the University of Bologna. Supervised by Francesca Bellini, she worked on the first ALICE measurement of f0(980) production in minimum bias pp collisions at 5.02 TeV at mid-rapidity, which is important to provide a reference for further studies of the f0(980) resonance in high-multiplicity events.

Last May she participated for the first time in an international conference, Quark Matter 2018, where she contributed a poster on the topic of her Master thesis. This work earned her a poster prize: “I was very happy with this award, since I was given the opportunity to present my research in a five-minute talk,” Alessandra comments. “I explained what we can learn from f0(980) and why the signal extraction was so challenging; then, I commented the first results in terms of pT-dependent production yields and in comparison to the production yields of other resonances and stable hadrons.

Kunal Garg is a Ph.D. student at the University and INFN of Catania, working with Angela Badala and Franco Riggi. He became a member of the ALICE experiment in December 2015, after completing his Master studies at the National Institute of Science Education and Research (NISER) in Bhubaneswar, India. “I was very happy to be able to join a LHC experiment,” comments enthusiastically Kunal, “since working at CERN was a dream for me”.

Currently, he is analysing ALICE data of pp collisions at 13 TeV to study the properties of the charged K* resonance. This is a very short-lived strange resonance with a lifetime of about 4 fm/c, thus it can provide valuable information about the hadronic phase formed in the heavy-ion collisions and, maybe, in the high multiplicity pp collisions as well. Its production in minimum bias pp collisions represents a baseline for heavy-ion collision measurements and helps in understanding hadron production processes – constraining theoretical models – and in studying strangeness production.

He is also working with his group in Catania on the ITS upgrade for Run 3. 

Kunal participated in the LHCP 2018 Conference with a poster on measurements of the K∗(892)±resonance in pp collisions at 5.02 TeV, 8 TeV and 13 TeV and was given the possibility to present his work in a flash talk, as a best poster award. “I did not expect to win the prize but I’m extremely grateful and happy for it,” he declares. “I surely want to continue doing physics because my curiosity is not yes satisfied and I hope that I will be able to keep working in ALICE after the end of my PhD.”