Focus on: Daniel Tapia Takaki

When did you hear about ALICE for the first time?

I read an article about the ALICE experiment written by Prof. Gerardo Herrera in 2002. That year I had applied for a summer scholarship award given by the Mexican Academy of Science, which allowed me to spend two months working with a professor at a different university. I went from Hermosillo, Sonora to Mexico City to work with Gerardo that summer. At that time they were constructing the ALICE VZERO-A detector. I joined some of their technical discussions and visited their lab at CINVESTAV several times, but my summer project at the end was more oriented to medical imagining physics.

Why did you go to Birmingham for your PhD?

VZERO-A is a triggering detector. I found triggering a fascinating thing, something you really need to collect data at the LHC. I wanted to carry out a PhD and learn more about triggering as well as heavy-ion physics. I found out that the Birmingham group was the leader of the ALICE Central Trigger Processor, and thought that if I want to become an expert on triggering I should study there. I also found the study of strangeness production in heavy-ion physics quite appealing, and was aware of their work in that direction with NA57, a former CERN SPS experiment. The postgraduate admission advisor at Birmingham was Prof. Dave Charlton, who is now the spokesperson of the ATLAS collaboration. He encouraged me to apply for several scholarships. I obtained two prestigious scholarships from the UK and the European Union that allowed me to study in Birmingham. For my PhD I worked on several projects under the supervision of Dr. Orlando Villalobos Baillie and Prof. David Evans. Indeed, I was involved in the Central Trigger Processor, and it was such a great experience for me to work with many colleagues from different countries. Apart from my trigger work, I studied strange resonance production and led the Phi meson analysis. I also made a feasibility study of exclusive dilepton production in pp collisions.

What did you do after your PhD?

When I finished my PhD in December 2007, I stayed in Birmingham for a few more months as a research associate, and then moved to Orsay to work with the ALICE team led by Prof. Bruno Espagnon at Paris-sud University. I worked for the Orsay group for 5 years. It was also a great experience that allowed me to work for several projects in the context of the ALICE Muon spectrometer.

How was your experience in Paris?

I enjoyed and learned a lot working for the muon project. When I joined the project there were many preparations for the first LHC run. After a few months we had this incident in the LHC in September 2008 but, as you know, we all recovered and the LHC has been working beyond expectations.

How did you feel after the first LHC collisions?

I was part of the trigger experts at point 2 that day and it was a very special moment for all of us. Everyone was quite enthusiastic in November 2009. Prof. Guy Paic and I visually scanned all the 284 proton-proton events collected after a couple of hours. We reported our findings the next morning. We got the same charged particle multiplicity value that other analysis people found.

What did you do after that?

I was the co-leader of the first J/psi analysis in proton-proton with the Muon spectrometer together with Dr. Enrico Scomparin. I started supervising the work of several ALICE students from France and Mexico. At the same time, I continued working as trigger on-call expert in many occasions, including when we had the Pb-Pb runs.

How did you start working on ultra-peripheral heavy-ion collisions?

During my PhD I became very interested in photon-induced processes in proton-proton and heavy-ion collisions. At the time, ALICE did not have a working group on that topic. I first started forming a working group. It was clear that we needed to prepare for the future. Together with Gerardo we put together a Letter of Intent for new scintillator detectors in the forward region, a proposal that is now called AD/AD-A and that is currently being installed at Point 2. In 2010, I started working on ultra-peripheral heavy-ion collisions using the Muon Spectrometer, together with Evgeny Kryshen. We then made a proposal to the ALICE management to have a UPC group where Joakim Nystrand and Eugenio Scapparone were the coordinators. Almost immediately after, Eugenio got promoted to be the convener of a new physics working group. I then officially became the UPC co-leader in 2012, a position that I have kept until now. We are a very productive working group. Our UPC results have already been highlighted in the cover of journals and in review talks at international conferences.

What have been the main challenges?

In order to collect data from ultra-peripheral heavy-ion collisions, unique triggers are required which are often orthogonal to the general triggering strategy. Indeed, we have spent a lot of time in trigger preparations.

Why are you leaving ALICE now?

I have been an Assistant Professor from the University of Kansas since last year. I have continued my association to ALICE as a full member for almost a year now, but will finally move to CMS. My colleagues from Kansas work for the CMS Collaboration, and they would like me to join their efforts. I am very excited about my future projects.

How do you feel?

I am happy and grateful with the experience and skills that I acquired working for the experiment in the last 10 years. Now that I am starting this transition I wish to the ALICE Collaboration, led by Paolo Giubellino, a great success in the future.

What are you plans in the future?

I would like to continue working on ultra-peripheral heavy-ion and proton-proton collisions, and with physics projects in the forward rapidity region. There are many new analyses we can continue exploring which cover several topics in both nuclear and particle physics. I shall create my own group to work on photon-induced reactions with CMS.

What is your suggestion to young people joining this research?

My suggestion is to always try to seek ambitious projects and try to work with clever people, and be ready to support and guide younger students than you. ?I feel fortunate to have worked with many of them; it would be impossible for me to list them all here. Do the best you can to produce the best possible physics results in the context of a collaboration, and be ready for discoveries!

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