A chat with Gin?s Mart?nez Garc?a, new director of SUBATECH

Virginia Greco

On September 1, Gin?s Mart?nez Garc?a started his mandate as director of the SUBATECH research laboratory, located in Nantes (France). A member of the ALICE Collaboration since 1998, he has been the leader of the Nantes ALICE group and of the MFT upgrade project.

 Gin?s Mart?nez Garc?a in a drawing by his daughter, Carla Mart?nez Rivera.

Gin?s Mart?nez, a long-time member of the ALICE Collaboration, has just taken another important step forward in his successful and fast-progressing career, which led him to be recently appointed Director of the SUBATECH laboratory in Nantes (France).

Soon after completing his PhD at the University of Valencia (Spain) in 1994, working on heavy ions at intermediate energies, he obtained a permanent position at the French Centre National de la Recherche Scientifique(CNRS) and joined the Grand Acc?l?rateur National de Ions Lourdslaboratory (GANIL) in Caen (France).

Four years later, he moved to the SUBATECH laboratory, following the group led by Yves Schutz, who had been invited by Hans Gutbrod (director at the time) to take part in their research programme on heavy ions at relativistic energies. Thus, Gin?s joined the PHENIX experiment, which would become operative at RHIC in 2000, and, immediately after, the ALICE experiment, which was in full development phase.

Between 1998 and 2004, with the SUBATECH PHENIX group he studied mainly neutral mesons and photons and worked on the analysis of the high ptsuppression of neutral mesons. “Using gold-gold and deuteron-gold collision data from PHENIX, we were able to perform the first measurement of this suppression and observe for the first time the jet quenching phenomenon,”Gin?s explains. On the ALICE side, he worked on the PHOS electromagnetic calorimeter and was involved in the project, proposed by his group, to build a VETO detector using large area micromegas chambers.

More and more interested in heavy flavour and quarkonia, later he joined the sub-collaboration working on the dimuon spectrometer, a part of the ALICE detector that is optimized for the study of these heavy quark resonances, and in 2003 he became its offline coordinator. In the meanwhile, in 2002, he was appointed leader of the ALICE Nantes group and, in 2005, physics convener (together with Federico Antinori) of the ALICE physics group dedicated to heavy flavour and quarkonia analysis. “At the time, we were also building the detector,” highlights Gin?s, “so it was a very intense period.

When ALICE started to take data – in 2010 – the ALICE group of SUBATECH focused on the study of the J/psi nuclear modification factor, using in particular the ALICE muon spectrometer. This measurement was performed quickly and showed that this factor was much larger than the one observed at RHIC energies. Theoretical models including heavy quark deconfinement and later recombination were able to explain the experimental data.  This important result was later followed by another one: the confirmation of the non-zero J/psi elliptic flow. This pioneering work was started by his post-doc Laure Massacrier (currently at IPN Orsay) and continued by his student Audrey Francisco (now a post-doc at Yale University). He was also involved in the measurements of the electroweak bosons (W and Z) – with his student Zaida Conesa del Valle (IPN Orsay) – and in the first observation of the low-ptJ/psi enhancement in nuclear Pb-Pb collisions – with Laure Massacrier and another student, Antoine Lardeux (now at Oslo University).

In 2013, Gin?s became leader of the Muon Forward Tracker (MFT) project, one of the upgrades of the ALICE detector for the high-luminosity LHC, role from which he stepped down last summer to embrace the new challenge: the direction of the SUBATECH laboratory.

SUBATECH has about 200 employees organized in 8 research groups and 5 services (informatics, electronics, mechanics, radioprotection and administration). It is involved in a large range of research activities in the domain of subatomic physics: particle, astroparticle and nuclear physics and radiochemistry. It also includes groups working on reactors for nuclear energy and applications of radionuclei and particle detectors in the medical field.

I think that one of my skills is the ability to manage people,” Gin?s states, “nevertheless, being the director of SUBATECH is quite a big responsibility and challenge. It is already keeping me very busy: besides following all the research activities carried out at the centre, I need to sit in many decisional meetings with representatives of the institutes that co-operate the laboratory, of other research centres and of external partners.

Anyway,” he continues, “I am also trying to keep a foot in research by supervising the PhD work of two students, who are studying: Oph?lie Bugnon, the previously mentioned low-ptexcess analysing the 2015 Pb-Pb data, and Manuel Guitti?re, the properties of charmonia resonances in high multiplicity pp collisions.”

Gin?s has five years ahead to contribute to the development of the SUBATECH laboratory and implement his vision of it. “A key characteristic of this centre,” he explains, “is its balance between fundamental and applied physics research. I expect important results on both sides.”

He wants the laboratory to continue giving an important contribution to the search for dark matter particle candidates, in particular with the XENON experiment, and to the development of neutrino physics, participating in various experiments: JUNO, which will take place in China, Solid (in Belgium), and the Cubic Kilometre Neutrino Telescope (KM3NeT). Of course, SUBATECH will also keep its strong involvement in the study of the Quark-GluonPlasma, both on the experimental side – with ALICE and its upgrade – and on the theoretical side.

For what concerns applied physics, as Gin?s explains, the laboratory is investing in research on the use of detectors developed for fundamental physics in medical imaging and the employment of some radionuclei (like astatine) in cancer treatment. There are also research lines dedicated to environmental matters, such as the tracing of radionuclei and the analysis of radioactivity in nature.

What will be the next step in his brilliant career? “I cannot tell what will happen after these 5 years,” claims Gin?s, “I might be confirmed for a second mandate or just go back to research. Anyway, at the moment my horizon is the next 5 years and I will do all in my power in order to allow my colleagues to develop the best research they can here at SUBATECH.”

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