The International Masterclasses 2015, taking place over a five-week period (25 February – 2 April), finished just before Easter . This year saw a record participation with more than 210 institutes in 42 countries. More than 10 500 students were introduced to the fascinating world of particle physics and had the opportunity to analyse data from one of the LHC experiments.
ALICE masterclasses took place in 15 institutes, CERN being one of them. One session took place on March 3, with a class of 8 students accompanied by a teacher from the Collège Rousseau in Geneva. A second session took place on March 27, with a class (terminal scientifique) from the Lycée George Brassens, Rive de Gier; this time there were 32 students accompanied by 3 teachers, and they had made a two-and-a-half hour trip to come to CERN from the region of St. Etienne.
The novelty this year was that the masterclasses took place in CERN's s’cool lab, a new teaching facility for modern physics at CERN.
The s’cool lab focuses on hands-on activities, and offers the possibility to high-school students to perform experiments (such as making their own cloud chamber or studying X-rays). In addition it is equipped with video- conference facilities and a number of laptops, and it was the latter that we used for this year’s masterclasses. We also made use of the virtual machine containing the ALICE masterclass packages in the newly launched CERN Open Data portal.
The students started their day with visits of the Synchrocyclotron and the Universe of Particles exhibition in the Globe. They were then introduced to particle physics and to ALICE’s quest of the primordial matter, the quark-gluon plasma, as well as the particulars of the ALICE experiment. After lunch they analysed data from proton and lead collisions recorded by ALICE, studying V0 decays of strange particles such as neutral kaons and lambdas; combining the results of their analysis they observed strangeness enhancement in the case of lead collisions. At the end of the day they joined a video conference moderated by ALICE physicists at CERN; in this way they had the opportunity to discuss their results with participants from other Institutes (Nantes, Sao Paulo, Prague and Trieste), in the same way that big collaborations “meet” over vidyo. It was a long day for both classes, especially those who had another two-and-half hours by bus to go back, but they seemed satisfied from their experience.
The events were organized by the CERN local communications group and had the support of the CERN education group. ALICE members gave the introductory lectures and helped the students during the analysis session.
In addition, a third session took place just after Easter, this time in the CERN Training Centre, for a class from New Zealand, who had wanted to combine a CERN visit with a particle physics masterclass.
We are now collecting feedback from all involved. Soon we will have to get ready for the 2016 sessions. Those who did not have this experience yet are strongly encouraged to give it a try. It takes some effort - like everything - but the excitement and enthusiasm of the students make it worth it.