CERN researcher Despina Hatzifotiadou called for Greece to address its brain-drain, which saw thousands of youth leave the country to pursue employment opportunities overseas, particularly during the economic crisis. Hatzifotiadou made the comments during a media interview on Tuesday with Greek news agency ANA, saying that to lure bright young people to return to Greece will require more than just individual jobs, it will need a comprehensive and long-term policy for growth that creates prospects. Greeks that do return after having absorbed other cultures, mindsets and ways of working, through their experiences abroad, "can play a very positive role in changing Greek society," Hatzifotiadou acknowledged. She also spoke about the useful role that the Greek scientists participating in major international experiments can play as mentors, guiding and promoting younger Greek colleagues, helping them join research teams and secure funding from programmes, as well as by using their networks and knowledge of how things work to secure orders for Greek companies. When questioned about the next major milestones in her own field, particle physics, Hatzifotiadou said that one of the big unanswered questions at this time concerned the nature of dark matter. "We hope to get some answers after increasing the luminosity of the Large Hadron Collider," she said. Another conundrum, she added, was why matter had prevailed over anti-matter. Scientists worked to verify - or disprove - their theories, she noted, but surprises were always a possibility and also of great interest, since they led to new theories and models. Talking about the work underway to upgrade the luminosity of the LHC, she said this was going as planned and that experiments were also being upgraded in order to use the greater capability and greater scope for discoveries after 2021. At the same time, she added, an analysis of the data collected in previous years until the end of 2018 was underway.