BERLIN (AP) — German researchers studying the spread of the coronavirus packed a Leipzig arena with volunteers on Saturday, collecting data in a “real life” simulation of a pop concert with strict health and safety controls. About 1,500 people took part in the experiment run by the University Hospital in Halle. Researchers equipped each volunteer with contact tracers to record their routes and the path of the aerosols they emitted. Fluorescent disinfectants were used to highlight which surfaces were touched most frequently. German pop singer Tim Bendzko appeared on stage to create as realistic a reaction from the crowd as possible for three scenarios: no social distancing, some distancing and strictly enforced distancing.