First 0 nu half-life limit from the Gotthard xenon time projection chamber

A xenon time-projection-chamber (TPC) with an active volume of 207 liters has been built to study 0 nu and 2 nu double beta decay in 136Xe. The TPC has been installed in the Gotthard Tunnel Underground Laboratory, and is currently taking data with 5 atm of xenon enriched in 62.5% 136Xe. The first 166 hours of data are presented. Based on this data set, the authors deduce a half-life limit of T12/0 nu (0+ to 0+)>6.2*1021 years for the 0 nu mode, at a 90% CL.