New limits on double beta decay of 136Xe

Abstract A Xenon TPC with an active volume of 207 liters has been built to study the neutrinoless double beta decay in 136 Xe. Data were taken in the Gotthard Underground Laboratory with 5 atm of xenon enriched to 62.5% in 136 Xe. A total of 6830 hours of data has been taken. New limits on neutrino mass and majoron decay are presented.