High-pressure xenon gas electroluminescent TPC for 0-ν ββ-decay search

A high-pressure xenon gas TPC can provide both event topology information and optimized energy resolution for the detection of ββ decay in 136Xe. The result of optimization indicates that, at the 136Xe Q-value of 2480 keV, an energy resolution of δE/E<5×10−3 FWHM may be realizable, even at the 1000 kg scale. Signal detection by electroluminescence appears essential to realize this performance. A specific method for generation and detection of the electroluminescent signal and particle tracking in high-pressure xenon gas is advanced. Strengths and weaknesses of high-pressure xenon gas TPC detectors are evaluated and compared to detectors based on liquid xenon.