Energy calibration of the NEXT-White detector with 1% resolution near Q${}_{{\hat{I}}^2{\hat{I}}^2}$ of ${}^{136}$Xe

Abstract

Excellent energy resolution is one of the primary advantages of electroluminescent high pressure xenon TPCs, and searches for rare physics events such as neutrinoless double-beta decay (${\hat{I}}^2\beta 0\hat{I}½$) require precise energy measurements. Using the NEXT-White detector, developed by the NEXT (Neutrino Experiment with a Xenon TPC) collaboration, we show for the first time that an energy resolution of 1% FWHM can be achieved at 2.6 MeV, establishing the present technology as the one with the best energy resolution of all xenon detectors for ${\hat{I}}^2\beta 0\hat{I}½$ searches.

13 pages, 7 figures; accepted to JHEP