Work

Performance evaluation of GYGAG crystals for neutrinoless double beta decay search

Year: 2026

Type: article

Abstract: Neutrinoless double beta decay (0$\nu \beta \beta$) is crucial for confirming the Majorana characteristics of neutrinos. Previous searches for 0$\nu \beta \beta$ decay of $^{160}$Gd using GSO crystals were conducted, but the sensitivity was limited by background $\alpha$ rays from radioactive impurities. To distinguish the backgrounds, PSD (pulse shape discrimination) and energy resolution are essential. GAGG (Gd$_{3}$(Al, Ga)$_5$O$_{12}$) is a $^{160}$Gd-containing crystal that exhibits a higher light yield than GSO and excellent PSD capabilities. GYGAG (Gd$_{3-x}$Y$_x$(Al, Ga)$_5$O$_{12}$) is a variant crystal where a portion of Gd is substituted with yttrium and can have enhanced light yield, motivating its investigation for 0$\nu \beta \beta$ decay searches. In this study, GYGAG crystals with different yttrium concentrations were fabricated and their energy resolution, pulse shape discrimination capability between $\alpha$ and $\gamma$ rays, and scintillation timing characteristics were evaluated for applications in 0$\nu \beta \beta$ decay searches. Y substitution enhanced the light yield, and the best energy resolution was achieved for Gd$_{2.5}$Y$_{0.5}$Al$_2$Ga$_3$O$_{12}$. GYGAG exhibited high pulse shape discrimination performance across various yttrium concentrations.

Source: Progress of Theoretical and Experimental Physics

DOI: 10.1093/ptep/ptag102