Challenges in Double Beta Decay

Table 2

Theoretically evaluated 𝛽𝛽(0𝜈) matrix elements 𝑀^0𝜈 according to different authors and methods. Where needed, values have been scaled to 𝑅₀ = 1.2 fm and 𝑔_𝐴 = 1.25 (𝑀^′0𝜈 = 𝑀^0𝜈(1.25/𝑔_𝐴)²) for a uniform comparison. Ranges refer to variation which arise due to model details.

Isotope	NSM [42]	GCM [45]	QRPA [139–141]	IBM [44]	PHFB [49]
48Ca	0.85	2.37		2.00
76Ge	2.81	4.60	4.20–7.24	4.64–5.47
82Se	2.64	4.22	2.94–6.46	3.81–4.41
96Zr		5.65	1.56–3.12	2.53	2.24	3.46
100Mo		5.08	3.10–6.07	3.73–4.22	4.71	7.77
110Pd				3.62	5.33	8.91
116Cd		4.72	2.51–4.52	2.78
124Sn	2.62	4.81		3.53
128Te		4.11	3.50–6.16	4.52
130Te	2.65	5.13	3.19–5.50	3.37–4.06	2.99	5.12
136Xe	2.19	4.20	1.71–3.53	3.35
148Nd				1.98
150Nd		1.71	3.45	2.32–2.89	1.98	3.70
154Sm				2.51
160Gd				3.63
198Pt				1.88