A Quantum Sensor for Neutrino Mass Measurements

Table 1

𝑄-values for double 𝛽 transformations determined from Penning-trap mass measurements on the mother and the daughter nuclei. In case where the measurement was performed at two different Penning-trap facilities, only the value with smaller relative mass uncertainty is shown.

Double	Decay	𝑇1/2 (double decay)	N.A. (mother)	𝛿𝑟/𝑟	𝑄-value
decay	type	(years)	(%)		(keV)
^76Ge-^76Se^(a)	0𝜈𝛽𝛽	>7.2×10^20 [11]	7.73	7.8×10^−10∗∗	2039.006 (50) [60]
^74Se-^74Ge^(b)	0𝜈𝜖𝜖	∼5.0×10^43 [61]*	0.89	7.4×10^−10	1209.169 (49) [61]
^96Ru-^96Mo^(c)	0𝜈𝜖𝜖	—	5.54	1.4×10^−9	2714.51 (13) [62]
^100Mo-^100Ru^(b)	0𝜈𝛽𝛽	>2.7×10^22 [11]	9.82	1.8×10^−9	3034.40 (17) [63]
^110Pd-^110Cd^(d)	0𝜈𝛽𝛽	6.8×10^23 [56]	11.72	6.38×10^−9	2017.85 (64) [56]
^112Sn-^112Cd^(b)	0𝜈𝜖𝜖	5.9×10^29 [12]*	0.97	1.5×10^−9	1919.82 (16) [12]
^116Cd-^116Sn^(b)	0𝜈𝛽𝛽	>8×10^21 [11]	7.49	2.0×10^−9	2813.50 (13) [64]
^130Te-^130Xe^(e)	0𝜈𝛽𝛽	>2.2×10^21 [11]	34.08	9.8×10^−11	2527.518 (13) [65]
^136Xe-^136Ba^(e)	0𝜈𝛽𝛽	>1.6×10^22 [11]	8.8573	7.9×10^−11∗∗	2457.83 (37) [55]
^136Ce-^136Ba^(b)	0𝜈𝜖𝜖	>3.2×10^32 [66]*	0.185	3.8×10^−9	2378.53 (27) [66]
^150Nd-^150Sm^(b)	0𝜈𝛽𝛽	>1.5×10^21 [11]	5.638	1.4×10^−9	3371.38 (20) [67]
^152Gd-^152Sm^(c)	0𝜈𝜖𝜖	∼1.0×10^26 [13]*	0.20	1.3×10^−9	55.70 (18) [13]
^156Dy-^156Gd^(c)	0𝜈𝜖𝜖	6.0×10^28 [68]^*#	0.053	7.0×10^−10	2005.95 (10) [68]
^162Er-^162Dy^(c)	0𝜈𝜖𝜖	—	0.139	2.0×10^−9	1846.95 (30) [62]
^164Er-^164Dy^(c)	0𝜈𝜖𝜖	∼1.0×10^30 [69]*	1.601	7.6×10^−10	25.07 (12) [69]
^168Yb-^168Er^(c)	0𝜈𝜖𝜖	—	0.123	1.6×10^−9	1409.27 (25) [62]
^180W-^180Hf^(c)	0𝜈𝜖𝜖	∼5.0×10^27 [70]*	0.12	1.6×10^−9	143.20 (27) [70]

The superscript besides the nuclides in the column “Double decay” serves to indicate the facility where the measurements were performed: ^(a)SMILETRAP, ^(b)YFLTRAP, ^(c)SHIPTRAP, ^(d)ISOLTRAP, and ^(e)MIT trap at FSU. The natural abundances of the daughter nuclei are in general higher compared to those of the mother. ^(*)Assuming 𝑚_𝜈𝑒=1 eV. ^(#)Partial half-life. ^(**) Individual ratios are given with respect to a molecular ion.