Talk:Double beta decay

message: Double beta of u-238 is listed in the table. Is this really possible? It seems to be energetically impossible since the Q value would be negative using data from https://www-nds.iaea.org/relnsd/vcharthtml/VChartHTML.html  — Preceding unsigned comment added by Peter Andersson (UU) (talk • contribs) 12:26, 13 February 2019 (UTC)
thread_title:  Double beta of U-238 

message: I would like to make a few comments about double beta decay page:
1) I do not completely agree that double beta decay was discovered in 1986; it has been seen before in geochemical experiments. In 1986, M. Moe discovered two-neutrino mode of 82Se in direct measurement with TPC at UC Irvine.
2) 48Ca, 96Zr can also decay via a single beta decay and it has been seen recently.
3) For more details, please visit http://www.nndc.bnl.gov/bbdecay.
Pritychenko 00:39, 18 September 2007 (UTC)
replies: text: Thank you, but I don't know about observation of single beta for 48Ca and 96Zr, could you please provide the references? --V1adis1av 21:47, 22 September 2007 (UTC)
thread_title: Untitled

message: I don't agree when you say that an neutrino is an Majorana particle, indeed, in 1955 Davis used and reaction with an neutrino and 37Cl wich produces and electron an 37Ar, this is a clasical proof that the neutrinos are Dirac particles. I saw a reference in Wong pp. 202-203.  —Preceding unsigned comment added by 201.141.39.114 (talk) 22:49, 6 October 2007 (UTC)
thread_title:  About the neutrinoless double beta decay 

message: The latest results from the xenon expriments   are in tension with the claimed measurement from Heidelberg-Moscow. This is no longer stated on this page. Surely this wants to be said somewhere on this page. Before reinserting this, I was wondering whether there was a reason to delete this. Yes I understand that to refute the measurement can only be achive via a germainium detector but the comparision with xenon shows that with all know nuclear models that the clamed measurement is extremely unlikely to be correct.Dja1979 (talk) 20:13, 16 December 2012 (UTC)
thread_title:  Xenon contradicts the neutrinoless measurement with germanium. 

message: I cannot sort out what the poster means by the doubled sets +/- in the half life chart. Is the first referencing, margin of error and the second a confidence interval? That doesn't make much sense to me. Plus, I am not aware of such usage in scientific publications. More frustrating, is that the reference cited just previous to the chart is closed access, and the abstract, as is usual, reveals little. Of course closed access is symptomatic of current subscriber funded journal system, yet open access, save a few highly reliable forums, can be notoriously unreliable. But I digress. The double errors should definitely be disambiguated and attached to a reference which is open to the public, that way it can be investigated further if so desired. Moreover, this so called "double error" must not be in common usage (or a valid term for the thing) as Google reveals nothing, nor do the top results for "margin of error." I will be adding a please clarify tag as soon as I figure out how, which as a new Wikipedian (on the editing side) may take a second. I am genuinely interested in the meaning of this, as knowledge of error formatting beyond the confidence bars on a graph and the plus minus sign would be useful in my future work. That is, should this prove a genuine notation rather than a copy editing issue. inthedryer (talk) 8:54, 17 December 2013 (EST)
:There are two different types of error associated with the measurement. There is the statistical error, which is the error associated with the amount of data collected and then there is the systematic error. The systematic error is the error associated with the technique (experiment) used. They are usually quoted separately, as they are unrelated, and gives the reader a quick idea on whether the number can be improved by just waiting and taking more data, or whether a new technique for analysing the data/new experiment is needed. It is standard to report results in this way, at least in particle physics.Dja1979 (talk) 03:25, 5 February 2014 (UTC)
replies: text: Thank-you for the clarification. Now that it is explained, it makes sense. Also, the footnote is very well written. inthedryer (talk) 03:01, 28 March 2015 (UTC)
thread_title:  The double +/- error or margins of error in the half life chart is very confusing 

message: I've tried to update the experiment list and determine the status of the collorations and which have major results and deserve their own articles.
I'd like a dediiated page for neutrinoless decay, which could go into the search history, status, and plans in detail.
*MOON seems to have faded away, but it seems no one announces when science collaborations definitely end.  MOON-1 prototype happened and people are still working on Mo, so I kept it in the proposed list.
*DCBA, COBRA are clearly running, but no major results  — Preceding unsigned comment added by Timetraveler3.14 (talk • contribs) 19:58, 4 November 2014 (UTC)
thread_title:  Searches for neutrinoless decay 

message: Would it be better to discuss this very similar process in this article? It is a bit odd not to find much about Kr-78 and Ba-130 here. Double sharp (talk) 06:56, 8 September 2017 (UTC)
thread_title:  [[Double electron capture]] 

message: The section Known double beta decay isotopes has lists of nuclides with several nuclides given in red, as:
:The following known nuclides with A ≤ 260 are theoretically capable of double beta decay: 46Ca, , 70Zn, , 80Se, , 86Kr, etc.
Could someone please explain what the red color is supposed to mean? Dirac66 (talk) 02:40, 22 April 2019 (UTC)
replies: text:  I've added some text to explain it. See if it helps. Basically, it's measured and unmeasured isotopes. Dja1979 (talk) 15:49, 23 April 2019 (UTC)
replies: text:  Thank you, that is clear now. Dirac66 (talk) 18:22, 23 April 2019 (UTC)
thread_title:  Color code?? 

message: can be found here https://doi.org/10.1006/adnd.2001.0873
on page 85: "First of all, from the total number of
35 potential 0ν2β − decay candidates, 28 have been studied
in direct experiments, [...]"
maybe someone who knows more about Wikipedia wants to add that reference109.239.240.233 (talk) 17:58, 13 May 2021 (UTC)
replies: text: That paper is already cited in the article. Ruslik_Zero 20:38, 13 May 2021 (UTC)
thread_title:  Reference for "35 naturally occurring isotopes capable of double beta decay" 

message: Note: I do not list 222Rn as being almost beta-stable, as its predicted 6.7×104 − 2.4×108 years β− half-life is far too short compared with a double beta decay; this is because the spin change 0+ → 2− (ΔJΔπ = 2−, 1 forbidden unique) of 222Rn → 222Fr is not high. The estimated β− half-life of 222Rn is similar to the EC half-life of 202Tl and the β− half-life of 250Cm.
Z  	Double β+        	No double beta decay	Double β−
18 	36               	38, 40              	
20 	40               	42, 44              	46, (48)
22 	                 	46, 48, 50          	
24 	50               	52, 54              	
26 	54               	56, 58              	
28 	58               	60, 62, 64          	
30 	64               	66, 68              	70
32 	                 	70, 72, 74          	76
34 	74               	76, 78              	80, 82
36 	78               	80, 82, 84          	86
38 	84               	86, 88              	
40 	                 	90, 92              	94, (96)
42 	92               	94, 96              	98, 100
44 	96               	98, 100, 102        	104
46 	102              	104, 106, 108       	110
48 	106, 108         	110, 112            	114, 116
50 	112              	114, 116, 118, 120  	122, 124
52 	120              	122, 124, 126       	128, 130
54 	124, 126         	128, 130, 132       	134, 136
56 	130, 132         	134, 136, 138       	
58 	136, 138         	140                 	142
60 	                 	142, 144            	146, 148, 150
62 	144              	146*, 148, 150, 152 	154
64 	(148)*, 150*, 152	154, 156, 158       	160
66 	154*, 156, 158   	160, 162, 164       	
68 	162, 164         	166, 168            	170
70 	168              	170, 172, 174       	176
72 	174              	176, 178, 180       	
74 	180              	182, 184            	186
76 	184              	186, 188, 190       	192
78 	190              	192, 194, 196       	198
80 	196              	198, 200, 202       	204
82 	                 	204, 206, 208       	
84 	                 	210*, 212*, 214*    	216*
86 	212*, 214*       	216*, 218*          	220*
88 	218*             	220*, 222*, 224*    	226*
90 	224*             	226*, 228*, 230*    	232
92 	230*             	232*, 234*, 236*    	238
94 	236*             	238*, 240*, 242*    	244*
96 	242*             	244*, 246*          	248*
98 	                 	248*, 250*, 252*    	254*, 256*, 258*?
100	252*             	254*, 256*, 258*    	260*, 262*?
Mass numbers with a * = non-primordial
() = not beta-stable but almost be, single beta decay hindered by high spin change
green = double beta decay observed
red = branching ratio of double beta decay is expected to be too small compared to alpha decay (most likely < 10-10%) to make the decay mode observable
orange = small branching ratio (perhaps between 10-10% and 10-8%) but there is still some chance to observe it
The same applies also in the next section. 129.104.241.214 (talk) 02:12, 9 March 2024 (UTC)
thread_title:  Theoretical double beta status of beta-stable even-even nuclides 

message: Data of decay energies taken from here.
Nuclide 	Decay mode	Double EC/β− decay energy (keV)	Note
164Er   	β+β+      	23.33                          	
260Fm*  	β−β−      	32.6#                          	If 261Md is beta-stable, then the isobaric pair 260Fm-260No surrounds N = 159 which has no beta-stable isotones and Z = 101 which has two beta-stable isotopes
152Gd   	β+β+      	54.16                          	The isobaric pair 152Sm-152Gd surrounds N = 89 which has no beta-stable isotones and Z = 63 which has two beta-stable isotopes
146Nd   	β−β−      	70.83                          	The isobaric pair 146Nd-146Sm surrounds Z = 61 which has no beta-stable isotopes and N = 85 which has two beta-stable isotones
242Cm*  	β+β+      	86.43                          	The isobaric pair 242Pu-242Cm surrounds N = 147 which has no beta-stable isotones and Z = 95 which has two beta-stable isotopes
98Mo    	β−β−      	112.75                         	The isobaric pair 98Mo-98Ru surrounds Z = 43 which has no beta-stable isotopes and N = 55 which has two beta-stable isotones
80Se    	β−β−      	132.56                         	The isobaric pair 80Se-80Kr surrounds N = 45 which has no beta-stable isotones and Z = 35 which has two beta-stable isotopes
180W    	β+β+      	143.52                         	
214Rn*  	β+β+      	149.76                         	
248Cm*  	β−β−      	152.44                         	
40Ca    	β+β+      	193.22                         	The isobaric pair 40Ar-40Ca surrounds N = 21 which has no beta-stable isotones and Z = 19 which has two beta-stable isotopes
108Cd   	β+β+      	271.58                         	The isobaric pair 108Pd-108Cd surrounds N = 61 which has no beta-stable isotones and Z = 47 which has two beta-stable isotopes
158Dy   	β+β+      	284.24                         	
220Rn*  	β−β−      	340.55                         	
122Sn   	β−β−      	368.08                         	The isobaric pair 122Sn-122Sb surrounds N = 71 which has no beta-stable isotones and Z = 51 which has two beta-stable isotopes
192Os   	β−β−      	412.36                         	The isobaric pair 192Os-192Pt surrounds N = 115 which has no beta-stable isotones and Z = 77 which has two beta-stable isotopes
204Hg   	β−β−      	419.49                         	The isobaric pair 204Hg-204Pb surrounds N = 35 which has no beta-stable isotones and Z = 29 which has two beta-stable isotopes
36Ar    	β+β+      	432.13                         	The isobaric pair 36S-36Ar surrounds N = 19 which has no beta-stable isotones and Z = 17 which has two beta-stable isotopes
254Cf*  	β−β−      	436.6                          	
236Pu*  	β+β+      	455.99                         	
226Ra*  	β−β−      	472.04                         	
186W    	β−β−      	489.94                         	
114Cd   	β−β−      	539.96                         	
170Er   	β−β−      	654.35                         	
54Fe    	β+β+      	679.69                         	
138Ce   	β+β+      	692.7                          	
230U*   	β+β+      	750.33                         	
252Fm*  	β+β+      	782.99                         	
196Hg   	β+β+      	820.37                         	
134Xe   	β−β−      	825.38                         	
232Th   	β−β−      	837.57                         	
132Ba   	β+β+      	845.24                         	
128Te   	β−β−      	867.95                         	
126Xe   	β+β+      	895.64                         	
46Ca    	β−β−      	988.35                         	
70Zn    	β−β−      	998.46                         	The isobaric pair 70Zn-70Ge surrounds N = 39 which has no beta-stable isotones and Z = 31 which has two beta-stable isotopes
198Pt   	β−β−      	1046.77                        	
258No*  	β+β+      	1053#                          	
176Yb   	β−β−      	1083.38                        	
64Zn    	β+β+      	1095.28                        	The isobaric pair 64Ni-64Zn surrounds N = 35 which has no beta-stable isotones and Z = 29 which has two beta-stable isotopes
174Hf   	β+β+      	1102.57                        	
94Zr    	β−β−      	1142.87                        	
238U    	β−β−      	1144.2                         	
50Cr    	β+β+      	1166.77                        	
224Th*  	β+β+      	1168.7                         	
102Pd   	β+β+      	1172.57                        	
74Se    	β+β+      	1209.3                         	
154Sm   	β−β−      	1251.62                        	
86Kr    	β−β−      	1258.01                        	
150Gd*  	β+β+      	1288.17                        	
104Ru   	β−β−      	1301.17                        	
244Pu*  	β−β−      	1351.9                         	
190Pt   	β+β+      	1382.5                         	
142Ce   	β−β−      	1416.72                        	
168Yb   	β+β+      	1421.69                        	
218Ra*  	β+β+      	1433.1                         	
184Os   	β+β+      	1450.76                        	
216Po*  	β−β−      	1528.27                        	
256Cf*  	β−β−      	1553                           	
92Mo    	β+β+      	1648.48                        	
120Te   	β+β+      	1700.09                        	
212Rn*  	β+β+      	1709.41                        	
160Gd   	β−β−      	1729.44                        	
144Sm   	β+β+      	1780.81                        	
84Sr    	β+β+      	1786.75                        	
162Er   	β+β+      	1843.79                        	
112Sn   	β+β+      	1918.85                        	
58Ni    	β+β+      	1925.32                        	
148Nd   	β−β−      	1928.77                        	
110Pd   	β−β−      	2003.8                         	
156Dy   	β+β+      	2011.97                        	
76Ge    	β−β−      	2039                           	
124Sn   	β−β−      	2287.8                         	
136Ce   	β+β+      	2418.2                         	
136Xe   	β−β−      	2461.8                         	
130Te   	β−β−      	2530.3                         	
130Ba   	β+β+      	2619.71                        	
96Ru    	β+β+      	2718.03                        	
106Cd   	β+β+      	2769.58                        	
116Cd   	β−β−      	2808.71                        	
78Kr    	β+β+      	2845.96                        	
124Xe   	β+β+      	2864.04                        	
82Se    	β−β−      	2995.5                         	
100Mo   	β−β−      	3034.68                        	
(148Gd)*	β+β+      	3065.94                        	Not beta-stable, but single beta decay hindered by high spin change 0+ → 5− (ΔJΔπ = 5−, 5 forbidden non-unique)
154Dy*  	β+β+      	3314.66                        	
(96Zr)  	β−β−      	3347.7                         	Not beta-stable, but single beta decay hindered by high spin change 0+ → 6+ (ΔJΔπ = 6+, 6 forbidden non-unique)
150Nd   	β−β−      	3367.68                        	
(48Ca)  	β−β−      	4273.6                         	Not beta-stable, but single beta decay hindered by high spin change 0+ → 6+ (ΔJΔπ = 6+, 6 forbidden non-unique)
129.104.241.214 (talk) 02:38, 9 March 2024 (UTC)
thread_title:  List of theoretical double beta decay energies