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Double beta of U-238

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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) (talkcontribs) 12:26, 13 February 2019 (UTC)[reply]


Untitled

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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)[reply]

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)[reply]

About the neutrinoless double beta decay

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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)[reply]

Contradictory information about Ca-48

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The text states that single beta decay of Ca-48 is possible but the entry for Ca-48 states that double beta decay is the only possible decay mode for this nuclide. 69.72.27.106 (talk) 07:47, 15 February 2011 (UTC)[reply]

Single beta decay to 48Sc is allowed just looking at energetics. The reason why it does not happen is because all the facts are conspiring against it. First of all you have the problem of angular momentum conservation; there's a huge spin mismatch between 48Ca (zero spin as even-even) and all the energetically possible states of 48Sc to decay to. The one with the lowest spin is an excited state with spin 4, resulting in a fourth-forbidden decay that ends up being ridiculously slow. The decay also does not release very much energy (only about 0.15 MeV), so the momentum of the outgoing electron and antineutrino is also very small. So pR/ħ is tiny (about 0.01), and since this is a fourth-forbidden decay we are looking at ((pR/ħ)−2)4, which is on the order of 1016, as a hindrance factor. And furthermore there is also more than one final state for the daughter to decay to, and with that minuscule energy release we have to throw in another hindrance factor of 103 for that.
The end result is that while single beta decay for 48Ca is possible energetically, it is so hindered that double beta decay is actually more likely to happen first. The same thing happens with 96Zr. Double sharp (talk) 14:58, 16 May 2017 (UTC)[reply]

Xenon contradicts the neutrinoless measurement with germanium.

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The latest results from the xenon expriments [1] [2] 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)[reply]

References

  1. ^ Auger, M. (2012). "Search for Neutrinoless Double-Beta Decay in ^{136}Xe with EXO-200". Physical Review Letters. 109 (3). doi:10.1103/PhysRevLett.109.032505. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
  2. ^ Gando, A (2012). "Limit on Neutrinoless ββ Decay of 136Xe from the First Phase of KamLAND-Zen and Comparison with the Positive Claim in 76Ge". arXiv:1211.3863. {{cite arXiv}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

The double +/- error or margins of error in the half life chart is very confusing

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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)[reply]
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)[reply]

Searches for neutrinoless decay

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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 (talkcontribs) 19:58, 4 November 2014 (UTC)[reply]

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)[reply]

Color code??

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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, 48Ca, 70Zn, 76Ge, 80Se, 82Se, 86Kr, etc.

Could someone please explain what the red color is supposed to mean? Dirac66 (talk) 02:40, 22 April 2019 (UTC)[reply]

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)[reply]
Thank you, that is clear now. Dirac66 (talk) 18:22, 23 April 2019 (UTC)[reply]

Reference for "35 naturally occurring isotopes capable of double beta decay"

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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)[reply]

That paper is already cited in the article. Ruslik_Zero 20:38, 13 May 2021 (UTC)[reply]

Theoretical double beta status of beta-stable even-even nuclides

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The status of 222Rn is disputed, but I believe that it is beta-stable; idem for the following sections.

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*, 222*
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)[reply]

List of theoretical double beta decay energies

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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# [1]
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
222Rn* β−β− 2052
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)[reply]

In order to have a picture of the difficulty to observed double EC for the nuclides marked with red above, I tried to use a simple model to estimate the half-lives, which is . I chose a = 8.16 and b = 24.76.

Nuclide (estimated) -lg(branching ratio)
(148Gd)* 20.79 1.94 18.85
150Gd* 23.86 6.25 17.61
152Gd 35.09 14.03 21.06
154Dy* 20.51 6.15 14.36
174Hf 24.41 16.85 7.56
180W 31.64 18.26 13.38
184Os 23.44 13.05 10.39
190Pt 23.61 11.68 11.93
212Rn* 22.86 -4.34 27.20
214Rn* 31.49 -14.07 45.56
218Ra* 23.48 -12.10 35.58
224Th* 24.21 -7.59 31.80
230U* 25.78 -1.24 27.02
236Pu* 27.54 0.46 27.08
242Cm* 33.44 -0.35 33.79
252Fm* 25.63 -2.54 28.17

129.104.241.214 (talk) 16:06, 9 March 2024 (UTC) [reply]

References

  1. ^ 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

Double beta decay & Double election capture nuclides can be measured by geochemistry method

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I only include nuclides which its decay haven't been discovered

  • 40Ca (alkali earth metal) => 40Ar (noble gas)

50Cr (moderate siderophile) => 50Ti (lithophile) 64Zn (chalcophile/lithophile) => 64Ni (siderophile)

  • 80Se (chalcophile) => 80Kr (noble gas)
  • 84Sr (alkali earth metal) => 84Kr (noble gas)

94Zr (lithophile) => 94Mo (moderate siderophile) 92Mo (moderate siderophile) => 92Zr (lithophile) 98Mo (moderate siderophile) => 98Ru (orthodox siderophile) 96Ru (orthodox siderophile) => 96Mo (moderate siderophile) 110Pd (orthodox siderophile) => 110Cd (chalcophile) 106Cd (chalcophile) => 106Pd (orthodox siderophile) 108Cd (chalcophile) => 108Pd (orthodox siderophile)

  • 132Ba (alkali earth metal) => 132Xe (orthodox siderophile)
    • 180W (moderate siderophile) => 180Hf (lithophile)
    • 186W (moderate siderophile) => 186Os (orthodox siderophile)
    • 184Os (orthodox siderophile) => 184W (moderate siderophile)
    • 198Pt (solid siderophile) => 198Hg (liquid chalcophile)
    • 196Hg (liquid chalcophile) => 196Pt (solid siderophile)

204Hg (liquid chalcophile) => 204Pb (solid chalcophile) Some cases below might be less exactly to discover 136Ce (Lanthanide) => 136Ba (alkali earth metal) 138Ce (Lanthanide) => 138Ba (alkali earth metal)

    • 176Yb (Lanthanide lithophile) => 176Hf (non lathanide lithophile)
    • 174Hf (non lanthanide lithophile) => 174Yb (Lathanide lithophile)
  • These decays were very ideal to discovery because noble gas is trapped in solid mineral
Where did you find this data? Is this your Original Research? 77.188.16.51 (talk) 21:19, 26 July 2024 (UTC)[reply]

Theoretical double decay directions

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Here mass numbers in red indicate that at least one isobar of these mass number is not primordial, so isobars would not get mixed up in natural samples. There are at most four pairs of natural isobars of two elements, but if there are exactly four then one of the element must be xenon, which is a gas and can be easily separated from other substances.

Z change Mass numbers Z change Mass numbers QEC of other isotopes (keV) Qβ- of other isotopes (keV)
18→16 36 16→18
20→18 40 18→20
22→20 20→22 46, (48) 44Ti = 267.63
24→22 50 22→24
26→24 54 24→26
28→26 56 26→28
30→28 64 28→30
32→30 30→32 70 68Ge = 106.34
34→32 74 32→34 76
36→34 78 34→36 80, 82
38→36 84 36→38 86
40→38 38→40 88Zr = 676 90Sr = 545.86
42→40 92 40→42 94, (96)
44→42 96 42→44 98, 100
46→44 102 44→46 104
48→46 106, 108 46→48 110
50→48 112 48→50 114, 116
52→50 120 50→52 122, 124
54→52 124, 126 52→54 128, 130
56→54 130, 132 54→56 134, 136
58→56 136, 138 56→58 140Ba = 1049.66
60→58 58→60 142 140Nd = 443.5
62→60 144 60→62 146, 148, 150
64→62 (148), 150, 152 62→64 154
66→64 154, 156, 158 64→66 160
68→66 162, 164 66→68 166Dy = 486.778
70→68 168 68→70 170
72→70 174 70→72 176
74→72 180 72→74 182Hf = 374.69
76→74 184 74→76 186
78→76 190 76→78 192
80→78 196 78→80 198
82→80 80→82 204 202Pb = 49.7
84→82 82→84 208Po = 1400.31 210Pb = 63.486
86→84 212, 214 84→86 216
88→86 218 86→88 220, 222
90→88 224 88→90 226
92→90 230 90→92 232
94→92 236 92→94 238
96→94 242 94→96 244
98→96 96→98 248 246Cf = 123.3
100→98 252 98→100 254, 256, 258(?)
102→100 258 100→102 260, 262(?)

14.52.231.91 (talk) 06:56, 15 August 2024 (UTC)[reply]

Which nuclides have similar alpha and double beta half-lives in theory?

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By similarity I means that the two half-lives differ by at most 3 orders of magnitude. I use theoretical alpha half-lives from 1908.11458.

I think there are 146Nd, 156Dy, 164Er and 168Yb (see above for their double beta energies). The other nuclides:

142Ce = 2β-;

148,150Nd = 2β-;

144Sm = 2β+;

148,150,152Gd = α, 160Gd = 2β-;

154Dy = α, 158Dy = 2β+;

162Er = 2β+, 170Er = 2β-;

176Yb = 2β-;

174Hf, 180W, 184Os, 190Pt = α;

186W, 192Os, 198Pt, 204Hg = 2β-

196Hg = 2β+. 103.166.228.86 (talk) 10:42, 5 September 2024 (UTC)[reply]

Is α decay energetically possible for 204Hg? I had been under the impression that it was not. Double sharp (talk) 04:34, 9 September 2024 (UTC)[reply]
It is not, so 204Hg can only decay by 2β (along with 150Nd, 144Sm, 154Sm, and 160Gd) :) 103.166.228.86 (talk) 15:24, 9 September 2024 (UTC)[reply]
So I suppose you are then listing which decay mode dominates between α and β? Double sharp (talk) 03:57, 10 September 2024 (UTC)[reply]
Yes, exactly :) 129.104.241.231 (talk) 10:58, 19 September 2024 (UTC)[reply]
See here for predicted decay modes of 156Dy. So alpha decay would be ~1% compared to double beta decay. But considering that single beta decays of 48Ca and 96Zr, which have potentially greater branching ratio, are still unknown... 129.104.241.68 (talk) 22:06, 29 September 2024 (UTC)[reply]

Notable nuclides that are energetically allowed to undergo 3β or 4β

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Theoretical decay energies are in unit of keV. Only ground states of daughters are considered.

Decay mode 48Ca 96Zr 150Nd Decay mode 148Gd 154Dy
β- 279 164 - β+ 28 -
- 4268 3356 3371 + 3067 3312
- 253 383 1112 + 597 1344
- - 642 2084 + 1139 2062

129.104.241.231 (talk) 11:07, 19 September 2024 (UTC)[reply]