${{\mathit p}}$ MEAN LIFE

INSPIRE   JSON  (beta) PDGID:
S016T
A test of baryon conservation. See the “${{\mathit p}}$ Partial Mean Lives” section below for limits for identified final states. The limits here are to “anything” or are for “disappearance” modes of a bound proton (${{\mathit p}}$) or (${{\mathit n}}$). See also the 3${{\mathit \nu}}$ modes in the “Partial Mean Lives” section. Table$~$1 of BACK 2003 is a nice summary.
LIMIT (years) PARTICLE CL% DOCUMENT ID TECN  COMMENT
$ \bf{>0.96 \times 10^{30}} $ $\bf{{{\mathit p}}}$ 90 1
ALLEGA
2022
SNO+ ${{\mathit p}}$ $\rightarrow$ invisible
$ \bf{>0.9 \times 10^{30}} $ $\bf{{{\mathit n}}}$ 90 2
ALLEGA
2022
SNO+ ${{\mathit n}}$ $\rightarrow$ invisible
• • We do not use the following data for averages, fits, limits, etc. • •
$ >1.3 \times 10^{24} $ ${{\mathit p}}$ 90 3
AGOSTINI
2024A
 HPGE ${{\mathit p}}$ $\rightarrow$ invisible
$ >1.5 \times 10^{24} $ ${{\mathit n}}$ 90 4
AGOSTINI
2024A
 HPGE ${{\mathit n}}$ $\rightarrow$ invisible
$ >3.6 \times 10^{29} $ ${{\mathit p}}$ 90 5
ANDERSON
2019A
 SNO+ ${{\mathit p}}$ $\rightarrow$ invisible
$ >2.5 \times 10^{29} $ ${{\mathit n}}$ 90 5
ANDERSON
2019A
 SNO+ ${{\mathit n}}$ $\rightarrow$ invisible
$ >5.8 \times 10^{29} $ ${{\mathit n}}$ 90 6
ARAKI
2006
KLND ${{\mathit n}}$ $\rightarrow$ invisible
$ >2.1 \times 10^{29} $ ${{\mathit p}}$ 90 5
AHMED
2004
SNO ${{\mathit p}}$ $\rightarrow$ invisible
$ >1.9 \times 10^{29} $ ${{\mathit n}}$ 90 5
AHMED
2004
SNO ${{\mathit n}}$ $\rightarrow$ invisible
$ >1.8 \times 10^{25} $ ${{\mathit n}}$ 90 7
BACK
2003
BORX
$ >1.1 \times 10^{26} $ ${{\mathit p}}$ 90 7
BACK
2003
BORX
$ >3.5 \times 10^{28} $ ${{\mathit p}}$ 90 8
ZDESENKO
2003
${{\mathit p}}$ $\rightarrow$ invisible
$ >1 \times 10^{28} $ ${{\mathit p}}$ 90 9
AHMAD
2002
SNO ${{\mathit p}}$ $\rightarrow$ invisible
$ >4 \times 10^{23} $ ${{\mathit p}}$ 95
TRETYAK
2001
${{\mathit d}}$ $\rightarrow$ ${{\mathit n}}{+}$ ?
$ >1.9 \times 10^{24} $ ${{\mathit p}}$ 90 10
BERNABEI
2000B
 DAMA
$ >1.6 \times 10^{25} $ ${{\mathit p}}$, ${{\mathit n}}$ 11, 12
EVANS
1977
$ >3 \times 10^{23} $ ${{\mathit p}}$ 12
DIX
1970
CNTR
$ >3 \times 10^{23} $ ${{\mathit p}}$, ${{\mathit n}}$ 13, 12
FLEROV
1958
1  ALLEGA 2022 look for ${{\mathit \gamma}}$ rays from the de-excitation of a residual ${}^{15}\mathrm {N}{}^{*}$ following the disappearance of ${{\mathit p}}$ in ${}^{16}\mathrm {O}$.
2  ALLEGA 2022 look for ${{\mathit \gamma}}$ rays from the de-excitation of a residual ${}^{15}\mathrm {O}{}^{*}$ following the disappearance of ${{\mathit n}}$ in ${}^{16}\mathrm {O}$.
3  AGOSTINI 2024A look for ${{\mathit \gamma}}$ rays from the de-excitation of a residual ${}^{75}\mathrm {As}{}^{*}$ following the disappearance of ${{\mathit p}}$ in ${}^{76}\mathrm {Ge}$ (through the transition chain ${}^{76}\mathrm {Ge}$ $\rightarrow$ ${}^{75}\mathrm {Ga}$ $\rightarrow$ ${}^{75}\mathrm {Ge}$ $\rightarrow$ ${}^{75}\mathrm {As}$).
4  AGOSTINI 2024A look for ${{\mathit \gamma}}$ rays from the de-excitation of a residual ${}^{75}\mathrm {As}{}^{*}$ following the disappearance of ${{\mathit n}}$ in ${}^{76}\mathrm {Ge}$ (through the transition chain ${}^{76}\mathrm {Ge}$ $\rightarrow$ ${}^{75}\mathrm {Ge}$ $\rightarrow$ ${}^{75}\mathrm {As}$).
5  AHMED 2004 and ANDERSON 2019A look for ${{\mathit \gamma}}$ rays from the de-excitation of a residual ${}^{15}\mathrm {O}{}^{*}$ or ${}^{15}\mathrm {N}{}^{*}$ following the disappearance of a neutron or proton in ${}^{16}\mathrm {O}$.
6  ARAKI 2006 looks for signs of de-excitation of the residual nucleus after disappearance of a neutron from the $\mathit s$ shell of ${}^{12}\mathrm {C}$.
7  BACK 2003 looks for decays of unstable nuclides left after ${{\mathit N}}$ decays of parent ${}^{12}\mathrm {C}$, ${}^{13}\mathrm {C}$, ${}^{16}\mathrm {O}$ nuclei. These are ``invisible channel'' limits.
8  ZDESENKO 2003 gets this limit on proton disappearance in deuterium by analyzing SNO data in AHMAD 2002.
9  AHMAD 2002 (see its footnote 7) looks for neutrons left behind after the disappearance of the proton in deuterons.
10  BERNABEI 2000B looks for the decay of a ${}^{128}_{53}{}^{}\mathrm {I}$ nucleus following the disappearance of a proton in the otherwise-stable ${}^{129}_{54}{}^{}\mathrm {Xe}$ nucleus.
11  EVANS 1977 looks for the daughter nuclide ${}^{129}\mathrm {Xe}$ from possible ${}^{130}\mathrm {Te}$ decays in ancient Te ore samples.
12  This mean-life limit has been obtained from a half-life limit by dividing the latter by ln(2) = 0.693.
13  FLEROV 1958 looks for the spontaneous fission of a ${}^{232}\mathrm {Th}$ nucleus after the disappearance of one of its nucleons.
Conservation Laws:
BARYON NUMBER
References