Primordial Black Holes and Cosmological Phase Transitions Report ...

PBHs and Cosmological Phase Transitions 42
Table 8: The most stable known baryons. For each baryon it is shown the symbol, the quark content, the electric
charge e, the spin s, the mass m, the mean lifetime t, the most probable decaying reaction(s) and probabilities. In
the case of charmed and bottom baryons it is not known, in general, the most probable decaying reaction. In these
cases we have selected one or two examples (if available) of possible decaying reactions (according to the PDG results –
http://pdg.lbl.gov/2007/listings/contents listings.html, Yao et al., 2006).
Name Symbol quarks e s m(MeV) t(s) Most probable decaying Second most probable
reaction decaying reaction
proton p uud +1 1/2 938.272 > 1029 years
neutron n udd 0 1/2939.565 885.7 n → p + e− +¯νe 100%
sigma Σ− dds −1 1/2 1197.45 1.48 × 10−10 Σ− → π− + n 99.8%
Σ0 uds 0 1/21192.64 7.4 × 10−20 Σ0 → Λ0 + γ 100%
Σ + uus +1 1/2 1189.37 8.0 × 10−11 Σ + → π + + n 52% Σ + → π0 + p 48%
xi Ξ− dss −1 1/2 1321.7 1.64 × 10−10 Ξ− → Λ0 + π− 99.9%
Ξ0 uss 0 1/2 1314.9 2.9 × 10−10 Ξ0 → Λ0 + π0 99.5%
charmed xi Ξ + c usc +1 1/2 2467.9 4.42 × 10−13 Ξ + c → Λ0 + ¯ K0 + π + — Ξ + c → p + K− + π + —
Ξ0 c dsc 0 1/2 2471.0 1.12 × 10−13 Ξ0 c → p + K− + K− + π + — Ξ0 c → Λ0 + ¯ K0 + π + + π− —
double charmed xi Ξ + cc dcc +1 1/2 3518.9 < 3.3 × 10−14 Ξ + cc → p + D+ + π + — Ξ + cc → Λ+ c + K− + π + —
bottom xi Ξ0 b usb 0 1/2 — 1.42 × 10−12 — —
Ξ −
b dsb −1 1/2 — 1.42 × 10−12 Ξ −
b → J/ψ +Ξ− —
lambda Λ0 uds 0 1/21115.68 2.63 × 10−10 Λ0 → p + π− 63.9% Λ0 → n + π0 35.8%
charmed lambda Λ + c udc +1 1/2 2286.46 2.0 × 10−13 Λ + c → p + K− + π + 5% Λ + c → p + ¯ K0 + π0 3.3%
bottom lambda Λ0 b udb 0 1/2 5620.2 1.41 × 10−12 Λ0 b → Λ+ c + l− +¯νl + π + + π− 5.6% Λ0 b → Λ+ c + l− +¯νl 5.0%
(here l represents any lepton)
omega Ω − sss −1 3/2 1672.5 8.2 × 10 −11 Ω − → Λ 0 + π + 67.8% Ω − → Ξ 0 + π − 23.6%
charmed omega Ω 0 c ssc 0 1/2 2697.5 6.92 × 10 −14 Ω 0 c → Ξ 0 + K − + π + — Ω 0 c → Ω − + π + —