pdgLive

BOTTOM BARYONS
($\mathit B$ = $-1$)
${{\mathit \Lambda}_{{{b}}}^{0}}$ = ${{\mathit u}}{{\mathit d}}{{\mathit b}}$, ${{\mathit \Sigma}_{{{b}}}^{0}}$ = ${{\mathit u}}{{\mathit d}}{{\mathit b}}$, ${{\mathit \Sigma}_{{{b}}}^{+}}$ = ${{\mathit u}}{{\mathit u}}{{\mathit b}}$, ${{\mathit \Sigma}_{{{b}}}^{-}}$ = ${{\mathit d}}{{\mathit d}}{{\mathit b}}$
${{\mathit \Xi}_{{{b}}}^{0}}$ = ${{\mathit u}}{{\mathit s}}{{\mathit b}}$, ${{\mathit \Xi}_{{{b}}}^{-}}$ = ${{\mathit d}}{{\mathit s}}{{\mathit b}}$, ${{\mathit \Omega}_{{{b}}}^{-}}$ = ${{\mathit s}}{{\mathit s}}{{\mathit b}}$

INSPIRE JSON PDGID:

${{\mathit b}}$-baryon ADMIXTURE (${{\mathit \Lambda}_{{{b}}}}$, ${{\mathit \Xi}_{{{b}}}}$, ${{\mathit \Omega}_{{{b}}}}$)

${{\mathit b}}$-baryon ADMIXTURE MEAN LIFE

${{\mathit b}}$-baryon ADMIXTURE DECAY MODES (${{\mathit \Lambda}_{{{b}}}},{{\mathit \Xi}_{{{b}}}},{{\mathit \Omega}_{{{b}}}}$)

These branching fractions are actually an average over weakly decaying ${{\mathit b}}$-baryons weighted by their production rates at the LHC, LEP, and Tevatron, branching ratios, and detection efficiencies. They scale with the ${{\mathit b}}$-baryon production fraction B(${{\mathit b}}$ $\rightarrow$ ${{\mathit b}}$ -baryon).
The branching fractions B(${{\mathit b}}$ -baryon $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \ell}^{-}}{{\overline{\mathit \nu}}_{{{{{\mathit \ell}}}}}}$ anything) and B(${{\mathit \Lambda}_{{{b}}}^{0}}$ $\rightarrow$ ${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \ell}^{-}}{{\overline{\mathit \nu}}_{{{{{\mathit \ell}}}}}}$ anything) are not pure measurements because the underlying measured products of these with B(${{\mathit b}}$ $\rightarrow$ ${{\mathit b}}$ -baryon) were used to determine B(${{\mathit b}}$ $\rightarrow$ ${{\mathit b}}$ -baryon), as described in the note ``Production and Decay of ${{\mathit b}}$-Flavored Hadrons.''
For inclusive branching fractions, $\mathit e.g.,$ ${{\mathit B}}$ $\rightarrow$ ${{\mathit D}^{\pm}}$ anything, the values usually are multiplicities, not branching fractions. They can be greater than one.

Mode

Fraction ($\Gamma_i$ / $\Gamma$)

Scale Factor/
Conf. Level

P(MeV/c)

${{\mathit p}}{{\mathit \mu}^{-}}{{\overline{\mathit \nu}}}$ anything

($5.8^{+2.3}_{-2.0}$ ) $\%$

${{\mathit p}}{{\mathit \ell}}{{\overline{\mathit \nu}}_{{{{{\mathit \ell}}}}}}$ anything

($5.6$ $\pm1.2$ ) $\%$

${{\mathit p}}$ anything

($70$ $\pm22$ ) $\%$

${{\mathit \Lambda}}{{\mathit \ell}^{-}}{{\overline{\mathit \nu}}_{{{{{\mathit \ell}}}}}}$ anything

($3.8$ $\pm0.6$ ) $\%$

${{\mathit \Lambda}}{{\mathit \ell}^{+}}{{\mathit \nu}_{{{{{\mathit \ell}}}}}}$ anything

($3.2$ $\pm0.8$ ) $\%$

${{\mathit \Lambda}}$ anything

($39$ $\pm7$ ) $\%$

${{\mathit \Xi}^{-}}{{\mathit \ell}^{-}}{{\overline{\mathit \nu}}_{{{{{\mathit \ell}}}}}}$ anything

($4.6$ $\pm1.4$) $ \times 10^{-3}$

Except where otherwise noted, content of the 2025 Review of Particle Physics is licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) license. The publication of the Review of Particle Physics is supported by US DOE, MEXT (Japan), INFN (Italy) and CERN. Individual collaborators receive support for their PDG activities from their respective institutes or funding agencies. © 2025. See LBNL disclaimers.