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

INSPIRE JSON (beta) PDGID:

${{\mathit \Lambda}_{{{b}}}^{0}}$

$I(J^P)$ = $0(1/2^{+})$

In the quark model, a ${{\mathit \Lambda}_{{{b}}}^{0}}$ is an isospin-0 ${{\mathit u}}{{\mathit d}}{{\mathit b}}$ state. The lowest ${{\mathit \Lambda}_{{{b}}}^{0}}$ ought to have $\mathit J{}^{P} = 1/2{}^{+}$. None of $\mathit I$, $\mathit J$, or $\mathit P$ have actually been measured.

▸	${{\mathit \Lambda}_{{{b}}}^{0}}$ MASS

${\mathit \tau}_{{{\mathit \Lambda}_{{{b}}}^{0}}}/{\mathit \tau}_{{{\mathit B}^{0}}}$ MEAN LIFE RATIO

${\mathit \tau}_{{{\mathit \Lambda}_{{{b}}}^{0}}}/{\mathit \tau}_{{{\mathit B}^{0}}}$ (direct measurements)

$0.964 \pm0.007$

▸	PARTIAL BRANCHING FRACTIONS IN ${{\mathit \Lambda}_{{{b}}}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$

▸	$\mathit CP$ VIOLATION

▸	$\mathit CP$ AND $\mathit T$ VIOLATION PARAMETERS

▸	$\mathit P$ VIOLATION PARAMETERS

▸	${{\mathit \Lambda}_{{{b}}}^{0}}$ DECAY PARAMETERS

▸	FORWARD-BACKWARD ASYMMETRIES

${{\mathit \Lambda}_{{{b}}}^{0}}$ ${{\overline{\mathit \Lambda}}_{{{b}}}^{0}}$ Production Asymmetry

${{\mathit A}}_{P}({{\mathit \Lambda}_{{{b}}}^{0}}$)

$0.014 \pm0.004$ (S = 1.8)

Decay Modes

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, $\mathit e.g.,$ ${{\mathit \Lambda}_{{{b}}}}$ $\rightarrow$ ${{\overline{\mathit \Lambda}}_{{{c}}}}$ anything, the values usually are multiplicities, not branching fractions. They can be greater than one.

${{\mathit J / \psi}{(1S)}}{{\mathit \Lambda}}{\times }$ B( ${{\mathit b}}$ $\rightarrow$ ${{\mathit \Lambda}_{{{b}}}^{0}}$ )

$(5.8\pm{0.8})\times 10^{-5}$

${{\mathit J / \psi}{(1S)}}{{\mathit \Lambda}}$

${{\mathit J / \psi}{(1S)}}{{\mathit \Lambda}}{{\mathit \phi}}$

${{\mathit \psi}{(2S)}}{{\mathit \Lambda}}$

${{\mathit p}}{{\mathit D}^{0}}{{\mathit \pi}^{-}}$

$(6.2\pm{0.6})\times 10^{-4}$

${{\mathit p}}{{\mathit D}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{-}}$

$(2.7\pm{0.4})\times 10^{-4}$

${{\mathit p}}{{\mathit D}^{*}{(2010)}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{-}}$

$(5.2\pm{1.0})\times 10^{-4}$

${{\mathit \Lambda}_{{{c}}}{(2860)}^{+}}{{\mathit \pi}^{-}}$ , ${{\mathit \Lambda}_{{{c}}}^{+}}$ $\rightarrow$ ${{\mathit D}^{0}}{{\mathit p}}$

${{\mathit \Lambda}_{{{c}}}{(2880)}^{+}}{{\mathit \pi}^{-}}$ , ${{\mathit \Lambda}_{{{c}}}^{+}}$ $\rightarrow$ ${{\mathit D}^{0}}{{\mathit p}}$

${{\mathit \Lambda}_{{{c}}}{(2940)}^{+}}{{\mathit \pi}^{-}}$ , ${{\mathit \Lambda}_{{{c}}}^{+}}$ $\rightarrow$ ${{\mathit D}^{0}}{{\mathit p}}$

${{\mathit p}}{{\mathit D}^{0}}{{\mathit K}^{-}}$

$(4.5\pm{0.8})\times 10^{-5}$

${{\mathit p}}{{\mathit D}}{{\mathit K}^{-}}$ , ${{\mathit D}}$ $\rightarrow$ ${{\mathit K}^{-}}{{\mathit \pi}^{+}}$

${{\mathit p}}{{\mathit D}}{{\mathit K}^{-}}$ , ${{\mathit D}}$ $\rightarrow$ ${{\mathit K}^{+}}{{\mathit \pi}^{-}}$

${{\mathit p}}{{\mathit J / \psi}}{{\mathit \pi}^{-}}$

$(2.6^{+0.5}_{-0.4})\times 10^{-5}$

${{\mathit p}}{{\mathit \pi}^{-}}{{\mathit J / \psi}}$ , ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$

$(1.6\pm{0.8})\times 10^{-6}$

${{\mathit p}}{{\mathit J / \psi}}{{\mathit K}^{-}}$

$(3.2^{+0.6}_{-0.5})\times 10^{-4}$

${{\mathit p}}{{\mathit \eta}_{{{c}}}{(1S)}}{{\mathit K}^{-}}$

$(1.06\pm{0.26})\times 10^{-4}$

${{\mathit P}_{{{c}}}{(4312)}^{+}}{{\mathit K}^{-}}$ , ${{\mathit P}_{{{c}}}{(4312)}^{+}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \eta}_{{{c}}}{(1S)}}$

$<2.5\times 10^{-5}$

${{\mathit P}_{{{c}}}{(4380)}^{+}}{{\mathit K}^{-}}$ , ${{\mathit P}_{{{c}}}}$ $\rightarrow$ ${{\mathit p}}{{\mathit J / \psi}}$

$(2.7\pm{1.4})\times 10^{-5}$

${{\mathit P}_{{{c}}}{(4450)}^{+}}{{\mathit K}^{-}}$ , ${{\mathit P}_{{{c}}}}$ $\rightarrow$ ${{\mathit p}}{{\mathit J / \psi}}$

$(1.3\pm{0.4})\times 10^{-5}$

${{\mathit \chi}_{{{c1}}}{(1P)}}{{\mathit p}}{{\mathit K}^{-}}$

$(7.6^{+1.5}_{-1.3})\times 10^{-5}$

${{\mathit \chi}_{{{c1}}}{(1P)}}{{\mathit p}}{{\mathit \pi}^{-}}$

$(5.0^{+1.3}_{-1.1})\times 10^{-6}$

${{\mathit \chi}_{{{c2}}}{(1P)}}{{\mathit p}}{{\mathit K}^{-}}$

$(7.9^{+1.6}_{-1.4})\times 10^{-5}$

${{\mathit \chi}_{{{c2}}}{(1P)}}{{\mathit p}}{{\mathit \pi}^{-}}$

$(4.8\pm{1.9})\times 10^{-6}$

${{\mathit p}}{{\mathit J / \psi}{(1S)}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit K}^{-}}$

$(6.6^{+1.3}_{-1.1})\times 10^{-5}$

${{\mathit p}}{{\mathit \psi}{(2S)}}{{\mathit K}^{-}}$

$(6.6^{+1.2}_{-1.0})\times 10^{-5}$

${{\mathit \chi}_{{{c1}}}{(3872)}}{{\mathit p}}{{\mathit K}^{-}}$

$(3.2\pm{1.4})\times 10^{-5}$

${{\mathit \chi}_{{{c1}}}{(3872)}}{{\mathit \Lambda}{(1520)}}$

$(1.9\pm{0.9})\times 10^{-5}$

${{\mathit \psi}{(2S)}}{{\mathit p}}{{\mathit \pi}^{-}}$

$(7.5^{+1.6}_{-1.4})\times 10^{-6}$

${{\mathit p}}{{\overline{\mathit K}}^{0}}{{\mathit \pi}^{-}}$

$(1.3\pm{0.4})\times 10^{-5}$

${{\mathit p}}{{\mathit K}^{0}}{{\mathit K}^{-}}$

$<3.5\times 10^{-6}$

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{-}}$

$(4.9\pm{0.4})\times 10^{-3}$

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit K}^{-}}$

$(3.56\pm{0.28})\times 10^{-4}$

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit a}_{{{1}}}{(1260)}^{-}}$

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit D}^{-}}$

$(4.6\pm{0.6})\times 10^{-4}$

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit D}_{{{s}}}^{-}}$

$(1.10\pm{0.10})\%$

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \pi}^{-}}$

$(7.6\pm{1.1})\times 10^{-3}$

${{\mathit \Lambda}_{{{c}}}{(2595)}^{+}}{{\mathit \pi}^{-}}$ , ${{\mathit \Lambda}_{{{c}}}{(2595)}^{+}}$ $\rightarrow$ ${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$

$(3.4\pm{1.4})\times 10^{-4}$

${{\mathit \Lambda}_{{{c}}}{(2625)}^{+}}{{\mathit \pi}^{-}}$ , ${{\mathit \Lambda}_{{{c}}}{(2625)}^{+}}$ $\rightarrow$ ${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$

$(3.3\pm{1.3})\times 10^{-4}$

${{\mathit \Sigma}_{{{c}}}{(2455)}^{0}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ , ${{\mathit \Sigma}_{{{c}}}^{0}}$ $\rightarrow$ ${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{-}}$

$(5.7\pm{2.2})\times 10^{-4}$

${{\mathit \Sigma}_{{{c}}}{(2455)}^{++}}{{\mathit \pi}^{-}}{{\mathit \pi}^{-}}$ , ${{\mathit \Sigma}_{{{c}}}^{++}}$ $\rightarrow$ ${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{+}}$

$(3.2\pm{1.5})\times 10^{-4}$

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit K}^{+}}{{\mathit K}^{-}}{{\mathit \pi}^{-}}$

$(1.02\pm{0.11})\times 10^{-3}$

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit p}}{{\overline{\mathit p}}}{{\mathit \pi}^{-}}$

$(2.63\pm{0.27})\times 10^{-4}$

${{\mathit \Sigma}_{{{c}}}{(2455)}^{0}}{{\mathit p}}{{\overline{\mathit p}}}$ , ${{\mathit \Sigma}_{{{c}}}^{0}}$ $\rightarrow$ ${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{-}}$

$(2.3\pm{0.5})\times 10^{-5}$

${{\mathit \Sigma}_{{{c}}}{(2520)}^{0}}{{\mathit p}}{{\overline{\mathit p}}}$ , ${{\mathit \Sigma}_{{{c}}}{(2520)}^{0}}$ $\rightarrow$ ${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{-}}$

$(3.1\pm{0.7})\times 10^{-5}$

${{\mathit \Lambda}}{{\mathit K}^{0}}$2 ${{\mathit \pi}^{+}}$2 ${{\mathit \pi}^{-}}$

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

$(10.9\pm{2.2})\%$

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

$(6.2^{+1.4}_{-1.3})\%$

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \tau}^{-}}{{\overline{\mathit \nu}}_{{{\tau}}}}$

$(1.9\pm{0.5})\%$

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}{{\mathit \ell}^{-}}{{\overline{\mathit \nu}}_{{{{{\mathit \ell}}}}}}$

$(5.6\pm{3.1})\%$

${{\mathit \Lambda}_{{{c}}}{(2595)}^{+}}{{\mathit \ell}^{-}}{{\overline{\mathit \nu}}_{{{{{\mathit \ell}}}}}}$

$(7.9^{+4.0}_{-3.5})\times 10^{-3}$

${{\mathit \Lambda}_{{{c}}}{(2625)}^{+}}{{\mathit \ell}^{-}}{{\overline{\mathit \nu}}_{{{{{\mathit \ell}}}}}}$

$(1.3^{+0.6}_{-0.5})\%$

${{\mathit \Sigma}_{{{c}}}{(2455)}^{0}}{{\mathit \pi}^{+}}{{\mathit \ell}^{-}}{{\overline{\mathit \nu}}_{{{{{\mathit \ell}}}}}}$

${{\mathit \Sigma}_{{{c}}}{(2455)}^{++}}{{\mathit \pi}^{-}}{{\mathit \ell}^{-}}{{\overline{\mathit \nu}}_{{{{{\mathit \ell}}}}}}$

${{\mathit p}}{{\mathit h}^{-}}$

$<2.3\times 10^{-5}$

${{\mathit p}}{{\mathit \pi}^{-}}$

$(4.5\pm{0.8})\times 10^{-6}$

${{\mathit p}}{{\mathit K}^{-}}$

$(5.4\pm{1.0})\times 10^{-6}$

${{\mathit p}}{{\mathit D}_{{{s}}}^{-}}$

$<4.8\times 10^{-4}$

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

$(4.1\pm{1.0})\times 10^{-4}$

${{\mathit \Lambda}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$

$(1.08\pm{0.28})\times 10^{-6}$

${{\mathit p}}{{\mathit \pi}^{-}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$

$(6.9\pm{2.5})\times 10^{-8}$

${{\mathit p}}{{\mathit K}^{-}}{{\mathit e}^{+}}{{\mathit e}^{-}}$

$(3.1\pm{0.6})\times 10^{-7}$

${{\mathit p}}{{\mathit K}^{-}}{{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$

$(2.6^{+0.5}_{-0.4})\times 10^{-7}$

${{\mathit \Lambda}}{{\mathit \gamma}}$

$(7.1\pm{1.7})\times 10^{-6}$

${{\mathit \Lambda}}{{\mathit \eta}}$

$(9^{+7}_{-5})\times 10^{-6}$

${{\mathit \Lambda}}{{\mathit \eta}^{\,'}{(958)}}$

$<3.1\times 10^{-6}$

${{\mathit \Lambda}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$

$(4.6\pm{1.9})\times 10^{-6}$

${{\mathit \Lambda}}{{\mathit K}^{+}}{{\mathit \pi}^{-}}$

$(5.6\pm{1.2})\times 10^{-6}$

${{\mathit \Lambda}}{{\mathit K}^{+}}{{\mathit K}^{-}}$

$(1.60\pm{0.22})\times 10^{-5}$

${{\mathit \Lambda}}{{\mathit \phi}}$

$(9.8\pm{2.6})\times 10^{-6}$

${{\mathit p}}{{\mathit \pi}^{-}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$

$(2.09\pm{0.21})\times 10^{-5}$

${{\mathit p}}{{\mathit K}^{-}}{{\mathit K}^{+}}{{\mathit \pi}^{-}}$

$(4.0\pm{0.6})\times 10^{-6}$

${{\mathit p}}{{\mathit K}^{-}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$

$(5.0\pm{0.5})\times 10^{-5}$

${{\mathit p}}{{\mathit K}^{-}}{{\mathit K}^{+}}{{\mathit K}^{-}}$

$(1.25\pm{0.13})\times 10^{-5}$

FOOTNOTES

Constrained Fit information

Except where otherwise noted, content of the 2023 Review of Particle Physics is licensed under a Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license. The publication of the Review of Particle Physics is supported by US DOE, MEXT (Japan), INFN (Italy), JPS and CERN. Individual collaborators receive support for their PDG activities from their respective institutes or funding agencies. © 2023. See LBNL disclaimers.