pdgLive

CHARMED BARYONS
($\mathit C$ = $+1$)
${{\mathit \Lambda}_{{{c}}}^{+}}$ = ${{\mathit u}}{{\mathit d}}{{\mathit c}}$, ${{\mathit \Sigma}_{{{c}}}^{++}}$ = ${{\mathit u}}{{\mathit u}}{{\mathit c}}$, ${{\mathit \Sigma}_{{{c}}}^{+}}$ = ${{\mathit u}}{{\mathit d}}{{\mathit c}}$, ${{\mathit \Sigma}_{{{c}}}^{0}}$ = ${{\mathit d}}{{\mathit d}}{{\mathit c}}$,
${{\mathit \Xi}_{{{c}}}^{+}}$ = ${{\mathit u}}{{\mathit s}}{{\mathit c}}$, ${{\mathit \Xi}_{{{c}}}^{0}}$ = ${{\mathit d}}{{\mathit s}}{{\mathit c}}$, ${{\mathit \Omega}_{{{c}}}^{0}}$ = ${{\mathit s}}{{\mathit s}}{{\mathit c}}$

INSPIRE JSON PDGID:

B119

${{\mathit \Lambda}_{{{c}}}{(2595)}^{+}}$

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

The ${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ mode is largely, and perhaps entirely, ${{\mathit \Sigma}_{{{c}}}}{{\mathit \pi}}$, which is just at threshold; since the ${{\mathit \Sigma}_{{{c}}}}$ has $\mathit J{}^{P} = 1/2{}^{+}$, the $\mathit J{}^{P}$ here is almost certainly ${}^{}1/2{}^{-}$. This result is in accord with the theoretical expectation that this is the charm counterpart of the strange ${{\mathit \Lambda}{(1405)}}$.

${{\mathit \Lambda}_{{{c}}}{(2595)}^{+}}$ MASS

$2592.25$ $\pm0.28$ MeV

${{\mathit \Lambda}_{{{c}}}{(2595)}^{+}}-{{\mathit \Lambda}_{{{c}}}^{+}}$ MASS DIFFERENCE

$305.79$ $\pm0.24$ MeV

${{\mathit \Lambda}_{{{c}}}{(2595)}^{+}}$ WIDTH

$2.6$ $\pm0.6$ MeV

${{\mathit \Lambda}_{{{c}}}{(2595)}^{+}}$ DECAY MODES

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}}{{\mathit \pi}}$ and its submode ${{\mathit \Sigma}_{{{c}}}{(2455)}}{{\mathit \pi}}$ $-$ the latter just barely $-$ are the only strong decays allowed to an excited ${{\mathit \Lambda}_{{{c}}}^{+}}$ having this mass; and the submode seems to dominate.

Mode

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

Scale Factor/
Conf. Level

P(MeV/c)

$\Gamma_{1}$

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

^[1]

117

$\Gamma_{2}$

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

$(24 \pm7 ) \%$

$\Gamma_{3}$

${{\mathit \Sigma}_{{{c}}}{(2455)}^{0}}{{\mathit \pi}^{+}}$

$(24 \pm7 ) \%$

$\Gamma_{4}$

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ 3-body

$(18 \pm10 ) \%$

117

$\Gamma_{5}$

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{0}}$

${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \gamma}}$

not seen

288

[1]	See AALTONEN 2011H, Fig. 8, for the calculated ratio of ${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{0}}{{\mathit \pi}^{0}}$ and ${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{+}}{{\mathit \pi}^{-}}$ partial widths as a function of the ${{\mathit \Lambda}_{{{c}}}{(2595)}^{+}}$ $−$ ${{\mathit \Lambda}_{{{c}}}^{+}}$ mass difference. At our value of the mass difference, the ratio is about$~$4.
[2]	A test that the isospin is indeed 0, so that the particle is indeed a ${{\mathit \Lambda}_{{{c}}}^{+}}$.

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.

CONTACT US

Email:

Mailing Address:

Were you looking to order PDG products?

CITATION

MIRRORS

${{\mathit \Lambda}_{{{c}}}{(2595)}^{+}}$