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${{\mathit \Lambda}}$ DECAY PARAMETERS

See the ``Note on Baryon Decay Parameters'' in the neutron Listings. Some early results have been omitted.

$\alpha _{−}$ FOR ${{\mathit \Lambda}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \pi}^{-}}$

INSPIRE   PDGID:

S018A-

OUR FIT value is obtained from measurements of $\alpha\mathrm {({{\mathit \Xi}^{-}})}$, $\alpha _{−}({{\mathit \Lambda}}$), and $\alpha\mathrm {({{\mathit \Xi}^{-}})}{}\alpha _{−}({{\mathit \Lambda}}$).

VALUE EVTS DOCUMENT ID TECN  COMMENT $\bf{ 0.748 \pm0.007}$ OUR FIT  Error includes scale factor of 2.1. $\bf{ 0.746 \pm0.007}$ OUR AVERAGE  Error includes scale factor of 2.1.  See the ideogram below. $0.757$ $\pm0.011$ $\pm0.008$ 73k ABLIKIM 2022 AD BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \Xi}}{{\overline{\mathit \Xi}}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\overline{\mathit \Lambda}}}{{\mathit \pi}}{{\mathit \pi}}$ $0.7519$ $\pm0.0036$ $\pm0.0024$ 3.2M ABLIKIM 2022 AG BES3 ${{\mathit J / \psi}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\overline{\mathit \Lambda}}}$ $0.750$ $\pm0.009$ $\pm0.004$ 420k ABLIKIM 2019 BJ BES3 ${{\mathit J / \psi}}$ to ${{\mathit \Lambda}}{{\overline{\mathit \Lambda}}}$ $0.721$ $\pm0.006$ $\pm0.005$ 1 IRELAND 2019 CLAS ${{\mathit K}}$ production • • We do not use the following data for averages, fits, limits, etc. • • $0.74$ ${}^{+0.04}_{-0.03}$ AAIJ 2020 O LHCB ${{\mathit \Lambda}_{{b}}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \Lambda}}$ $0.584$ $\pm0.046$ 8500 ASTBURY 1975 SPEC $0.649$ $\pm0.023$ 10325 CLELAND 1972 OSPK $0.67$ $\pm0.06$ 3520 DAUBER 1969 HBC From ${{\mathit \Xi}}$ decay $0.645$ $\pm0.017$ 10130 OVERSETH 1967 OSPK ${{\mathit \Lambda}}$ from ${{\mathit \pi}^{-}}{{\mathit p}}$ $0.62$ $\pm0.07$ 1156 CRONIN 1963 CNTR ${{\mathit \Lambda}}$ from ${{\mathit \pi}^{-}}{{\mathit p}}$ 1  This is a new analysis based on existing kaon photoproduction data of the CLAS collaboration and using spin algebra constraints.

$\alpha _{−}$ FOR ${{\mathit \Lambda}}$ $\rightarrow$ ${{\mathit p}}{{\mathit \pi}^{-}}$

References:

ABLIKIM 2022AD NAT 606 64 Probing CP symmetry and weak phases with entangled double-strange baryons ABLIKIM 2022AG PRL 129 131801 Precise Measurements of Decay Parameters and $CP$ Asymmetry with Entangled $\Lambda-\bar{\Lambda}$ Pairs Pairs AAIJ 2020O JHEP 2006 110 Measurement of the $\Lambda^0_b\rightarrow J/\psi\Lambda$ angular distribution and the $\Lambda^0_b$ polarisation in $pp$ collisions ABLIKIM 2019BJ NATP 15 631 Polarization and Entanglement in Baryon-Antibaryon Pair Production in Electron-Positron Annihilation IRELAND 2019 PRL 123 182301 Kaon Photoproduction and the $\Lambda$ Decay Parameter $\alpha_-$ ASTBURY 1975 NP B99 30 Measurement of the Differential Cross Section and the Spin Correlation Parameters $\mathit P$, $\mathit A$, and $\mathit R$ in the Backward Peak of ${{\mathit \pi}^{-}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit K}^{0}}{{\mathit \Lambda}}$ at 5 ${\mathrm {GeV/}}\mathit c$ CLELAND 1972 NP B40 221 A Measurement of the $\beta $-Parameter in the Charged Nonleptonic Decay of the ${{\mathit \Lambda}^{0}}$ Hyperon DAUBER 1969 PR 179 1262 Production and Decay of Cascade Hyperons OVERSETH 1967 PRL 19 391 Time Reversal Invariance in ${{\mathit \Lambda}}$ Decay CRONIN 1963 PR 129 1795 Measurement of the Decay Parameters of the ${{\mathit \Lambda}}$ Particle

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