Semileptonic decays of spin-entangled baryon-antibaryon pairs

Abstract

A modular representation for the semileptonic decays of baryons originating from spin polarized and correlated baryon-antibaryon pairs is derived. The complete spin information of the decaying baryon is propagated to the daughter baryon via a real-valued matrix. It allows to obtain joint differential distributions in sequential processes involving the semileptonic decay in a straightforward way. The formalism is suitable for extraction of the semileptonic formfactors in experiments where strange-baryon-antibaryon pairs are produced in electron-positron annihilation or in charmonia decays. We give examples such as the complete angular distributions in the $e^{+}{e}^{-}\to \Lambda \bar{\Lambda }$ process, where $\Lambda \to p{e}^{-}{\bar{\nu }}_e$ and $\bar{\Lambda }\to \bar{p}{\pi }^{+}$. The formalism can also be used to describe the distributions in semileptonic decays of charm and bottom baryons. Using the same principles, the modules to describe electromagnetic and neutral current weak baryon decay processes involving a charged lepton-antilepton pair can be obtained. As an example, we provide the decay matrix for the Dalitz transition between two spin-1/2 baryons.

37 pages, 4 figures, 4 tables

References in corpus (7)

• Nucleon Electromagnetic Form Factors
• Number of $J/\psi$ events at BESIII
• Weak phases and CP-symmetry tests in sequential decays of entangled double-strange baryons
• Precise Measurements of Decay Parameters and $CP$ Asymmetry with Entangled $\Lambda -\bar{\Lambda }$ Pairs
• ${\Sigma }^{+}$ and ${\bar{\Sigma }}^{-}$ polarization in the $J/\psi$ and $\psi (3686)$ decays
• Study of CP violation in hyperon decays at Super Charm-Tau Factories with a polarized electron beam
• A new angle on an old problem: Helicity approach to neutron beta decay in the Standard Model

Cited by in corpus (2)

• Spin correlations and Bell nonlocality in $\Lambda \bar{\Lambda }$ pair production from $e^{+}{e}^{-}$ collisions with a thrust cut
• Measurements of the Absolute Branching Fraction of the Semileptonic Decay ${\mathbf{\Xi }}^{-}\to \mathbf{\Lambda }{\mathbf{e}}^{-}{\bar{\nu }}_{\mathbf{e}}$ and the Axial Charge of the ${\mathbf{\Xi }}^{-}$