Determination of the ${\Lambda }_c^{+}$ spin via the reaction $e^{+}{e}^{-}\to {\Lambda }_c^{+}{\bar{\Lambda }}_c^{-}$

Abstract

We report on a comparison of two possible ${\Lambda }_c^{+}$ spin hypotheses, $J=\frac{1}{2}$ and $\frac{3}{2}$, via the process $e^{+}{e}^{-}\to {\Lambda }_c^{+}{\bar{\Lambda }}_c^{-}$, using the angular distributions of ${\Lambda }_c^{+}$ decays into $p{K}_S^0$, $\Lambda {\pi }^{+}$, ${\Sigma }^0{\pi }^{+}$, and ${\Sigma }^{+}{\pi }^0$. The data were recorded at $\sqrt{s}=4.6$ GeV with the BESIII detector and correspond to an integrated luminosity of 587 pb${}^{-1}$. The ${\Lambda }_c^{+}$ spin is determined to be $J=\frac{1}{2}$, with this value favored over the $\frac{3}{2}$ hypothesis with a significance corresponding to more than 6 Gaussian standard deviations.

References in corpus (18)

• Heavy quarkonium: progress, puzzles, and opportunities
• Design and Construction of the BESIII Detector
• Coherent Exclusive Exponentiation For Precision Monte Carlo Calculations
• Future Physics Programme of BESIII
• Observation of the doubly charmed baryon ${\Xi }_{cc}^{++}$
• A review of the open charm and open bottom systems
• Baryon spectroscopy
• Measurements of absolute hadronic branching fractions of ${\Lambda }_c^{+}$ baryon
• Quantum numbers of the $X(3872)$ state and orbital angular momentum in its ${\rho }^{0}J\psi$ decay
• Polarization observables in $e^{+}{e}^{-}$ annihilation to a baryon-antibaryon pair
• Electromagnetic dipole moments of charged baryons with bent crystals at the LHC
• An amplitude analysis of the ${\pi }^0{\pi }^0$ system produced in radiative $J/\psi$ decays
• Measurements of Weak Decay Asymmetries of ${\Lambda }_c^{+}\to p{K}_S^0$, $\Lambda {\pi }^{+}$, ${\Sigma }^{+}{\pi }^0$, and ${\Sigma }^0{\pi }^{+}$
• Feasibility of measuring the magnetic dipole moments of the charm baryons at the LHC using bent crystals
• Measurement of absolute branching fraction of the inclusive decay ${\Lambda }_c^{+}\to \Lambda +X$
• Heavy baryons as polarimeters at colliders
• Search for the rare decays $J/\psi \to D_s^{-}{\rho }^{+}$ and $J/\psi \to \overline{D}{}^0\overline{K}{}^{\ast 0}$
• Spin rotation and depolarization of high-energy particles in crystals at Hadron Collider (LHC) and Future Circular Collider (FCC) energies and the possibility to measure the anomalous magnetic moments of short-lived particles

Cited by in corpus (8)

• Precise Measurements of Decay Parameters and $CP$ Asymmetry with Entangled $\Lambda -\bar{\Lambda }$ Pairs
• Luminosities and energies of $e^{+}{e}^{-}$ collision data taken between $\sqrt{s}$=4.612 GeV and 4.946 GeV at BESIII
• Masses and radiative decay widths of S- and P-wave singly-, doubly- and triply-heavy charm and bottom baryons
• Production and decay of polarized hyperon-antihyperon pairs
• Molecular states of $D^{\ast }{D}^{\ast }{\bar{K}}^{\ast }$ nature
• 70 Years of Hyperon Spectroscopy: A review of strange $\Xi$, $\Omega$ baryons, and the spectrum of charmed and bottom baryons
• Topological amplitudes of charmed baryon decays in the $SU(3{)}_F$ limit
• The electromagnetic form factors and spin polarization of ${\Lambda }_c^{+}$ in the process $e^{+}{e}^{-}\to {\Lambda }_c^{+}{\bar{\Lambda }}_c^{-}$