Observation of $\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}{\pi }^0$ and $\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}2{\pi }^0$

Abstract

Using $(10087\pm 44)\times 10^6$ $J/\psi$ events collected with the BESIII detector at a center-of-mass energy of $\sqrt{s}=3.097$ GeV, the antihyperon-nucleon annihilation processes $\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}+k{\pi }^0$ ($k=1,2,3$) are studied at an incident $\bar{\Lambda }$ momentum of approximately 1.074 GeV/$c$. The reactions $\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}{\pi }^0$ and $\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}2{\pi }^0$ are observed for the first time, with corresponding cross sections ${\sigma }_{\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}{\pi }^0}=8.5_{-1.1}^{+1.2}(stat.)\pm 0.4(syst.)$ mb and ${\sigma }_{\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}2{\pi }^0}=7.9_{-1.7}^{+1.9}\pm 0.4$ mb. No significant signal is found for $\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}3{\pi }^0$, and an upper limit of 7.2 mb is set at a 90\% confidence level. An evidence for the $K^{\ast }(892{)}^{+}$ resonance is seen in the $K^{+}{\pi }^0$ invariant mass spectrum $M_{K^{+}{\pi }^0}$ for $k=1$, and the corresponding cross section for $\bar{\Lambda }p\to K^{\ast }(892{)}^{+}{\pi }^{+}{\pi }^{-}$ is measured to be ${\sigma }_{\bar{\Lambda }p\to K^{\ast }(892{)}^{+}{\pi }^{+}{\pi }^{-}}=12.5_{-3.4}^{+3.8}\pm 1.2$ mb. Owing to the limited statistics, possible interference effects are not considered. These findings offer crucial input to deepen our understanding of the antihyperon-nucleon interactions.

References in corpus (20)

• Shapiro delay measurement of a two solar mass neutron star
• A Massive Pulsar in a Compact Relativistic Binary
• Chiral effective field theory and nuclear forces
• Future Physics Programme of BESIII
• Hyperon Puzzle: Hints from Quantum Monte Carlo Calculations
• In-medium nuclear interactions of low-energy hadrons
• Strangeness in Nuclei and Neutron Stars
• STCF Conceptual Design Report: Volume 1 -- Physics & Detector
• Number of $J/\psi$ events at BESIII
• Precise Measurements of Decay Parameters and $CP$ Asymmetry with Entangled $\Lambda -\bar{\Lambda }$ Pairs
• Measurement of proton electromagnetic form factors in the time-like region using initial state radiation at BESIII
• Tests of $CP$ symmetry in the entangled ${\Xi }^0-{\bar{\Xi }}^0$ Pairs
• First study of reaction ${\Xi }^{0}n\to {\Xi }^{-}p$ using ${\Xi }^0$-nucleus scattering at an electron-positron collider
• A cornucopia of antineutrons and hyperons from super J/psi factory for next-generation nuclear and particle physics high-precision experiments
• Strong and weak $CP$ tests in sequential decays of polarized ${\Sigma }^0$ hyperons
• Prospects to study hyperon-nucleon interactions at BESIII
• Precision measurement of the matrix elements for $\eta \to {\pi }^{+}{\pi }^{-}{\pi }^0$ and $\eta \to {\pi }^0{\pi }^0{\pi }^0$ decays
• First measurement of $\Lambda N$ inelastic scattering with $\Lambda$ from $e^{+}{e}^{-}\to J/\psi \to \Lambda \bar{\Lambda }$
• Measurements of the absolute branching fractions of ${\Omega }^{-}$ decays and test of the $\Delta I=1/2$ rule
• First measurement of ${\Sigma }^{+}n\to \Lambda p$ and ${\Sigma }^{+}n\to {\Sigma }^{0}p$ cross sections via ${\Sigma }^{+}$-nucleus scattering at an electron-positron collider