Related papers: New Window on Matter-Antimatter Differences
A search for $CP$ violation with an entangled system of $\Xi^-\bar\Xi^+$ pairs is performed, using $(10,087\pm44)\times10^{6}$ $J/\psi$ events collected with the BESIII experiment. A nine-dimensional helicity amplitude is used to fit…
Non-conservation of CP symmetry can manisfest itself in non-leptonic hyperon decays as a difference in the decay parameter between the strange-baryon decay and its charge conjugate. By comparing the decay distribution in the $\Lambda$…
Motivated by the recent LHCb observation of doubly-charmed baryon $\Xi_{cc}^{++}$ in the $\Lambda_c^+ K^-\pi^+\pi^+$ final state, we analyze the weak decays of doubly heavy baryons $\Xi_{cc}$, $\Omega_{cc}$, $\Xi_{bc}$, $\Omega_{bc}$,…
The non-leptonic two-body weak decays $\Sigma^{+} \to p \pi^{0}$ and $\bar{\Sigma}^{-} \to \bar{p} \pi^{0}$ are investigated, utilizing $(1.0087\pm0.0044)\times10^{10}$ $J/\psi$ events and $(2.7124\pm0.0143)\times10^{9}$ $\psi(3686)$ events…
Non-leptonic two-body weak decays of baryons are an important tool to probe the combined charge-conjugation--parity symmetry (CP) violation. We explain why the decays of strange baryons provide complementary information to the decays of…
Measurements on the weak decay asymmetry parameters of charmed baryon, say $\Xi_c$, provide more information on the $W$-emission and $W$-exchange mechanisms controlled by the strong and weak interactions. Taking advantage of the spin…
A sizable strong-interaction phase shift in weak two-body nonleptonic baryon decay would enhance the possibility of discovering charge-conjugation parity ($CP$) violation in the baryon sector, which might help in the quest for understanding…
Symmetry studies represent one of the most promising frontiers in particle physics research. This investigation focuses on exploring $P$ and $CP$ symmetries in the charm system through the measurement of asymmetry decay parameters in the…
The decays $\Xi_b \to \Lambda_b \pi$ are strangeness changing weak transitions involving only the light diquark in the baryon. Thus these decays can test the properties of such diquarks, in particular the suggestions existing in the…
The parity-conserving $a$ and parity-violating $b$ amplitudes for weak radiative hyperon decay are studied using chiral perturbation theory. The imaginary parts of $a$ and $b$ are computed using unitarity. The real part of $b$ is dominated…
Using a sample of $1.31\times10^9$ $J/\psi$ events collected with the BESIII detector at the electron-positron collider BEPCII, we analyse the full $J/\psi \to$ $\Xi^-\overline{\Xi}^+$, $\Xi^-\to \Lambda \pi^-$, $\Lambda\to p\pi^-$,…
Experiments with $\Xi^-$ atoms are proposed in order to study the nuclear interaction of $\Xi$ hyperons. The production of $\Xi^-$ in the ($K^{-}$, $K^{+}$) reaction, the $\Xi^-$ stopping in matter, and its atomic cascade are incorporated…
Spin polarization and entanglement are utilized by the BESIII experiment to learn more about the production and decay properties of hyperon-antihyperon pairs in a series of recent analyses of its unprecedented datasets at the $J/\psi$ and…
Weak radiative hyperon decays represent a rich interplay between weak interactions and the internal structure of baryons, offering profound insights into Quantum Chromodynamics and weak interactions. Recent experimental observations,…
The $J/\psi \to \Xi^0 \bar{\Xi}^{0}$ process and subsequent decays are investigated using $(10087 \pm 44)\times 10^6$ $J/\psi$ events collected at the BESIII experiment. The decay parameters of $\Xi^0$ and $\bar{\Xi}^0$ are measured with…
The $\Xi^0$ asymmetry parameters are measured using entangled quantum $\Xi^0$-$\bar{\Xi}^0$ pairs from a sample of $(448.1 \pm 2.9) \times 10^6$ $\psi(3686)$ events collected with the BESIII detector at BEPCII. The relative phase between…
Weak radiative hyperon decays, important to test the strong interaction and relevant in searches for beyond the standard model physics, have remained puzzling both experimentally and theoretically for a long time. The recently updated…
Polarized hyperon-antihyperon pairs shed light on various unresolved puzzles in contemporary physics: How the strong interaction confines quarks into hadrons, how accurately the Standard Model describes microcosmos and even why our universe…
The strangeness-changing ($\Delta S = 1$) weak baryon-baryon interaction is studied through the nonmesonic weak decay of double-$\Lambda$ hypernuclei. Besides the usual nucleon-induced decay $\Lambda N \to N N$ we discuss novel…
We present a concise overview on $CP$ violation in hyperon decays, including past, present, and future efforts to search for it. We highlight in particular the most recent results of the BESIII experiment using a quantum-entangled pair of…