CP violation in the hyperon decays $Σ\to Nπ$

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: He, Xiao-Gang, Ma, Xiao-Dong, Tandean, Jusak, Valencia, German
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866911356820652032
author He, Xiao-Gang
Ma, Xiao-Dong
Tandean, Jusak
Valencia, German
author_facet He, Xiao-Gang
Ma, Xiao-Dong
Tandean, Jusak
Valencia, German
contents The study of $CP$ violation in hyperon transitions has a long history. In the early 2000s the HyperCP experiment made a major effort to seek $CP$-odd signals in the decay sequence $Ξ^-\toΛπ^-$ and $Λ\to pπ^-$, which motivated more searches. Most recently the BESIII and LHCb Collaborations have acquired or improved the upper bounds on $CP$ violation in a variety of hyperon nonleptonic processes, including $Σ^+\to nπ^+$ and $Σ^+\to pπ^0$. These measurements have not reached the standard-model level yet, but have stimulated a renewed interest in $CP$-violating new physics in strange-quark decay beyond what is constrained by the parameters $\varepsilon$ and $\varepsilon^\prime$ from the kaon sector. In this paper, after updating the standard-model expectations for $CP$-odd observables in the modes $Σ^\pm\to Nπ$, we revisit new-physics scenarios that could enhance the corresponding quantities in $Λ\to Nπ$ and $Ξ\toΛπ$ and apply them to the $Σ^\pm$ modes. We find that the $CP$ asymmetries in the latter can be significantly increased over the standard-model expectations, at levels which may be tested in the ongoing BESIII experiment and in future endeavors such as PANDA and the Super Tau Charm Facility.
format Preprint
id arxiv_https___arxiv_org_abs_2510_01134
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle CP violation in the hyperon decays $Σ\to Nπ$
He, Xiao-Gang
Ma, Xiao-Dong
Tandean, Jusak
Valencia, German
High Energy Physics - Phenomenology
High Energy Physics - Experiment
The study of $CP$ violation in hyperon transitions has a long history. In the early 2000s the HyperCP experiment made a major effort to seek $CP$-odd signals in the decay sequence $Ξ^-\toΛπ^-$ and $Λ\to pπ^-$, which motivated more searches. Most recently the BESIII and LHCb Collaborations have acquired or improved the upper bounds on $CP$ violation in a variety of hyperon nonleptonic processes, including $Σ^+\to nπ^+$ and $Σ^+\to pπ^0$. These measurements have not reached the standard-model level yet, but have stimulated a renewed interest in $CP$-violating new physics in strange-quark decay beyond what is constrained by the parameters $\varepsilon$ and $\varepsilon^\prime$ from the kaon sector. In this paper, after updating the standard-model expectations for $CP$-odd observables in the modes $Σ^\pm\to Nπ$, we revisit new-physics scenarios that could enhance the corresponding quantities in $Λ\to Nπ$ and $Ξ\toΛπ$ and apply them to the $Σ^\pm$ modes. We find that the $CP$ asymmetries in the latter can be significantly increased over the standard-model expectations, at levels which may be tested in the ongoing BESIII experiment and in future endeavors such as PANDA and the Super Tau Charm Facility.
title CP violation in the hyperon decays $Σ\to Nπ$
topic High Energy Physics - Phenomenology
High Energy Physics - Experiment
url https://arxiv.org/abs/2510.01134