Publication

Search for a massless particle beyond the Standard Model in the Ξ0 → Λ + invisible decay

2026

Abstract

A search for a massless beyond-standard-model particle is performed in the decay Ξ 0 → Λ + invisible using (1.0087 ± 0.0044) × 10 10 J / ψ events collected with the BESIII detector at the BEPCII collider. No significant signal is observed and the upper limit on the branching fraction ℬ(Ξ 0 → Λ + invisible) is set to be 2.3 × 10 − 4 at the 90% confidence level. This is the first search for a flavor-changing neutral current process with missing energy in Ξ 0 decays. Throughout this paper, charge-conjugate processes are always implied.

Official source

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

2026

Abstract

Official source

Related concepts (32)

Standard Model

The Standard Model of particle physics is the theory describing three of the four known fundamental forces (electromagnetic, weak and strong interactions – excluding gravity) in the universe and classifying all known elementary particles. It was developed in stages throughout the latter half of the 20th century, through the work of many scientists worldwide, with the current formulation being finalized in the mid-1970s upon experimental confirmation of the existence of quarks.

Elementary particle

In particle physics, an elementary particle or fundamental particle is a subatomic particle that is not composed of other particles. The Standard Model presently recognizes seventeen distinct particles, twelve fermions and five bosons. As a consequence of flavor and color combinations and antimatter, the fermions and bosons are known to have 48 and 13 variations, respectively. Among the 61 elementary particles embraced by the Standard Model number electrons and other leptons, quarks, and the fundamental bosons.

Mathematical formulation of the Standard Model

This article describes the mathematics of the Standard Model of particle physics, a gauge quantum field theory containing the internal symmetries of the unitary product group SU(3) × SU(2) × U(1). The theory is commonly viewed as describing the fundamental set of particles – the leptons, quarks, gauge bosons and the Higgs boson. The Standard Model is renormalizable and mathematically self-consistent, however despite having huge and continued successes in providing experimental predictions it does leave some unexplained phenomena.

Related publications (25)

Search for a massless particle beyond the Standard Model in the Ξ0 → Λ + invisible decay

Chat with Graph Search

Probing the flavour structure of dimension-6 EFT operators in multilepton final states in proton-proton collisions at s=13 TeV

Measurement and effective field theory interpretation of the photon-fusion production cross section of a pair of W bosons in proton-proton collisions at s=13 TeV

Search for heavy neutral leptons in B-meson decays