Physicists spot rare particle decay, advancing understanding of matter
Researchers at China's BESIII collider have detected evidence of a previously unseen particle interaction, marking a milestone in high-energy physics. The finding could refine models of fundamental particle behavior and informs long-term research strategies for physics facilities—priorities for governments investing billions in next-generation accelerators.
Originaltitel: Measurement of the cross sections of <em>e</em><sup>+</sup><em>e</em><sup>-</sup> → K− ¯Ξ+Λ/Σ0 at center-of-mass energies between 3<em>.</em>510 and 4<em>.</em>914 GeV
<p>Using e(+)e(-) collision data collected with the BESIII detector at the BEPCII collider at center-of-mass energies between 3.510 and 4.914 GeV, corresponding to an integrated luminosity of 25 fb(-1), we measure the Born cross sections for the process e(+)e(-)-> K-(Xi) over bar (+)Lambda/Sigma(0) at thirty-five energy points with a partial-reconstruction strategy. By fitting the dressed cross sections of e(+)e(-)-> K-(Xi) over bar (+)Lambda/Sigma(0), evidence for psi(4160)-> K-(Xi) over bar (+)Lambda is found for the first time with a significance of 4.4 sigma, including systematic uncertainties. No evidence for other possible resonances is found. In addition, the products of electronic partial width and branching fraction for all assumed resonances decaying into K-(Xi) over bar (+)Lambda/Sigma(0) are determined.</p>