Physics lab spots helium nuclei in particle collisions with new precision
Physicists at CERN's LHCb experiment have demonstrated a reliable method for detecting helium nuclei in high-energy collisions, identifying roughly 100,000 candidates with minimal false positives. The breakthrough opens doors to new measurements in nuclear physics and may help advance understanding of cosmic rays and dark matter—areas with commercial interest in space exploration and detection technologies.
Originaltitel: Helium identification with LHCb
<p>The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using <em>pp</em> collision data at √(<em>s</em>) = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5 fb<sup>-1</sup>. A total of around 10<sup>5</sup> helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background rejection rate of up to <img src="https://cdn.images.iop.org/Entities/calO.gif" />(10<sup>12</sup>). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei.</p>