The mystery of why there is more matter than antimatter in the universe has puzzled scientists for years. One possible explanation lies in the behavior of neutrinos, particles that lack electrical charge and can change their identity as they travel through space. Researchers are conducting experiments, such as the NOvA experiment in the US and future experiments like DUNE, to investigate how neutrinos and their antimatter counterparts, antineutrinos, oscillate.
In these experiments, neutrino beams are measured after traveling a long distance, and then antineutrino beams are compared to see if they oscillate in a similar or different way. However, accurately estimating the number of neutrinos in these beams is challenging. The beams are produced by colliding proton beams with targets, creating other particles that eventually transform into neutrinos. Determining the content of these beams, including the number of neutrinos, relies on understanding the proton-target interactions.
To address this issue, the NA61 experiment, also known as SHINE, at CERN is recreating these interactions using high-energy proton beams from the Super Proton Synchrotron. By measuring the electrically charged hadrons produced in the interactions, the experiment has improved estimations of the neutrino content in existing experiments.
Recently, the NA61/SHINE collaboration released new measurements of electrically neutral hadrons that decay into charged hadrons, which in turn yield neutrinos. These measurements, conducted using a 120-GeV proton beam and a carbon target, are crucial for estimating the neutrino yield in experiments like NOvA and potentially DUNE. By directly measuring the particle production from this specific proton-carbon interaction, researchers can reduce the uncertainties associated with extrapolations from older measurements.
The findings of the NA61/SHINE collaboration have been published in the journal Physical Review D, providing valuable insights into the neutrino production process and improving estimations for future neutrino experiments.