Particle.news
Get it on Google Play
Download on the App Store
9 ARTICLES
·
4mo ago

NOvA–T2K Publish First Joint Neutrino Analysis, Pointing to Possible CP Violation

The work stops short of determining the neutrino mass ordering, keeping definitive conclusions out of reach.

Image
Image
The world’s first neutrino observation in a hydrogen bubble chamber. It was found November 13, 1970, on this photograph from the Zero Gradient Synchrotron’s 12-foot bubble chamber. The invisible neutrino strikes a proton where three particle tracks originate (lower right). The neutrino turns into a mu-meson, the long center track (extending up and left). The short track is the proton. The third track (extending down and left) is a pi-meson created by the collision. Image credit: Argonne National Laboratory.
Image

Overview

  • Pooling roughly a decade of data from both long‑baseline experiments, the collaborations report sharpened measurements of neutrino oscillation parameters in Nature.
  • The combined dataset shows a suggestive difference between neutrino and antineutrino oscillations, indicating a possible violation of CP symmetry.
  • Results do not favor normal versus inverted mass ordering, and the CP‑violation interpretation depends on which ordering is ultimately confirmed.
  • Complementary designs boosted sensitivity: NOvA sends a beam 810 km from Fermilab to a 14,000‑ton detector in Ash River, while T2K spans 295 km from J‑PARC to Super‑Kamiokande.
  • Both teams continue taking data and plan updates, with next‑generation experiments expected to deliver decisive tests later this decade.