New Results Confirm Erstwhile Anomaly Inwards Neutrino Data

The collaboration of a neutrino experiment called MiniBooNe but published their novel results:

Observation of a Significant Excess of Electron-Like Events inwards the MiniBooNE Short-Baseline Neutrino Experiment
MiniBooNE Collaboration
arXiv:1805.12028 [hep-ex]

It’s a rather unassuming paper, but it deserves a betoken boost because for in i lawsuit nosotros accept an anomaly that did non vanish alongside farther examination. Indeed, it truly increased inwards significance, right away standing at a whopping 6.1σ.

MiniBooNE was designed to depository fiscal establishment check the results of an before experiment called LSND, the Liquid Scintillator Neutrino Detector experiment that ran inwards the 1990s. The LSND results were famously incompatible the results of a mass of other neutrino experiments. So incompatible, indeed, that the LSND information are ordinarily excluded from global fits – they but don’t fit.

All the other experimental information could hold upwards neatly fitted alongside assuming that the 3 known types of neutrinos “oscillate,” which agency they alter dorsum as well as forth into each other every bit they travel. Problem is, inwards a three-neutrino oscillation model, in that place are solely maximally ix parameters (the masses, mixing angles, as well as a few phases, the latter depending on the type of neutrino). These parameters are non sufficient to too agree the LSND data.

See figure below for the LSND trouble: The turquoise/yellow areas inwards the figure produce non overlap alongside the red/blue ones.

[Figure: Hitoshi Murayama]

The novel information from MiniBooNE, now, confirms that this tension inwards the information is real. It’s non a quirk of the LSND experiment. This information tin (to my best knowledge) non hold upwards fitted alongside the measure framework of 3 types of neutrinos (one for the electron, i for the muon, as well as i of the tau). Fitting this information requires either novel particles (sterile neutrinos) or but about sort of symmetry violation, typically CPT violation or Lorentz-invariance violation (or both).

This is the telephone substitution figure from the novel paper. See how the novel results grip alongside the before LSND results. And banker's complaint the pale grayness problem indicating that this expanse is “ruled out” yesteryear other experiments (assuming the measure explanation).

[Figure v from arXiv:1805.12028]

So this is super-exciting news: An quondam anomaly was re-examined as well as confirmed! Now it’s fourth dimension for theoretical physicists to come upwards up alongside an explanation.