Question
The 2015 Nobel Prize in Physics was co-awarded to Art McDonald at the Sudbury Observatory for experimental confirmation of this phenomenon. For 10 points each:
[10m] Name this phenomenon described by the PMNS matrix. It was proposed to resolve a problem in which the Homestake experiment observed a much-lower-than-expected flux of a certain particle from the Sun.
ANSWER: neutrino oscillations [or neutrino flavor oscillation; prompt on neutrino mixing or lepton mixing]
[10e] Due to neutrino oscillation, Homestake observed only a third of expected neutrinos of this flavor. During beta decay, one of these negatively-charged particles is emitted along with a neutrino.
ANSWER: electron [or electron neutrinos]
[10h] The bicycle model and puma model are theories of neutrino oscillation that violate this property, as part of the Standard Model Extension. Physicists observe ultra-high energy cosmic rays to detect violations of this continuous property.
ANSWER: Lorentz invariance [or Lorentz invariant, or Lorentz symmetry; prompt on Lorentz covariance or Lorentz covariant; prompt on invariant or invariance]
<Physics>
Summary
| 2024 ACF Regionals @ Berkeley | 01/27/2024 | Y | 3 | 16.67 | 67% | 100% | 0% |
| 2024 ACF Regionals @ JMU | 01/27/2024 | Y | 9 | 11.11 | 78% | 33% | 0% |
| 2024 ACF Regionals @ Minnesota | 01/27/2024 | Y | 2 | 20.00 | 100% | 100% | 0% |
| 2024 ACF Regionals @ Nebraska | 01/27/2024 | Y | 6 | 11.67 | 83% | 33% | 0% |
| 2024 ACF Regionals @ Ohio State | 01/27/2024 | Y | 3 | 13.33 | 67% | 67% | 0% |
| 2024 ACF Regionals @ Rutgers | 01/27/2024 | Y | 5 | 16.00 | 80% | 80% | 0% |
| 2024 ACF Regionals @ Imperial | 01/27/2024 | Y | 8 | 17.50 | 100% | 75% | 0% |
| 2024 ACF Regionals @ Vanderbilt | 01/27/2024 | Y | 5 | 12.00 | 80% | 40% | 0% |
Data
| Ohio State A | Cedarville | 10 | 10 | 0 | 20 |
| Michigan A | Kenyon | 10 | 10 | 0 | 20 |
| Michigan B | Michigan C | 0 | 0 | 0 | 0 |