Building Blocks of the Universe

Standard Model of Particle Physics

Force-carrying bosons

Three generations of fermions:

Quarks - �Make up protons, neutrons, etc.

Leptons - �3 charged�3 neutral

Neutrinos only interact with gravity and the weak force

• Gravity is negligible at this scale.
• So the weak force is only relevant force here �- mediated by W+, W-, or Z

Neutrino Oscillation

Note: Don’t worry about getting lost in the details…the main takeaway is that neutrinos oscillate!

Far Detector

Near Detector

Far Detector

Near Detector

Our Task Today…

Determine if we see evidence of neutrino oscillation between NOvA Near and Far Detectors.

• To do this, we first need to learn about Charged Current (CC) interactions & Neutral Current (NC) interactions. How do tracks in NOvA from these interactions look different?
• Later, we will compare the ratios of CC/NC at both the NOvA Far and Near Detectors to determine if we see evidence of neutrino oscillations.

Example of “Charged Current” Muon Neutrino Interaction

Neutrino Interactions: Charged Current (NuMu)

Analyzing Neutrino Events in Far Detector

Charged Current - Muon Neutrino (“NuMu”) Events

Charged Current (Nu Mu) Interaction Reporting

Part 1A: Let’s analyze some data!!

Far Detector

​

Part 1B - Far Detector, Neutral Current Events (All Neutrinos)

In neutral current measurements, we are not able to differentiate which neutrino flavor produced the interaction…

…Our measurements of these include interactions from electron, muon, and tau neutrinos.

Part 1B - Neutral Current Events @ Far Detector

• Mediated by Z Boson
• Z is Uncharged…No Charged Particle Seen…Cannot Identify Flavor

Same Event Display You Know

Part 1B: Let’s analyze some data!!

Far Detector

So for NOvA Far Detector…

Based on your measurements, decide a cut-off length that will used in Part 2 to separate

from

Part 2 - NOvA Near Detector

• 6300 + events
• Let’s use our coding notebook and the cut-off length

Conclusion -

Compare Far Detector ratio to Near Detector ratio

Do we see evidence of neutrino oscillation between Near and Far Detectors?

Near Ratio:

Far Ratio:

versus