1. MUONS!

2. What are we going to talk about? How muons are created Detecting methods Muon half life and decay rate Muon decay data Problems with the data and muons

3. How muons are created. Protons from the cosmic rays interact with the atoms in the upper atmosphere and create a shower of particles which decay further to produce muons.

4. Feynman diagrams

5. Detecting methods Muon Enters A flash is emitted Decays into an electron The scintillator detects the electron and emits a flash

6. Muon Half Life and Decay Rate.

7. Muon decay data 02/07/2014 – 03/07/2014

8. 03/07/2014 – 04/07/2014

9. Problems with the data Systematic errors: The PMT cable was faulty which fluctuated the results giving inaccurate results as it affected the rate of decay. Affecting flux rate. “11’o’clock drop”

10. How many muons pass through you everyday? When the person is standing up: 0.155*(6719073/24)*16=515129 (±0.5) When the person is lying down: 0.885*(6719073/24)*8=1982127 (±0.5) Shoulder: 0.115m 2 0.5m 0.23m Standing: 0.885m 2 0.5m 0.177m

11. How many interact with you Muons decayed in detector Total muons through detector Muons passed through your body = 3946

12. Problems with muons They have a half life of 2.2µ yet they can still travel 660m. This is due to time dilation, as muons travel 98% the speed of light. Therefore, time slows down.