1. When is a fit good??? Ulrich Becker 3/4/2009 Repeat from last Mini lecture Fit exercises 1,2, and 2008 Likelihood and goodness of fit

3. 8

5. More in Bevington, ch 11 and Taylor. Let’s go to :

6. Your data analysis

7. Problem 1
good: error bars comparison
not so: Size of letters/#’s
Result: Can’t tell ! But for higher statistics Poisson-> Gauss

8. Problem 2.1
not good worse

9. learned: very sensitive to background
2.1 was a Lorentzian with little background results:
learned: very sensitive to background

10. Problem 2.2
Result: Gaussian

11. 2.2 was a Gaussian with background. 2008 results:
Note: for set a) hypotheses are indistinguishable!

12. Problem 3
I0 = 98± ±3
= ± ±.03
= ± ±.016
Bkgrd = 18.0 ±.2
2/394 =  = 3.46 ±.02

14. PDG: for future use….