1 CC analysis update New analysis of SK atm. data –Somewhat lower best-fit value of  m 2 –Implications for CC analysis – 5 year plan plots revisited Effect of energy scale errors on CC analysis –How large are parameter shifts for uncorrected n/f differences? –By how much do parameter measurement contours bloat if energy shifts are included in the fit? D. A. Petyt 30/07/03

2 Slides from Hayato’s talk, EPS 2003 Assuming null oscillation Allowed region of the oscillation parameters from atmospheric  data 68% C.L. 90% C.L. 99% C.L. FC + PC + up-going   combined Preliminary! 1489 days Best fit Assuming    oscillation  2 min = 170.8/170 d.o.f. at (sin 2 2   m 2 ) = (1.0,2.0 x eV 2 ) 90% confidence level allowed region sin 2 2  > x10 -3 <  m 2 <3.0x10 -3 (eV 2 )  2 = 445.2/172 d.o.f. (complete SK-I dataset) Previous limits: 1.6e-3,3.8e-3

3 Neutrino flux ( Honda 1995 Honda 2001) 3D flux calculation Comparison between old and new results from atmospheric data Improved event reconstruction tools Each change slightly shifted the allowed region to lower  m 2 Neutrino interaction models (several improvements, agree with K2K near data) Improved detector simulation Slides from Hayato’s talk, EPS 2003 Previous best fit outside physical region

4 MINOS CC sensitivity updated

5 Seeing a dip/rise in spectrum ratio ‘Hard’ to see a significant rise in spectrum ratio for values of  m 2 below eV 2 (E dip ~ GeV). Almost all of new SK region is below this  m 2 range – motivation for plans to improve low E flux? New SK region

6 Energy scale uncertainties What are the effects of Near/far energy scale differences on the CC energy analysis? –This was brought up at the collaboration meeting – this systematic error is not currently included in 5 year plan plot calculations –Chris has looked at this in connection with his QEL analysis. I last looked at it >5 years ago… Current energy scale calibration requirements: –2% relative near to far, 5% absolute Not entirely certain where these numbers came from. False signal searches using the Z-test? The following is a quick study to see how energy scale uncertainties affect parameter measurement in the 5-year plot era analysis –Shift far energy scale relative to near –Assume a constant factor: E far =(1+  )E near –Look at effects of shifts in hadron and muon energy scales separately –Perform fits where n/f energy scale is allowed to float. –Second-order effects (changes in selection efficiencies etc.) not included

7 CC energy fits, +/- 5% overall shifts Shifts in both  m 2 and sin 2 2 . +5% best fit is outside physical region

8 CC energy fits, +/- 2% overall shifts

9 +/- 5% shifts in hadron energy scale only

10 +/- 5% shifts in muon energy scale only Predominance of low-y/QEL events in CC sample – effect of muon energy scale shift is therefore greater than an equivalent shift in the hadron energy scale

11 Incorporating energy scale uncertainties into the fit For each pair of  m 2,sin 2 2  values, there is an additional loop over the energy scale parameter,  (100 points, 0.9<  <1.1). I calculate chisq for this (  m 2,sin 2 2  and add a penalty factor       where   is the expected uncertainty in the near/far energy scale.   is then minimised with respect to the parameter 

12 Shape-only fits

13 Results and conclusions Including simple energy scale uncertainties of the form E far =(1+  )E near into the fit increases the size of the contours by a small amount –Fit is tightly constrained by shape and normalisation at the value of  m 2 used here May be a different story at low  m 2, where dip is not resolved. Should also look at this for high proton intensities (only looked at ‘low’ 7.4e20 p.o.t. proton intensity here). When do systematic uncertainties dominate over statistical uncertainties? (This is one of the main themes of the new PAC questions.)  normshape % -6.8% % -7.87% 2% % -7.15% % -8.43% 5% % -7.41% % -8.76% Size of  m 2 measurement errors