S K The Many Uses of Upward- going Muons in Super-K Muons traveling up into Super-K from high-energy  reactions in the rock below provide a high-energy insight into many different problems. Alec Habig, Univ. of Minnesota Duluth for the Super-K Collaboration

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 2 Upward-going  High energy  can interact in rock some distance away and still produce a  seen by detector –Higher energy particles, more range, more effective volume! –Increasing target mass at high E offsets falling  spectra Down-going entering cosmic ray muons restrict this technique to upward-going entering muons SK   Stop-   SK  Through- 

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 3 Up-  ’s in Super-K For “SK- I ” –4/96 to 7/ live-days up- thru (1657 up- stop) –More than other SK analyses, this one is insensitive to poor detector conditions For >7m path (>1.6 GeV): –1878 thru-  –456 stop- 

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 4 Atmospheric  Up-  flux is presented as a function of cos  and thus baseline –cos  =-1 (Up) have L~10,000 km –cos  =0 (Horizontal) have L~500 km Lower E, longer L ’s oscillate more The data match the oscillated MC far better than the non- oscillated MC –sin 2 2  =1.0,  m 2 =2.7x10 -3 Thru-  data Stop-  data No-osc MC (best norm.) Osc. MC

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 5 Energy Lever Arm For  seen as up-  : –Typical E ~ 10 GeV for stop- ,~ 100 GeV for thru-  –Compare to contained event energies ~ GeV –From the soft atmospheric spectrum. A harder spectrum would produce a larger fraction of high energy parent Disadvantage – for any single event, the parent energy is known only to be larger than the observed  energy

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 6 ,  Oscillation Even with comparatively small statistics and lousy energy resolution, the observation of  disappearance at higher energies further refines the oscillation fit Left – 90% C.L. contours with and without up-  data Best fit (physical region)*: –sin 2 2  = 1.0 –  m 2 = 2.5x % C.L. FC,PC Alone With up-  *(absolute best fit slightly unphysical at sin 2 2  =1.03)

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 7  to sterile ? High energy experience matter effects which suppress oscillations to sterile –Matter effects not seen in up-  or high-energy PC data –Reduction in neutral current interactions also not seen –constrains s component of  disappearance oscillations Pure  - s disfavored – s fraction < 20% at 90% c.l.

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 8 Unusual Models Alternative ways to make  disappear without invoking standard ,  flavor oscillations include –Lorentz invariance violation –Neutrino decay, decoherence Fits using all available SK data (FC+PC+NC+multiring+ up- , 190 d.o.f.) strongly constrains many such models –Hard for a model to get a good fit over 5 orders of magnitude in energy and 4 in baseline –Long   decay and  decoherence disfavored but not eliminated ModeBest Fit 22 P(  2 )  2   -  sin 2 2  sin 2 (1.27  m 2 L/E) sin 2 2  =1.00  m 2 =2.1x %0.0 00  - e ~sin 2 2  sin 2 (1.27  m 2 L/E) sin 2 2  =0.97  m 2 =5.1x %   - s ~sin 2 2  sin 2 (1.27  m 2 L/E) sin 2 2  =0.98  m 2 =2.9x %  LxE (L.I. violation) sin 2 2  sin 2 (  LxE) sin 2 2  =0.90  =5.6x %   decay (short  ) sin 4  +cos 4  (1-e -  L/E ) cos 2  =0.50  =3.7x %   decay (long  ) (sin 2  +cos 2  e -  L/2E ) 2 cos 2  =0.33  =1.2x %   decoherence 0.5sin 2 2  (1-e -  L/E ) sin 2 2  =0.98  =7.3x %  Null Hypothesis427.40% 

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 9 Galactic Atmospherics? Cosmic rays interact with interstellar medium as well as our atmosphere –Would also produce ISM most dense at low galactic latitudes –Do we see excess in the galactic plane? A search for these does not see this weak signal

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 10 Astrophysical A hard spectrum: more likely a signal will be seen as up-  space-time coincidences with GRBs not seen at any energy in SK AGNs or other astrophysical sources would produce point sources of high-energy –All sky searches for such point-sources are negative –Unbinned searches for unusual clustering of up-  also negative

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 11 Pick a Source, Any Source To test your favorite model of production at some high energy astrophysical source: –Up-  near sources counted, a sampling shown here –Expected count from atm. background calculated –No excess seen, flux limits computed

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 12 WIMP Detection WIMPs could be seen indirectly via their annihilation products (eventually  ) if they are captured in a gravitational well WIMPs of larger mass would produce a tighter beam –Differently sized angular windows allow searches to be optimized for different mass WIMPs

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 13 WIMP Results The Sun, Earth, and Galactic center are potential WIMP traps No excess of are seen in any angular cone about them –Upper limit of WIMP- induced calculated –Varies as a function of possible WIMP mass –Lower limits for higher masses are due to the better S/N in smaller angular search windows

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 14 Probing for WIMPs Most model dependence in indirect searches lies in the cross-section –Most conservative limits are taken for other uncertainties Direct-detection experiments also do not know cross-sections –Comparisons can be made between direct and indirect searches Both spin-dependent (left) and spin-independent (right) WIMP- nucleon interactions can be probed (a la Kamionkowski, Ullio, et al)

S K Neutrino 2002, May 25-30, Munich Alec Habig Page 15 Summary The high-energy end of the  spectrum observed by Super-K is seen as up-going  The extra lever arm in energy contributes to oscillation parameter estimation out of proportion to the small statistics and poor energy resolution of the sample The high parent energies allow probes of unusual areas of physics and astrophysics –Nothing unexpected seen, unfortunately The presenter gratefully acknowledges support for this poster from the National Science Foundation via its RUI grant # , and from The Research Corporation’s Cottrell College Science Award