The many uses of upward-going muons in super-K

✍ Scribed by Alec Habig

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 104 KB
• Volume: 118
• Category: Article
• ISSN: 0920-5632
• DOI: 10.1016/s0920-5632(03)01361-6

✦ Synopsis

Data:

p traveling up into Super-K from vfi interactions with the surrounding rock provide a high-energy insight into many different problems. V~ can interact in rock some distance away from the detector and still produce an observable 1-1. The larger energy the up, the more range the resulting ,u has in the rock, resulting in an experiment with more effective volume at higher energies, offsetting the falling vfi spectrum. However, the large number of down-going cosmic ray ,LL restricts this technique to upward-going entering p ("UGM"). UGM which have the energy to cross the entire detector and exit are termed "throughgoing $' ("TGM") and come from a parent atmospheric vfi population with a typical energy of -100 GeV [l], while those which range out inside Super-K are called "stopping $' ("STM") and come from -10 GeV vfi .

From the start of Super-K in 4/1996 through a maintenance shutdown in 7/2001 (the "SK-I" detector), 1678 live-days of TGM and 1657 of STM data were acquired and analyzed. This analysis is insensitive to poor detector conditions, resulting in a larger live-time than the contained-vertex [3] or solar v [4] analyses. For a 1-1 path-length in the detector of > 7m (E, > l.GGeV), 1878 TGM and 456 STM were observed. Atmospheric Y: The observed UGM are consistent with those expected from atmospheric V~ experiencing up +) v, flavor oscillations with sin' 26 = 1.0, Am2 = 2.7 x 10-3, as up with larger baselines and smaller energies are less likely to remain up and be observed. The large range in up energy these UGM provide narrows the allowed *The presenter gratefully acknowledges support for this poster from the NSF through its RUI grant #0098579, and from Research Corp.% Cottrell College Science Award