Atmospheric neutrinos Primary spectrum Hadronic interactions Fluxes of muons and neutrinos Emphasis on high energy

Atmospheric neutrino beamUp-down symmetric except for geomagnetic effectsOne detector for both long baseline short baseline1 < L/E < 105 km/GeV nm/ne ~ 2 for En < GeV at productionD. Ayres, A.K. Mann et al., 1982Also V Stenger, DUMAND, 1980

Overview of the calculation

Summary of Atmospheric Neutrino CalculationsA

Zatsepin, KuzminSP JETP 14:1294(1961)MuMany calculations ~ 1965 --- ~1990 1DD.H. PerkinsAsp.Phys. 2: 249 (1994)MuHonda, Kajita, Kasahara, MidorikawaPRD 52: 4985 (1995)1DFRITIOFAgrawal, Gaisser, Lipari, StanevPRD 53: 1314 (1996)1DTargetBattistoni et alAsp.Phys 12:315 (2000)Asp.Phys 19:269 (2003) 3DB FLUKAP. LipariAsp.Phys 14:171 (2000)3DV. PlyaskinPL B516:213 (2001)hep-ph/0303146 3DGHEISHATserkovnyak et alAsp.Phys 18:449 (2003)3DCALOR-FRITIOFGFLUKA/GHEISHAWentz et alPRD 67 073020 (2003)3DCorsika: DPMJET VENUS, UrQMDLiu, Derome, BunerdPRD 67 073022 (2003)3DFavier, Kossalsowski, ViallePRD 68 093006 (2003)3DGFLUKABarr, Gaisser, Lipari, Robbins, StanevPRD 70 023006 (2004)3DCTargetHonda, Kajita, Kasahara, MidorikawaPRD 64 053011 (2001)PRD 70 043008 (2004)3DDPMJET

Comparison of 3 calculations used by Super-KDifferences come fromAssumptions about primary spectrumTreatment of hadronic interactionsY. Ashi et al. (Super-K Collaboration) hep-ex/0501064 nm + nm

Flavor ratio at production r =nm/ne at production sets background for search for effects of solar and s13 mixing De = P2(r cos2q23 -1) Peres & Smirnov, 2004 0 for r = 2, q23=45o rsub-GeV ~2.04 2.1

Range of n flux calculations

Primary spectrumLargest source of overall uncertainty1995: experiments differ by 50% (see lines)Present: AMS, BESS within 5% for protons discrepancy for He larger, but He only 20% of nucleon fluxCAPRICE lower by 15-20%

Primary spectrum: new standard?Fit BESS and AMSInclude small contributions from heavy elementsExtrapolate to high EUse m and n measurements as constraints

Classes of atmospheric n eventsContained (any direction) n-induced m (from below)m

Super-K atmospheric neutrino data (hep-ex/0501064) 1489day FC+PC data + 1646day upward going muon data CC neCC nm

Super-K fits38 parameters represent uncertainties in flux of atmospheric neutrinos

nm-induced upward mMACROSuper-KAMIOKANDE

High-energy n in Super-KIn Super-K fit, primary spectrum shifts:Overall normalization up 11%Slope < 100 GeV changes: -2.74 -2.71Slope > 100 GeV changes: -2.71 -2.66K/p decreases by 6%Can we use Super-K measurements (together with muon measurements) to constrain extrapolation of neutrino spectrum to high energy?Work in progress with P. Lipari, T. Stanev & G. Barr

Neutrino response to primary spectrumNeutrino energyPrimary energy / nucleon

All-nucleon spectrum

Analytic approximations for E>10 GeVSimilar forms for muons but Zpm = 0.67

Atmospheric n-induced mNo oscillationsPaolo Lipari calculation with standard Z-factorsWith oscillationsQGSjet

0.1670.0810.0320.0280.00470.0032

Vertical muon flux

Importance of kaons at high EImportance of kaonsmain source of n > 100 GeVp K+ + L importantCharmed analog important for prompt leptons at higher energy

Differences in kaon production

Comparison of n flux calculations: Importance of K at high energhyABC

n / anti-n ratios

atmospheric neutrinoscan we use AMANDA-II atmospheric neutrino data to probe these uncertainties ?Log10(E)E3dN/dE (cm-2 s-1 sr-1GeV2)CORSIKA ~ - 30:50% than NUSIM/LipariPaolo Desiati

Calibration with atmospheric nMINOS, etc.Neutrino telescopesExample*** of nm / neflavor ratioangular dependence***Note: this is maximal effect:horizontal = 85 - 90 deg in plots

Global view of atmospheric n spectrum

Diffuse signal vs charmed background in IceCubeIceCube Collaboration J. Ahrens et al., Astropart.Phys. 20 (2004) 507-532E-2 signal spectrum:E2dN/dE=10-7 GeV/cm2sr s

Concluding commentsDiscovery of neutrino oscillations depends on measured ratios; therefore robustSuper-K fits suggests relatively hard spectrumAir-shower data also suggests hard spectrumZ-factors explain differences of calculationsUncertainty in level of charm production limits sensitivity to diffuse astrophysical neutrinos