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Final results on atmospheric   oscillations with MACRO at Gran Sasso

E   4 GeV. Final results on atmospheric   oscillations with MACRO at Gran Sasso. Bari, Bologna, Boston, Caltech, Drexel, Frascati, Gran Sasso, Indiana, L’Aquila, Lecce, Michigan, Napoli, Pisa, Roma1, Texas, Torino, Oujda Gran Sasso Lab. – MACRO  oscillations. Atmospheric neutrinos

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Final results on atmospheric   oscillations with MACRO at Gran Sasso

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  1. E 4 GeV Final results on atmospheric  oscillations with MACRO at Gran Sasso Bari, Bologna, Boston, Caltech, Drexel, Frascati, Gran Sasso, Indiana, L’Aquila, Lecce, Michigan, Napoli, Pisa, Roma1, Texas, Torino, Oujda Gran Sasso Lab. – MACRO  oscillations.Atmospheric neutrinos Upthroughoing muons (E  50 GeV ) Zenith distribution Absolute value L/E distribution: E from  M.C.S. Monte Carlos Semicontained muons Upstopping muons Combining all information Conclusions Ratio Absolute value G. Giacomelli University of Bologna EPS, Aachen

  2.  - Oscillations Weak flavour eigenstates e, ,  Mass eigenstates1, 2, 3 Decays, Interactions +  +  , n-p Propagation 1(t) = 1(0) e-E t Mixing 1 = 3m = 1 Ulm m 2-Flavour  = 2 cos23 + 3 sin 23 Mixing = -2 cos23 + 3 sin 23 Oscillations in Vacuum (over a distance L) Disappearance P(  ) = 1 – sin2 223 sin2 (1.27 m223 L/E) Appareance P(  ) = 1 – P(  ) m223 = m23 – m22 Simple formulae -Additional flavour oscillations Modified by -Matter effects In case of -Neutrinos have masses m≠ 0 Oscillations -Le, L, L, L violation -neutrino decays

  3. Atmospheric neutrinos E :  0.1 GeV   100 GeV L :  20 km   13000 km L/ E :  1 km/GeV   105 km/GeV Downgoing  : “near” neutrino source Upgoing  : “far” neutrino source

  4. NIM A324(1993)337 NIM A486(2002)663 12 m horizontal Dimensions: 76.6 m in length 9.3 m height Subdivided in 6 supermodules, with a lower and an upper part The MACRO detector 3 types of Scintillators ( 600 t) Subdetectors Streamer tubes Nuclear track detectors Acceptance in : 10-4    1 S   10,000 m2 sr for isotropic flux

  5. MACRO cross section(schematic)

  6. PL B357(1995)481 PL b434(1998)451 hep-ex/0206027 Upthroughgoing muons MC SIMULATION (17% scale error): Bartol Group  flux  Phys. Rev. D53 (1996) 1314  inter. Cross sections:  Z. Phys. C67 (1995) 433  Transport in the rock  CERN-EP / 85-03 (1985) Detector simulation: GEANT3 Shape of zenith distribution + L/E distribution m2 = 2.5  10-3 eV2, sin2 2 = 1 Significance ~ 4.7 

  7. Monte Carlos New FLUKA and HKKM: complete three dimensional MCs with improved hadronic model Predictions of FLUKA and HKKM agree perfectly Shapes of zenith distributions with and without oscillations are the same in old Bartol flux, new FLUKA and new HKKM Using the latest primary Cosmic Ray fits: Absolute values are ~ 20-30% lower than MACRO and SUPER K data Using previous Cosmic Ray fits: Absolute values are 5-10% lower than MACRO, SUPER K Need to improve these fits

  8. NIM A492(2002)376 hep-ex/0304037 L/EDistribution ● Black points : upthroughgoing  data ○ Open point : Internal Up (IU)  data Green and red lines: MC predictions for    oscillations with the mentioned parameters point-to-point syst. error (12%) Shaded region:

  9. PL B478(2000)5 hep-ex/0206027 Zenith distributions for IU and (ID+UGS) 164 events < E > 4 GeV Shaded regions: no oscillation MC (21% scale error) Black lines: MC predictions for    oscillations with m2 = 2.5  10-3 eV2 and sin2 2 = 1 Data are in agreement with MCOSC with the quoted parameters 262 events

  10. Combination of indipendent data H.E. 50 GeV L.E. 4 GeV Absolute H.E. Scale error  17% Values L.E. Scale error  21% Zenith distrib. Energy measur. Conclusions MACRO data are consistent with    oscillations, with Maximal mixing m2 = 0.0023 eV2 ( 5  significance)

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