Atmospheric neutrino fluxes Teresa Montaruli, Paolo Desiati, Aya Ishihara, UW, IceCube Meeting, Mar 2005 A background and an interesting measurement How well do we know the atmospheric neutrino fluxes? The primary CR spectrum Can we have a muon and neutrino flux from the same code? A tool for simulation and analysis: a C++ class and a library for fluxes (suitable for ANIS and IceTray) It is a beautiful measurement with the largest data sample AMANDA (IceCube) have since K physics and prompt Fluxes are poorly constrained by accelerator data

Super-Kamiokande and MACRO MACRO final data Bartol 96 HKKM (2001 CR) FLUKA (2001 CR) FLUKA (1996 CR) E  >1 GeV predictions no oscill. ~20%  Honda 2001  Honda 1995  Bartol 1996  SK Data predictions  m 2 = eV 2 SK and MACRO through-going muon data pointed out that the CR assumed after ICRC2001 by HKKM and Bartol was too steep and that a better agreement was achieved with the previous Agrawal et al CR flux Moreover ATIC data preferred E -2.7 to steeper spectra TM, ICRC2003 HE rapporteur talk

Primary CRs Primary spectra: ICRC2001 (softer), Agrawal or Old Bartol (harder) He p 5% agreement between AMS and Bess98 < 100 GeV BUT CAPRICE -20% ICRC2001 assumes AMS-Bess The region relevant for AMANDA/IceCube is higly uncertain due to large errors of Jacee and RunJob data Moreover He and heavy components are worse known and their relevance increases

The inputs: primary CRs in most recent calculations Main difference between ICRC2001/Gaisser-Honda 2002: CNO+Si-Mg+Fe E -2.7 /harder Main difference between ICRC2001/HKKM 2004: He [average of E E ]/ E ] + protons [E / E-2.74+E (E>100 GeV)] Results: HKKM 2004 is closer to previous Agrawal et al, 1996, harder than ICRC2001 and Gaisser-Honda fit resulting in more through-going muons Gaisser-Honda 2002

Theoretical Errors Though HKKM 2004 uses a harder spectrum than Bartol, it is lower! Interaction models are different (Target 2/DPMJET-III – to be updated 15% lower than L3  data) Lots of comparisons between Bartol, HKKM and FLUKA groups resulted in uncertainty reduction also thanks to muon data in the atmosphere. These groups published their results in Can AMANDA data help? How does Lipari flux (used in AMANDA) compare to the more recent calculations? These results agree with: Gaisser astro-ph/

hep-ex/ AMANDA works in a higher E region where oscillations play a small role BUT in the region where hadronic models are worsely known (K physics, prompts…) Systematics need to be reduced – Paolo’s talk!!!! AMANDA DATA SK data prefer higher fluxes by 12% and harder spectra than HKKM >100 GeV

Atmospheric s and  s with FLUKA FLUKA ( new runs extending up to 10 6 GeV/nucleon started at UW. The goal is to have neutrinos from 4  and atmospheric muons from the same interaction and transport code (first 3D code, Astr.Phys.19, 2003) Prompt neutrinos and muons will be addressed when DPMJET-III interface will be ready FLUKA yet poor statistics L3  data can help reducing systm at HE

The inputs: primary CR for VHE spectrum NEW FLUKA generation: CR suitable for VHE

The AtmosphericFlux Class The constructor: AtmosphericFlux mymodel(model); Class Methods: Init: Read Tables in prepared in common format Flux: returns the flux at a given energy, angle and for a flavor eg:double flux = mymodel.Flux(1,1.e3,0.1); returns: flux in GeV -1 cm -2 sr -1 s -1 given: Neutrino type: e, anti- e, , anti-  Neutrino Energy Cos(zenith) Average flux: returns averaged over lower hemisphere Compatible with ANIS Usable by IceTray (A. Hishihara) Usable in analysis stage with ROOT as a shareable library Extensible to ANY FLUX (can become a library of fluxes to be used for event reweighting purposes)