文档介绍：1 NEW RESULTS FROM HARP (mainly for atmospheric ν) HARP A fixed-target experiment at the CERN Proton Synchrotron (2000-2002) Hadron Production Experiment (PS214) Neutrino Factory Atmospheric Neutrino Flux Accelerator Neutrino Beams Hadron Production Models Overview of new results M. Bonesini Sezione I NFN Milano a, Dipartimento di Fisica G. Occhialini 2 Physics goals of HARP ? Input for prediction of neutr ino fluxes for the MiniBooNE and K2 K exper iments ? P i on/Kaon y ield for the design of the proton driver of neutr ino factories and SPL- b ased super-beams ? Input for precise calculation of the atmospher i c neutr i no flux and EAS ? Input for Monte Carlo generators ( G EANT4, . for LHC or space applications) 2000 – 2001 Installation 2001- 2002 Data tak i ng S ystematic study of hadr on production: Beam momentum : 3-15 GeV/ c Target: fr om hydr ogen to lead ? Acceptance over full solid angle ? F i nal s t ate par tic l e identification 3 Ta rg etl Ta rg et length ( λ% ) Be a m Momentum (G eV) #e v e n t s (Mev ts) Solid targ et s K2 K Al +1 2 . 9 Cu “button” Cu +1 2 . 9, + 1 5 1. 7 1 Cu “ske w ” Cu 2 +1 2 1. 6 9 5 , 50 , 100, re p l ica MiniBooN E Be +8 . 9 Cry ogenic targ et s Wat e r H 1 H 2 18 c m ±3, ±8, ± Be C Al Cu Sn Ta Pb 2 ( 2 001) 5 100 ±3 ±5 ±8 ±1 2 ±1 5 For neg a tiv e pola r ity , only 2 % and 5% N 7 0 8 D 1 H 2 0 10, 100 +1 . 5 , +8( 1 0% ) 9. 6 6 c m ±3 ±5 ±8 ±1 2 ±1 5 Harp detector layout and data taken . Barrel spectrometer ( TPC ) + forward spectrometer ( DCs ) to cover the full solid angle, complemented by PID detectors π K p HARP forward elect r ons hadrons elect r ons hadrons Calorimeter E/p and E (1st layer)/E for p above p ion threshold TOF fo r p=2+- N cherenkov for p below p io n threshold 45 PID performance (GeV/c) p 12 3 4 5 6 Cherenkov efficiency - pions 10 10 1 (GeV/c) p 1 2 3 4 567 8 Cherenkov efficiency - protons 0