Hadron Production Measurements presented by Giles Barr, Oxford ICRR-Kashiwa December 2004

Hadron production needed for understanding... Neutrino beams spectrum, composition Extensive Air Showers muon component, energy determination Neutrino Factories optimisation of pion collection

Primary cosmic ray N N K π π μ ν Atmospheric Neutrinos

Outline Section 1: Introduction Section 2: NA49 –Experiment –Data taking –Errors and corrections Section 3: Other experiments –HARP –E910,MIPP

1 GeV TeV 1 GeV TeV 10 Parent energy Daughter energy Boxes show importance of phase space region for contained atmospheric neutrino events. 10 Summary of measurements available

1 GeV TeV 1 GeV TeV 10 Parent energy Daughter energy Barton et. al. Atherton et. al. SPY Serpukov Allaby et. al. Abbott et. al. Eichten et. al. Cho et. al. Existing measurements. 10 Existing measurements Boxes show importance of phase space region for contained atmospheric neutrino events.

Barton et. al. Atherton et. al. SPY Serpukov Allaby et. al. Abbott et. al. Eichten et. al. Cho et. al. Measurements. 1-2 p T points 3-5 p T points >5 p T points 1 GeV TeV Parent energy 10 1 GeV TeV 10 Daughter energy P T range covered Boxes show importance of phase space region for contained atmospheric neutrino events.

1 GeV TeV Parent energy 10 1 GeV TeV 10 Daughter energy New measurements. HARP NA49 MIPP New measurements Boxes show importance of phase space region for contained atmospheric neutrino events.

Another view (MINOS)... Plot courtesy of M. Messier Atherton 400 GeV Be Barton 100 GeV C Spy 450 GeV Be

NA20 (Atherton et al.), CERN-SPS (1980) Secondary energy scan: 60,120,200,300 GeV H2 beam line in the SPS north-area Overall quoted errors Absolute rates: ~15% Ratios: ~5%

Needs... Pion and kaon production Projectile: p, He, π, K etc. Very large range of primary energies [2 GeV,>1 TeV] Target: Air nuclei (nearby isoscalar nuclei acceptable) Full phase space coverage p T distribution not interesting Full coverage of p T important Importance of kaons at high energy (Thanks to S. Robbins for plot)

NA49

NA49 experimental layout Target Gap TPC S4 counter Vertex TPCsMain TPCs

NA49 originally designed for Lead-Lead collisions. Also used for pp and pA collision physics

NA49 Proton-Carbon run ‘P322 group’ consisting of some atmospheric neutrino flux calculators, HARP experimentalists and MINOS experimentalists formed collaboration with NA49 and proposed a series of measurements. Received a 1 week test run with a carbon target. It took place in June –158 GeV run, 500k triggers. –100 GeV run, 160k triggers. –1% interaction length carbon target. –Proton selected beam (using Cerenkov). –TPCs, HCAL, CD, no TOF. Immediately preceeding run was an NA49 proton-proton run, using a liquid hydrogen target.

Beam line Cerenkov CEDAR counters Beam chambers Trigger S1-S3 S4 veto

Vertex TPC 1 B=1.7T Vertex TPC 2 B=1.7T Gap TPC Main TPC Left Main TPC Right

NA49 dE/dx plots P (GeV) dE/dx plot for positives Particle ID

NA49 dE/dx fits Particle ID

Bins Technique: Follow closely the analysis of p-p data x F and p T bins Some corrections are identical Pion analysis

Analysis: 1.Get pion yields for proton-proton, 2.followed by pion yields for proton-carbon 3.Later, do kaons, antiprotons. Pion extraction straightforward –shifts and resolution easy to determine –Above x F = 0.5, dE/dx information not available near gap. We do have the track distributions. –Particular region at low x F where π and p dE/dx curves overlap. Use reflection in p-p. –Almost no information at negative x F

Corrections and errors on pion yields Binning correction~1% Target re-interaction<1% Detector material interaction<1%→few % S4 trigger correction5-15% Feed down correction K 0, Λ 0, Σ decays In progress Pion→Muon decaysmall K→pion decaysmall

Prospects Pions for proton-proton available shortly. Pions for proton-carbon follow rapidly after this. –Some atmospheric specific changes can be made Use X LAB Feed down required ? Kaon yields is next priority –Extraction not too bad in positives – N K not strongly correlated to K-peak position. –Challenge at high x F in negatives.

HARP

The Harp detector: Large Acceptance, PID Capabilities, Redundancy TPC, momentum and PID (dE/dX) at large Pt TPC, momentum and PID (dE/dX) at large Pt Drift Chambers: Tracking and low Pt spectrometer Drift Chambers: Tracking and low Pt spectrometer 1.5 T dipole spectrometer Threshold gas Cherenkov:  identification at large Pl Threshold gas Cherenkov:  identification at large Pl 0.7T solenoidal coil Target-Trigger EM filter (beam muon ID and normalization) EM filter (beam muon ID and normalization) Drift Chambers: Tracking Drift Chambers: Tracking TOF:  identification in the low Pl and low Pt region TOF:  identification in the low Pl and low Pt region

HARP Experiment Beam 3-15 GeV protons, CERN PS Collected data 2001, 2002 Secondary hadron yields –Beam momenta –As a function of momentum and angle of daughter particles –For different daughter particles As close as possible to full acceptance The aim is to provide measurements with few % overall precision  efficiencies must be kept under control, down to the level of 1% –primarily trough the use of redundancy from one detector to another Thin, thick and cryogenic targets LH 2, LD 2, LO 2 LN 2 Be, C, Al, Cu, Tn, Sn, Pb T9 secondary beam line on the CERN PS allows a 2  15 GeV energy range O(10 6 ) events per setting A setting is defined by a combination of target type and material, beam energy and polarity –Fast readout Aim at ˜10 3 events/PS spill, one spill=400ms. Event rate ˜ 2.5KHz Corresponds to some 10 6 events/day  Very demanding (unprecedented!) for the TPC.

Beam Particle Identification Beam Time Of Flight (TOF): separate  /K/p at low energy over 21m flight distance –time resolution 170 ps after TDC and ADC equalization –proton selection purity >98.7% Beam Cherenkov: Identify electrons at low energy,  at high energy, K above 12 GeV –~100% eff. in e-  tagging 12.9 GeV/c (K2K) Beam Cherenkov ADC  K p/dp/d  K p d 3.0 GeV/c beam

Forward PID: TOF Wall TOF time resolution ~160 ps 3  separation:  /p up to 4.5 GeV/c K/  up to 2.4 GeV/c  7  separation of  /p at 3 GeV/c 3 GeV beam particles data  p Separate  /p (K/  ) at low momenta (0–4.5 GeV/c) 42 slabs of fast scintillator read at both ends by PMTs PMT Scintillator

Use K2K thin target (5% ) To study primary p-Al interaction To avoid absorption / secondary interactions 5% Al target (20mm) Raw data p > 0.2 GeV/c |  y | < 50 mrad 25 < |  x | < 200 mrad Pion yield: K2K thin target K2K replica (650mm) P(GeV/c)  x (mrad) p-e/  misidentification background

Y. Fisyak Brookhaven National Laboratory R. Winston EFI, University of Chicago M.Austin,R.J.Peterson University of Colorado, Boulder, E.Swallow Elmhurst College and EFI W.Baker,D.Carey,J.Hylen, C.Johnstone,M.Kostin, H.Meyer, N.Mokhov, A.Para, R.Raja,S. Striganov Fermi National Accelerator Laboratory G. Feldman, A.Lebedev, S.Seun Harvard University P.Hanlet, O.Kamaev,D.Kaplan, H.Rubin,N.Solomey, C.White Illinois Institute of Technology U.Akgun,G.Aydin,F.Duru,Y.Gunyadin,Y.Onel, A.Penzo University of Iowa N.Graf, M. Messier,J.Paley Indiana University P.D.BarnesJr.,E.Hartouni,M.Heffner,D.Lange,R.Soltz, D.Wright Lawrence Livermore Laboratory R.L.Abrams,H.R.Gustafson,M.Longo, H-K.Park, D.Rajaram University of Michigan A.Bujak, L.Gutay,D.E.Miller Purdue University T.Bergfeld,A.Godley,S.R.Mishra,C.Rosenfeld,K.Wu University of South Carolina C.Dukes, H.Lane,L.C.Lu,C.Maternick,K.Nelson,A.Norman University of Virginia ~50 people, 11 graduates students, 11 postdocs.

MIPP :Physics Program Particle Physics-To acquire unbiased high statistics data with complete particle id coverage for hadron interactions. –Study non-perturbative QCD hadron dynamics, scaling laws of particle production –Investigate light meson spectroscopy, pentaquarks, glueballs Nuclear Physics –Investigate strangeness production in nuclei- RHIC connection –Nuclear scaling –Propagation of flavor through nuclei Netrinos related Measurements –Atmospheric neutrinos – Cross sections of protons and pions on Nitrogen from 5 GeV- 120 GeV (5,15,25,5070,90) GeV –Improve shower models in MARS, Geant4 –Make measurements of production of pions for neutrino factory/muon collider targets –MINOS target measurements – pion production measurements to control the near/far systematics Complementary with HARP at CERN

E910 Note added after end of talk: –The nw BNL measurements with the E910 experiment have been reported by J. Link at NuFact 2004 in WG2

Summary HARP 3-15 GeV at CERN PS MIPP GeV at FNAL MI NA49 100,160 GeV at SPS