nufact04 - osaka, japan
DESCRIPTION
NuFact04 - Osaka, Japan. WG2 Summary - Part 1 Neutrino Scattering Physics Topics. Conveners: Makoto Sakuda and Jorge G. Morfín. Hadron production cross section p + A (Be,C,Al,Fe) p +- + X. - PowerPoint PPT PresentationTRANSCRIPT
NuFact04 - Osaka, Japan
WG2 Summary - Part 1Neutrino Scattering Physics Topics
Conveners: Makoto Sakuda and Jorge G. Morfín
Hadron production cross section p + A (Be,C,Al,Fe) +- + X
• Previous neutrino cross sections in the few GeV region are published using only 100-1000 events and using the old hadron production cross sections with 10-20% errors. K2K/MiniBOONE have >10K-100K events.
• This is a fundamental input to not only neutrino beam and atmospheric neutrino flux calculations but also any detector simulators.
• We need better accuracy at a few % (<10%).
pn +→+ −μν μ
D.Casper (Prenary talk on July 30)(Eν) =N(Eν)/(F(Eν) nTarget)
np +→+ +μν μ
_
pn +→+ −μν μ
K2K/MiniBOONE have enough statistics to measure cross sections. All they need is flux.
MiniBOONEK2K
SciBar (Carbon)1-track
SciBar (Carbon)2-track
SciFi (Water) has QE. KT (Water) NC0
WG2 July 31
New experiments (BNL-E910, HARP, MIPP) on hadron production
1. HARP measurements of pion yield
for neutrino experiments I.Kato (Kyoto)
2. Pion Production on Be at 6, 12 and 18 GeV in Brookhaven E910 -- J.Link (Columbia)
HARP Detectors
Beam DetectorsBeam DetectorsBeam Cherenkov:
p//K separationBeam TOF:
p//K separationMWPC:
Beam direction
T9 beamLarge angle tracksLarge angle tracks(inside solenoid)TPC: Tracking & PIDRPC: PID
Forward trackingForward trackingNOMAD drift chambers:
Dipole magnet:Tracking &
Momentum analysis
Forward Particle IDForward Particle IDTOF wall:PID for 0–4.5 GeV/cCherenkov:PID for 3–15 GeV/cEM calorimeter:e/ separation
Used for Forward AnalysisForward Analysis
I.Kato
Use K2K thin target (5%Use K2K thin target (5%))• To study primary p-Al interaction• To avoid absorption / secondary interactions
5%5% Al target (20mm) Al target (20mm)
Raw dataRaw data
p > 0.2 GeV/c|y | < 50 mrad
25 < |x| < 200 mrad
Pion yield: K2K thin target
K2K replica (650mm)K2K replica (650mm)
0 42 6P(GeV/c)
8 10 0 100 200-100-200x(mrad)
p-e/ misidentification background
I.Kato
Pion yieldAfter After
all correctionall correction
5% Al target p > 0.2 GeV/c|y | < 50 mrad
25 < |x| < 200 mrad
Systematics are still to be evaluated:• tracking efficiency known at 5% level• expect small effect from PID
0 42 6P(GeV/c)
8 10 0 100 200-100-200x(mrad)
Brookhaven Experiment 910Brookhaven Experiment 910E910 used a spectrometer with good acceptance and particle ID over the momentum and angular range of interest to MiniBooNE.
Particle ID from dE/dx in the TPC, threshold Čerenkov, and Time of Flight.
J.Link
E910 E910 cross section and Sanford-Wang Fit Resultscross section and Sanford-Wang Fit Results
6.4 GeV/c 12.3 GeV/c
PreliminaryPreliminary
J.Link
E910 cross section and Sanford-Wang Fit ResultsE910 cross section and Sanford-Wang Fit Results
17.6 GeV/c
Preliminary
Parameter
Value
C1 262±27
C2 0.970±0.096
C3 1.3±1.2
C4 2.28±0.77
C5 1.50±0.61
C6 5.01±0.22
C7 0.0739±0.0096
C8 16.9±2.4
J.Link
( )⎟⎟⎠
⎞⎜⎜⎝
⎛−−−⎟⎟
⎠
⎞⎜⎜⎝
⎛
−−= 8
5
4
2 cosexp1
1),,( 763
1C
BCB
C
B
CB pCpC
p
pC
p
ppCppS
Comparison to Earlier DataComparison to Earlier DataThe measured π+ cross section is similar to that measured by past experiments.
The spectrum is a little softer and the flux normalization is slightly higher at 8.9 GeV/c
Still, the production spectrum is in agreement with the old fits to within errors. (>10% in total ν flux)
Current Analysis
Cho, et al., 1971
Preliminary
J.Link
Cho et al., 1971, p+Be at 12 GeV,
d/ddp at =0,2,4,6,8,10,12 deg.
Summary
• HARP pion yield (arbitrary units) for K2K thin Al target (20mm) are available for p > 0.2 GeV/c, |y | < 50 mrad, 25 < |x| < 200 mrad. Systematics are still to be evaluated.
• BNL E910 has presented a preliminary + cross section at 6.4,12.3 and 17.6 GeV. Comparison with Sanford-Wang fit and the previous measurements shows agreement at 10% or so. Some difference at forward angle and <3 GeV region exists. Systematic errors are being studied.
• K2K/MiniBOONE wait for the publication.