Fermilab Accelerator Physics Center MARS 15 Modeling of
Fermilab Accelerator Physics Center MARS 15 Modeling of Neutrino Spectra Sergei Striganov, Byron Lundberg, Nikolai Mokhov Fermilab Meeting on Neutrino Flux Prediction Fermilab 22 September, 2014
Outline ü MARS generators ü Mini. Boone neutrino flux simulation ü MARS and NA 61/SHINE data at 31 Ge. V/c ü MARS simulation vs MIPP measurement of charged pion yields off Nu. MI target ü MARS simulation and neutrino spectra at 120 Ge. V (MINOS measurements, G 4 LBNE simulation) 2
Introduction MARS code was not specially tuned to calculate neutrino spectra Goal of this study to check MARS simulation of neutrino flux by comparison: 1) with data on charged pion and kaon production off light targets (beryllium, carbon) at actual proton energies: 8. 9 Ge. V/c – FNAL Booster Neutrino, 31 Ge. V/c - T 2 K neutrino beam 2) with Mini. Boo. NE simulation of neutrino fluxes 3) with MIPP measurement of charged pion production off Nu. MI target at 120 Ge. V/c 4) with MINOS measurement of muon neutrino and antineutrino spectra at near detector 5) with G 4 LBNE simulation of neutrino flux 3
MARS 15 EXCLUSIVE EVENT GENERATORS Improved Cascade-Exciton Model code, CEM 03. 03, combined with the Fermi break-up model, the coalescence model, and an improved version of the Generalized Evaporation-fission Model (GEM 2) is used for hadronnucleus interactions below 0. 3 to 3 Ge. V. Recent multi-fragmentation extension. The Los Alamos Quark-Gluon String Model code, LAQGSM 03. 03 (2013), is used in MARS 15 for photon, particle and heavy-ion projectiles at a few Me. V/A to 1 Te. V/A. This provides a power of full theoretically consistent modeling of exclusive and inclusive distributions of secondary particles, spallation, fission, and fragmentation products. S. G. Mashnik, K. K. Gudima, A. J. Sierk, M. I. Baznat, N. V. Mokhov, “CEM 03. 03 and LAQGSM 03. 03 Event Generators for the MCNP 6, MCNPX and MARS 15 Transport Codes”, LANL LA-UR-08 -2931 (2008). For quite some time, MARS has used the Dual-Parton Model code, DPMJET 3, for the very first vertex in a cascade tree. This is used in our numerous studies for the LHC 7 x 7 Te. V collider and its detectors, and at very high energies up to 100 Te. V. 4
Recent LAQGSM Developments at E < 10 Ge. V (1) • New and better approximations for elementary total, elastic, and inelastic cross sections for NN and πN interactions • Several channels have been implemented for an explicit description: N+N→N+N+mπ, π+N→N+mπ (m<5), B+B→B+Y+K, π+B→Y+K, Kbar+B→Y+π, and K+Kbar, N+Nbar pair production • Combination of the phase space and isobar models and experimental data • g. A reactions extended down to GDR and below • Arbitrary light nuclear projectile (e. g. , d) and nuclear target (e. g. , He) 5
MARS 15 INCLUSIVE GENERATOR Inclusive generator uses a combination of phenomenological models, parameterizations and integration algorithms, covering energy range from 3 Ge. V to 100 Te. V. Charged pion/kaon production is described mainly on basis of experimental data obtained in XX century, but agree well with new generation experiments – NA 49, HARP, NA 61/SHINE. It is much more simple to tune this type of generator to specific task than improve exclusive model to agree with new data. 6
Yield off beryllium at 8. 9 Ge. V/c –PI-. Blue – LAQGSM, red – MARS-INCL 7
Yield off beryllium at 8. 9 Ge. V/c -PI+. Blue – LAQGSM, red – MARS-INCL 8
Yield off beryllium at 8. 9 Ge. V/c -PI+. Blue – LAQGSM, red – MARS-INCL 9
Mini. Boone collaboration - neutrino flux simulations Proton beam with 8 Ge. V kinetic energy hit beryllium target. Monte Carlo simulation uses Geant 4 framework Differential cross sections of pion and kaon production have been tuned to match external measurements Systematic errors in flux simulation have been determined by varying parameters within their uncertainties Estimated systematic uncertainties of Mini. Boo. NE calculations is about 20%. Observed data rate a factor 1. 21 ± 0. 24 higher than predicted 10
MARS Mini. Boo. NE geometry – imported from G 4 Boo. NE 11
Mini. Boone vs MARS simulations Horn in neutrino mode Horn in anti-neutrino mode 12
Total neutrino fluxes at Mini. Boo. Ne detector horn in neutrino mode numubar nuebar Mini. Boo. NE 5. 19 10 -10 3. 26 10 -11 2. 87 10 -12 3. 00 10 -13 MARS 4. 64 10 -10 2. 80 10 -11 2. 36 10 -12 1. 79 10 -13 horn in anti-neutrino mode numubar nuebar Mini. Boo. NE 5. 42 10 -11 2. 93 10 -10 6. 71 10 -13 1. 27 10 -12 MARS 4. 54 10 -11 2. 95 10 -10 4. 62 10 -13 1. 22 10 -12 13
Yield off carbon at 31 Ge. V/c. NA 61/SHINE data – PI+ 14
Yield off carbon at 31 Ge. V/c. NA 61/SHINE data – PI- 15
Yield off carbon at 31 Ge. V/c NA 61/SHINE data. – K+ 16
Yield off carbon at 31 Ge. V/c. NA 61/SHINE data – K- 17
MARS description of Nu. MI target 18
MIPP measurement vs MARS simulation -I positive pion negative pion 19
MIPP measurement vs MARS simulation -II 20
MIPP measurement vs MARS simulation -III 21
MIPP measurement vs MARS-LAQGSM – PI+. Black – carbon rod, blue – Nu. MI target, read – Nu. MI target with water. positive pions 22
MIPP measurement vs MARS-LAQGSM – PI-. Black – carbon rod, blue – Nu. MI target, read – Nu. MI target with water. negative pions 23
Simple Nu. MI channel geometry Simple model of secondary Nu. MI channel consists from target, 2 horns, decay pipe, absorber. Model does not take into account many details – production of secondary particles in interactions with horns, walls of decay tube; scattering in horns. But it describes well measurement of neutrino spectra. 24
MINOS measurement of neutrino spectra at near detector vs MARS simulation 25
MARS model: LBNE Zoom to Target Hall
MARS model: LBNE Baffle to start of DK pipe Target Hall shielding subject to revision, but won’t change neutrino flux much.
MARS model: LBNE Nu. MI-type Horns
Compare to G 4 LBNE From Laura Fields Horns OFF
Conclusions MARS predictions agree within 20 -30% with HARP and NA 61/SHINE measurement of charged pion/kaon production in proton-light nuclei interaction MARS simulation agrees within 20 -30% with MIPP measurement of charged pion production off Nu. MI target. MARS simulations of muon neutrino and anti-neutrino agree within ~30% with other calculations and MINOS measurements. MARS generators should be improved to better description of high energy tails of charged pion production 30
backup 31
NA 49 vs MARS-INCL 32
NA 49 vs MARS-LAQGSM 33
- Slides: 33