Muon Monte Carlo: a versatile tool for lepton propagation through matter

Dmitry Chirkin, LBNL, Berkeley, USA

October 31, 2006, Dortmund University

Introduction

Muon propagation: why do we need it?

Muon/neutrino detectors?

Particles observed by neutrino detectors

Muon Monte Carlo

A tool for muon propagation simulation

Structure of the program

Simulation of muon propagation

Starting with Ei Ending with Ef

f(E)dx

P(E)dx

Continuous losses

Stochastic losses

1.0

vcut=0.05

Ecut=500 MeV

Method of propagation

Distribution of the final energy of the muons that crossed 300 m of Frejus rock starting with 100 TeV

0.05

10-4

0.05

0.01

10-3

10-4

Method of propagation

Distribution of the final energy of the muons that crossed 300 m of Frejus rock starting with 100 TeV

0.05

10-4

0.05

0.01

10-3

10-4

0.05

0.05

0.0110-3

10-4

Muon cross sections

Ionization losses + knock-on electrons

Bremsstrahlung

Photonuclear

Electron pair production

Decay

10 TeV muon

Bremsstrahlung

muons electrons

Photonuclear interaction

Photon-nucleon Photonuclear

Q2

1 GeV2soft hard

photoproduction DIS

GVDM CKMT ALLM

Bezrukov-Bugaev Butkevich-Mikheyev Abramowicz Levin Levy Maor

1991 19972002BB 1981

BB + Hard 03Bugaev Shlepin

ZEUS 94

Kokoulin 99

Nuclear effects

Dutta Smirnov

Muon propagator (MMC) settings: ph-nu settings

Mass effects

Delta-correction to ionization (included into the ionization cross section)

LPM suppression of the bremsstrahlung and direct electron pair production

Dialectric suppression of the bremsstrahlung cross section

Moliere scattering

Electron, tau, and monopolemuon electron

tau monopole

Neutrino propagation

Neutrino cross sections

Also: oscillations

Earth density profile is implemented

Interpolation errors

Distribution of the final energy of the muons that crossed 300 m of Frejus rock starting with 100 TeV

Comparison: parameterized vs. non-parameterized

Interpolation precision: (epa-enp)/epa

Interpolation order: g=2,…6

vcut=0.01vcut=10-4vcut=10-4

Elow=10 TeV

Algorithm errors: average propagation

Deviation from average energy loss (with vcut=1)Propagating 4 106 muons through 100 m of Frejus rock

Algorithm errors: survival probability

106 muons with energy 9 TeV propagated through 10 km of water

Comparison with other codes: MUM (MUons + Medium)

MUM code by E. Bugaev, I. Sokalski, S. Klimushin

Spectra of the secondaries

MMC MUMLOHLIP

Number and energy of secondaries

Implementation for muon/neutrino detector

3 propagation regions:

• before the detector: propagation with fixed vcut

• inside the detector: propagation with fixed vcut or Ecut

• after the detector: fast propagation with vcut=1.0

Parameterization of atmospheric lepton fluxes withCORSIKA

Primaries with Z=1,…,26: Poli-gonato composition model

Run CORSIKA

Parameterize simultated fluxes with

With corrections for zenith angle, muon energy loss and decay

Parameterization of the atmosphere

Muon energy losses

Atmospheric lepton fluxes

muons muon neutrinos electron neutrinos

Integrated fluxes

Quality of the fits

fit quality stability of the result

Things to remember• mmc was written in 2000 and has been updated a few times with new cross sections and features

• mmc has been used by AMANDA and now IceCube, also in data analysis of Frejus

• mmc is available at http://icecube.berkeley.edu/~dima/work/MUONPR

• mmc stands for Muon Monte Carlo and propagates muons

• perhaps more appropriate name is ALMC: All Lepton Monte Carlo, since it propagates muons, taus, electrons, all neutrinos

• mmc can also stand for monopole monte carlo

Applet demonstration