Muon Bundle Reconstruction in Baikal Event: Classification and Analysis
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This study focuses on the event reconstruction in the Baikal experiment, applying hit classification and events criteria to identify muon bundles and showers. Quality cuts and post-analysis techniques were implemented to improve reconstruction accuracy. Results indicate a promising survival rate for neutrino events and successful tests on shower energy reconstruction. Future outlook includes increasing hit analysis selectivity and exploring additional track parameters.
Muon Bundle Reconstruction in Baikal Event: Classification and Analysis
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4-string stage (1996) Event reconstruction in the Baikal experiment I. Belolaptikovbelolap@nu.jinr.ru (Baikal collaboration)
AGENDA • Hit classification criterion. • Events classification criteria. • Reconstruction (fitting) • Quality cuts. • Post analysis and outlook.
Conditions of reconstruction • Scattering length(~30-40m) > absorption length (~20m) • Time response for muon reconstruction is close to single muon. • Muon track length > geometrical size of array.
Hit classification - apply it for each pair in response Find channels with the number of violations >1 BUT: Still can be pairs which have wrong causality For each pair on the same string. If • There is at least 1 channel violating single muon model in time
PA,q(R) Ti, Ai zij=Tj-Ti-DTmin(Lij,Ai,Aj)+d>0 S= min{zij}; Lij Tj, Aj R1 R2 R Event classification Aim: Find a parameter(s) which are sensitive to muon bundles and showers. Compare MC and experiment over this parameter. All events Nmu=1 S, nsec
Multiplicity distribution of registrated muons for events with S<-0 Distribution over shower energy for events with S<-0 and Nm=1
Quality cuts. • phit*pnonhit + • Amplitude correlation • Track length in array response • Amplitude Chi2 • Chi2_sh/Chi2_mu
Neutrino selection cuts: • Zenith angle > 90 • Time-Z correlation • Nchan >6 RESULTS: (median) – for upward going events ≈ 3o Survival rate with respect to trigger 6/3 for neutrino events ≈20 % at S/N ≈ 10 (90% CL)
Test of shower energy reconstruction with laser s(lgA)<0.1
Postanalysis and outlook • Use all pairs to define “allowed” region in θ,φ to try tofind another track parameters. • Increase a selectivity of thehit analysis. • In case of finding hits out of single muon model, use a modelwith shower(s). μ(φ,θ,x,y,t0) l