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The focusing mirror system. spherical (elliptical) mirror within gap volume for backward refl. plane mirror just beyond radiator for forward reflections. Minimize detector area (~1 m 2 /sector) interference with FTOF. TOF. Low material budget. Reflecting inside. direct &
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The focusing mirror system • spherical (elliptical) mirror within gap volume for backward refl. • plane mirror just beyond radiator for forward reflections Minimize detector area (~1 m2/sector) interference with FTOF TOF Low material budget Reflecting inside direct & reflected Preliminary studies with mirrors (to reduce instrumented area): - focalization capabilities shown - ring patterns for positive and negative mesons at different angles and momenta reconstructed Different scenarios (refractive index, radiator thickness, mirror geometry) are being explored
Hit prob > 3 10-4 Hit prob
Unidentified events: reduced by better treatment of unwanted events (i.e. muon from meson decay) Mismatch in number of N p.e.: wrong seed assignment Protons weird probability: feature of the LH definition close to the threshold
Direct ring example: Hit prob > 3 10-3 200 trials per point Aerogel: - n=1.06 - thick. increasing with radius: 2-4-6-8-10 cm Mirror: 14-25o PMTs: UBA Hit prob
Hybrid ring example: Hit prob > 3 10-3 200 trials per point Aerogel: - n=1.06 - thick. increasing with radius: 2-4-6-8-10 cm Mirror: 14-25o PMTs: UBA Hit prob
Average N p.e. : Mirror 14-25o PMTs: UBA 200 trials per point Aerogel: - n=1.06 - thick. increasing with radius: 2-4-6-8-10 cm N p.e. > 5 for reflected rings N p.e. > 12 for direct rings
LHp-LHk,p : Mirror 14-25o PMTs: UBA 200 trials per point Aerogel: - n=1.06 - thick. increasing with radius: 2-4-6-8-10 cm Low angles more challenging Possibly due to limited number of trials Protons benefit the small number of unfired PMTs whit expected signal (P is small when C=0) -
Average N p.e. : Mirror 14-25o PMTs: UBA 200 trials per point Aerogel: - n=1.06 - thick. increasing with radius: 2-4-6-8-10 cm Mandatory for positive hadrons Benefit for negative hadrons at large angles and small energy Big dot = studies show in the previous slide
Average N p.e. : PMTs: UBA Mirror 14-25o Mirror 14-35o Worse for positive hadrons Better for negative hadrons
LHp-LHk,p : PMTs: UBA Mirror 14-25o Mirror 14-35o Worse for positive hadrons Better for negative hadrons
Average N p.e. : PMTs: UBA 200 trials per point Aerogel: - n=1.06 - thick. increasing with radius: 2-4-6-8-10 cm Mirror up to 35o: Worse for positive hadrons Better for negative hadrons
Average N p.e. : Mirror 14-25o PMTs: UBA n=1.03 Aer. thick 3-6-9-12-15 cm n=1.06 Aer. thick 2-4-6-8-10 cm n=1.03 gives less photons regardeless the increase thickness due to same assumed transmission length
LHp-LHk,p : Mirror 14-25o PMTs: UBA n=1.03 Aer. thick 3-6-9-12-15 cm n=1.06 Aer. thick 2-4-6-8-10 cm n=1.03 still good due to the larger Cherenkov angle separation
Average N p.e. : PMTs: UBA 200 trials per point Aerogel: - n=1.06 - thick. increasing with radius: 2-4-6-8-10 cm n=1.06 better for patter recognition in the presence of backgrouns
Wrong ID example: Hit prob > 3 10-3 200 trials per point Aerogel: - n=1.06 - thick. increasing with radius: 2-4-6-8-10 cm Mirror: 14-25o PMTs: UBA Hit prob