Luminosity Measurement using BHABHA events Tel Aviv University HEP experimental Group MDI SLAC Ronen Ingbir Lumical - A Future Linear Collider detector HEP Tel Aviv University

Strip design ΔE~0.31√E L R Cracow Lumical - A Future Linear Collider detector

Pad design 15 cylinders * 24 sectors * 30 rings = 10800 cells 8 cm 0.31 cm Silicon 28 cm 0.34 cm Tungsten Cell Size 1.3cm*2cm> 1.3cm*6cm< ~1 Radiation length ~1 Radius Moliere L R 6.10 m Lumical - A Future Linear Collider detector HEP Tel Aviv University

Reconstruction Algorithm We explored two reconstruction algorithms: Events Num. T.C Awes et al. Nucl. Inst. Meth. A311 (1992) 130. The log. weight fun. was designed to reduce steps in a granulated detector : 1. Selection of significant cells. 2. Log. smoothing. Log. weight. E weight. Lumical - A Future Linear Collider detector HEP Tel Aviv University

Logarithmic Constant 400 GeV Constant value Constant value After selecting: We explored a more systematic approach. The first step is finding the best constant to use under two criteria: 1. Best resolution. 2. Minimum bias. Constant value Constant value Lumical - A Future Linear Collider detector HEP Tel Aviv University

Energy dependent constant The goal is to find a global weight function. Is the the log. weight constant really a constant ? Constant value Lumical - A Future Linear Collider detector HEP Tel Aviv University

Shower reconstruction What happens when we select the best log. weight constant ? Num. of Cells Num. of Sectors Shower size Log. Weight Selection Energy portion (%) Num. of Cylinders Most of the information is in the selected cells. En>90% Lumical - A Future Linear Collider detector HEP Tel Aviv University

Magnetic field Lumical - A Future Linear Collider detector HEP Tel Aviv University

Background studies BHWIDE + CIRCE Lumical - A Future Linear Collider detector HEP Tel Aviv University

Geometric acceptance In Eout-Ein P= Eout+Ein Out Energy Resolution 3 cylinders 33 mrad 2 cylinders 1 cylinders Lumical - A Future Linear Collider detector HEP Tel Aviv University

Left-Right balance L R Simulation distribution Distribution after acceptance and energy balance selection Right signal - Left signal Left side detector signal Right side detector signal Lumical - A Future Linear Collider detector HEP Tel Aviv University

Energy resolution Ntuple 31% 29% 42% 24% 45% 46% 25% 49% No cuts   Ntuple No cuts With cuts Pure electrons 31% 29% Bhabha 42% 24% Bhabha + Beamstrahlung 45% Bhabha + Beamstrahlung + Beam spread (0.05%) 46% 25% Bhabha + Beamstrahlung + Beam spread (0.5%) 49% Lumical - A Future Linear Collider detector HEP Tel Aviv University

Angular resolution Lumical - A Future Linear Collider detector HEP Tel Aviv University

‘Pure’ electrons simulation Bias study ‘Pure’ electrons simulation Bhabha+Beam+BS(5e-4) Lumical - A Future Linear Collider detector HEP Tel Aviv University

Real life algorithm Working with both sides of the detector and looking at the difference between the reconstructed properties: (In real life we don’t have generated properties) Lumical - A Future Linear Collider detector HEP Tel Aviv University

Dense design 0.1 cm Silicon 0.55 cm Tungsten 0.34 cm Tungsten Lumical - A Future Linear Collider detector HEP Tel Aviv University

Moliere radius & Radiation length Detector Signal 0.8cm 1.1cm Z (cm) 30 radiation length detector 47 radiation length detector Lumical - A Future Linear Collider detector HEP Tel Aviv University

New geometric acceptance Events Energy Resolution Lumical - A Future Linear Collider detector HEP Tel Aviv University

Optimization Lumical - A Future Linear Collider detector HEP Tel Aviv University

Margins in between cells Energy resolution Polar resolution Lumical - A Future Linear Collider detector HEP Tel Aviv University

Maximum peak shower design Our basic detector is designed with 30 rings * 24 sectors * 15 cylinders = 10,800 channels Do we use these channels in the most effective way ? 20 cylinders 10 cylinders 24 sectors * 15 rings * (10 cylinders + 20 cylinders) = 10,800 channels 4 rings 15 rings 11 rings 30 rings 15 cylinders Lumical - A Future Linear Collider detector HEP Tel Aviv University

Polar reconstruction Maximum peak shower design Basic Design 0.11e-3 rad 0.13e-3 rad Constant value Angular resolution improvement without changing the number of channels Other properties remain the same Constant value Lumical - A Future Linear Collider detector HEP Tel Aviv University

High Statistics MC BHWIDE + fast detector simulation Lumical - A Future Linear Collider detector HEP Tel Aviv University

R&D status & future steps Pure electron MC Detector properties Events selection ‘Real physics’ MC Bhabha + Beamstrahlung + Beamspread High statistics MC Luminosity with a crossing angle Luminosity with polarised beams (Gideon Alexander) ‘Real physics’ MC + digitization + elec. noise + New max peak design + Margins Final optimization Lumical - A Future Linear Collider detector HEP Tel Aviv University

THE END Lumical - A Future Linear Collider detector HEP Tel Aviv University