Final Report Zheng LIANG SA 18004017 Modern Physics

Final Report Zheng LIANG SA 18004017 Modern Physics Department 1

Contents • CEPC: Precision Frontier – Higgs physics – Other precision measurement • Experimental Conditions – Beam conditions – Physics requirements • Detector Concept – – Tracking system Calorimetry Magnet system Muon detector system 2

CEPC: Precision Frontier • 3

Higgs Physics • 4

Other Precision Measurements • 5

Experimental Conditions • 6

Physics Requirements • 7

Detector Concepts • Baseline detector concept – High granular calorimetry system: separate final state particles – Low material tracking system: minimize interaction of particles in tracking system (TPC & silicon / pure silicon) – Large volume 3 Tesla solenoid system enclosing calorimetry system • Alternative detector concept – Innovative Detector for Electron-positron Accelerator (IDEA) 8

Baseline Detector Concept • Introduction – Principle: measure final state particles in most suited detector subsystem – Particle Flow Algorithm(PFA) reconstructs list of PFA particles (low level particles), and associate detector hits with them – Each event, all physics objects ( produced particles) are identified or reconstructed from the list • Simple particles, such as leptons, are identified directly from the list • Compound particles, such as Kaons, reconstructed from the list – High efficiency & purity reconstruction • Composition – Silicon pixel vertex detector, silicon inner tracker, TPC surrounded by silicon external tracker – Silicon-tungsten sampling Electromagnetic Calorimeter (ECAL), Steel. Glass Resistive Plate Chamber (GRPC) sampling Hadronic Calorimeter(HCAL), 3 -Tesla superconducting solenoid – Flux return yoke embedded with a muon detector 9

Track System • Vertex detector – 6 concentric cylindrical pixel layers – Radii between 1. 6 cm and 6. 0 cm, resolution ~ 5μm • Silicon inner tracker – Outside vertex detector, consists of 2 microstrip layers, radii are 15. 3 cm and 30 cm, before TPC • Silicon external tracker – 1 microstrip layer at radius 181 cm, after TPC • Forward silicon tracker – 5 pairs of silicon disks located at either side of the IP in between z positions 20 – 100 cm – Closet pair to IP use the pixel technology, due to high occupancy, others use microstrip technology • Spatial resolution: better than 7 μm 10

Track System 11

Time Projection Chamber (TPC) • 12

Calorimeter • 13

Solenoid • • • Cylindrical superconducting solenoid Bore diameter 6. 8 m, length 8. 3 m, at room temperature Surround HCAL Provide 3 Tesla axial magnetic field A steel yoke outside, with muon detector system inside (RPC) 14

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Thank you 16