Effect of the Solenoid Field on the Luminosity Monitor The XXX PANDA meeting Sep.7-11,2009, Juelich Effect of the Solenoid Field on the Luminosity Monitor Huagen Xu LuMo @ IKP: T. Randriamalala, J. Ritman and T. Stockmanns 15 September, 2018 15 September, 2018

Outline One Tentative Geometry of LuMo Effect of the Solenoid Field on LuMo Confirmed Results Summary 2

1. One Tentative Geometry 16 Silicon sensors with trapezoidal shape on 4 planes; Distance between neighbouring planes: 20cm. Dimension: 2 cm(short side)X5 cm(height)X5.33 cm(long side); Thickness : 150 μm; Single/Double side stripped; 3

Digi & Reco Reco Hits Plot Strip on Front/Back Side, pitch = 50 μm FrontSide BackSide 4 Reco Hits Plot

Spatial Resolution σ = 10 μm/30 μm 52.7 μm σ = 30 μm/10 μm 158.2 μm 5

Track Theta RecoHitsTheta : Theta by fitting RecoHits , Beam axis θ Hits RecoHitsTheta : Theta by fitting RecoHits , MCHitsTheta : Theta by fitting MCHits, MCtrue Theta : Theta of particle’s mother track 6

RecoHitsTheta - MCTruetheta MCHitsTheta - MCTruetheta Theta resolution RecoHitsTheta - MCTruetheta MCHitsTheta - MCTruetheta 7

2. Effect of the Solenoid Field Field on Field off RecoHitsTheta Resolution vs Beam Momentum for antiproton Difference 8

Peak of MCHits Theta RMS of MCHits Theta Field On Field Off On - Off 03.09.09 9 Field On Field Off On - Off

Field Map plotted one map file map file1+2+3+4 10

MCHits’ plot with field and with no field Field On Field Off MCHits’ plot with field and with no field BoxGenerator; Beam Particle: antiProton; Beam momentum: 1.5GeV/c; Fixed theta: 5mrad; Azimuth: 0~360; Give rise to ~0.5 mrad shift toward beam axis for antiProton. 11

3. Confirmed Information Reason: due to the rectangular aperture of downstream door for solenoid, the Y-field is much higher than X-field. Figure from Jost Lühning 12

Track of Proton from IP Emitted from IP with 1.5GeV/c and 5mrad Figure from Jost Lühning 13

Track of Proton and antiProton from IP Emitted from IP with 1.5GeV/c and 5mrad Proton: red antiProton: blue Figure from Jost Lühning 14

Geane prediction (forward mode) Start plane: IP plane; Start position: IP position(0,0,0); (antiProton with 1.5GeV/c and 5mrad) 15

(Geane – MC)/ (Geane Propagation Error) Pull distribution (Geane – MC)/ (Geane Propagation Error) 16 Geane Hits fit theta MCHits theta

Geane prediction (Backward) Start plane: the first detector plane; Start position: the MC Hits of antiProton on the first detector plane;

Position and Theta (Backward) fX, fY at IP Theta = 5.022mrad

4. Summary With a new tentative geometry of LuMo the effect of the Solenoid field was found, for antiProton with momentum of 1.5GeV/c the theta of track would be shifted ≈ 0.5mrad@ LuMo ; The effect was confirmed by Solenoid experts; The effect was convinced by using Geane packages with forward and backward mode as well. 19

Thanks for your attention! 20