Relative alignment of LXE and DCH using AIF Tae Im Kang and William Molzon Oct 22 2013 MEG Coll Meeting

Outline AIF event selection Analysis of relative alignment using AIF Results Relative alignment for 2009, 2010 data Relative alignment stability check for 2011 data by W. Molzon Comparison Relative alignment using Cosmic ray for 2009 data by T. Iwamoto etc.

motivation Annihilation in Flight (AIF) is background event of MEG AIF pattern recognition by G. Lim and W. Molzon AIF event from reconstructed data Good resolution Relative alignment of LXE-DCH using AIF

analysis Run number Reconstructed data (open) Oldkalman used 2009 data : 51xxx – 64xxx (all statistics) 2010 data : 73xxx – 92xxx (all statistics) Reconstructed data (open) Oldkalman used MEG trigger (Trigger = 0)

Looking for AIF ievent=315 of run73999 aif candidate ★ gamma position ★ projection on LXE from last Hit using px, py, pz At last hit : Δθ = θϒ – θ aif , ΔΦ = Φϒ – Φ aif At projected position on LXE : ΔX = Xϒ – X proj, ΔY, ΔRphi (on circumference), ΔZ

Looking for AIF Positron track selections Best chi-square (GhostRank = 0) Time from DCH (TICIter = 0) single hit at last chamber of the track aif candidate

Cuts : dT -> dZ

Cuts: … dZ -> dRphi, dE, Eϒ, Ee 1hit + dZ + dT

Cuts : no wire# 0 wire # 0 - 8 integrated in chamber all 288 wire

Selected AIF

Gamma correction Gamma (from Target) AIF gamma (not from Target) Correction for reconstructed gamma position by Y. Uchiyama Assuming gamma coming from Target Xgamma, Ygamma : correction not needed Zgamma in reconstructed data : already corrected Correction parameter : 1.855 cm/rad by Y. Uchiyama (MC) AIF gamma (not from Target) different incident angle in XY and ZR plane Using correction parameter 1.855 cm/rad

AIF incident angle correction in XY plane UVW position gamma from target incident angle wrt. Perpendicular = 0 deg. gamma from AIF incident angle is about 17 deg. AIF incident angle correction 1.855 cm/rad = L / incident angle (rad) L ~ 0.55 cm for incident angle of 17 deg. (0.30 rad) rotation about theta’ = L / gamma radius L Aif incident angle theta’ target aif position gamma radius

AIF incident angle correction in ZR plane Zgamma_Target, corrected by 1.855 cm/rad * incd_Target Vertex Z Incd_Target aif positon Zgamma_uncor ~ Ugamma, uncorrection Incd_AIF Zgamma_incd_AIF, corrected by 1.855 cm/rad * incd_AIF Zgamma_Target Zgamma_uncor LXE UVW position (reconstructed info) R

Zϒ – Z proj (= ΔZ ) of AIF event with different incident angle correction Zgamma_AIF Zgamma_Target Zgamma_uncor

alignment check if LXE shifted by + 1 mm in Y-axis, (ΔY > 0) Xg – X proj gamma aif projection 180 phi angle ΔY Yg – Y proj  180 deg   180 phi angle Rphi g – Rphi proj Y gamma radius X 180 phi angle

alignment check if LXE shifted by - 1 mm in Y-axis, (ΔY < 0) Xg – X proj gamma aif projection 180 phi angle ΔY Yg – Y proj 180 deg    180 phi angle Rphi g – Rphi proj Y gamma radius X 180 phi angle

alignment check if LXE shifted by + 1 mm in X-axis, (ΔX > 0) gamma aif projection Xg – X proj 180 phi angle ΔY Yg – Y proj 180 deg    180 phi angle Rphi g – Rphi proj Y gamma radius X 180 phi angle

alignment check if LXE shifted by - 1 mm in X-axis, (ΔX < 0) gamma aif projection Xg – X proj 180 phi angle ΔY Yg – Y proj 180 deg    180 phi angle Rphi g – Rphi proj Y gamma radius X 180 phi angle

2010 data Y = 1 ± 0.8 mm, Rphi = - 1 ± 0.6 mm at phi = 180 Fitting range : 140 ~ 220 deg.

2010 data: Yϒ - 2 mm ΔY slop => ΔX < 0

2010 data: Xϒ + 2 mm, Yϒ – 2 mm

2010 data ΔZ = - 3 ± 1 mm, at Zϒ = 0

2010 data: Zϒ + 4 mm

2009 data Y = - 1 ± 0.6 mm, Rphi = 1 ± 0.6 mm at phi = 180 deg. Fitting range : 140 ~ 220 deg.

2009 data: Yϒ + 2 mm ΔY slop => ΔX > 0

2009 data: Xϒ – 2 mm, Yϒ + 2 mm

2009 data: Xϒ + 2 mm (wrong dir), Yϒ + 2 mm

2009 data ΔZ = - 4 ± 1 mm, at Zϒ = 0

2009 data: Zϒ + 4.7 mm

Cosmic ray and AIF for 2009 data Cosmic ray, technical note by T. Iwamoto etc. Δ V = -1.9 ± 0.7 mm Δ Z = -6.1 ± 0.3 mm AIF (preliminary results) Δ Y = - 1.0 ± 0.5 mm Δ Rphi = - Δ V = 1.0 ± 0.5 mm Δ Z = - 4.0 ± 1 mm Consistent results in sign and value within 2 mm error

Resolutions of ΔY, ΔRphi and ΔZ Typical resolution of 25 mm for ΔY and 18 mm for ΔZ Broaden distribution due to the gap of 3 mm between planes if AIF happens in two foils with same probability 3 mm / 14 mm = 0.2 deg = 3.7 mrad

Stability During 2011 Run W. Molzon beginning end X residual Y residual

Residuals for X Offset Changes W. Molzon Xϒ + 20 mm 0 mm Xϒ - 10 mm dY dX

Conclusions AIF event can be used for relative alignment research Sign determination and relative alignment value within 1 mm error (stat.) Relative alignment (preliminary) 2009 data ΔY = - 1 ± 0.8 mm, Δ Rphi = 1 ± 0.6 mm at phi = 180 deg. Δ X > 0 from ΔY slop 2010 data Δ Y = 1 ± 0.6 mm, ΔRphi = -1 ± 0.6 mm at phi = 180 deg. Δ X < 0 from ΔY slop Cosmic ray and AIF show consistent results for 2009 data Same sign and consistent value within 2 mm error Outlook reanalysis of data with newkalman technical note in 1 month how to incorporate in MEG analysis

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geometry effect in cosmic ray TN 69 by T. Iwamoto etc. geometry effect in cosmic ray November June November June

TN 69 by T. Iwamoto etc. Cosmic ray by T. Iwamoto

TN 69 by T. Iwamoto etc. cosmic ray shower different from gamma in general, but deltaZ at Z= 0 should be same 18.5 deg 72.5 deg 113.5 101.5 90 78.4 66.4 (deg) displacement of delta rphi (red) due to geometry = 0.085 cm /deg * 18.5 deg = 1.6 cm 113.5 101.5 90 78.4 66.4 (deg) slop = 4cm / (113 deg – 64 deg) = 0.085 cm/deg = 4.87 cm / rad.

2009 data : geometry effect aif suppresed All gamma AIF event Y g – Y proj aif suppresed

2010 data: geometry effect All gamma AIF event aif suppresed