External Alignment Maya Shimomura (ISU) Attempt to solve the problem of dφ alignment 12/02/23 VTX Meeting

The problem Some parts of DCA distribution by standalone tracks are shifted. Inner alignment shows the slope depending on φ.  the ladder is tilted ?  the radius is wrong ? Check the external alignment (dφ) vs. φ distribution. dφ vs. φ for B2 using pixel clusters DCA West and East by SA tracks Different color indicates different ladder in pixel dφ Φ[rad] Φ[rad] 12/02/23 VTX Meeting Φ[rad]

Some ladders have slops Not in CNT acceptance Weak signal Dead slope 12/02/23 VTX Meeting

Attempt to solve 1 (did not work) Make East coordinate shift with 190 microns along with x direction. set_OffsetEastToWest(0.151,-0.010,0.) set_OffsetEastToWest(0.113,-0.010,0.) default : (unit is [cm]) set_OffsetEastToWest(0.132,-0.010,0.) No hot dead map is applied. 12/02/23 VTX Meeting

dφ vs. vtx φ at B0 East (L5-9) Default Shift 1. Ladders have slopes. 12/02/23 VTX Meeting

dφ vs. vtx φ at B0 East (L5-9) Default Shift 2. Attempt 2 looks better than 1. Slopes are reduced. 12/02/23 VTX Meeting

dφ vs. vtx φ at B1 East (L10-19) Shift 2. Default Slope became flatter than the default. Phi center might be shifted. 12/02/23 VTX Meeting

dφ vs. vtx φ at B2 East (L8-15) Shift 2. Default Small slope appeared ? ? 12/02/23 VTX Meeting

dφ vs. vtx φ at B3 East (L12-23) Shift 2. Default No significant change is detected. 12/02/23 VTX Meeting

Peak position vs. ladder number (shift 2) B0 West B0 East B1 West B1 East B2 West B2 East B3 West B3 East East has slope. 12/02/23 VTX Meeting

Attempt to solve 2 Since the whole shift for the east coordinate does not solve the problem, we decided to shift the ladder by ladder individually along each radius direction. Calculate the amount of needed r-shift by fitting the profile slope of dϕ vs. ϕ distribution for each ladder. Shift the r position for each ladder and create the new DST with this new geometry file. (waiting for finishing the jobs now.) Will check if the DCA with standalone tracks are improved or not. 12/02/23 VTX Meeting

Fitting function Fitting function : y = [0]*tan(x-[1]) Parameter [0] is the necessary amount to shift. Parameter [1] is the ϕ center position at each ladder where dϕ =0. x is ϕ and y = dϕ here. Track dϕ ladder In Software ϕ Needed shift [0] ladder In Real Fitting ϕ profile 12/02/23 VTX Meeting

Condition and Selection Run #349369 DST production is done in RCAS. (We have to use rcas instead of 1008 machines.) Reconstruct from PRDF files ( under /phenix/zdata03/phnxreco/VTX/prdf/eventdata/) Au+Au peripheral collision (10<BBC charge<200 ) -15<bbcz<15 Suppose the magnetic filed is uniform. (0.9 Tesla) Coordinate systems are matched between VTX and CNT. OffsetVtxToCnt :(-0.169,-0.122,0.) X Y vertex Xoffset = 0.052 and Yoffset = -0.054 for West Hot dead map is applied. Z vertex --- VTX vertex VTX Meeting 12/02/23

DCA distribution before and after shift [0] Before West After West Before East After East West around phi = 1 is slightly better than before ? 12/02/23 VTX Meeting

dϕ vs. vtx ϕ before and after shift B0 West After B0-L0 and L4 became flatter than before. 12/02/23 VTX Meeting

dϕ vs. vtx ϕ before and after shift B0 East After B0-East became steeper than before. Looks like there are some phi shift occurred. 12/02/23 VTX Meeting

dϕ vs. vtx ϕ before and after shift B1 West After B1-West became slightly flatter than before. 12/02/23 VTX Meeting

dϕ vs. vtx ϕ before and after shift B1 East After B1-East became steeper than before. Looks like there are some phi shift occurred. 12/02/23 VTX Meeting

dϕ vs. vtx ϕ before and after shift B2 West After B2-West looks same before and after shift. 12/02/23 VTX Meeting

dϕ vs. vtx ϕ before and after shift B2 East After B2-L8 became flatter and L12 became steeper than before. Looks like there are some phi shift occurred. 12/02/23 VTX Meeting

dϕ vs. vtx ϕ before and after shift B3 West After B2-L7 and L11 looks flatter than before. 12/02/23 VTX Meeting

dϕ vs. vtx ϕ before and after shift B3 West After Looks like there are some phi shift occurred. 12/02/23 VTX Meeting

dϕ peak position vs. Ladder number B0 West B0 East B1 West B1 East B2 West B2 East B3 West B3 East There are a lot of dϕ shift on East. They have some structure as same as beam offset was shifted. 12/02/23 VTX Meeting

Shift [0] is better than –[0] at West? DCA distribution before and after shift –[0] Just for the confirmation I tried opposite shift also. Before West After West Before East After East Shift [0] is better than –[0] at West? 12/02/23 VTX Meeting

dϕ peak position vs. Ladder number with opposite sift (–[0]) B0 West B0 East B1 West B1 East B2 West B2 East B3 West B3 East There are a lot of dϕ shift on East. They have some structure as same as beam offset was shifted. 12/02/23 VTX Meeting

Back Up 12/02/23 VTX Meeting

σ vs. ladder number (shift 2) B1 West B1 East B0 West B0 East B2 West B2 East B3 West B3 East No strange behavior. 12/02/23 VTX Meeting

Possible reason In this case, we see the ϕ dependence. r ϕ DC track Real hit VTX layer Real position VTX layer position in the software Hit we see dϕ dϕ r ϕ In this case, we see the ϕ dependence. 12/02/23 VTX Meeting

dφ vs. vtx z at B0 East (L5-9) West (L0-4) Ladders at East have slopes. 12/02/23 VTX Meeting

dφ vs. vtx z at B1 East (L10-19) West (L0-9) Some ladders at East have slopes. 12/02/23 VTX Meeting

dφ vs. vtx z at B2 East (L8-15) West (L0-7) East ladders have slopes. 12/02/23 VTX Meeting

dφ vs. vtx z at B3 West (L0-11) East (L12-23) 12/02/23 VTX Meeting

Correlation cut is applied. dφ correlation cut : dφ_{3} – dφ_{x} (x:0~2) < 2σ  Background is reduced. dϕ3 vs. dϕ1 (L5) Red line y= ax +b dϕ3 vs. dϕ1 (L5) Red line y= ax +b dϕ1 (B1L5) dϕ1 (B1L5) 12/02/23 VTX Meeting

dφ vs. vtx φ before/after the correlation cut The background is reduced. However,, the distribution is not significantly sharped as Yasuyuki expected. The dead areas increase due to requiring the B3 correlation. B1 West Read: Average (Profile) 12/02/23 VTX Meeting

Both run#349369 and run#349679 are in this period. Zero field run 346977 Zero field run 347148, 347149 Zero field run 347796, 347797 Zero field run 349005, 349006,349007 Both run#349369 and run#349679 are in this period. 12/02/23 VTX Meeting

Calculation details on x-y plane hit in VTX (xvtx,yvtx) Distance(D) between the VTX hit and the straight line projection from (xoffset1,yoffset1) along the vector u can be calculated as the cross product (vector product) of vector x and vector u. x = (xx,xy)=(xvtx-xoffset,yvtx-yoffset) u = (ux,uy)=(cos(ϕ0),sin(ϕ0)) D = xx*uy - xy*ux Track from (xoffset,yoffset) Magnetic bending correction is approximated as bend ~ 0.5*r2/R r: length of vector x Since p = 0.3*B*R with B=0.9T p ~ 0.27*R 1/R ~ 0.27/p bend ~ 0.0013*r2/p (r in cm) u = (cos(ϕ0),sin(ϕ0)) initial direction of the CNT track used as the seed or guide Beam center (xoffset,yoffset) 12/02/23 VTX Meeting

Central Track Cut Track quality = 31 or 63 1.0<p[GeV/c]<4.0 |pc3dphi - emcdphi-0.0003|<0.02 |pc3dz - emcdz + 0.2|<5.0 VTX Meeting 12/02/23

Mikhail’s slide 12/02/23 VTX Meeting