Kin Yip
Collider-Accelerator Department
Brookhaven National Lab.
Elastic pp scattering, AN and r5
Nov. 15, 2011, STAR Collaboration Meeting
Mostly stuff shown in the previous pp2pp/STAR meetings
A little bit about the cross-angle corrections (in angle vs in coordinates)
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Before cross-angle corrections
After cross-angle correctionsfor the East ( -100 rad, 60 rad)
Obviously, no fiducial cuts and hotspot cuts applied in both cases.
All these plots are for all runs.
Nov. 15, 2011 Kin Yip
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Before Before
AfterAfter
Nov. 15, 2011 Kin Yip
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After cross-angle corrections With fiducial and hotspot cuts
Nov. 15, 2011 Kin Yip
Before the crossing angle corrections were applied
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Before cross-angle corrections
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After cross-angle corrections (-100 rad, 60 rad)
Nov. 15, 2011 Kin Yip
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After cross-angle corrections (-100 rad, 60 rad)
Nov. 15, 2011 Kin Yip
I’ve used Steve’s Sep. 29 transport, Igor’s latest correction and the crossing angle corrections (including hotspot/fiducial cuts).
Systematic errors: (0.03 rad.) and instead of t/t ~10% for all –t bins, I’ve read off the t/t values from JH’s Sept. 21’s talk :
Systematic errors include those of beam divergence & offset, geometry and Leff.
Re(r5) = 0.00124 0.00255
Im(r5) = 0.00751 0.04124
Compared with when t/t ~10% (and no error in ) :
Re(r5) = 0.00124 0.00312
Im(r5) = 0.00719 0.048349
-t 0.00389 0.00775 0.0125 0.0175 0.0232
t/t 9.5% 7% 5.75% 5.25% 4.5%
Nov. 15, 2011 Kin Yip
After all corrections/cuts previously mentioned
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2009
2003
3 2
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Nov. 15, 2011 Kin Yip
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After cross-angle corrections( -100 rad, 60 rad)
Obviously, no fiducial cuts and hotspot cuts applied in both cases.
All these plots are for all runs.
Nov. 15, 2011 Kin Yip
After cross-angle corrections( -2.5mm, 1.5 mm)
-100 rad & 60 rad are in fact from the asymmetries in coordinate space: -2.5 mm (x) and 1.5 mm (y).
Divided by Leff if (Leff = 25), you get those -100 rad & 60 rad .
Looks identical.
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Obviously, no fiducial cuts and hotspot cuts applied in both cases.
All these plots are for all runs.
Nov. 15, 2011 Kin Yip
After cross-angle corrections( -2.5mm, 1.5 mm)
Before
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After cross-angle corrections in coordinates ( -2.5 mm, 1.5 mm )
Nov. 15, 2011 Kin Yip
Differed by ~0.005 mradians or 5 radians.
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After cross-angle corrections in coordinates ( -2.5 mm, 1.5 mm )
Nov. 15, 2011 Kin Yip
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After cross-angle corrections in coordinates ( -2.5 mm, 1.5 mm )
Though most Leff is ~25, but for the vertical pot in y, Leff is more like 22.9.
1.5mm / 22.9 ~ 65.5, rather than ~60 -radians.
I can similarly estimate the effect if we include x0/y0 corrections …
I didn’t do the fiducial/hotspot cuts in this case of using coordinates (as cross-angle corrections or whatever you call) as people are still discussing various options/methods and it takes quite a bit of time to do.
Nov. 15, 2011 Kin Yip
