A SUMMARY ON POLARISATION IN RUN15 FOR 100

A SUMMARY ON POLARISATION IN RUN-15 FOR 100 GEV P+P E. C. ASCHENAUER PRESENTING THE WORK DONE BY BILL, DIMA, GRANT AND OLEG

WHY IS POLARISATION CRITICAL Double-spin helicity asymmetry: versus ALL 1 N++/L++ N+ /L+ P 1 P 2 N++/L++ + N+ /L+ Single-spin asymmmetry: N /L 1 AN P 1 N /L + N /L Pr ot s ve pin on ct or E. C. Aschenauer versus If <P 1/2> drops from 0. 5 to 0. 4 to compensate it with integrated lumi we need SSA: 1. 5 x ∫Ldt DSA: 2. 5 x ∫Ldt 2015/02/24 2

2015: H-JET RESULTS 2012: 55. 8 +/- 0. 5 2012: 61. 2 +/- 0. 46 E. C. Aschenauer 2015/02/24 3

p. C: POLARISATION RESULTS PER FILL before normalizing to H-Jet corrected for R and t. P <p>=64. 63 corrected for R and t. P <p>=64. 68 E. C. Aschenauer 2015/02/24 4

PC NORMALISATION FROM H-JET Yellow-2 Yellow-1 E. C. Aschenauer 2015/02/24 5

PC NORMALISATION FROM H-JET Blue-1 Blue-2 E. C. Aschenauer 2015/02/24 6

Y 1 -Y 2 AND B 1–B 2 RATIO Ratio after scaling to H-Jet: bad target in B 1 E. C. Aschenauer 2015/02/24 7

RAMP EFFICENCY E. C. Aschenauer 2015/02/24 8

ROTATOR RAMP EFFICENCY E. C. Aschenauer 2015/02/24 9

HADRON POLARISATION FOR EXPERIMENTS Account for beam polarization decay through fill P(t)=P 0 exp(-t/tp) growth of beam polarization profile R through fill Collider Experiments p. Carbon polarimeter x=x 0 correlation of d. P/dt to d. R/dt for all 2013 fills at 100 Ge. V Polarization lifetime has consequences for physics analysis à different physics triggers mix over fill different <P> E. C. Aschenauer 2015/02/24 10

p. C RESULTS: PROFILE R flattop at injection 2015 -yellow: 0. 048+/-0. 01 at injection 2015 -blue: 0. 019+/-0. 015 flattop E. C. Aschenauer 2015/02/24 11

p. C RESULTS: POLARISATION DECAY 2015 -yellow: -0. 56+/-0. 08 2015 -blue: -0. 74+/-0. 08 E. C. Aschenauer 2015/02/24 12

SUMMARY q Polarisation lifetime Ø blue and yellow d. P/dt < 1% per hour q Energy and Rotator Ramp efficiency Ø both look good q Polarisation profile Ø currently similiar as in 2012 q targets: Ø behave okay E. C. Aschenauer 2015/02/24 13