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EIC TF meeting, Feb 16 th , 2012. Another Update: eRHIC Impact on Helicity PDFs progress on plots for white paper. Marco Stratmann. marco@bnl.gov. work based on Elke’s DIS/SIDIS pseudo-data; in collaboration with Rodolfo . recall: new pseudo-data .
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EIC TF meeting, Feb 16th, 2012 Another Update: eRHIC Impact on HelicityPDFs progress on plots for white paper Marco Stratmann marco@bnl.gov work based on Elke’s DIS/SIDIS pseudo-data; in collaboration with Rodolfo
recall: new pseudo-data data for DIS & SIDIS (π± and K±) Elke 5x100 and 5x250 10 fb-1 each, 70% beam pol. cuts: • W2 > 10 GeV2 • depol. factor > 0.1 • 0.01 < y < 0.95 • pelec > 0.5 GeV • 1o < θ < 179o • phadr > 1 GeV global analysis: • use relative uncertainty of each point to produce mock data (based on DSSV) • “randomize” data within 1-sigma • for SIDIS: incl. 5% (10%) uncertainty from pion (kaon) frag. fcts. • map out χ2 profiles with Lagrange multiplier method (Hessian is work in progress)
recall: first profiles for sea quarks read off PDF parameters for a given Δχ2 • very encouraging results • as expected, DIS has no impact • need to translate into • error on x-shape
first results on sea quark asymmetry to propagate uncertainties properly this is based on its own L.M. analysis
new plot showing kinematic coverage & current data 20x250 stage-1 5x100 ✔Salvatore plan: produce similar plots for GPDs, TMDs, and nuclear PDFs
impact of 20x250 data on helicityPDFs ? • range 0.001-1 covered best • by 5 x 100 data • 5x250 add more Q2 bins • to play with Q2min cut
hot off the press: Δg profile at small x 20x250 matters a lot here !
white paper: g1 scaling violation plot ? x best probe for small x gluons pQCD scaling violations positive Dg fixed target data
the “scaling violation plot” 5x250 data start t0 contribute 5x100 data start t0 contribute try to put in other theoretical curves for different Δg
last minute result: alternative Δg’s more negative Δg DSSV+ positive Δg
to do list: PDF correlations a la CTEQ need to produce Hessian sets first – goal: ΔΣ – Δg correlation