1 / 8

Richard Seto University of CA, Riverside Hard Scattering PWG Sept 13, 2001

Hijing calculations of dA and other things. Richard Seto University of CA, Riverside Hard Scattering PWG Sept 13, 2001. Hijing study of dA. Look at dA Can we separate jet quenching from other effects? Will we get enough statistics? Hijing is used as an example before our data is taken

nuru
Download Presentation

Richard Seto University of CA, Riverside Hard Scattering PWG Sept 13, 2001

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hijing calculations of dA and other things Richard Seto University of CA, Riverside Hard Scattering PWG Sept 13, 2001 Richard Seto

  2. Hijing study of dA • Look at dA • Can we separate jet quenching from other effects? • Will we get enough statistics? • Hijing is used as an example before our data is taken • I would like our final result to be INDEPENDENT of the model. • dA will give us this handle • Statistics assuming Tony’s numbers appear to been enough (as shown by many others) • I place no credence in the model – in fact it is probably not correct. Its just to see the general effect Richard Seto

  3. What are the effects? • Effects – hard scattering is the probe • Npart /Nbin scaling • Initial state multiple scattering-the cronin effect • Shadowing • Jet quenching (!) • Handles • pp gives us the initial hard scattering • dA should give exhibit the first three effects • Will allow us to MEASURE shadowing and cronin • AA either • Exibits first three effects (should look like ~ dA) • Exibits all 4 effects (should look different than dA) Richard Seto

  4. Parameters used • Hijing • pp,dA,AA, SiSi – various energies (mostly 200 GeV), centralities • Cronin (default values) • Shadowing (default values) • Jet quenching • Parameters • dE/dx ~ .25 GeV/fm for quarks (2x for gluons) • Mean free path = 1 fm (default) • Hijing model has • Constant dE/dx • Uniform fireball • More realistic • dE/dx ~ L (interference) • More dense in center Richard Seto

  5. Where are we, vs prediction? • Pi0 data • Compare 130 GeV data vs predictions at 200 (data from table 10 of final analysis note- errors=+, band drawn by paw) • Black dotted error bars – from lack of statistics in MC (sorry) • Bins chosen to get reasonable statistics in MC. Smaller bins assumed for data • Colored error bars (barely visible) – statistical error bars we should get • Notes • Data far away from 1 • Consistent with the jet quench hypothesis • But the non-quench hypothesis is scary. E.g. x0.7 (more shadowing) makes non-quench data also consistent Shadowing, cronin (no jet quench) RAA PHENIX data Shadowing, cronin+Jet quenching Richard Seto

  6. First assume NO jet quench • dA/pp and AA/pp have simillar shapes • Below 1 at high pt because of shadowing • Rise different because dA and pp have different number of participants • Cronin effect and shadowing oppose each other AA/dA dA/pp R AA/pp Richard Seto

  7. Assume jet quench • dA/pp and AA/pp look very different! • Only AA exhibits the quench • Bottom line • If dA and AA look alike no jet quenching • If dA and AA look different – jet quenching (I.e. look at AA/dA) • Looks like we will have enough statistics in pp,dA,AA if we get what is in Tony’s write up. projected data statisical error dA/pp AA/dA R AA/pp Richard Seto

  8. Notes • Cronin and shadowing offset each other • I will show some stuff with cronin and shadowing separately • At first I thought there were some inconsistencies between what I have seen from Xin-Nian and my stuff. On looking more closely I see that my stuff is consistent. • There may be some inconsistencies with • How nbin is calculated between xin-nian and me (I.e. from glauber_mc) – this might be ~10% • The cronin alone- I will show this Richard Seto

More Related