1 / 18

Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies

Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies. Szilveszter Miklós Harangozó Zimányi Winter School 2013. Supervisor: Dr. Gergely Gábor Barnaföldi Wigner RCP of the HAS Department of Particle & Nuclear Physics. Consultant: Dr . Gábor Papp ELTE – TTK

verdi
Télécharger la présentation

Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies

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. Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies SzilveszterMiklósHarangozó Zimányi Winter School 2013 Supervisor: Dr. GergelyGáborBarnaföldi Wigner RCP of the HAS Department of Particle & Nuclear Physics Consultant: Dr. GáborPapp ELTE – TTK Department of Theoretical Physics

  2. pQCDbased parton model • Nucleon-Nucleon reactions • Factorization: we assume, the process can be factorized into 3 independent phase

  3. pQCD based parton model • We calculate the cross sections with a convolution described above. • We characterize the PDFs & FFs as probability density functions, which can not be calculated perturbatively. Parton Distribution Function (PDF) hard partonic scattering Fragmentation Function (FF)

  4. Improving the model • 40% uncertanity is too much. • Phenomenological input. • Parton’s transverse (intrinsic) momentahave been taken into account. Assume: transverse momentum distribution is Gaussian:

  5. The c.m. energy dependence of • Comparison of experimental spectra and results of the calculations • Uncertanities come from the Principle of Minimal Sensitivity • The model is more sensitive at low pT-s for the parameter • Take a look at the tendency…

  6. The pT& dependence of pT dependence of the dependence of the • best fit for every pT value • for a fixed , pT independent values can be assumed • best fit for the average pT • intrinsic transverse momentum seems to decrease Good pp reference spectra can be obtained

  7. Proton-Nucleus (pA) collision • Experience: the yield differs from the expected: atomic number (A) times the one from pp spectra • Measuring tool: Nuclear Modification Factor (NMF), RpA • Difference: Nuclear Effects Nuclear Effects where is the number of binary collisions

  8. Nuclear Effects Multiple Scattering Nuclear Modifications of PDF’s Nuclear Effects • Classic and Saturated Glauber model • Dependence on the impact parameter, b • Intrinsic transverse momentum distribution broadens: • Suppression of the yield at low pT-s • Several parameterizations has been implemented by different groups

  9. Parameters for the saturated Glauber model in pAcollisions Search for the universal Csat constant Maximum 3-4 collision with CSat≈ 0.35

  10. Cronin-effect in the saturated Glauber model Dependency of the Cronin-peak’s maximum against the Atomic number • ν: number of semihard collisions • parameters fitted for experiments • at fixed , peak stays put

  11. Cronin-effect in the saturated Glauber model Dependency of the Cronin-peak’s maximum against the Atomic number • shadowing and saturation also suppresses the spectra • in fully saturated case we get the original dependency • we can apply a correction to the formula:

  12. The kTpQCD v2.0 code PDF FF pQCD

  13. The kTpQCD v2.0 code Pro.: • Several parameterization can be probed within the same framework • Original codes has been implemented • Easy to add new type of PDFs, FFs, etc.

  14. The kTpQCD v2.1 code Example: New shadowing: EPS09s eps09s.cpp Ref.: 10.1007/JHEP07(2012)073

  15. Reconstruction • HIJING shadowing + Multiple scattering • EPS09s shadowing • Both parameterizations gives acceptable results • For HIJING ν= 4 gives the best fit • For RHIC results EPS09s is the best

  16. Questions - Motivation • Which nuclear effects cause the peripheral anomalies? • Can we model model them? • To claim a better understand of the Glauber-model • Find the limits (or a better implementation) of the saturated picture

  17. Summary We have: • pp reference • first results on minimum bias collisions • an updated code with “easy-to-upgrade” properties We don’t have: • good enough parameterization for LHC energies • better understand of the peripheral collisions • an updated code with “easy-to-upgrade” properties

  18. Thank you for your consideration!

More Related