1. 1 Jet quenching, Nov. 2003 hep-ph/0310079; CERN-TH-2003-244

2. 2 During last VRVS meeting I suggested to look at http://www-cdf.fnal.gov/physics/talks_transp/2003/cipanp_qcd_mesropian.pdf

3. 3

4. 4 Higher p T jets are “more focused”

5. 5 http://www-cdf.fnal.gov/physics/talks_transp/2003/cipanp_qcd_mesropian.pdf

6. 6 Medium Modification of Jet Shapes and Jet Multiplicities Salgado, C ASalgado, C A; Wiedemann, U A hep-ph/0310079; CERN-TH-2003-244Wiedemann, U A Distribution of gluons radiated from initial hard parton  2 =k 2 / (mean p T 2 transferred from the medium to the projectile on the length L Soft gluons dominate and they populate small p T

7. 7 Medium Modification of Jet Shapes and Jet Multiplicities Salgado, C ASalgado, C A; Wiedemann, U A hep-ph/0310079; CERN-TH-2003-244Wiedemann, U A Observable Vacuum shapes from Fixed cone jet definitions in D0 and R(sep) Abbott, BAbbott, B- D0 Collaboration. FERMILAB-Pub-97-242-E

8. 8 Medium Modification of Jet Shapes and Jet Multiplicities Salgado, C ASalgado, C A; Wiedemann, U A hep-ph/0310079; CERN-TH-2003-244Wiedemann, U A Calo granularity i.e. L=32 !?! Jet (not subjet) E resolution 50%/  E+2% for 50 GeV = 9% for 100 GeV = 7%

9. 9 Medium Modification of Jet Shapes and Jet Multiplicities Salgado, C ASalgado, C A; Wiedemann, U A hep-ph/0310079; CERN-TH-2003-244Wiedemann, U A I have a “challenged” child and I know what it means

10. 10 Medium Modification of Jet Shapes and Jet Multiplicities Salgado, C ASalgado, C A; Wiedemann, U A hep-ph/0310079; CERN-TH-2003-244Wiedemann, U A Some optimism Partonic jet multiplicity is a new perspective …

11. 11 Medium Modification of Jet Shapes and Jet Multiplicities Salgado, C ASalgado, C A; Wiedemann, U A hep-ph/0310079; CERN-TH-2003-244Wiedemann, U A Upper limit of radiated gluons energy A visible broadening!

12. 12 Medium Modification of Jet Shapes and Jet Multiplicities Salgado, C ASalgado, C A; Wiedemann, U A hep-ph/0310079; CERN-TH-2003-244Wiedemann, U A Pesimism? Optimism? A challenge …

13. 13 But we will always have some averaging … T A (b).T B (b) driving the probability of a jet creation Pb T A (b)+T B (b) driving the density of the medium (no expansion here)

14. 14 Some references A Dynamical Scaling Law for Jet Tomography /Salgado, C A; Wiedemann, U A hep-ph/0204221; CERN-TH-2002-086.- Geneva : CERN, 18 Apr 2002. - 4 p Published in: Phys. Rev. Lett. 89 (2002) 092303/1-4Salgado, C AWiedemann, U A Phys. Rev. Lett. 89 (2002) 092303/1-4 On the Angular Dependence of the Radiative Gluon Spectrum /Baier, R; Dokshitzer, Yu L; Müller, A H; Schiff, D hep-ph/0105062; Published in: Phys. Rev., C 64 (2001) 057902Baier, RDokshitzer, Yu LMüller, A HSchiff, DPhys. Rev., C 64 (2001) 057902 Energy Loss of Hard Partons in Nuclear Matter /Wiedemann, Urs A hep-ph/0103332; 30 Mar 2001. Published in: Nucl. Phys., A 698 (2002) 615-618Wiedemann, Urs ANucl. Phys., A 698 (2002) 615-618 Jet Quenching versus Jet Enhancement : a Quantitative Study of the BDMPS-Z Gluon Radiation Spectrum /Wiedemann, Urs A hep-ph/0008241; Published in: Nucl. Phys., A 690 (2001) 731-51Wiedemann, Urs ANucl. Phys., A 690 (2001) 731-51 Gluon Radiation off Hard Quarks in a Nuclear Environment : Opacity Expansion /Wiedemann, Urs A hep-ph/0005129; Published in: Nucl. Phys., B 588 (2000) 303-344 ….Wiedemann, Urs ANucl. Phys., B 588 (2000) 303-344 Hard Probes in Heavy Ion Collisions at the LHC: Jet Physics /Accardi, A et al. hep-ph/0310274; 23 Oct 2003. - 123 pAccardi, A