# Presentation: 236747

##   Jet Tomography

**      **
**  ****Jet Tomography**

**Ivan Vitev**
**         *****Iowa State University***

- Ivan Vitev

- December 10, 2003

## Outline of the Talk

**Outline of the Talk**

**  ****Conclusions:**
-                              ****** ****Properties of cold and hot nuclear matter**
-                            **Evidence for the creation of the QGP at RHIC**

** ****  ****Applications of Jet Tomography**
- _  _
-                               **Suppression of hadrons in semi-inclusive DIS  **
**                          ** **Jet quenching in hot nuclear matter, transverse **
**                             ****momentum, centrality and rapidity dependence**
-                            **Correlations and di-hadron tomography**
**             **

**   ****Principles of Jet Tomography**
-                          **Medium-induced gluon bremsstrahlung in QCD**
**                        ** **Implementations of jet energy loss**

**Ivan Vitev,** **ISU**

**   ****Future Experimental Directions**
-                            **Entropy growth, reappearance of the lost energy**
**                          ** **Jet cone and intra-jet correlation studies**

- Ivan Vitev

- December 10, 2003

## Principles of Jet Tomography

**Principles of Jet Tomography**

**Ivan Vitev,** **ISU**

**The QCD *****analogue***** of positron emission tomography**

**Radionuclides: **
**11****C, ****13****N, ****15****O, ****18****F**

** **_**Calibrated**_** source**
**  **_**Calculable**_** absorption**
**    ****cross sections **
**  **_**Interpretation**_** of the**
**    ****results **

**e****+**

**e****+**

**Prerequisites:**

**e****+**

- Ivan Vitev

- December 10, 2003

##    perturbative QCD 

** ****Inclusive hadron distributions – calculable in **
**   ****perturbative QCD**** **

**Ivan Vitev,** **ISU**

**Leading order pQCD phenomenology**

**Next-to-Leading order pQCD**

**5**

**10**

**p****T**** [GeV]**

**Parton distribution functions**

**Fragmentation functions**

**Perturbative cross sections**

**Calibrated Probes**** **

**PHENIX Collab., Phys.Rev.Lett.  91 (2003)**

**I.V., hep-ph/0212109 [in CERN Yellow report] **

- Ivan Vitev

- December 10, 2003

## Radiative QCD Energy Loss 

**Ivan Vitev,** **ISU**

**M.Gyulassy *****et al.,***** Nucl.Phys.B594**
**(2001); Phys.Rev.Lett.85 (2000)**

**Effective 2D **
**Schroedinger equation**

**R.Baier *****et al., *****Nucl.Phys.B**
**483 (1997); *****ibid. *****484 (1997****)**

**B.Zakharov,***** *****JETP Lett. 63 (1996)**
**U.Wiedemann, Nucl.Phys.B588 (2000)**

**Radiative QCD Energy Loss **

** ****Elastic energy loss**

** ****Radiative energy loss**

**J.D.Bjorken, SLAC preprint (1982) **
**unpublished**

**versus**

- Ivan Vitev

- December 10, 2003

## Gluon Absorption and Mass Effects

**Gluon Absorption and Mass Effects**

**Ivan Vitev,** **ISU**

** ****Detailed balance significantly **
** ****reduces energy loss  for**
-                              **at RHIC**

**E.Wang, X.-N.Wang, Phys.Rev.Lett. 87 (2001)**

**M.Djordjevic, M.Gyulassy, nucl-th/0310076****  **

**Mass corrections and Ter-Mikayelian **
**plasmon effect in QCD**

**Reduction of E-loss**

**Heavy quarks**

- Ivan Vitev

- December 10, 2003

## Modified Jet Cross Sections

**Modified Jet Cross Sections**

**Ivan Vitev,** **ISU**

**R.Baier *****et al.,***** JHEP0109 , (2001)**

**Quenching factor Q(p****T****)  **
**same as****  **
**Leading ****parton**** R****AA****(p****T****)**

**g***

**g****rad**

**q**

** ****Modified fragmentation **
**  ****functions**

** ****Reduced partonic cross**
**  ****sections**

**Typical LHC**

- Ivan Vitev

- December 10, 2003

## Effective Suppression 

**Effective Suppression **
**of Fragmentation Functions **

**Ivan Vitev,** **ISU**

**C.Salgado, U.Wiedemann, **
**Phys.Rev.Lett. 89 (2002)**

** ****Kniehl, Kramer, Potter **
**fragmentation functions**

- z=ph/pc

** ****Independent Poisson approximation **
**   ****for multiple gluon emission **

**   ****Probability for fractional energy **
**    ****loss**** **

**Normalized for suppressed leading **
**hadrons (no feedback) **

- Ivan Vitev

- December 10, 2003

## DIS Tomography

**Ivan Vitev,** **ISU**

**DIS Tomography**

**E.Wang, X.-N.Wang, Phys.Rev.Lett. 89 (2002)**

**F.Arleo, Eur.Phys.J. C30 (2003)**

**         ****- radiative energy loss fraction**

**         ****- energy transfer**

- Ivan Vitev

- December 10, 2003

## QGP Tomography 

**Ivan Vitev,** **ISU**

**QGP Tomography**** **

**I.V., M.Gyulassy, Phys.Rev.Lett. 89 (2002)**

**PHENIX Collab., Phys.Rev.Lett. 91 (2003)**

**STAR Collab., Phys.Rev.Lett. 91 (2003)**

**Absolute scale**

- Ivan Vitev

- December 10, 2003

## Centrality Dependence

**Centrality Dependence**

**Ivan Vitev,** **ISU**

**X.-N.Wang, nucl-th/0305010**

**G.G.Barnafoldi *****et al.,***** hep-ph/0311343**

**   ****Small number of semihard **
**   ****scatterings **** **

**1+1D  GLV**

- Ivan Vitev

- December 10, 2003

## Rapidity Dependence 

**Rapidity Dependence**** **

**Ivan Vitev,** **ISU**

**1+1D  GLV**

**(a double ratio)**

** ****Energy loss in a 3+1D hydro**

- Ivan Vitev

- December 10, 2003

## Di-Hadron Tomography

**g***

**g****rad**

**Di-Hadron Tomography**

**Ivan Vitev,** **ISU**

**q**

**g****rad**

**QGP**

**J.W.Qiu, I.V., Phys.Lett.B570 (2003)**

** ****Di-jet acoplanarity (insufficient)**
** ****Away-side quenching**

- Ivan Vitev

- December 10, 2003

## Near- and Far-Side Correlations

**Ivan Vitev,** **ISU**

**Near- and Far-Side Correlations**

**T.Hirano, Y.Nara, Phys.Rev.Lett.91 (2003) **

**  ****Unaltered near-side **
**    ****correlations**
**  ****Disappearance of the **
**   ****away-side correlations**

**K. Filimonov [STAR Collab.], DNP’03 meeting**

- Ivan Vitev

- December 10, 2003

## The “Remnants of Lost Jets”

**The “Remnants of Lost Jets”**

- d+Au

**Ivan Vitev,** **ISU**

**I.V., GLV e-loss simulation**

**4 GeV < p****T****tig ****< 6 GeV**

**|y|<1**
**b=0 fm**

**y=0**
**b=0 fm**

**100% recovered**

**600 MeV**

** ****Reappearance of the lost energy**

** ****Entropy growth **
** ****Momentum sum rules**

**S.Pal, S.Pratt, Phys.Lett.B574 (2003) **

- Ivan Vitev

- December 10, 2003

## Broadening of the Jet Cone

**Broadening of the Jet Cone**

**Ivan Vitev,** **ISU**

**C.Salgado, U.Wiedemann, hep-ph/0310079**

** ****Jet cone opening angle **

** ****Intra-jet correlations**

**            ****-  fraction of the total **
** ****energy within a jet  subcone**

** ****Very small effect even at **
** ****the LHC **

- Ivan Vitev

- December 10, 2003

## Summary of Dense Nuclear Matter

|  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- |
| SPS |  2-3.5             0.8    | 210-240 | 1.5-2.5 | 1.4-2 | 200-350 |
| RHIC |   7-10             0.6 | 380-400 | 14-20 | 6-7 | 800-1200 |
| LHC | 17-28            0.2     | 710-850 | 190-400 | 18-23 | 2000-3500 |

**SPS**

**RHIC**

**LHC**

**F.Karsch, Nucl.Phys.A698 (2002)**

**Ivan Vitev,** **ISU**

|  |  |  |
| --- | --- | --- |
| DIS quenching | 0.5 | 0.12 |
| Drell-Yan | 0.6    0.45 | 0.14    0.45 |
| Cronin effect | 0.4-0.6 | 0.1-0.14 |
| Th. estimate | 0.2 | 0.05 |

**F.Arleo, hep-ph/0310274 [CERN Yellow Report]**

_**Hot versus cold nuclear matter**_

**Properties of Dense Nuclear Matter**

- Ivan Vitev

- December 10, 2003

## Conclusions

**Conclusions**

**Ivan Vitev,** **ISU**

-  **Significant theoretical advances in understanding**
-     **non-Abelian** **bremsstrahlung:**
-            -  **Regimes far from asymptopia (E,L) relevant at RHIC**
-             -  **Incorporating mass and** **gluon absorption corrections**
-  **Jet tomographic analysis:**
-                            -  **Cold nuclear matter **
-            -  **Suggests energy density                                      at RHIC**
**                                                          ****(static)**
** ****Future directions of high-p****T**** studies in dense **
**     ****nuclear matter:**
-                            -  **Correlations and jet structure, redistribution of  **
**           **-  **Quantitative studies of open charm and direct photons **
-  **Results from Jet Tomography** **correlated with other**
-  **   ****theoretical approaches are**** **_**in strong support of the**_
**    **_**QGP paradigm at RHIC**__** **_

- Ivan Vitev

- December 10, 2003

## Conclusions

**Conclusions**

**Ivan Vitev,** **ISU**

- Ivan Vitev

- December 10, 2003

## Discovery of “Jet Quenching”

**Discovery of “Jet Quenching”**

**Ivan Vitev,** **ISU**

- Ivan Vitev

- December 10, 2003

## The Phase Diagram of QCD

**Ivan Vitev,** **ISU**

**The Phase Diagram of QCD**

- Ivan Vitev

- December 10, 2003

## Energy Loss in Dense QCD Matter 

**Energy Loss in Dense QCD Matter**** **

**Ivan Vitev,** **ISU**

** ****Elastic energy loss**

**J.D.Bjorken, SLAC preprint (1982) **
**unpublished**

** ****Radiative energy loss**

**Rather small to have significant observable effect**

**   ****Landau-Pomeranchuk-**
**   ****Migdal effect in QCD**

**M.Gyulassy, X.-N.Wang, **
**Nucl.Phys.B420, (1994) **

**I.Lokhtin , A.Snigirev *****in*****  hep-ph/0310274 **
**[CERN Yellow report]**

**   ****May be significant for large cone **

**Parent parton**

**Radiative gluon**

- Ivan Vitev

- December 10, 2003

## From Drell-Yan to DIS

**Ivan Vitev,** **ISU**

**From Drell-Yan to DIS**

**F.Arleo, Eur.Phys.J. C30 (2003)**

**  ****Gluon transport coefficient **
**    ****fixed from Drell-Yan **

**Finite formation time**

**Large number of scatterings**
**approximation**

- Ivan Vitev

- December 10, 2003

## Correlations with Respect to

**Ivan Vitev,** **ISU**

**K. Filimonov [STAR Collab.], DNP’03 meeting**

**p****T****trigger ****= 4-6 GeV/c**
**2 GeV/c < p****T****associated ****< p****T****trigger****, |********|<1**

**Correlations with Respect to**
**the Reaction Plane**

** ****Very direct evidence **
**  ****for the path length **
**  ****dependence of  **

- Ivan Vitev

- December 10, 2003