La frontière de haute energe en collisions noyau-noyau Federico Antinori INFN, Padoue, Italie

La frontière de haute energeen collisions noyau-noyau

Federico Antinori

INFN, Padoue, Italie

The High Energy Frontier of AA

Federico Antinori

INFN, Padua, Italy

Intro• my charge:

perspective on high energy AA frontier in the aftermath of QM2011– high energy = top RHIC and upwards

• disclaimers:– you will get my own biased (and “immediate”)

perspective• but with a little help from my friends…

– I had to make hard decisions on what to show…• I had to leave out many beautiful measurements and

important details…

– I will mostly reuse slides presented at this conference

Federico Antinori - QM2011 - Annecy 3

Contents

• The bulk• Correlations• Quarkonia

• High pT Suppression

• Identified Particles• Jets• Heavy Flavour


Le “Bulk”


Alberica Toia - ALICE


Peter Steinberg – ATLAS


Constantin Loizides – ALICE


Adam Kisiel – ALICE (HBT)

La frontière

• explore forward rapidities– multiplicities vs η– CGC/saturation effects?– pA !!

• identified particle HBT


Les corrélations

Federico Antinori - QM2011 - Annecy11

Federico Antinori - QM2011 - Annecy 12Raimond Snellings – ALICE


same hydro?

Raimond Snellings – ALICE

Federico Antinori - QM2011 - Annecy 14Jiangyong Jia – ATLAS


Matthew Luzum


Matthew Luzum


Matthew Luzum


weaker centrality dependence than v2

no correlation wrt reaction plane



Andrew Adare – ALICE

Federico Antinori - QM2011 - Annecy 20Jiangyong Jia – ATLAS


Andrew Adare – ALICE


Jiangyong Jia – ATLAS


Wei Li – CMS


ShinIchi Esumi – PHENIX

Federico Antinori - QM2011 - Annecy 25Paul Sorensen – STAR

Death of ridge and cone?

• “le ridge” and “le Mach cone” seem to be in serious trouble…

• Le Roi est mort…?

• … vive le Roi !

la symphonie des corrélations…


Results from Correlations in ALICE - Jan Fiete Grosse-Oetringhaus 27

Flow vs Non-Flow Correlations

• Flow-related effects imply correlation of two particles through a plane of symmetry ψn

– vn factorizes:

• Jets cause correlations of a few energetic particles by fragmentation– There can be indirect correlations: length-dependent quenching

– Would be largest w.r.t. ψ2 since it reflects the collision geometry

• Assess flow vs. non-flow by testing the collectivity relation– Instead of calculating Vn in each pT,assoc x pT,trig bin (N(N-1)/2=55

bins), allow only one Vn per pT bin (11 parameters)

assocn

trignn vvV

assocn

trignn vvV

Jan Fiete Grosse-Oetringhaus – ALICE

Results from Correlations in ALICE - Jan Fiete Grosse-Oetringhaus 28

Flow vs Non-Flow Correlations

• Compare single calculated values with global fit

• To some extent, a good fit suggests flow-type correlations, while a poor fit implies non-flow effects

• v2 to v5 factorize until pT ~ 3-4 GeV/c, then jet-like correlations dominate

• v1 factorization problematic (influence of away-side jet)

Jan Fiete Grosse-Oetringhaus – ALICE

La frontière

• any residual room for medium response?look at the small print on the away side

– two-dimensional in η,φ

– use information on direction of recoiling parton• around re-emerging away-side jets• around away-side heavy flavour

• “Annecy spectrum” promises a beautiful toolquantitative comparisons with full hydro

– extract information on η/s, initial conditions

(Glauber, CGC, …)

• speaking of which…


Speaking of which…

• “how ‘bout a fulla Fourier decomposition of de CMS pp ridge?”


Les Quarkonia


Cesar da Silva – PHENIX


Hiroshi Masui – STAR


Ginés Martínez – ALICE


Ginés Martínez – ALICE

Federico Antinori - QM2011 - Annecy 36Catherine Silvestre – CMS





La frontière

• establish charmonium, bottomonium suppression(/recombination?) pattern in full glory– high statistic measurements– open flavour baseline / contamination– pA baseline

• the full picture should unravel before our eyes in the near future


La suppression à haut pT


Harald Appelshäuser (ALICE), Yen-Jie Lee (CMS) & Co


Peter Steinberg – ATLAS

Federico Antinori - QM2011 - Annecy 44Harald Appelshäuser – ALICE


further constraint to models (l2, l3, …)

Harald Appelshäuser – ALICE


Stefan Bathe - PHENIX

La frontière…

• RAA from 100’s MeV to 100 GeV and beyond!

• dependence on orientation wrt reaction plane– l2, l3, l? behaviour !

• asymmetric collisions at RHIC (U-U, Cu-Au,…)

tight constraints on energy loss models


Les particules identifiéesainsi font, les protons:

… trois p’tits tours, et puis s’en vont!



Michele Floris – ALICE

are protons misbehaving?

p/ and K/ ratios are very similar at RHIC energiesRatio Data (1) (2)

p/+ 0.0454+-0.0036 0.072 0.090

p/- 0.0458+-0.0036 0.071 0.091+0.009-0.007

K/+ 0.156 +- 0.012 0.164 0.180+0.001-0.001

K/- 0.154 +- 0.012 0.163 0.179+0.001-0.001

Integrated ratios vs Centrality

STAR (Not feed-down corrected)

ALICE, BRAHMS, PHENIX (feed-down corrected)

p/-

K-/-

STAR, PRC 79 , 034909 (2009)PHENIX, PRC69, 03409 (2004)

BRAHMS, PRC72, 014908 (2005)

(1) A. Andronic et al, Nucl. Phys. A772 167 (2006) (2) J. Cleymans et al, PRC74, 034903 (2006)T = 164 MeV, B = 1 MeV T = (170±5) MeV and μB =1+4 MeV

–

Predictions for the LHC




naughty protons…


protons again…


La frontière

• understand protons’ hydrodynamics– fly in the ointment of otherwise triumphant hydro …

• how about the thermal model?– took a bit of a beating this time– need full-glory, high stats fits including Ξ-, Ω-, φ, …– can it be cured?

– at what price? (s, q, anyone?)


Les Jets


Federico Antinori - QM2011 - Annecy 55Christof Roland – CMS

Federico Antinori - QM2011 - Annecy 56Christof Roland – CMS


Brian Cole – ATLAS




radiative Eloss in trouble?


Federico Antinori - QM2011 - Annecy 60Bolek Wyslouch – CMS

Federico Antinori - QM2011 - Annecy 61Helen Caines – STAR


Helen Caines – STAR


Martin Purschke – PHENIX


Martin Purschke – PHENIX

La frontìère…• up to the stratosphere…

– /W/Z-jet fragmentation functions!

• and down to the fertile soil again…– explore the surroundings of away-side jets

• broadening? softening? re-heating?

– more “organic” jet algorithms?• can one catch the whole jet, and then look inside as a function of distance?

– in-medium fragmentation vs reaction plane• path length dependence!

– hadrochemistry of in-medium fragmentation– jet-hadron correlations

• b-tagged jets (quark vs gluon jets)• extreme suppression?

– true “mono-jet” events? what do they look like?

• pA reference, reconstructed jets at RHIC, …Federico Antinori - QM2011 - Annecy 65

Les Saveurs Lourdes


PHENIX v STAR electrons

• progress since QM2009 on NPE discrepancy

new result from STAR in pp– e.g.: Wei Xie (STAR) @ Hard Probes 2010





Stefan Bathe - PHENIX

Federico Antinori - QM2011 - Annecy 70Carl Gagliardi – STAR

Federico Antinori - QM2011 - Annecy 71Andrea Dainese – ALICE



How about the colour factor?

• quarks (CR = 4/3) expected to couple weaker than gluons (CR = 3)

at pT ~ 8 GeV, factor ~ 2 less suppression expected for D than for light hadrons in BDMPS-ADSW

• data do show a hint of deviation (RAA

D > RAAπ ), but at much lower

pT …

… to be continued with higher statistics…N Armesto et al., Phys. Rev. D71 (2005) 054027



La frontière…

• high statistics D measurements are really D as suppressed as light hadrons?

• charm thermalisation? measure D mesons v2

• subtract D background pure B electron spectrum– beauty energy loss in wide pT range

• in-medium fragmentation of b-tagged jets !• results from RHIC upgrades


Conclusions

• high energy AA collisions have entered an era of high precision measurements– LHC, RHIC upgrades– constrain dynamic and coupling properties of medium

• many ideas we were taking more or less for granted at QM 2009, are now being seriously questioned– death of Mach cone and ridge?– thermal yields, radiative Eloss are challenged

• the outlook is bright– high lumi (5×) Pb-Pb run this year, possibly p-Pb next year

there could be some serious paradigm shifting at QM 2012!


Un grand merci…

• … aux organisateursfor the invitation to present this closing talk

• … à:Peter Braun-Munzinger, Brian Cole, Andrea Dainese, David d’Enterria, Paolo Giubellino, Barbara Jacak, Peter Jacobs, Karel Šafařík, Carlos Salgado, Jürgen Schukraft, Edward Shuryak, Peter Steinberg, Xin-Nian Wang, Urs Wiedemann, Nu Xu and many others…

• … à vous tous


Documents

La frontière de haute energe en collisions noyau-noyau Federico Antinori INFN, Padoue, Italie