Highlights from CMS Gunther Roland MIT for the

Highlights from CMS Gunther Roland (MIT) for the CMS Collaboration Quark Matter conference, Washington DC Aug 13 th, 2012 Gunther Roland Quark Matter 2012, Washington DC 1

CMS experiment ar. Xiv: 1207. 7235 Accepted by PLB CMS excels at - Resolution of tracking and calorimetry - Trigger selectivity over a large range in rapidity and full azimuth Gunther Roland Quark Matter 2012, Washington DC 2

CMS heavy-ion papers 18 published/submitted papers, 10 Physics Analysis Summaries (CMS PAS): https: //twiki. cern. ch/twiki/bin/view/CMSPublic/Physics. Results. HIN Gunther Roland Quark Matter 2012, Washington DC 3

CMS highlights in five acts i. A bigger bang Ultra-central collisions ii. A classicist view of jet quenching The RAA zoo iii. A new kind of PID Parton ID, not particle ID iv. Anatomy of a jet Jet shapes and fragmentation functions v. Lost and bound Debye-screening and recombination Gunther Roland Quark Matter 2012, Washington DC 4

A bigger bang Nuclear stopping p 0 elliptic flow Ultra-central collisions Transverse energy CMS-PAS HIN-12 -006 See ar. Xiv this evening UCC trigger: 1. 8 M most central events out of 1 B ar. Xiv: 1205. 2488 Parallel talks: Rylan Conway High p. T correlations (Tue) Parallel talks: Magdalena Malek, d. ET/dh (Wed) Shenquan Tuo Bulk vn (Fri) Hauke Woehrmann Energy flow (Wed) Gunther Roland Eric Appelt Bulk v 2 (Fri) Quark Matter 2012, Washington DC 5

Ultra-central collisions nth order eccentricities vs b 0. 2% most central n=2 n=3 n=4 e 2 -5 n=5 e 1 b<2 fm e 2 -e 5 converge in ultra-central collisions Gunther Roland Quark Matter 2012, Washington DC n=6 Participant distribution relative to the nth order participant plane 6

Ultra-central collisions Calculation by Heinz et al. Calculation by Luzum et al. CMS-PAS HIN-12 -011 v 2 CMS-PAS HIN-12 -011 v 3 v 4 v 5 v 6 v 7 Unique perspective on hydrodynamic flow • Hierarchy of coefficients reproduced by hydro • Some tension between v 2 and v 3. . 7 Note, AMPT 0 -0. 2%: <b> = 1. 6 fm, RMS(b) = 0. 6 fm Gunther Roland Quark Matter 2012, Washington DC Parallel talk Shenquan Tuo Poster: Wei Li 7

Anisotropy at high p. T PRL 109 (2012) 022301 v 2 persists to p. T > 40 Ge. V Pathlength-dependent energy loss CMS-PAS HIN-12 -010 v 3 vanishes for p. T > 20 Ge. V Weaker correlation of pathlength and Y 3 plane Parallel talks Rylan Conway(Tue) Victoria Zhukova (Tue) Gunther Roland Quark Matter 2012, Washington DC 8

A classicist view of jet quenching The CMS RAA Zoo (QM’ 11) Fate of charged hadron RAA for p. T> 60 Ge. V? RAA remains a critical tool in the study of parton energy loss Gunther Roland Quark Matter 2012, Washington DC 9

A classicist view of jet quenching Start from blank slate Repopulate RAA Zoo with new analyses (since QM’ 11) Gunther Roland Quark Matter 2012, Washington DC 10

(Non-) Suppression of colorless probes Parallel talk George Stephans (Wed) Isolated photon RAA with 2. 76 Te. V pp reference PLB 710 (2012) 256 Z 0 CMS-PAS HIN-12 -008 m+m- W mn usingle muon recoil against missing p. T Ncoll scaling confirmed Gunther Roland Parallel talk Lamia Benhabib (Wed) Quark Matter 2012, Washington DC ar. Xiv: 1205. 6334 Accepted by PLB ar. Xiv: 1205. 6334 11

Suppression of charged particles EPJC 72 (2012) 1945 Charged hadron RAA flat from p. T = 30 - 100 Ge. V Gunther Roland Added full 2011 jet-triggered data set to charged hadron RAA measurement Quark Matter 2012, Washington DC 12

Suppression of inclusive jets Fully unfolded inclusive jet RAA pp 2. 76 Te. V reference CMS-PAS HIN-12 -004 Like for charged particles, high-p. T jet RAA flat at ≈ 0. 5 Gunther Roland Quark Matter 2012, Washington DC 13

A new kind of PID Parton ID, not particle ID: b-quark quenching 6. 5 < p. T < 30 Ge. V: Displaced J/ψ mm p. T > 80 Ge. V: Jet + high mass secondary vertex Obtain B RAA Obtain b-jet fraction CMS-PAS HIN-12 -003 CMS-PAS HIN-12 -014 Gunther Roland Quark Matter 2012, Washington DC 14

Parton ID: b-quarks Parallel talk Mihee Jo (Fri) Parallel talk Matt Nguyen (Tue) Distinct b-quark suppression pattern at low p. T Gunther Roland Poster Jorge Robles First observation of b-jet suppression at high p. T Quark Matter 2012, Washington DC 15

g+jet: u, d quark energy loss Photon (191 Ge. V) Jet (98 Ge. V) Photon tag: • Identifies jet as u, d quark jet • Provides initial quark direction • Provides initial quark p. T Gunther Roland Quark Matter 2012, Washington DC 16

g+jet: u, d quark energy loss ar. Xiv: 1205. 0206 Area normalized to unity 0 -10% Pythia+Hydjet Pb. Pb Pythia+Hydjet Photon-jet momentum balance Parallel talk Yue Shi Lai (Tue) Gunther Roland Quark Matter 2012, Washington DC 17

g+jet: u, d quark energy loss ar. Xiv: 1205. 0206 Area normalized to unity pp Pythia+Hydjet 0 -10% Pb. Pb Jet-photon p. T balance drops by 14% Pythia+Hydjet pp Pythia+Hydjet Photon-jet momentum balance Pb. Pb 20% of photons lose jet partner Parallel talk Yue Shi Lai (Tue) Gunther Roland Quark Matter 2012, Washington DC 18

Anatomy of a jet PYTHIA 100 Ge. V inclusive jet Anti-k. T R=0. 3 jet Charged particle energy fraction 95% of energy in r < 0. 2 Is the jet energy in Pb. Pb redistributed in radius: Differential jet-shapes 95% of energy in p. T > 4 Ge. V particles Radius r Gunther Roland Is the jet energy in Pb. Pb redistributed in particle p. T: Fragmentation functions Quark Matter 2012, Washington DC 19

Anatomy of a jet Ratio of Pb. Pb/pp differential jet shapes Parallel talk Pelin Kurt (Wed) Poster Yaxian Mao CMS-PAS HIN-12 -013 No medium effect Ratio of Pb. Pb/pp fragmentation functions CMS-PAS HIN-12 -013 highp. T low p. T No medium effect z = p. T(track)/p. T(jet) Gunther Roland Quark Matter 2012, Washington DC Parallel talk Frank Ma (Wed) 20

ar. Xiv: 1205. 5872 2010 data: ar. Xiv: 1205. 5872 Change from “ξ” to “p. T” Pb. Pb – pp (1/Ge. V) A consistent view of jet quenching No change at small r, high p. T Narrowing/depletion at intermediate r, p. T Consistent with 2010 result Recall (2010 vs 2011): • Track p. T > 4 Ge. V vs p. T > 1 Ge. V • Leading vs inclusive jet • 0 -30% vs 0 -10% and 10 -30% Broadening/excess at large r, low p. T Radius r Gunther Roland Quark Matter 2012, Washington DC (~2% of jet energy) 21

A consistent view of jet quenching Looking at the same p. T range Charged particles from parton p. T =50 -100 Ge. V: z = p. T(track)/p. T(jet) = 0. 4 -0. 6 x<1 Pb. Pb fragmentation function = pp for ξ <1 Consistent message from charged hadron RAA, inclusive jet RAA and fragmentation functions! Gunther Roland Quark Matter 2012, Washington DC 22

Dimuons: Lost and bound QM’ 13 Guillermo Breto Tuesday Dongho Moon Tuesday Mihee Jo Friday Lamia Benhabib Wednesday Gunther Roland Quark Matter 2012, Washington DC 23

Sequential Upsilon suppression 2010 data 2011 data PRL 107(2011)052302 Indication of suppression of (Y(2 S)+Y(3 S)) relative to Y(1 S) 2. 4 s significance Gunther Roland Observation of sequential suppression of Y family Detailed studies Quark Matter 2012, Washington DC 24

Building a quarkonium-thermometer Note: 6. 5<p. T<30 Ge. V for J/y and y(2 s) CMS-PAS HIN-11 -011 Npart Clear hierarchy in RAA of different quarkonium states Expected in terms of binding energy CMS-PAS HIN-12 -014, HIN-12 -007 Gunther Roland Quark Matter 2012, Washington DC 25

Lost and bound: J/y vs y(2 S) Pb. Pb (p. T > 3 Ge. V) CMS-PAS HIN-12 -007 pp (p. T > 3 Ge. V) Pb. Pb fit Indication that loosely bound y(2 S) less suppressed than more tightly bound J/y for p. T > 3 Ge. V not more than 2 s significance, limited by pp statistics Gunther Roland Quark Matter 2012, Washington DC 26

Summary • Rich harvest of new data and results since QM ’ 11 • Highlights include: – Flow harmonics in ultra-central collisions – v 2 and v 3 for p. T of 40 -60 Ge. V – Nuclear modification factors - g, Z 0, W, charged hadrons, jets, b-tagged jets, B J/y – First results on g-jet correlations – Detailed studies of jet fragmentation – Observation of sequential melting of the Y family and indications of un-melting of y(2 S) • Enjoy the excellent presentations our young colleagues have prepared! Gunther Roland Quark Matter 2012, Washington DC 27

QM ‘ 12 talks from CMS Mon 12: 25 pm, Gunther Roland, Experimental highlights Mon 5: 15 pm, Stephen Sanders, Overview of results on flow and correlations Tue 9: 30 am, Gabor Veres, Overview of results on jets Tue 2: 15 pm, Yue Shi Lai, Study of jet quenching using photon-jet events in Pb. Pb collisions Tue 2: 15 pm, Dongho Moon, Detailed measurements of charmonium suppression in Pb. Pb collisions Tue 3: 15 pm, Rylan Conway, Short- and long-range very-high-p. T triggered dihadron correlations in Pb. Pb collisions Tue 3: 55 pm, Victoria Zhukova, Azimuthal anisotropy of charged hadrons at very high p. T in Pb. Pb collisions Tue 4: 45 pm, Matthew Nguyen, Studies of jet quenching and b-jet tagging in Pb. Pb collisions Tue 4: 45 pm, Guillermo Rangel, Detailed measurements of bottomonium suppression in Pb. Pb collisions Tue 5: 25 pm, Marguerite Tonjes, Inclusive jet and charged hadron nuclear modification factors in Pb. Pb collisions Tue 5: 45 pm, Magdalena Malek, Pseudorapidity and centrality dependence of transverse energy flow in Pb. Pb collisions Wed 8: 30 am, Hauke Wohrmann, Studies of the nuclear stopping power in Pb. Pb collisions Wed 9: 10 am, Pelin Kurt, Jet shapes in pp and Pb. Pb collisions Wed 9: 50 am, Frank Ma, Jet fragmentation functions in Pb. Pb and pp collisions Wed 11: 20 am, George Stephans, Inclusive isolated photons in pp and Pb. Pb collisions Wed 12: 00 pm, Lamia Benhabib, Jet shapes in pp and Pb. Pb collisions Thu 9: 45 am, Raphael Granier de C. , Overview of results on photon and electroweak boson production Thu 11: 05 am, Camelia Mironov, Overview of results on heavy flavor and quarkonia Fri 2: 20 pm, Eric Appelt, Elliptic azimuthal anisotropy of charged hadrons and neutral pions in Pb. Pb collisions Fri 3: 40 pm, Mihee Jo, Suppression of open bottom at high p. T via non-prompt J/psi decays in Pb. Pb collisions Fri 5: 30 pm, Shengquan Tuo, Studies of higher-order flow harmonics and factorization of dihadron correlations in Pb. Pb collisions Gunther Roland Quark Matter 2012, Washington DC 28