Nuggets from the Long Island gold rush Steven Manly Univ. of Rochester REU Seminar June 4, 2003 steven.manly@rochester.edu http://hertz.pas.rochester.edu/smanly/ REU Seminar, University of Rochester June 4, 2003

Places to learn more: Particle and nuclear physics links http://pdg.lbl.gov http://particleadventure.org http://www.aps.org/dpf/education.html http://www.slac.stanford.edu/gen/edu/aboutslac.html http://www.bnl.gov/bnlweb/sciindex.html http://www.rhic.bnl.gov/ http://welcome.cern.ch/welcome/gateway.html http://www.fnal.gov/ http://www.er.doe.gov/production/henp/np/index.html REU Seminar, University of Rochester June 4, 2003

Inquiring minds want to know ... Yo! What holds it together? REU Seminar, University of Rochester June 4, 2003

Stuff Lump A little bit A molecule An atom REU Seminar, University of Rochester June 4, 2003

REU Seminar, University of Rochester June 4, 2003

Before REU Seminar, University of Rochester June 4, 2003

How do they interact? After REU Seminar, University of Rochester June 4, 2003

What forces exist in nature? What is a force? How do they interact? How do forces change with energy or temperature? How has the universe evolved? REU Seminar, University of Rochester June 4, 2003

The fundamental nature of forces: virtual particles Et  h Heisenberg E = mc2 Einstein e- REU Seminar, University of Rochester June 4, 2003

REU Seminar, University of Rochester June 4, 2003

leptons quarks Gauge bosons u c t d s b e e   e   W, Z, , g, G Strong interaction Hadrons Baryons qqq qq mesons p = uud n = udd K = us or us  = ud or ud nuclei atoms Electromagnetic interaction REU Seminar, University of Rochester June 4, 2003

Similar to QED … But ... Gauge field carries the charge Quantum Chromodynamics - QCD q q qq Similar to QED … But ... Gauge field carries the charge distance energy density, temperature relative strength asymptotic freedom q q qq qq confinement REU Seminar, University of Rochester June 4, 2003

From D.H. Perkins, Intro. to High Energy Physics Why do we believe QCD is a good description of the strong interaction? Deep inelastic scattering: There are quarks. From D.H. Perkins, Intro. to High Energy Physics REU Seminar, University of Rochester June 4, 2003

Why do we believe QCD is a good description of the strong interaction? No direct observation of quarks: confinement REU Seminar, University of Rochester June 4, 2003

Need the “color” degree of freedom Why do we believe QCD is a good description of the strong interaction? Need the “color” degree of freedom P. Burrows, SLAC-PUB7434, 1997 R. Marshall, Z. Phys. C43 (1989) 595 REU Seminar, University of Rochester June 4, 2003

Why do we believe QCD is a good description of the strong interaction? e+e-  Zo  qq e+e-  Zo  qqg Event shapes REU Seminar, University of Rochester June 4, 2003

Why do we believe QCD is a good description of the strong interaction? Measure the coupling P. Burrows, SLAC-PUB7434, 1997 REU Seminar, University of Rochester June 4, 2003

Strong interaction is part of our heritage REU Seminar, University of Rochester June 4, 2003

Chiral symmetry breaking: the “other” source of mass A naïve view … Quark condensate qq qq qq qq qq qq QCD vacuum Strongly interacting particles interact with the vacuum condensate … which makes them much heavier than the constituent quark masses. q REU Seminar, University of Rochester June 4, 2003

REU Seminar, University of Rochester June 4, 2003

Relativistic heavy ions AGS: fixed target, 4.8 GeV/nucleon pair SPS: fixed target, 17 GeV/nucleon pair RHIC: collider, 200 GeV/nucleon pair LHC: collider, 5.4 TeV/nucleon pair Two concentric superconducting magnet rings, 3.8 km circum. A-A (up to Au), p-A, p-p collisions, eventual polarized protons Funded by U.S. Dept. of Energy $616 million Construction began Jan. 1991, first collisions June 2000 Annual operating cost $100 million Reached 10% of design luminosity in 2000 (1st physics run)!! REU Seminar, University of Rochester June 4, 2003

The view from above REU Seminar, University of Rochester June 4, 2003

STAR REU Seminar, University of Rochester June 4, 2003

Au-Au collision in the STAR detector REU Seminar, University of Rochester June 4, 2003

Isometric of PHENIX Detector REU Seminar, University of Rochester June 4, 2003

Brahms experiment From F.Videbœk REU Seminar, University of Rochester June 4, 2003

The PHOBOS Detector (2001) z y x q f ZDC Paddle Trigger Counter Ring Counters Time of Flight Spectrometer Vertex Octagon 1m Cerenkov 4p Multiplicity Array - Octagon, Vertex & Ring Counters Mid-rapidity Spectrometer TOF wall for high-momentum PID Triggering Scintillator Paddles Counters Zero Degree Calorimeter (ZDC) z y x q f 137000 silicon pad readout channels REU Seminar, University of Rochester June 4, 2003

Central Part of the Detector (not to scale) 0.5m REU Seminar, University of Rochester June 4, 2003

Au-Au event in the PHOBOS detector REU Seminar, University of Rochester June 4, 2003

The goals Establish/characterize the expected QCD deconfinement phase transition quarks+gluons hadrons Establish/characterize changes in the QCD vacuum at high energies: chiral symmetry restoration and/or disoriented chiral condensates Understand the nuclear eqn. of state at high energy density Polarized proton physics REU Seminar, University of Rochester June 4, 2003

Terminology: angles Beamline REU Seminar, University of Rochester June 4, 2003

Terminology: angles Pseudorapidity =  = Lorentz invariant angle with repect to the beampipe -3 +3 -2 +2 Beamline +1 -1 REU Seminar, University of Rochester June 4, 2003

 = azimuthal angle about the beampipe Terminology: angles  = azimuthal angle about the beampipe Beamline REU Seminar, University of Rochester June 4, 2003

Zero-degree Calorimeter Terminology: centrality peripheral collisions central collisions Nch “Spectators” Zero-degree Calorimeter “Participants” 6% Paddle Counter “Spectators” Npart Thanks to P. Steinberg for constructing much of this slide REU Seminar, University of Rochester June 4, 2003

Signatures/observables Strange particle enhancement and particle yields Temperature J/ and ’ production/suppression Vector meson masses and widths identical particle quantum correlations DCC - isospin fluctuations Flow of particles/energy (azimuthal asymmetries) jet quenching Measured value Energy density or number of participants Each variable has different experimental systematics and model dependences on extraction and interpretation MUST CORRELATE VARIABLES REU Seminar, University of Rochester June 4, 2003

RHIC operation Run 1 12 June, 2000: 1st Collisions @ s = 56 AGeV July 2001: 1st Collisions @ s = 200 AGeV Dec. 23, 2002: 1st d-Au collisions @ s = 200 AGeV Run 2 Run 3 Peak Au-Au luminosity = 5x1026 cm-2s-1 Design Au-Au luminosity = 2x1026 cm-2s-1 Ave luminosity for last week of ‘02 run = 0.4x1026 cm-2s-1 Run 2: REU Seminar, University of Rochester June 4, 2003

From Thomas Roser REU Seminar, University of Rochester June 4, 2003

From Thomas Roser REU Seminar, University of Rochester June 4, 2003

Energy density of proton and lattice QCD calculations Expect deconfinement phase transition to occur at an energy density of 1-2 GeV/fm3 Experimental results at RHIC imply 5 GeV/fm3 PHENIX Collaboration, PRL 87 (2001) 052301 4.6 GeV/fm3 Assumes R=size of Au nucleus and To=1fm/c REU Seminar, University of Rochester June 4, 2003

Basic systematics of particle production PHOBOS Data on dN/dh in Au+Au vs Centrality and s dN/dh h 19.6 GeV 130 GeV 200 GeV Preliminary PHOBOS Typical systematic band (90%C.L.) REU Seminar, University of Rochester June 4, 2003

Elliptic flow Collision region is an extruded football/rugby ball shape Central Peripheral REU Seminar, University of Rochester June 4, 2003

Elliptic flow b (reaction plane) Determine to what extent is the initial state spatial/momentum anisotropy is mapped into the final state. dN/d(f -YR ) = N0 (1 + 2V1cos (f-YR) + 2V2cos (2(f-YR) + ... ) Sensitive to the initial equation of state and the degree of equilibration. Affects other variables, such as HBT and spectra. REU Seminar, University of Rochester June 4, 2003

b (reaction plane) REU Seminar, University of Rochester June 4, 2003

Elliptic Flow at 130 GeV Phys. Rev. Lett. 89 222301 (2002) (PHOBOS : Normalized Paddle Signal) Hydrodynamic limit STAR: PRL86 (2001) 402 PHOBOS preliminary Thanks to M. Kaneta Phys. Rev. Lett. 89 222301 (2002) REU Seminar, University of Rochester June 4, 2003

(consider velocity and early, self-quenching asymmetry) Flow vs Pt and  Hydro describes low pt vs. particle mass, fails at high pt and high- (consider velocity and early, self-quenching asymmetry) T. Hirano REU Seminar, University of Rochester June 4, 2003

Spectra The fun starts when one compares this to pp spectra 0.2<yp <1.4 STAR results, shown at QM02 REU Seminar, University of Rochester June 4, 2003

Comparing Au+Au and pp Spectra _ Comparing Au+Au and pp Spectra Production of high pT particles dominated by hard scattering High pT yield prop. to Ncoll (binary collision scaling) Compare to pp spectra scaled up by Ncoll Violation of Ncoll scaling Jet quenching? Au+Au _ REU Seminar, University of Rochester June 4, 2003

Suppression in Hadron Spectra Show 130 GeV suppression in RAA plot. Shown by T. Peltzmann at QM02 REU Seminar, University of Rochester June 4, 2003

Jet-quenching: hard parton interacts with medium, which softens the momentum spectrum in A-A relative to pp REU Seminar, University of Rochester June 4, 2003

Peripheral Au+Au data vs. pp+flow Count tracks around very high pT particle STAR, David Hartke - shown at QM02 REU Seminar, University of Rochester June 4, 2003

Central Au+Au data vs. pp+flow Away side jet disappears!! STAR, David Hartke - shown at QM02 REU Seminar, University of Rochester June 4, 2003

Jet-quenching also gives break in flow vs. pT REU Seminar, University of Rochester June 4, 2003

RHIC/experiments running very well Showed you too much - I apologize Showed you too little - I apologize What are the lessons? RHIC/experiments running very well Up till now … characterization and refinement of models REU Seminar, University of Rochester June 4, 2003

Hot, dense, opaque medium is formed Energy density above lattice predictions for deconfined state Local thermal equilibrium achieved Full 3-d structure away from mid-rapidity not yet understood Interesting signals being pursued … jet-quenching? Is it a duck? Perhaps standing on the precipice of a claim/discovery Remains to be seen if systematic study and pursuit of the surprises leads to anything beyond the duck! Future = statistics (J/+ more), vary species/energies, LHC REU Seminar, University of Rochester June 4, 2003

REU Seminar, University of Rochester June 4, 2003