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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/. Places to learn more: Particle and nuclear physics links. http://pdg.lbl.gov http://particleadventure.org
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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
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
Inquiring minds want to know ... Yo! What holds it together? REU Seminar, University of Rochester
Stuff Lump A little bit A molecule An atom REU Seminar, University of Rochester
Before REU Seminar, University of Rochester
How do they interact? After REU Seminar, University of Rochester
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
e- The fundamental nature of forces: virtual particles Et h Heisenberg E = mc2 Einstein REU Seminar, University of Rochester
qq mesons K = us or us = ud or ud leptons quarks Gauge bosons u c t d s b e e e W, Z, , g, G g Strong interaction Hadrons Baryons qqq p = uud n = udd nuclei atoms Electromagnetic interaction REU Seminar, University of Rochester
q q qq q q qq qq relative strength asymptotic freedom confinement distance energy density, temperature Quantum Chromodynamics - QCD Similar to QED … But ... Gauge field carries the charge REU Seminar, University of Rochester
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
Why do we believe QCD is a good description of the strong interaction? No direct observation of quarks: confinement REU Seminar, University of Rochester
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
e+e- Zo qq e+e- Zo qqg Why do we believe QCD is a good description of the strong interaction? Event shapes REU Seminar, University of Rochester
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
Strong interaction is part of our heritage REU Seminar, University of Rochester
qq qq qq qq qq qq Chiral symmetry breaking: the “other” source of mass A naïve view … Quark condensate 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
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
The view from above REU Seminar, University of Rochester
STAR REU Seminar, University of Rochester
Au-Au collision in the STAR detector REU Seminar, University of Rochester
Isometric of PHENIX Detector REU Seminar, University of Rochester
Brahms experiment From F.Videbœk REU Seminar, University of Rochester
The PHOBOS Detector (2001) ZDC Paddle Trigger Counter Time of Flight Spectrometer Vertex Octagon Ring Counters Cerenkov y f x q z 1m • 4p Multiplicity Array • - Octagon, Vertex & Ring Counters • Mid-rapidity Spectrometer • TOF wall for high-momentum PID • Triggering • Scintillator Paddles Counters • Zero Degree Calorimeter (ZDC) 137000 silicon pad readout channels REU Seminar, University of Rochester
Central Part of the Detector (not to scale) 0.5m REU Seminar, University of Rochester
Au-Au event in the PHOBOS detector REU Seminar, University of Rochester
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
Terminology: angles Beamline REU Seminar, University of Rochester
Terminology: angles Pseudorapidity = = Lorentz invariant angle with repect to the beampipe -3 +3 -2 +2 +1 Beamline -1 0 REU Seminar, University of Rochester
Terminology: angles = azimuthal angle about the beampipe Beamline REU Seminar, University of Rochester
peripheral collisions central collisions Terminology: centrality Nch “Spectators” “Participants” Zero-degreeCalorimeter 6% “Spectators” Paddle Counter Npart Thanks to P. Steinberg for constructing much of this slide REU Seminar, University of Rochester
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
Run 2: 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 RHIC operation Run 1 12 June, 2000: 1st Collisions @ s = 56 AGeV 24 June, 2000: 1st Collisions @ s = 130 AGeV July 2001: 1st Collisions @ s = 200 AGeV Dec. 23, 2002: 1st d-Au collisions @ s = 200 AGeV Run 2 Run 3 REU Seminar, University of Rochester
From Thomas Roser REU Seminar, University of Rochester
From Thomas Roser REU Seminar, University of Rochester
Experimental results at RHIC imply 5 GeV/fm3 4.6 GeV/fm3 Energy density of proton and lattice QCD calculations Expect deconfinement phase transition to occur at an energy density of 1-2 GeV/fm3 PHENIX Collaboration, PRL 87 (2001) 052301 Assumes R=size of Au nucleus and To=1fm/c REU Seminar, University of Rochester
200 GeV 19.6 GeV 130 GeV PHOBOS PHOBOS PHOBOS Preliminary dN/dh Typical systematic band (90%C.L.) h h h Basic systematics of particle production PHOBOS Data on dN/dh in Au+Auvs Centrality and s REU Seminar, University of Rochester
Elliptic flow Collision region is an extruded football/rugby ball shape Central Peripheral REU Seminar, University of Rochester
b (reaction plane) Determine to what extent is the initial state spatial/momentum anisotropy is mapped into the final state. • Sensitive to the initial equation of state and the degree of equilibration. • Affects other variables, such as HBT and spectra. Elliptic flow dN/d(f -YR ) = N0 (1 + 2V1cos (f-YR) + 2V2cos (2(f-YR) + ... ) REU Seminar, University of Rochester
b (reaction plane) REU Seminar, University of Rochester
Hydrodynamic limit STAR: PRL86 (2001) 402 PHOBOS preliminary Thanks to M. Kaneta (PHOBOS : Normalized Paddle Signal) Elliptic Flow at 130 GeV Phys. Rev. Lett. 89 222301 (2002) REU Seminar, University of Rochester
Hydro describes low pt vs. particle mass, fails at high pt and high- T. Hirano Flow vs Pt and (consider velocity and early, self-quenching asymmetry) REU Seminar, University of Rochester
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
_ Comparing Au+Au and ppSpectra • 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
Suppression in Hadron Spectra Shown by T. Peltzmann at QM02 REU Seminar, University of Rochester
Jet-quenching: hard parton interacts with medium, which softens the momentum spectrum in A-A relative to pp REU Seminar, University of Rochester
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