HIGH challenges in LOW energy HADRON physics. G. Vesztergombi. Zimanyi School Budapest, 25 November 2008. OUTLINE. AA Landscape STAR plans pp,pA -Static quarks -High pT below 20 GeV -NA61 -CBM -QGP in pp -Barion versus parton propagation. AA. pp,pA.
HIGH challenges in LOW energy HADRON physics
Budapest, 25 November 2008
Science 21 November 2008: Vol. 322. no. 5905, pp. 1224 – 1227
Ab Initio Determination of Light Hadron Masses
S. Dürr,1 Z. Fodor,1,2,3 J. Frison,4 C. Hoelbling,2,3,4 R. Hoffmann,2 S. D. Katz,2,3 S. Krieg,2 T. Kurth,2 L. Lellouch,4 T. Lippert,2,5 K. K. Szabo,2 G. Vulvert4
More than 99% of the mass of the visible universe is made upof protons and neutrons. Both particles are much heavier thantheir quark and gluon constituents, and the Standard Model ofparticle physics should explain this difference. We presenta full ab initio calculation of the masses of protons, neutrons,and other light hadrons, using lattice quantum chromodynamics.Pion masses down to 190 mega–electron volts are used toextrapolate to the physical point, with lattice sizes of approximatelyfour times the inverse pion mass. Three lattice spacings areused for a continuum extrapolation. Our results completely agreewith experimental observations and represent a quantitativeconfirmation of this aspect of the Standard Model with fullycontrolled uncertainties.
Latest in LATTICE QCD
All baryonic states listed in PDG can be made of 3 quarks only
* classified as octets, decuplets and singlets of flavour SU(3)
* Strangeness range from S=0 to S=-3
observation of a S=+1 baryon implies a new large multiplet of
baryons (pentaquark is always ocompanied by its large family!)
Searches for such states started in 1966, with negative
results till autumn 2002[16 years after 1986 report of PDG !]
Searches were for heavy and wide states
Motivation for new measurements below = 20 GeV
Practically no high or medium Pt data between Einc = 24 and 200 GeV
Mysterious transition around 80-90 GeV: convex versus concave spectra
Energy threshold for Jet-quenching?
Emergence of Cronin-effect in pA interactions is completely unknown
particle type dependence
Production of Upsilon (9.5 GeV) particles near the threshold.
NA49 (CERN) results at 158
FODS (IHEP) at 70 GeV
Pb+Pb, 0-12.7% most central
CRONIN-effect removed by p+A baseline
WA98 and NA49 data presented in QM'06 by Gianluca USAI's plenary talk
Study of Hadron Production in Hadron-Nucleus and Nucleus-Nucleus Collisions at the CERN SPS
CERN Greybook 2008
Benchmark NA49pp at E = 158 GeV 30 events/spill
Events Energy > 3 GeV/c > 4 GeV/c > 5 GeV/c
2 106 158 100 1 0.01
Estimates with the assumption 1011 proton/sec 109 interaction/sec
1 day=1014 158 5 109 5 107 5 105
Suppression 10-1 10-2 10-3
1 day=1014 90 5 108 5 105 500
20 day=2 1015 90 1010 107 104
Suppression 10-3 10-6 10-10
20 day=2 1015 45 107 10 0
For symmetric nuclei max energy 90/2 assumed
Special requirements for Y-> e+e- and high pT
Extremely high intensity - Pile-up
Segmented multi-target - Relaxed vertex precision
Straight tracks - High momentum tracks
DREAM: 109 interactions/sec
QGP in pp?
Átlag pT (Van Hove)
Részecskeszám (Van Hove)
Single FIRE-BALL = QGP?
Double FIRE-BALL = Factorization?
BARION propagation through the NUCLEUS
Npart = 3+1 Ncoll = 3
Npart/2 = (13+12)/2 =12.5
Ncoll = (36+28)/2 = 32
(Some diffractive binary collisions included)
PHENIX 200 GeV
Ncoll = 1
Npart = 1
Earlier Cronin-effect at higher energies: 2 -> 1 GeV/c
Pizero smaller Cronin-effect.