清华大学：RHIC As an Exotic Particle Factory（PPT讲稿）Recent Result on Pentaquark Searches

RHIC As an Exotic Particle Factory Recent Result on Pentaquark Searches Huan Z Huang Department of Physics and astronomy University of California, Los Angeles Department of Engineering Physics Tsinghua university

RHIC As an Exotic Particle Factory -- Recent Result on Pentaquark Searches Huan Z. Huang Department of Physics and Astronomy University of California, Los Angeles Department of Engineering Physics Tsinghua University

QCD Structure of Hadrons Confinement- Hadrons must be color singlet Existing Hadrons: meson-quark and anti-quark pair Baryon -three quark system q Color Configuration

QCD Structure of Hadrons Confinement – Hadrons must be color singlet ! Existing Hadrons: meson – quark and anti-quark pair Baryon – three quark system q q q q q Color Configuration

OCD Allowed State 1)ggg-Glue Ball 2)qqQQ-Tetra-quark 3) q99qQ-Penta-quark 4)qqqqqq- Di-baryons: H(uuddss), di-Q2 (ssssss) 5) Strange Quark Matter

QCD Allowed State 1) ggg – Glue Ball 2) qqQQ – Tetra-quark 3) qqqqQ – Penta-quark 4) qqqqqq – Di-baryons: H(uuddss), di-W (ssssss) 5) Strange Quark Matter

Artist's view of proton and glueball proton glueball

Artist’s View of Proton and Glueball proton glueball

Not Easy to Identify glueball 1)We do not know the mass precisely probably 1.5-2.5 Ge V/c2 2)The width is probably wide Buried in many normal quark resonance states in the same mass region

Not Easy to Identify Glueball 1) We do not know the mass precisely probably ~ 1.5-2.5 GeV/c2 2) The width is probably wide Buried in many normal quark resonance states in the same mass region !

HOquuddss) detection ∑ HO H0→>p→pn兀

H0(uuddss) Detection H0 → p S - → p n p-

Strange Quark Matter Stable or metastable massive multiquark states involving u, d and s quarks Cs dd Artist's Interpretation Nuclear Matter Strange Matter (Carbon) (Strangelet) 6 =1 A=12 A=12 (36 quarks) Z/A=1/2 Z/A=0.083 Ns=10, IS=NSA=.83

Strange Quark Matter Stability Stable SQM-- ground State of QCD >1116 MeV unstable Stability M/Baryon[ [940, 1116]Mev Weak 03219 E Farhi and r L Jaffe, Phys. Rev. D30, 2379. Theoretical Prediction of stable particles often not reliable Particle mass c a few 1000 mev Binding energy a few mev(deuteron) No QCD or Phenomenological calculation has better than 1% accuracy

Strange Quark Matter Stability Stable SQM -- Ground State of QCD > 1116 MeV unstable Stability M/Baryon [940,1116] MeV Weak <940 MeV Stable { Witten, Phys. Rev. D30, 272 (1984) E. Farhi and R.L. Jaffe, Phys. Rev. D30, 2379. Theoretical Prediction of Stable Particles Often not Reliable -- Particle Mass ~ a few 1000 MeV -- Binding Energy a few MeV (deuteron) No QCD or Phenomenological calculation has better than 1% accuracy !

Stable(ct50 ns) strange quark matter has not been detected at the level -10%per central Au+Pb collisions! E886 10 E878 Z0 10 10 6 10 10 10 E864 Final 10 25 5O 255D0 25 5o Mass (Gev/c) Mass(Gev/c) Mass(Gev/c)

E878 E886 E864 Final Stable (ct>50 ns) strange quark matter has not been detected at the level ~10-9 per central Au+Pb collisions !

⊙+ Exotic Baryon D Diakonov, V Petrov, and M. Polyakov, uudds Z. Phys.A359(1997)305 e(1530) · Exotic:S=+1 N(1710) ow mass: 1530 Mev Narrow width:x15 Mev ∑(1890) ·JP=1/2+ 三(2070) ddss mussa M=[1890-180*￥]Mev Isospin =0

Q+ Exotic Baryon M = [1890-180*Y] MeV D. Diakonov, V. Petrov, and M. Polyakov, Z. Phys. A 359 (1997) 305. • Exotic: S=+1 • Low mass: 1530 MeV • Narrow width: ~ 15 MeV • J p=1/2+ Isospin = 0