1 / 28

Is There A Q ++ State? & RHIC – Exotic Factory !

Is There A Q ++ State? & RHIC – Exotic Factory !. Huan Z. Huang Department of Physics and Astronomy University of California, Los Angeles Thanks: Jingguo Ma, An Tai, Haibin Zhang and Sevil Salur. Outline. Pentaquark q +  nK + or pK S Is There a Q ++ ?

duc
Télécharger la présentation

Is There A Q ++ State? & RHIC – Exotic Factory !

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Is There A Q++ State? & RHIC – Exotic Factory ! Huan Z. Huang Department of Physics and Astronomy University of California, Los Angeles Thanks: Jingguo Ma, An Tai, Haibin Zhang and Sevil Salur

  2. Outline • Pentaquark q+ nK+ or pKS • Is There a Q++ ? • What may be the implication on production mechanism? • RHIC – an exotic particle factory!

  3. Q+ Spring-8 Result M = 1.540.01 GeV G < 25 MeV Gaussian significance 4.6s Q+ • + C(n/p)  K- K+ (n/ p) Cuts: no fK+K- no recoil p (gn only) Missing mass for n PRL 91, 012002 (2003)

  4. CLAS/JLAB Results g d → p K+ K-n g p → n K+ K- p+ • M = 15425 MeV • < 21 MeV 5.2 s • M = 155510 MeV • < 26 MeV 7.8 s Phys. Rev. Lett. 92, (2004) 032001 Phys.Rev.Lett.91, (2003) 252001

  5. Many Experiments Confirm Q+ *Gaussian statistical significance: estimated background fluctuation

  6. CDF p + p Very High Energy HERA-B p + A sqrt(s) 42 GeV Inclusive SPHINX p + C sqrt(s) 11.5 GeV Exclusive QK hep-ex/0407026 BES BaBar e+ + e- collisions ALEPH DELPHI Many Experiments with Null Results Noticeably (biased list)

  7. ICHEP04 Result • bump ~1480 MeV/c2 Q+K0p = (4.2+-0.9+1.2-0.9)% L ZEUS Result ??? No Q++pK+ was observed!

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

  9. Is There a q++ State (I=1, Instead 0)? The SAPHIR Collaboration at ELSA

  10. Is There a q++ State (I=1, Instead 0)? CLAS Results No signal in gpK-(K+p) channel The production of q++is not favored in photon reactions if the assumed mechanism for q production is correct !

  11. Magnet Coils Central Trigger Barrel (CTB) ZCal Time Projection Chamber (TPC) Year 2000 Barrel EM Cal (BEMC) Silicon Vertex Tracker (SVT)Silicon Strip Detector (SSD) FTPCEndcap EM CalFPD TOFp, TOFrYear 2001+ The STAR Detector DAQ: currently running at ~100x design rate for TPC

  12. Particle identification Particle Identification: dE/dx from TPC Future TOF Upgrade significantly enhances STAR PID

  13. STAR Pentaquark Searches X--  X- + p- (NA49 pentaquark state) N  L + KS Q+  p + KS Q++  p + K+ Data Set: Au + Au 200 GeV run 2 (~1.7 M, 30-80%) p + p data 200 GeV run 2 (~8 M, Z<75cm) d + Au 200 GeV run 3 (18.4 M) Au + Au 63 GeV run 4 (5.1 M) STAR can make an important contribution in this area !!

  14. A Stringent Limit from HERA-B HERA-B hep-ex/0408048 sqrt(s) 42 GeV pA (C,Ti,W) 200 M inelastic events q+/L <0.92%; 95%CL q+/L(1520) <2.7%; 95% CL Does this imply L(1520)/L ~ 34%? The Q++/L ratio should be small !

  15. D. Diakonov et al. (chiral quark soliton) Naive quark model S. Capstick et al. (isotensor formulation) Fl. Stancu, D.O. Riska (qq with p int.) A. Hosaka (chiral potential) M. Karliner et al.(qq-qqq) R. L. Jaffe et al. (qq-qq-q : 10 + 8) J. Sugiyama et al. (QCD sum rule) F. Csikor et al. (Lattice QCD) S. Sasaki (Lattice QCD) : 1/2+, I=0 : 1/2- : 1/2-, 3/2-, 5/2-, I=2 : 1/2+ : 1/2+ (strong p) : 1/2+, I=0 : 1/2+, I=0 : 1/2-, I=0 : 1/2+->1/2-, I=0 : 1/2-, I=0 Some Theory publications since 2003 ( Mass, width, Spin, Parity, Production mechanism, Partners… Q++implies I=1 and possibly invalids all these models ! Ohashi/Spring-8

  16. Possible Q+ Hadro-Production Reactions Q+ Q+ Coalescence or Secondary Production of q e+e- is not favored (deuteron is a good measure of sensitivity) very high energy (CDF) is not favored very violent collisions (central Au+Au, e.g.) not favored K+n and K+p experiments should be done again at appropriate energy !

  17. Q+ Possible Q+ Photo-Production Reactions CLAS/JLAB LEPS/SPring-8 Q+ Exclusive Channels ! Explains no Q++ in gpK-K+p

  18. Pentaquark or Molecule? If q state has isospin I = 1, there will be q0 n + KS Critical confirmation for I = 1 !! The structure of the q  NpK or DK molecule state cannot be ruled out ! A critical test of experimental sensitivity is the production of deuterons  how many (anti-)deuterons have been seen in CDF and e+e collisions?

  19. RHIC – Exotic Particle Factory • RHIC – Dense Partonic Matter and • Rapid Hadronization • Unique Production Mechanism for Possible Exotic Particles • Exotic Mesons, Pentaquarks, Di-baryons [WW] and Strangelets

  20. STAR PHENIX Empirical Quark Scaling in RAA and v2 Baryon Meson Constituent (n) Quark Scaling -- Meson n=2 and Baryon n=3 grouping Saturation of v2 at Intermediate pT

  21. PRL 92 (2004) 052302; PRL 91 (2003) 182301 Hadronization of Bulk Partonic Matter At hadron formation time there is a collective v2 among constituent quarks Recombination/coalescence provides a hadronization scheme (not necessarily related to partonic matter, works for d+Au) Possible geometrical nature of v2 saturation – surface emission

  22. Volcanic mediate pT – Spatter (clumps) Clustering and Surface Emission Enhancement of Clusters at intermediate pT ! Search for Multi-quark (>3) Cluster State at RHIC !

  23. RHIC – Exotic Particle Factory STAR – Exciting Physics Program A full TOF and Heavy Flavor Tracker upgrade will greatly enhance STAR’s capability !! Heavy Flavor Tracker Using Active Pixel Sensor two layers of thin silicon detector 1.5 cm and 4 cm radius Charmed Exotics?! Full Barrel TOF Using MRPC

  24. Exotic Particles Hadrons with internal structure beyond existing QCD qqq and q-qbar framework !! RHIC – Dedicated QCD Machine & Beyond Exotic (Deconfinement Phase Transition) AA AA pp pA pp pA (CGC,EMC) (spin)

  25. The End

  26. Embedding Theta++ Invariant Mass Kaon Momentum Proton Momentum Opening Angle ++ : Flat in rapidity –0.8<y<0.7 Flat in pt 0.4<pt<1.2

  27. ZEUS Result No Q++pK+ was observed! Why Q+, not Q++ ? Charge ordering in jet fragmentation? ???

  28. Au + Au Collisions at RHIC STAR Central Event (real-time Level 3)

More Related