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Zhangbu Xu （许长补）

Search for Exotic Particles. Zhangbu Xu （许长补）. Strange Quark Matter. n, e, . Low Charge-to-Mass Ratio |Z|/m<<1 (A=2 10 57 ) Hybrid states (H-d,  q -p). Witten, PRD 30 (1984)272 Jaffe, PRL 38 (1977)617E. Why Strange Quark Matter?. QCD Allowed New States

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Zhangbu Xu （许长补）

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  1. Search for Exotic Particles Zhangbu Xu （许长补）

  2. Strange Quark Matter n, e,  • Low Charge-to-Mass Ratio|Z|/m<<1 (A=2 1057) • Hybrid states (H-d, q-p) Witten, PRD 30(1984)272 Jaffe, PRL 38(1977)617E

  3. Why Strange Quark Matter? • QCD Allowed New States • QCD Lab. (quarks&gluons) • Future Energy Source • Star Fates

  4. Strangelet Production • High energy density and/or baryon density • Production models • Coalescence production • Distillation of QGP • Thermal production Greiner, et al, PRD 38(1988) 2797 Baltz, et al, PLB 325(1994) 7 P. Braun-Munzinger, et al, JPG 21(1995)L17

  5. http://www.th.physik.unifrankfurt.de/~stoecker/vortrag2/strangelet.htmlhttp://www.th.physik.unifrankfurt.de/~stoecker/vortrag2/strangelet.html

  6. Roughly equal numbers of u,d,s quarks in a single ‘bag’ of cold hadronic matter. Strangelets (Small Lumps of Strange Quark Matter) Bag model results with varying ms values • SQM is less stable for lower baryon number (due curvature energy) for A<~1000 • There are likely significant shell effects at low A. E/A (MeV) A

  7. Relics of Early Universe? (Dark Matter?) Sources of Stable Strangelets? • Skylab, TREK: Satellite based Lexan. No events Z>100 • ARIEL-6, HEAO-3. scintillators, cerenkov counters. No events Z>100 • HECRO-81:Saito et al. scintillator, Cerenkov in balloon at 9gm/cm2. 2 Z=14 undercutoff events. A of 110(370) to be above cutoff(mean rigidity). E/A~.45 GeV • ET event Ichimura et. Al. emulstion chamber in balloon at few g/cm2 but trajectory would have taken it through ~200gm/cm2. Z~30. A measured at 460 • Price monopole. Lexan and emulsions in balloon experiment. Constant ionization through Lexan and low number of delta rays for normal nucleus. One interperetation is Z=45 and mass of 1000-10000 • Centauro (original) • SLIM: mountaintop Lexan CR detector • Fossil Tracks (in meteorites) • Mica: look for tracks traversing 10**7 g/cm2 • Mountaintop. Look for tracks traversing ~600 g/cm2 • Sea Level:tracks traversing 10**3 g/cm2 • Underground: tracks traversing 10**4 g/cm2 • Centauro:1000Tev shower at 500g/cm2, mass~200. Small em component (decay into strange baryons?) and very penetrating (SQM glob which isn’t destroyed by nuclear interactions?) • Ke Han: PRL 103 (2009) 092302 Lunar Soil

  8. E. Finch-SQM 2006 “Best” way: measure cosmic ray spectrum with high precision spectrometer…AMS aboard the ISS How to find stable strangelets?

  9. Limits on Strangelet Production Also negatively charged, neutral

  10. Observation of and @ RHIC (观测反超氚核） • Introduction& Motivation • Evidence for first antihypernucleus • and signal (for discovery) • Mass and Lifetime measurements • Production rate and ratios • Yields as a measure of correlation • A case for RHIC energy scan • Conclusions and Outlook Zhangbu Xu （许长补） (for the STAR Collaboration)

  11. What are hypernuclei（超核）? Hypernuclei of lowest A Nucleus which contains at least one hyperon in addition to nucleons. • Y-N interaction: a good window to understand the baryon potential • Binding energy and lifetime are very sensitive to Y-N interactions • Hypertriton: DB=130±50 KeV; r~10fm • Production rate via coalescence at RHIC depends on overlapping wave functions of n+p+Lin final state • Important first step for searching for other exotic hypernuclei (double-L) The first hypernucleus was discovered by Danysz and Pniewski in 1952. It was formed in a cosmic ray interaction in a balloon-flown emulsion plate. M. Danysz and J. Pniewski, Phil. Mag. 44 (1953) 348 No one has ever observed anyantihypernucleus

  12. S=-2 S=-1 S=-0 from Hypernuclei to Neutron Stars • hypernuclei L-B Interaction Neutron Stars Saito, HYP06 Several possible configurations of Neutron Stars • Kaon condensate, hyperons, strange quark matter Singleand doublehypernuclei in the laboratory: • study thestrange sectorof the baryon-baryon interaction • provide info on EOS of neutron stars J.M. Lattimer and M. Prakash, "The Physics of Neutron Stars", Science 304, 536 (2004) J. Schaffner and I. Mishustin, Phys. Rev. C 53 (1996): Hyperon-rich matter in neutron stars

  13. PANDA at FAIR • 2012~ • Anti-proton beam • Double -hypernuclei • -ray spectroscopy • SPHERE at JINR • Heavy ion beams • Single -hypernuclei • HypHI at GSI/FAIR • Heavy ion beams • Single -hypernuclei at • extreme isospins • Magnetic moments • MAMI C • 2007~ • Electro-production • Single -hypernuclei • -wavefunction • JLab • 2000~ • Electro-production • Single -hypernuclei • -wavefunction • FINUDA at DANE • e+e- collider • Stopped-K- reaction • Single -hypernuclei • -ray spectroscopy • (2012~) • J-PARC • 2009~ • Intense K- beam • Single and double -hypernuclei • -ray spectroscopy  Basic map from Saito, HYP06 Current hypernucleus experiments

  14. Can we observe hypernuclei at RHIC? Z.Xu, nucl-ex/9909012 • Low energy and cosmic ray experiments (wikipedia): • hypernucleus production via • L or Kcapture by nuclei • the direct strangeness exchange reaction hypernuclei observed • energetic but delayed decay, • measure momentum of the K and p mesons | • In high energy heavy-ion collisions: • nucleus production by coalescence, characterized by penalty factor. • AGS data[1] indicated that hypernucleus production will be further suppressed. • What’s the case at RHIC? 聚并 [1] AGS-E864, Phys. Rev. C70,024902 (2004)

  15. A candidate event at STAR Run4 (2004) 200 GeV Au+Au collision

  16. Data-set and track selection • 3LH mesonic decay, m=2.991 GeV, B.R. 0.25; • Data-set used, Au+Au 200 GeV • ~67M Run7 MB, • ~23M Run4 central, • ~22M Run4 MB, • |VZ| < 30cm • Track quality cuts, global track • nFitsPts > 25, nFitsPts/Max > 0.52 • nHitsdEdx > 15 • Pt > 0.20, |eta| < 1.0 • Pion n-sigma (-2.0, 2.0) Secondary vertex finding technique DCA of v0 to PV < 1.2 cm DCA of p to PV > 0.8 cm DCA of p to 3He < 1.0 cm Decay length > 2.4 cm

  17. 3He & anti-3He selection • Select pure 3He sample: -0.2<Z<0.2 & dca <1.0cm & p >2 GeV • 3He: 2931(MB07) + 2008(central04) + 871(MB04) = 5810 • Anti-3He: 1105(MB07) + 735(central04) + 328(MB04) = 2168

  18. signal from the data STAR Preliminary • background shape determined from rotated background analysis; • Signal observed from the data (bin-by-bin counting): 157 ± 30 ; • Projection on antihypertriton yields: constraint on antihypertriton yields without direct observation

  19. signal from the data STAR Preliminary • Signal observed from the data (bin-by-bin counting): 70±17; • Mass: 2.991±0.001 GeV; Width (fixed): 0.0025 GeV;

  20. Combined signals Combine hypertriton and antihypertriton signal: 225±35 STAR Preliminary This provides a >6s signal for discovery

  21. Lifetime STAR Preliminary STAR Preliminary • Our data: • Consistency check on L lifetime yields t(L)=267±5 ps [PDG: 263 ps].

  22. Comparison to world data STAR Preliminary • Lifetime related to binding energy • Theory input: the L is lightly bound in the hypertriton [1] R. H. Dalitz, Nuclear Interactions of the Hyperons (Oxford Uni. Press, London, 1965). [2] R.H. Dalitz and G. Rajasekharan, Phys. Letts. 1, 58 (1962). [3] H. Kamada, W. Glockle at al., Phys. Rev. C 57, 1595(1998).

  23. STAR Preliminary Measured invariant yields and ratios In a coalescence picture: 0.45 ~ (0.77)3

  24. Antinuclei in nature (new physics) To appreciate just how rare nature produces antimatter (strange antimatter) RHIC: an antimatter machine Seeing a mere antiproton or antielectron does not mean much– after all, these particles are byproducts of high-energy particle collisions. However, complex nuclei like anti-helium or anti-carbon are almost never created in collisions. AMS antiHelium/Helium sensitivity: 10-9 Dark Matter, Black Hole antinucleus production via coalescence

  25. What can we do with antimatter Weapon? Rocket propulsion 《天使与魔鬼》

  26. hypernuclei and antimatter from correlations in the Vacuum Real 3-D periodic table Pullfrom vacuum (Dirac Sea)

  27. Matter and antimatter are not created equal But we are getting there ! 物质和反物质造而不平等 (AGS,Cosmic) AGS RHIC SPS STAR PRL 87(2003) NA52 Nucl-ex/0610035

  28. Flavors (u,d, s) are not created equal except in possible QGP J. Rafelski and B. Muller, Phys.Rev.Lett.48:1066,1982 STAR whitepaper, NPA757(2005)

  29. Yields as a measure of correlation UrQMD A=2Baryon density <B> S. Haussler, H. Stoecker, M. Bleicher, PRC73 UrQMD A=3  <2B>; <LB> Caution: measurements related to local (strangeness baryon)-baryon correlationSimulations of (all strangeness)—(all baryon) correlation

  30. (3He, t, 3LH)(u, d, s) • A=3, a simple and perfect system 9 valence quarks, (3He, t, 3LH)(u, d, s)+4u+4d • Ratio measures Lambda-nucleon correlation • RHIC: Lambda-nucleon similar phase space • AGS: systematically lower than RHIC • Strangeness phase-space equilibrium • 3He/t measures charge-baryon correlation STAR Preliminary uud uud uud 3LH uds udu udd 3He t udd udd udd

  31. : Primordial -B correlation • Majumder and B. Muller, Phys. Rev. C 74 (2006) 054901 STAR Preliminary Caution: measurements related to local (strangeness baryon)-baryon Lattice Simulations of (all strangeness)—(all baryon) correlation correlation at zero chemical potential

  32. Energy scan to establish the trend Hypertriton only STAR: DAQ1000+TOF

  33. Hypernuclei sensitive to phase transition AMPT Simulation of nucleon coalescence (with or w/o string melting):a) CBS is not sensitive to phase transition b) Strangeness population from hypertriton sensitive to phase transition

  34. The / ratio is measured as 0.49±0.18, and 3He / 3He is 0.45±0.02, favoring the coalescence picture. • The / 3He ratio is determined to be 0.89 ± 0.28, and Conclusions • has been observed for 1st time; significance ~4s. • Consistency check has been done on analysis; significance is ~5s • The lifetime is measured to be / 3He is 0.82 ± 0.16. No extra penalty factor observed for hypertritons at RHIC. Strangeness phase space equilibrium

  35. Outlook • Lifetime: • data samples with larger statistics • Production rate: • Strangeness and baryon correlationNeed specific model calculation for this quantity • Establish trend from AGS—SPS—RHIC—LHC • L3Hd+p+p channel measurement: d and dbar via ToF. • Search for other hypernucleus: 4LH, double L-hypernucleus. • Search for anti-a • RHIC: best antimatter machine

  36. What can CSR contribute? • CSR 12C, 40Ca ( GeV), At the threshold of K, L production • Perfect for hypernucleus production • Hypertriton lifetime, binding energy, absorption s • Strangeness phase space population at CSR energies • Exotic hypernuclei (proton/neutron rich, Sigma) • 外靶实验装置适合超核重建:Dipole, tracking, TOF and neutron wall • To do list: • Tracking before Dipole (GEM, Silicon, MPWC) • Model Simulations • Detector Simulations • Electronics and DAQ

  37. Vision from the past The extension of the periodic system into the sectors of hypermatter (strangeness) and antimatter is of general and astrophysical importance. … The ideas proposed here, the verification of which will need the commitment for 2-4 decades of research, could be such a vision with considerable attraction for the best young physicists… I can already see the enthusiasm in the eyes of young scientists, when I unfold these ideas to them — similarly as it was 30 years ago,… ---- Walter Greiner (2001)

  38. International Hyper-nuclear network CSR at IMP? • PANDA at FAIR • 2012~ • Anti-proton beam • Double -hypernuclei • -ray spectroscopy • SPHERE at JINR • Heavy ion beams • Single -hypernuclei • HypHI at GSI/FAIR • Heavy ion beams • Single -hypernuclei at • extreme isospins • Magnetic moments • MAMI C • 2007~ • Electro-production • Single -hypernuclei • -wavefunction • JLab • 2000~ • Electro-production • Single -hypernuclei • -wavefunction • FINUDA at DANE • e+e- collider • Stopped-K- reaction • Single -hypernuclei • -ray spectroscopy • (2012~) • J-PARC • 2009~ • Intense K- beam • Single and double -hypernuclei • -ray spectroscopy  • BNL • Heavy ion beams • Anti-hypernuclei • Single -hypernuclei • Double L-hypernuclei Basic map from Saito, HYP06

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