1. Why RHIC won’t make Long Island Disappear into a Black Hole James Nagle Columbia University

2. Why can’t RHIC make Long Island Disappear into a Black Hole?

3. The New Collider What physics are we trying to reveal at RHIC? What physics are we trying to reveal at RHIC? Will we destroy the earth in the process? Will we destroy the earth in the process? What signatures are we looking for? What signatures are we looking for? Where is the PHENIX experiment? Where is the PHENIX experiment?

4. Decent Deconfinement Normally quarks are bound together (confined) in hadrons There are no observations of free individual quarks However, QCD predicts that at high density (5 to 10   ) and high temperature (~ 150-200 MeV ~ 10 12 o F ), the quarks are no longer confined, but rather are “asymptotically free” and form a plasma of quarks and gluons u u d u u d u d d d u u u d d u

5. Phase Diagram of Nuclear Matter

6. Net Baryon Density Temperature RHIC (200 GeV/u) SPS (20 GeV/u) AGS (5 GeV/u) Early Universe Neutron Stars Quark-Gluon Plasma

7. How does the reaction proceed? Nuclei Collide at near the speed of light Temperatures get hot enough to create a plasma of quarks and gluons (phase transition) System expands outward and cools, thus going back through the phase transition

8. Why is this interesting? The Universe must have started out as a quark-gluon plasma just after the Big Bang. The core of neutron stars may be composed of very dense quark matter. Our theory of quarks (QCD) predicts a quark plasma, and this should be experimentally verified.

9. Relativistic Heavy Ion Collider Au + Au collisions at cms energy 40 TeV (200 GeV/u) 10 12 collisions per year p + p collisions at 500 GeV polarized beams Everything in between

10. First Beam ! At around 2 am on July 13th, 1999 the first beam made it around the ring. First measured via PHENIX beam-beam and scintillation counters.

12. 12 List of Potential Disasters 1. Black hole formation 2. Universe collapsing into new vacuum state 3. Strange Quark Matter eating the earth

13. (1) Black Holes Can be dismissed with some basic General Relativity The Schwarzschild radius of a heavy ion collision: Radius of Au+Au collision compressed by a factor of 100: much less than Planck length ! Even if it could form, it would evaporate by Hawking Radiation in 10 -83 seconds ! M. Chiu for calculations

14. Where did the idea come from? Journalists - when JFK Jr.’s flight disappeared, reporters called Brookhaven to ask if a black hole created at RHIC could have eaten the plane. Science Fiction - in this book, experiments including PHENIX and STAR study collisions which accidentally create baby universes.

15. (2) Vacuum Instability P. Hut’s proposal is it is possible that the ground state vacuum is not the vacuum we live in. We are simply trapped in a local minimum of the vacuum potential, deposited there in the early stages of the universe. U Present Universe True Ground State P. Hut, Nucl. Phys. A418, 301c (1984). P. Hut and M.J. Rees, Nature 302, 508 (1983). Why heavy ion reactions? Answer - bubble nucleation only beyond some critical volume.

16. Cosmic Ray Collisions Nature has been conducting RHIC-like collisions for a long time, and the universe is still here…. And this is over 10 RHIC years ! compared to

17. Caveat: Relative Abundances Relative yield of Fe nuclei now measured up to 2 TeV/nucleon. (well beyond RHIC energy) However, the additional penalty of “ultra” heavy nuclei (Pb, Au, Pt) of ~ 10 -5 is only measured at the lowest energies (GeV scale). W. Vernon Jones, Nucl. Phys. A418, 139c (1984). W.R. Binns et al., Astro. J. 346, 997 (1989).

18. (3) Strange Quark Matter SQM is a meta-stable or even stable multi-quark color singlet state roughly equal number of u, d, s quarks States have a low charge to mass ratio (or even neutral) reduced Fermi energy, reduced Coulomb, no fission Ed Witten proposed that nuggets of SQM could have survived from the early universe and present a major source of Dark Matter. Stable and negatively charged SQM present a possible danger if it exists ! ud uds Energy Level Strange Quark Mass Quark Matter Strange Quark Matter

19. Why Worry? 1. If small SQM (“strangelet”) is formed in RHIC collisions 2. If it has a long lifetime 3. If it slows down and comes to rest in matter 4. If it has negative charge, then it attracts a positively charged nucleus and absorbs it 5. If the negative state is more stable, the SQM may lose positive charge and adjust its strangeness via electron capture or positron beta-decay 6. If it maintains negative charge, it will grow until it falls to the center of the earth 7. Then it will then absorb the earth from the inside out, and due to the enormous release of energy, the planet would end in a “supernova-like” explosion

20. Strange Nucleosynthesis Experiment E864 at BNL-AGS no SQM at 10 -9 per collision   n  nn p p  u u u u u d d d d s s s s Heavy Ion Collision - Formation of hypernuclei - Doorway to SQM In this model, SQM production more likely at AGS rather than RHIC energies ! T.A. Armstrong et al., Phys. Rev. Lett. 79, 3612 (1997). T.A. Armstrong et al., Phys. Rev. C, R1829 (1999).

21. Not Cheese, and not Strange Quark Matter Some cosmic ray collisions could have produced dangerous SQM, but how would we know…. 10 28 Fe + Fe collisions (AGS energy) 10 18 Au + Au collisions (AGS energy) 10 22 Fe + Fe collisions (RHIC energy) 10 12 Au + Au collisions (RHIC energy) Dangerous SQM can also be produced in CR-CR collisions and then fall into other objects thus producing “supernova-like” explosions.

22. Lunar Abundances The abundance of Au is the lunar soil (regolith) is seven parts per billion. (Au,Pt,Pb)/Fe ~ 10 -5 Quite a large variation on the surface. Most of these “ultra” heavy elements were deposited there

23. 23 1. Black hole formation 2. Universe collapsing into new vacuum state 3. Strange Quark Matter eating the earth List of Potential Disasters Review of Speculative ‘Disaster Scenarios’ at RHIC, W. Busza et al., hep-ph/9910333 Will Relativistic Heavy Ion Colliders Destroy our Planet, A. Dar et al., hep-ph/9910471 Growing S Drops, G.L. Shaw et al., Nature 337: 436 (1989) Technological Implications of Stable Strange Quark Matter, M.S. Desai et al., Nucl.Phys.Proc. Suppl.24B:207 (1991)

24. Signatures of Plasma Formation A. Deconfinement Suppression of quarkonia (J/ ,  ’,  ) states B. Thermal Radiation Prompt ,  to e + e -,  +  - C. Chiral Symmetry Restoration Disappearance of  state Mass, width, B.R. modification of  D. Strangeness, Charm and Bottom Production Nuclear effects, fast thermalization E. Jet Quenching High pt jets via leading particle F. Equation of State Hydrodynamic flow Particle correlations, coalescence

25. J/  Suppression Vector meson J/   bound state of a charm quark and anti-charm quark The pair feels an attractive force and can form the above bound state. However, in the middle of a quark-gluon plasma the attractive force is screened.

26. QCD Thermometer Hadrons with radii greater than ~ D will be dissolved (suppressed) Debye screening length D ~ 0.5 fm at a temperature T = 200 MeV As the temperature is raised above the critical temperature, one should see the sequential suppression of the various “onium” states

27. Upcoming CERN Press Release “Strong evidence for the formation of a transient quark-gluon phase without color confinement is provided by the observed suppression of the charmonium states J/ ,  c, and  ’.” Maurice Jacob and Ulrich Heinz NA50 at the CERN-SPS Discontinuity due to  c melting Drop due to J/  melting Using Drell-Yan as control

28. Premature Conclusions “A clear onset of the anomaly is observed. It excludes models based on hadronic scenarios since only smooth behavior with monotonic derivatives can be inferred from such calculations” Phys. Lett. B 450, 456 (1999). The second suppression is preliminary and contradicts the published results shown here in the above paper.

29. Initial State Parton Scattering N = pp + (N-1)  p t 2 Prior collisions broaden the transverse momentum spectrum (“Cronin effect”) S. Gavin et al., hep/9610432v2

30. P t Broadening Deconfined plasma breaks up J/  formed at the core of the collision, which are the ones most likely to have high pt. D.Kharzeev, M.Nardi, H.Satz, Phys. Lett. B405, 14 (1997). JLN, M. Bennett, Phys. Lett. B465, 21 (1999).

31. What should we think? Net Baryon Density Temperature RHIC (200 GeV/u) SPS (20 GeV/u) AGS (5 GeV/u) Early Universe Neutron Stars If the most central Pb-Pb collisions at CERN are starting to create a region of deconfined quarks and gluons, then RHIC collisions will be dominated by this plasma (large volume and long lifetime). Thus opening up a number of critical tools for studying the nature of this new form of matter. However, I believe the CERN-SPS conclusions are premature, and require more study. RHIC’s higher energy also opens up high pt probes that are calculable in pQCD.

32. PHENIX Experiment at RHIC Two forward muon spectrometers PHENIX - only RHIC experiment specifically designed to measure rare probes in the lepton and photon channels. It can sample all Au + Au collisions up to 10 times RHIC’s design luminosity Two central electron/photon/hadron spectrometers

33. Threshold Effects RHIC is ideally situated for exploring charmonium as a probe of dense nuclear matter. J/  remains a “rare” probe, but measurable with fine binning as a function of centrality, pt, and collision energy.

34. Charm and Bottom Production D 0 K -  + D 0 K - e + e D 0 K -  +  B 0 D -  + B 0 D - e + e B 0 D -  +  D 0 D 0  +  - K + K -   D 0 D 0 e + e - K + K - e e D 0 D 0  + e - K + K - e  Direct reconstruction of open charm is optimal. One can also measure open charm and bottom contributions through single leptons and lepton pairs. In order to understand J/  yields, we must understand charm production Total production rates Shadowing (nuclear effects) Jet quenching in plasma

35. Direct Measure of Open Charm Large combinatoric background in the hadronic channel. D 0 K -  + Silicon Detector to measure displaced vertex not included in PHENIX, but also looks difficult for any experiment due to high multiplicity. Simple matching of all pairs is shown to work in PHENIX for p-p, p-A, and very peripheral A-A Study by Y. Akiba

36. Single Leptons charm e- beauty e- Drell-Yan e- Dalitz and conversions e- Electrons in PHENIXMuons in PHENIX Study by Mickey Chiu, JLNStudy by M. Brooks, J. Moss Also, additional measurement of e-  coincidence !

37. Critical addition of Upsilon measurement ! Statistics for pt spectra ! And excitation function ! Statistics chart: Dilepton Spectra

38. PHENIX - just about ready?

39. PHENIX - just about ready!

40. Exciting physics now We cannot calculate that these collisions will not destroy the universe, we only know this from the large number of cosmic ray collisions that have already occurred. Thus, as experimentalists, the whole world of possibilities for discovery are before us (except destroying the universe). RHIC Collider and PHENIX start the first run in March, 2000 !