# Presentation: 767090

## Born: April 13, 1936 (70 years ago) 

- Born: April 13, 1936 (70 years ago)

- After the war, family moved to the US.
- Father was “interned” by Russians

- B. Sc at MSU (1956)
- M. Sc at MSU (1959)
- Dr. in Physics at Hamburg (1963)
- Habilitation at Hamburg (1967)

- Postdocs: 1963-1971:
- DESY, UCLA, CERN, Helsinki

- Professor of Theoretical Physics, U of Bielefeld, 1971

## Bielefeld:

- Cultural capital of Westfalia

- Home of Herman the German

- Site of Sparrenburg Castle and its Dungeon of Horrors

- With memorable foods such as Pigs Blood Sausage

## University of Bielefeld founded in 1969: Helmut had chance to build a group.

## Bielefeld Fakultat fur Physik:

## ZIF is an interdisciplinary center for advanced study. It has conference facilities, cafeteria and apartments

- It also has a swimming pool, a sauna and a beer machine

## In 1980, it also had Helmut running the first Quark Matter Meeting

- Participants included: T. D. Lee, “Papa” Migdal, Andrei Linde, Rob Pisarski, Keijo Kajantie, Gordon Baym, Janos Polonyi, Johann Rafelski, Kysztof Redlich, Ludwig Turko

- I was supposed to talk about work on finite density, but because of the meeting, prepared two other papers:  Helmut only let me give two talks, however.

- First presentations on lattice gauge theory at finite
- Beginning of serious discussion of heavy ion collisions at high energy
- Linde presented work on magnetic mass
- Pisarski discussed instantons at finite T

- L. McLerran and Andrei Linde discovered the Ambassador Club

## Density of states rises so rapidly that one can not exceed a temperature where the number of states diverges 

- Hagedorn limiting temperature:
- Density of states rises so rapidly that one can not exceed a temperature where the number of states diverges
- Understood now in large Nc:
- Number of gluons proportional to

- Number of mesons O(1)

- Pre-QCD ideas confused:
- Density of states cannot diverge if hadrons have a finite size.
- Helmut, Hagedorn, Rafelski

- By the time of the meeting, Creutz’s calculations had shaken the QCD community and many of us wanted to see this solved in QCD,
- Also to see how confinement goes away

## Satz: 1980-1985:  Lattice Studies

- Satz with Celik, Celik, Engels, Gavai and Karsch began a systematic lattice Monte-Carlo study of deconfinement at finite T

- First:
-  To do realistic computation of deconfinement temperature,
- Established the  order of SU(3) pure gauge transition,
- Compute latent heat SU(3) pure gauge transition

- Established a very strong group in Bielefeld and BNL which is in the forefront of modern studies

## Satz: 1985 -> 

- Melting of the J/Psi

- The guilty parties:

## http://en.wikipedia.org/wiki/Quantum_chromodynamics

- In a hot QCD medium, when the temperature is raised well beyond the deconfinement temperature, the J/Psi and its excitations are expected to melt.  This is one of the signals predicted for the formation of a quark gluon plasma.  Several experiments at CERN’s Super Proton Synchrotron may have seen this phenomenon

- Evidence Suggests First Observation of Quark-Gluon Plasma in J/psi Particle Production, Changing Hadron Masses

- July 1998 Edition

## But maybe things are more complicated at RHIC?

- Co-mover recombination?
- Directly produced charm?

- Who ate the J/Psi?

## Sometimes life is tough:

- “Give not that which is holy unto the dogs, neither cast your pearls before swine, lest they trample them under your feet, and turn against and rend you”
- Mathew Chapter 7 Verse 6

## And sometimes life is good (for a while)

- (Ask Dima about the camel trip.)

- Helmut has introduced many others to the joy of finite T QCD

## From 1985-1992:  Staff Member at BNL

- From 1989-1994: Staff Member at CERN
- (Remains on Faculty at Bielefeld)

- Plays crucial role in arguing for RHIC within the DOE and physics community
- At CERN, served as the sole phenomenologist with an interest in heavy ions

## Helmut Satz:  Personal Comments

- Very close and reliable personal friend
- Introduced me to physics, people and places which I would never have experienced
- We have been  up mountains together, and we have shared many hard times.
- Without Helmut, IMHO, there would not be RHIC or the CERN heavy ion program, nor the systematic study of QCD at high energy density.

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