# Presentation: 497406

## Research Frontiers in Nuclear Physics

**Central truths of nuclear physics **
**driving research for more than one century**** **

** ****We are dust****	****	****(c. 1950)**

**We are nothing****	****	****(c. 1900)**

**We don’t matter ****	****(c. 2000)**

## Most of “us” is (nearly) empty space
99.9% of the mass of atoms is contained in the nucleus
The nucleus is about  10-12 of the size of the atom
Nuclear density 1014 times larger than density of water

**99.9% of the mass of atoms is contained in the nucleus**
**The nucleus is about  10****-12**** of the size of the atom**
**Nuclear density 10****14**** times larger than density of water**

**We are nothing !**

**birth of nuclear physics**

- Axel Drees

## Nuclear Zoology and the Nuclear Chart

**Nuclear Zoology and the Nuclear Chart**

**Categorize properties of nuclei and present in nuclear chart**

**valley of stability**
**near Z = N**

**No stable nuclei **
**                 ****beyond**** 208 ****Pb**
**limited range **
**           ****of nuclear force**

**Magic Z and N numbers with many stable nuclei**
**Indication of shell structure **

**Coulomb repulsion of protons**

**Fermi gas model**

- Axel Drees

## Going to the Extremes of Nuclear Structure

**Going to the Extremes of Nuclear Structure**

**The many body problem**
**Nucleus is complex system of many strongly interacting particles**
**Needs to be treated microscopically **
**Remains one of the major theoretical challenges**
**Search for super heavy nuclei**
**	**
**Island of stability near next shell closer**
**The ultimate test of shell models**
**Element 112 discovered at GSI**
**	****	****	****“****Ununbiium”**
**Nuclei with extreme angular momentum**
**Sensitive test of shell models**
**Actively pursued by Prof. Fossan and Starosta at Stony Brook NSL and other facilities**

- Axel Drees

## We are dust !

**Most elements create in stellar catastrophes long after big bang **

**Elements up to Fe fussed in Stars **
**Heavy elements created in super nova explosions **
** ****We are mostly stardust !**

- Axel Drees

## Nuclei far from Stability 

** ****Explore “Terra Incognita” to proton and neutron drip line**
** ****Important for creation of heavy elements in Supernovae**
** ****Proton rich created with stable beams**
** ****Neutron rich require radio active beams**
** ****Neutron rich nuclei only created **
**	****with radioactive beams**
** ****Interesting Atomic physics**
** ****ongoing experiments in NSL**
**	****(Prof.  Sprouse & Orozco)**

** ****R****are ****I****sotope ****A****ccelerator**
**       ****new  $800M US project****	**

- Axel Drees

## We don’t matter !

**More accurately: *****We’re ***_***not***_*** matter      ***

**Nearly all the mass of each atom is concentrated in the nucleus:**
**Each nucleus consists of**** neutrons and protons**
**Each neutron and proton                    consists of 3 quarks**
**Each quark has the mass of 5-7 MeV/c****2**
**	****~ 1% of a proton or neutron(!)**
**The rest of the mass of protons and neutrons (and hence **_**our**_** mass) **
**   ****is “frozen energy” from the Big Bang**

- Axel Drees

## The Big Freeze

**The Big Freeze**

- Axel Drees

**Notes:**
Hier zeige ich Ihnen die Entwicklung des Universums vom Urknall zur heuting Zeit. In dieser Entwicklung spielt die  Starken Wechselwirkung eine Endscheidende Rolle fuer das Erscheinungsbild von Materie - die uns umgibt. Besonders
wichtig in dieser Entwicklung sind zwei Eregnisse:

(i) hadron synthese

(ii) Nucleon synthese

Die Theorie der starke Wechselwirkung ist die QCD. Sie gibt uns zwei Raetzel auf die beide mit der Hadronsynthese zusammen haengen.

 (i) confinement
(ii) Zusammenbruch der Chiralen Symmetrie

## Fundamental Puzzles of Hadrons

**Confinement**
**Quarks do not exist as free particles**
**Large hadron masses**
**Free quark mass ~ 5-7 MeV **
**Quarks become “fat” in hadrons constituent mass ~ 330 MeV**
**Complex structure of hadrons**
**Sea quarks and anti quarks**
**Gluons**
**“****spin crisis” **
**	****Spin of protons not carried by quarks!**

**All addressed at RHIC **

**Go back in time to big bang**
**Feasible in heavy ion collisions **

**Measurement with polarized proton beams at high energy**

**nuclear matter **
**   ****p, n**

- Axel Drees

## “Travel” Back in Time 

**“****Travel” Back in Time **

**QGP in Astrophysics**
**early universe after ~ 10 ********s**
**possibly in neutron stars**

**R****elativistic**
**H****eavy**
**I****on **
**C****ollider  at BNL**
**Quest of heavy ion collisions**
**create QGP as transient state in heavy ion collisions**
**verify existence of QGP**
**Study properties of QGP**
**study QCD confinement and how hadrons get their masses**

- Axel Drees

**Notes:**
Lassen Sie mich diesen einleitened Teil meines Vortrags nun an hand des QCD phasendiagrams zusammen fassen.

Aufgetragen ist temperatur gegen baryo-chemisches potential (wenn ihnen das nichts sagt stellen sie sich vor es waehre baryon dichte). 

kern materie by proton masse oder dichte 1 und temperatur 0.  quarkmaterie bei hohen dichten und temperature getrennt von hadronischer materie durch diesen phasenuebergang getrennt.

Das fruehe universum hat den phasenuebergang vermutlich laengst der temperatur achse durchlaufen und moeglicherweise sind die dichten im inneren von neutroensternen hoch genug um jenseits des pahsenuebergangs zu kommen. In diesem bereich gibt es moeglicher weise noch ander phasen, zum beispiel farbsupraleidende -das wird zz rege erforscht.

Ziel der Schwerionen Physik ist es in Schwerionen kollision
voruebergehend Quarkmaterie zu erzeugen. Um 

(i) existence zu verifizieren

dann aber Quarkmaterie und die folgende hadron synthese
zu untersuchen um mehr ueber confinement und die entstehung der hadron massen zu lehren 

## Detecting the QGP “matter box”

**“****ideal” experiment**
**Rutherford experiment****	****   ********  ******** atom****	****discovery of nucleus**
**	****SLAC electron scattering ****	****   e  ******** proton****	****discovery of quarks**
**Experiments with QGP not quite that simple **
**QGP created in nucleus-nucleus collisions can not be put in “box”**
**Thousands of particles produced during collision**
** ****	**

**penetrating beam**

**absorption or scattering pattern**

- Axel Drees

## Au-Au Event in STAR summer 2001 

- Axel Drees

**Notes:**
Das man in diesen Kollisionen ueberhaupt irgentetwas lehren kann ist ein Wunder in sich. Hier ist eine Au-Au kollision aufgezeichnet mit STAR experiment am RHIC. Sie sehen tausende von Teilchen in der Spurkammer von STAR. Und daraus gilt es nun was zu lernen. 

Und mit vielen Jahren Erfahrung ist dies tatsachlich moeglich!

## A Silly Analogy 

**Suppose...**
**You lived in a frozen world where there’s only as ice**
**and the ice is quantized in ice cubes**
**Some weird physicists tell you there should be water**
**and suggest to heat the ice by colliding two ice cubes**
**So you form a “bunch” containing a billion ice cubes**
**which you collide with another such bunch**
**10 million times per second**
**which produces about 1000 IceCube-IceCube collisions per second**
**which you observe from the vicinity of Mars**
**Change the length scale by about 10 trillion **
**You’re doing physics at RHIC!**

- Axel Drees

**Notes:**
Call a cube ~ a few cm  scale change is 10^13, so 1 meter bunch long bunch becomes 10^10 km 

## Relativistic Heavy Ion Collider

**RHIC**

- Axel Drees

## 11 nations
51 institutions

Stony Book:
Prof. Averbeck, Drees, Jacak, Hemmick

**11 nations**
**51 institutions**
**Stony Book:**
**Prof. Averbeck, Drees, Jacak, Hemmick**

- Axel Drees

## PHENIX at RHIC

**2 central ****spectrometers**

**2 forward ****spectrometers**

**3 global ****detectors**

**West**

**East**

**South**

**North**

- Axel Drees

## PHENIX Central 

**East Carriage**

**West Carriage**

**Ring Imaging Cerenkov**
**Drift Chamber**

**PHENIX Central **

- Axel Drees

## Space-time Evolution of Collisions

**Space-time Evolution of Collisions**

**e**

****

**space**

**time**

******  ****Expansion  ******

********

- Axel Drees

## J/ Suppression in QGP

**Hard scattering creates also heavy “charm” quark pairs ********cc**
**Small fraction of charm pairs bind to J/******

**Traveling through  QGP **
**	********c  and c  are screened by “color” charges**
**J/******** states destroyed **

**In experiment measure J****/********  ******** ******************
**Suppression of J/******** in Pb-Pb observed at CERN**
**First data from RHIC, results coming soon**

- ?

- Axel Drees

## Jets: New Penetrating Probe at RHIC 

**jets contribute ~30% of particle production  at RHIC energies**
**hard to observe directly in A-A collisions**
**indirect measurements through**
**high p****T**** leading particles**
**azimuthal correlation**

**jet tomography of quark matter**

**in colored “quark matter” partons expected to lose significant energy via gluon bremsstrahlung**
**suppression of high p****T**** particles   “jet quenching”**
**suppression of angular correlation**
**p****T**** dependent modification of particle ratios**
**	**

- Axel Drees

**Notes:**
Bei hohen strahlenergien gibt es aber eine interesante neue probe --> Jets, und damit habe ich mich vorrangig in den letzten zwei Jahren beschaeftigt.

in pp collisionen bei Rhic energien stammen etwa 30% aller teilchen von jet oder minijet fragmentation.

jets resultieren von harten streu processen zwischen einlaufenden partonen, die gestreuten partonen fragmentieren in jets von hadronen. in pp collisionen bei RHIC energien stammen etwa 30% aller teilchen aus jetfragmentation. 

In SI collisionen ist es schwierig jets zu rekonstruieren - erinnern sie sich an das STAR event display - aber man kann harte streuprocesse indirekt nachweisen. Ein teilech das sogenannte leadding particle traegt etwa 30% des jet-impulse dh durch messung von teilchen mit hohen impulsen wird der jetanteil angereicheret, ausserdem gibt es winkel korrelationen zwischen diesen Teilchen. 

Muessen die gestreuten quarks geladene matterie durchdringen verlieren sie significante energy ueber gluon bremsstrahlung. die sollte zum einen zur unterdrueckung der jetproduction fuehren dem sogenanten jet quenching zum anderen aber auch zur unterdrueckung der winkelkorrelation.

## RHIC result on the suppression of high transverse momentum particles in high-energy gold-gold collisions is featured on the cover of next week’s Physical Review Letters  (14 January 2002)

**RHIC** result on the suppression of high transverse momentum particles in high-energy **gold-gold** collisions is featured on the cover of next week’s** ****Physical Review Letters**  (14 January 2002)
- and in the 12/21/01 **Physics Focus** article on the web:
- _http://focus.aps.org/v8/st34.html_

**Brookhaven Science Associates****U.S. Department of Energy**

**PHENIX**

- Axel Drees

## New  Au-Au data taken in 2001

**New  Au-Au data taken in 2001**

**Compare the yield per trigger for ******** ~0 and ******** ~******** **
**(Au+Au – flow) / p+p per trigger.**
**Near angle ~ 1, ****	****	****	****	****pT>4 GeV/c dominantly from jet.**
**Back angle decrease with centrality****	****	****	****Disappearance of away side jet.**

**Now (2003) taking data with d-Au and p-p **
**to complete picture**

- Axel Drees

## Frontiers of Nuclear Physics

**Extremes of Nuclear structure**
**Super heavy elements**
**High spin state nuclei**
**Radio active beams**
**Nuclei far from stability **
**Hadron structure**
**Spin structure of proton**
**Confinement **
**Hadron masses**
**Quark Gluon Plasma**
**Study phase diagram of QCD**

**Nuclear Structure Lab**

**future**
**   ****RIA**

**ongoing**
**   ****RHIC**
**Future **
**   ****upgrades**
**   ****e RHIC**

- Axel Drees