THEORETICALNUCLEAR and PARTICLE PHYSICS

Wolfram Weise

Theory Groups at work:

Andrzej Buras

Michael Ratz

Peter Ring

Norbert Kaiser

... plus two additionalpermanent positions

Fundamental Interactions

New Physics beyond the Standard Model

QCD: Phases and Structures

Nuclear Many-Body Systems

Theory Group T 31

Fundamental Interactions... from “Femto” to “Atto” Physics

Signals of New Physics beyond the Standard Model

CP Violation

Supersymmetry

Extra Dimensions

QCD Corrections

Weak Deacays of K and B Mesons:

PSfrag replacements!̄"̄

Br(KL)/10!11

Br(K+)/10!11

a!KS= 0.83

a!KS= 0.79

a!KS= 0.74

a!KS= 0.69

a!KS= 0.64

Br(KL)/Br(K+)

!"

524

20

16

8.0±0.8

4

3.0±0.3

7

11

12

00-0.25-0.25-0.5-0.5-0.75-0.75 0.250.25 0.50.5 0.750.75

1

1

1

1

0.80.8

0.60.6

0.40.4

0.20.2

GN-bound

"̄

!̄

Rb

#K

sin 2!

!Md

!Ms

Br(K+)

A. Buras, M. Ratz

TheoreticalAstro-Particle

Physics

Theoretical Nuclear Physics

Covariant Density Functional Theory

Theory Group T 30f P. Ring

broad range of Nuclear Structure

investigations from ...

Rare Isotopes

New Heavy Elements

New Collective Excitations ...

r-process

11Li

Halo Nuclei

... to:

Theory P. Ring

NuclearAstroPhysics

1 fm 10 fm 20km

tem

perature

Tc

baryon chemical potential

!q̄q" #= 0

〈qq〉 #= 0

quark ! gluon phase

µB1 GeV

nuclear

matter

0.2

T

[GeV] Nf = 2 (q = u,d)

critical point

hadron phase

CSC phasesuperconductor

(color)

matternuclear

density [fm!3]0.15

baryon chemical potential

0

0

CSC phases

PHASE DIAGRAM

nucleon

nuclei neutron stars

NUCLEAR PHYSICS : exploring the PHASES and STRUCTURES of QCD

Theory Group N. Kaiser, W. WeiseT 39

c

d

u

s

Hadrons

Nuclei

Matter under

Extreme Conditions

... exploring the PHASES

and STRUCTURES

of QCD

lattice(CP-PACS, JLQCD, QCDSF)

physical point

Masse des Nukleons[GeV]

25 50 75 100 150

Quarkmasse [MeV]

QCD

quark mass [MeV]

nucleon mass[GeV]

physical point

chiral theory

M. Procura et al.

T 39

c

d

u

s

Low-Energy QCD

Spontaneous Symmetry Breaking and Effective Field Theory

Chiral Perturbation Theory and Lattice QCD

Mass and Spin Structure of the Nucleon

u + u + d = proton

mass : 3 + 3 + 6 != 938 !

mu ! 3MeV md ! 6MeV

QCD Thermodynamicsand

Hadrons in Dense and Hot Matter

1 2 3 4 5T!Tc

0

1

2

3

4

5

3 p!!!!!!!!!!

T4

3 s!!!!!!!!!!!!!!

4 T3

!

!!!!!!!!!

T4

energy density, entropy density, pressure

S. Rößner, C. Ratti, W. W.: Phys. Rev. D 75 (2007)Figure 2: Comparison of phase diagram obtained in mean field approximation [23] (leftpanel) and the phase diagram (in the thermodynamic limit) implementing corrections tothe order ! ! 1 (right panel). Solid lines: cross-over transition of the real part of thePolyakov loop, dashed lines: first order phase transition and dotted: second order phasetransitions.

Where the first term is just the susceptibility of the Gaussian theory.In Fig. 2 we compare the phase diagram including corrections to the mean field result

with the mean field result shown in Ref. [23], where it is stated that the corrections due tofluctuations in the case of the phase diagram are quantitatively small, which is explicitlyapproved by Fig. 2. The cross-over transition fixed to the point where "(! + !!)/"T ismaximal.

There are several ways to determine the cross-over transition line separating the phaseof broken chiral symmetry from the quark gluon plasma phase. In Fig. 3 two such criteriaare compared. Firstly the maximum in the chiral or Polyakov loop susceptibility #Re !

(solid) indicate the cross-over transition, secondly the maximal change (dashed) of theconstituent quark mass and the Polyakov loop signalize the rapid cross-over transition. Asboth criteria are linked via the quadratic term in the action, all curves finally converge tothe same point, the critical point in the absence of diquark condensation. A singularity inthe second derivative of the action (or equivalently in the propagator) enforces this uniqueintersection point, where the specific heat and other quantities show singular behaviour.

In Fig. 4 we show the chiral and the Polyakov loop susceptibility as a function oftemperature at vanishing quark chemical potential (left panel) and compare them to thetemperature derivatives of the constituent quark mass and the Polyakov loop (right panel).Why is the behaviour for #M and #Re ! and #! at T " 0 di!erent? The width ofthe peak in the temperature derivative of the constituent quark mass m = m0#$ suggeststhat this cross-over is influenced by the cross-over of the Polyakov loop. At finite currentquark mass m0 the PNJL model produces an approximate coincidence of the peaks in thesusceptibilities of the Polyakov loop and the constituent quark mass m.

4.3 Moments of the pressure di!erence

One benchmark for the PNJL-model is the agreement with QCD lattice calculations. Oneway to treat the fermion sign problem in lattice QCD is to expand the calculated pressure

16

hadronic phase

quark ! gluon phase

diquark phase

!q̄q" #= 0

!qq" #= 0

phase diagram

T 39

c

d

u

s

7. Nuclei in the Universe 133

stable nucleiknown masses up to ‘95mass measurement s ‘95 - ’00mass measurement s ‘02

(on-line identification)unknown masses T > 1sunknown masses T < 1s

unknownmasses only

Neutron Number

Prot

onN

umbe

r

2028

50

82

8

8

20

28

50

82

126

Figure 7.6: The current knowledge of nuclear masses. Preliminary results obtained on-line from the frag-mentation or from the fission of a 238U beam are shown in yellow color. (Courtesy of Y. Litivinov)

significant impact on the r-process abundancepattern at the low-A wing of the peaks. Its firmverification, however, needs further experimen-tal study of the r-process progenitor nuclei inthe vicinity of the shell closure. In particular,major developments have to be started to pro-duce and study the refractory elements (Mo toPd) around N=82.

There are currently no data available for r-process nuclei in the region of the N=126 shellclosure, which is associated with the third r-process peak at around A ! 195. This is likelyto change, when this region can be reached bythe high-energy fragmentation of Pb or U beamsat GSI. These key experiments will then opena new era in nuclear structure and r-process re-search, in particular delivering the first measure-ments of halflives for N = 126 waiting points.Beyond N = 126, the r-process path reaches re-gions where nuclei start to fission, demandingan improved knowledge of fission barriers in ex-tremely neutron-rich nuclei to determine wherefission terminates the neutron capture flow andprevents the synthesis of superheavy elementswith Z>92. If the duration time of the r-process

is su!ciently long (as it could be found in neu-tron star mergers), the fission products can cap-ture again neutrons, ultimately initiating “fis-sion cycling” which can exhaust the r-processmatter below A = 130 and produce heavy nu-clei in the fission region. Fission can in partic-ular influence the r-process abundances of Thand U. This would change the Th/U r-processproduction ratio with strong consequences forthe age determination of our galaxy, which hasrecently been derived from the observation ofthese r-nuclides in old halo stars.

The direct measurement of neutron-capturecross sections on unstable nuclei is techni-cally not feasible. This goal can, however,be achieved indirectly by high resolution (d,p)-reaction, which are considered the key tool tostudy neutron capture cross sections of rare iso-topes at radioactive nuclear beam facilities. Forr-process nuclides, particular technical advance-ments need to be made to produce the requiredbeams of a few MeV/nucleon. Studies of betadelayed-neutron decays can help to determinethe existence of isolated resonances above theneutron-emission threshold in the daughter nu-

Z

N

... from QCD via

CHIRAL EFFECTIVE FIELD THEORY ...

NUCLEAR CHART ... to the

?

T 39

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d

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s

Nuclear Density Functional constrained by Low-Energy QCD

deviations (in %) between calculated and measured

-1

-0.5

0

0.5

1

E/A

(%

)

-1

-0.5

0

0.5

1

Rch(%

)

NL3

DD-ME1

FKVW_new

16

O

40

Ca48

Ca

72

Ni90

Zr

116

Sn124

Sn

132

Sn204

Pb

208

Pb214

Pb

210

Po

!E/A (%)

!!r2"1/2 (%)

Strategy :

Fix short distance constants (contact interactions) e.g. in Pb region

binding energies per nucleon ...

... and charge radii

Calculate physics at long and intermediate distances using nuclear chiral effective field theory

Predict systematics for all other nuclei

P. Finelli et al.: Nucl. Phys. A770 (2006) 1

P. Finelli et al., Nucl. Phys. A770 (2006) 1

T 39

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d

u

s

deviations (in %) between calculated and measured binding energies

130 140 150 160-0.5

0

0.5

140 150 160 170 150 160 170 180 190

140 150 160-0.5

0.0

0.5

!E

(%

)

150 160 170 170 180 190 200

140 150 160-0.5

0

0.5

150 160 170 180

A170 180 190 200

Nd

Sm

Gd

Dy

Er

Yb

Hf

Os

Pt

130 140 150 160

0

0.2

0.4

140 150 160 170 150 160 170 180 190

130 140 150 160

0

0.2

0.4

β2

150 160 170

Exp. data

FKVW [2005]

160 170 180 190 200

140 150 160 170

0

0.2

0.4

150 160 170 180

A160 170 180 190 200

Nd

Sm

Gd

Dy

Er

Yb

Hf

Os

Pt

P. Finelli et al., Nucl. Phys. A770 (2006) 1

Ground state deformations

Systematics through isotopic chainsgoverned by

isospin dependent forces from chiral pion dynamics

ππ

π

+

N N N N

TENSOR force

Nuclear Density Functional constrained by Low-Energy QCD

THEORY at the MPI for ASTROPHYSICS

SUPERNOVAE and NEUTRON STARS

Hydrodynamics Simulations of Core Collapse Supernovae

Th. Janka et al.(2006)

Wolfgang Hillebrandt Thomas Janka

Wolfram Weise

Theory Groups at work:

Andrzej Buras

Michael Ratz

Peter Ring

Norbert Kaiser

THEORETICALNUCLEAR and PARTICLE PHYSICS

Permanent Faculty (Professors): 5Postdocs: 10

PhD & Dipl. Students: 22

Visiting Scientists: ~10

MLL“UNIVERSE” Cluster