Measurement of GMR in unstable nuclei

and the determination of

nuclear matter incompressibility

E. Khan

Determination of K∞

E. K

han

PRC

80(2

009)

0113

07(R

)

Pairing Is the method well defined ?

J.P. B

laiz

ot, P

hys.

Rep

.64(

1980

)171

Microscopic (RPA)

Z.Y.

Ma

et a

l, N

PA68

6(20

01)1

73

Relativistic

G. C

olo

et a

l, PR

C70

(200

4)02

4307

Microscopic (CHF)

J.Li e

t al,

PRC

78(2

008)

0643

03

Sn data

K∞

Pairing effects on the incompressibility

Exp.

E. Khan, J. Margueron, G. Colo, K. Hagino, H. Sagawa, PRC82(2010)024322

Nuclear incompressibility vs. pairing

•  Cooper pairs favor compressibility

• Incompressibility of superfluid nuclear matter: K∞(Δ) ?

112-132Sn isotopes, SkM* , CHFB

E. Khan, PRC80(2009)011307;057302

Density dependence of the incompressiblity

•  K(ρ) is probed when measuring the GMR in a nucleus : not only K∞

•  K(ρ): large variations around ρ0

Why K∞ ? •  Liquid drop expansion not valid (Blaizot) for incompressibilities •  EOS: K(ρ) more relevant than K∞ Give up K∞ as a specific experimental point (used in the design of the functionals) Measure K(ρ): needs for GMR measurements on several nuclei

<ρ> = 0.12 ± 0.04 fm-3

The mean value of the density in a nuclei is NOT the saturation density

Saturation density: ρ0 = 0.16 fm-3

MAYA

56Ni @ 50 MeV/A (GANIL - SISSI) 5.104 pps July 2005

Measurement of the GMR in unstable nuclei

Au foil

Drift

chamber

Ionisation

chamber

Moving flap Si wall

CsI wall

Diamond

56Ni (5.104 pps)

50 A.MeV

+ contaminants

Beam shield

68Ni @ 50 MeV/A (GANIL - LISE) 105 pps Sept 2010

GMR+GQR

Results 56Ni excitation energy spectrum

recoiling d kinematics

C. Monrozeau et al., PRL100(2008)042501

Preliminary results on 68Ni

M. Vandebrouck, PhD

Solving puzzles ? •  GMR in nuclei (KA) are probing K(ρ) (variation of several ten’s of MeV) • This may explains:

• Puzzle2: different K∞ values obtained within the same model between Pb and Sn nuclei

• Puzzle1: different K∞ values obtained within the same nuclei between R (260 MeV) and NR (230 MeV) models

ρ ρ0 ρPb ρSn

Κ(ρ)

NR

R

ρ ρ0 ρPb ρSn

Κ(ρ)

Sn data Pb data

∂3E/∂ρ3 =?

K∞ is not the only part of the functional probed by the GMR measurement. K at different ρ are also involved. A compensation between K∞ and different density dependencies allows to reproduce the same data

Nuclei have different density fluctuations around ρ0 (skin, …). Only a functional with the correct K(ρ) may allow to describe both data.

Conclusions

•  Role of density dependence and pairing in the determination of the incompressibility

•  Interpretation: K(ρ) is probed when measuring the GMR in a nucleus : not only K∞ and Ksym (in progress)

•  Need for several measurements (isotopic chain) : mapping of K(ρ,δ) through the GMR using a microscopic method

Importance to follow up the Sn chain, especially until doubly magic 132Sn

GMR measurements on Pb isotopic chain (unstable nuclei)

Collaboration (Exp)

C.Monrozeau1, E.Khan1, Y. Blumenfeld1, C-E.Demonchy3,W. Mittig5, P.Roussel-Chomaz5 D.Beaumel1, M.Caamaño2,D.Cortina-Gil2,J.P. Ebran1, N.Frascaria1, U.Garg4, M.Gelin5,

A.Gillibert6, D.Gupta1, N. Keeley6, F.Maréchal7, A.Obertelli6, J-A.Scarpaci1

1 Institut de Physique Nucléaire (IN2P3/CNRS), 91406 Orsay Cedex, France 2 Univ. Santiago de Compostela, E-15706 Santiago de Compostela, Spain 3 Univ. of Liverpool, Dep. of Physics, Olivier Lodge Lab., Liverpool L69 7ZE, U.K. 4 Univ. of Notre-Dame, Dep. of Physics, Notre Dame, IN 46556 USA 5 GANIL (DSM/CEA, IN2P3/CNRS), BP 5027, 14076 Caen Cedex 5, France 6 CEA/DSM/DAPNIA/SPhN, Saclay, 91191 Gif-sur-Yvette Cedex, France 7 Institut de Recherches Subatomiques (IN2P3/CNRS), BP 28, 67037 Strasbourg, France

Collaboration (Exp)