CREX WS 2013 Tamii - Jefferson Lab · 2013-03-19 · CREX WS, March 17-19, 2013 Determination of...
Transcript of CREX WS 2013 Tamii - Jefferson Lab · 2013-03-19 · CREX WS, March 17-19, 2013 Determination of...
CREX WS, March 17-19, 2013
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Dipole Polarizability of Nuclei(208Pb)
Atsushi Tamii
Research Center for Nuclear Physics (RCNP)Osaka University
I.Poltoratska, P. von Neumann‐Coseland the RCNP‐E282 Collaboration
CREX WorkshopMarch 17‐19, 2013 at Jefferson Lab.
CREX WS, March 17-19, 2013
Determination of the Symmetry Energy Term in EOS.
Lattimer et al., Phys. Rep. 442, 109(2007)
Accreting neutron star/white dwarf,X‐Ray burst, Superburst
Neutron Star Mass and Radius
Neutron Star Structure
Core‐Collapse Supernova
Neutron Star Cooling
Nucleosynthesis
K. Sumiyoshi, Astrophys. J. 629, 922 (2005)
http://www.astro.umd.edu/~miller/nstar.html
Langanke and Martinez‐Pinedo
CREX WS, March 17-19, 2013
Sn Sp
Particle (neutron) separation energy
0
PDR?IVGDRg.s.
oscillation of neutron skin against core?
oscillation between neutrons and protons
E1 1-
coreneutron skin
Low-Lying Dipole Strength
Electric Dipole (E1) Response
CREX WS, March 17-19, 2013
Sn Sp
(,xn)
GR and Continuum (Main Strength)Discrete (Small Strength)
Particle (neutron) separation energy
(p,p’)
0
PDR IVGDRg.s.
208Pb(,)M1 strength measured by R.M. Laszewski et al, PRL61(1988)1710
Electric Dipole (E1) Response
(,’)NRF
CREX WS, March 17-19, 2013
P.‐G. Reinhard and W. Nazarewicz, PRC 81, 051303(R) (2010).
Self‐consistent mean field calc. based on the energy density functional theory using Skrym SV‐min interaction.‐ SV‐min parameters were determined to reproduce binding energies, r.m.s. radii, pairing gap, ls‐splitting, surface thickness, etc.
Correlation between the Neutron Skin Thicknessand Dipole Polarizability
CREX WS, March 17-19, 2013
(Electric) Dipole Polarizability
CREX WS, March 17-19, 2013
(Electric) Dipole Polarizability
E1‐field restoring force symmetry energy
balanced
CREX WS, March 17-19, 2013
(Electric) Dipole Polarizability
with neutron skinsmaller restoring force
w/o neutron skinlarger restoring force
CREX WS, March 17-19, 2013
larger restoring force
(Electric) Dipole Polarizability
with neutron skinsmaller restoring force
w/o neutron skin
thicker neutron skin
smaller restoring force
larger displacement
larger dipole polarizability
CREX WS, March 17-19, 2013
(Electric) Dipole Polarizability
with neutron skinsmaller restoring force
w/o neutron skinlarger restoring force
Sensitive to the difference between the proton and neutron density distribution.
CREX WS, March 17-19, 2013
(Electric) Dipole Polarizability
= inversely energy weighted sum‐rule of B(E1)
: excitation energy
)1(
98
2 22
EdBdc absD
CREX WS, March 17-19, 2013
Sn Sp
Particle (neutron) separation energy
0
PDR?IVGDRg.s.
oscillation of neutron skin against core?
oscillation between neutrons and protons
E1 1-
coreneutron skinLow-Lying
Dipole Strength
Electric Dipole (E1) Response
CREX WS, March 17-19, 2013
Coulomb Excitation at 0 deg.
Excited StateTarget Nucleus
Real Photon Measurements, NRF and (,xn)
Probing EM response of the target nucleus
Decay -rays or neutrons are measured.
Select low momentum transfer (q~0) kinematical condition,i.e. at zero degrees
Excited StateTarget Nucleus
Missing Mass Spectroscopy with Virtual Photon
Insensitive to the decay channel.Total strengths are measured.
Only the scattered protons are measured.
EM Interaction iswell known
(model independent)
A
A* A (or xn)
detector
(or A-x)
A
p pdetector
A*virtual photon q,
CREX WS, March 17-19, 2013
•An electromagnetic probe (Coulomb excitation)
•High‐resolution (20‐30keV), high (~90%)/uniform efficiency
•Covers a broad Ex of 5‐25MeV
•Insensitive to the decay property
•Requires small amount of target (several mili‐gram)and a few days of beam time
•Applicable to stable nuclei
Proton Inelastic Scattering at Forward Angles
CREX WS, March 17-19, 2013
Experimental Method
High-Resolution (p,p’) measurement at zero degrees and forward angles
AT et al., NIM A605, 326 (2009)
CREX WS, March 17-19, 2013
TOKYO
OSAKA
KYOTO
RIKENRCNP, Osaka Univ.
July 28 2008 seminar @ LNL
J-PARC
CREX WS, March 17-19, 2013
High-resolution Spectrometer
Grand Raiden
High-resolution WS beam-line(dispersion matching)
Research Center for Nuclear Physics, Osaka Univ.
CREX WS, March 17-19, 2013
Spectrometers in the 0-deg. experiment setup
Intensity : 3 ~ 8 nA
As a beam spot monitor in the vertical direction
Transport : Dispersive mode
Polarized Proton Beam at 295 MeV
Focal Plane Polarimeter
CREX WS, March 17-19, 2013
CREX WS, March 17-19, 2013
CREX WS, March 17-19, 2013
B(E1) strength distribution in 208Pb below the GDR region
I. Poltoratska, PhD thesis
B(E1) of discrete states
CREX WS, March 17-19, 2013
Multipole Decomposition
Neglect of data for >4: (p,p´) response too complex
Included E1/M1/E2 or E1/M1/E3 (little difference)
CREX WS, March 17-19, 2013
S=1 (M1)
S=0 (E1)
Concentration of spin‐M1 strength
CREX WS, March 17-19, 2013
Comparison between the two methods
Total
S = 1
S = 0
CREX WS, March 17-19, 2013
I. Poltoratska, PhD thesis
CREX WS, March 17-19, 2013
E1 Response of 208Pb and D
8.2 MeV 20 MeV 130 MeV
17.6 1.2D
in total 20.1±0.6 fm3/e2
AT et al., PRL107, 062502(2011)
CREX WS, March 17-19, 2013
Relativistic Quasiparticle Time Blocking Approximation
Quasiparticle Phonon Model
up to 130 MeV20.1±0.6 fm3/e2
I. Poltoratska, PhD thesis
Electric Dipole Polarizability
CREX WS, March 17-19, 2013
The dipole polarizability of 208Pb has been precisely determined.
D=20.1±0.6 fm3/e2
Theoretical models will be best constrained if neutron skin thickness (Rnp), in addition to D, is precisely determined,.
We try to extract Rnp symmetry energy parameters from D by using theoretical models.
accuracy of Rnp is not good enough yet
CREX WS, March 17-19, 2013
Calc. P.‐G. Reinhard and W. Nazarewicz, PRC81, 051303(R) (2010).
0.156+0.025‐0.021 fm
20.1±0.6 fm3/e2
PREX 0.33+0.16‐0.18 fm 0.49
proton elastic scattering0.211+0.054‐0.063 fm
0.15
0.15 0.27
Antiproton Atoms 0.18±0.02 fm0.16 0.20
J. Zenihiro et al., PRC82, 044611 (2010)
Friedman and Gal, Phys. Rep. 452, 89 (2007)
S. Abrahamyan et al., PRL108, 112502 (2012)
AT et al., PRL107, 062502(2011)
CREX WS, March 17-19, 2013
Correlation Between Dipole Polarizabilityand Neutron Skin Thickness
J. Piekarewicz et al., PRC85, 041302(2012)
769.0MODEL ABC
CREX WS, March 17-19, 2013
J. Piekarewicz, W. Nazarewicz, et al., PRC85, 041302(2012)
769.0MODEL ABC
Correlation Between Dipole Polarizabilityand Neutron Skin Thickness
CREX WS, March 17-19, 2013
J. Piekarewicz, W. Nazarewicz, et al., PRC85, 041302(2012)
769.0MODEL ABC
Correlation Between Dipole Polarizabilityand Neutron Skin Thickness
CREX WS, March 17-19, 2013
Neutron Skin Thickness Measurement by Electromagnetic Interaction
CREX WS, March 17-19, 2013
Neutron Skin Thickness of 208Pb
0.168±0.022 fm (this work)
CREX WS, March 17-19, 2013
Based on the work by X. Roca‐Maza et al., PRL106, 252501 (2011)
DP: Dipole Polarizability
L±15 MeV
Determination of Symmetry Energy
0.168±0.022 fm
CREX WS, March 17-19, 2013
PreliminaryGaussian weight func.
L±18 MeV
Determination of Symmetry Energy
CREX WS, March 17-19, 2013
DP: Dipole PolarizabilityHIC: Heavy Ion CollisionPDR: Pygmy Dipole ResonanceIAS: Isobaric Analogue StateFRDM: Finite Range DropletModel (nuclear mass analysis)
n‐star: Neutron Star ObservationEFT: Chiral Effective Field Theory
Determination of Symmetry EnergyM.B. Tsang et al., PRC86, 015803 (2012).
I. Tews et al., PRL110, 032504 (2013)
CREX WS, March 17-19, 2013
PreliminaryL45±18 MeVJ=30.9±1.5 MeV
M.B. Tsang et al., PRC86, 015803 (2012).
and this work
DP: Dipole PolarizabilityHIC: Heavy Ion CollisionPDR: Pygmy Dipole ResonanceIAS: Isobaric Analogue StateFRDM: Finite Range DropletModel (nuclear mass analysis)
n‐star: Neutron Star ObservationEFT: Chiral Effective Field Theory
Determination of Symmetry Energy
DP:
I. Tews et al., PRL110, 032504 (2013)
CREX WS, March 17-19, 2013
J. Birkhan et al.
18 keV
Existing data (E249)
CREX WS, March 17-19, 2013
J. Birkhan et al.
CREX WS, March 17-19, 2013
Multipole‐decomposition analysisin progress
Sorry, we don’t have the results yet.
CREX WS, March 17-19, 2013
The dipole polarizability of 208Pb has been precisely determined. D=20.1±0.6 fm3/e2
Model‐independent precise determination of the neutron skin thickness (Rnp), PREX‐II and CREX, are very important. Theoretical models will be best constrained if both D and Rnp are precisely determined.
Summary
Our methods can be applied to other stable nuclei for studying systematically dipole‐polarizability, PDR’s, and their dependence on mass, neutron excess, and deformation.
CREX WS, March 17-19, 2013Summary•Other nuclei: DP, PDR, spin‐M1 (data analysis in progress)96Mo (DCS and PT): Dirk Martin 48Ca (DCS): Jonny Birkhan90Zr (DCS): C. Iwamoto
(PDR‐region, published in PRL108, 262501 (2012))120Sn (DCS and PT): A.M. Krumbholtz, T. Hashimoto154Sm (DCS and PT): A. Krugmann88Sr, 92Mo (DCS): C. Iwamoto70Zn (DCS):
CREX WS, March 17-19, 2013
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Collaborators RCNP, Osaka UniversityA. Tamii, H. Matsubara, H. Fujita, K. Hatanaka,
H. Sakaguchi Y. Tameshige, M. Yosoi and J. Zenihiro
Dep. of Phys., Osaka UniversityY. Fujita
Dep. of Phys., Kyoto UniversityT. Kawabata
CNS, Univ. of TokyoK. Nakanishi,
Y. Shimizu and Y. Sasamoto
CYRIC, Tohoku UniversityM. Itoh and Y. Sakemi
Dep. of Phys., Kyushu UniversityM. Dozono
Dep. of Phys., Niigata UniversityY. Shimbara
IKP, TU-DarmstadtP. von Neumann-Cosel, A-M. Heilmann,
Y. Kalmykov, I. Poltoratska, V.Yu. Ponomarev,A. Richter and J. Wambach
KVI, Univ. of GroningenT. Adachi and L.A. Popescu
IFIC-CSIC, Univ. of ValenciaB. Rubio and A.B. Perez-Cerdan
Sch. of Science Univ. of WitwatersrandJ. Carter and H. Fujita
iThemba LABSF.D. Smit
Texas A&M CommerceC.A. Bertulani
GSIE. Litivinova
RCNP‐E282
CREX WS, March 17-19, 2013
0‐5.3 deg
90Zr(p,p’) PDR region
0‐1.8 deg3.8‐5.3 deg
C. Iwamoto, et al., PRL108, 262501 (2012).
E=~20 keV
CREX WS, March 17-19, 2013
A. Krugmann et al., analysis in progress
CREX WS, March 17-19, 2013
Lattimer et al., arXiv1203.4286v1(2012)
Constant term of the Symmetry Energy
Slop
e Pa
rameter of the Sym
metry Energy
Determination of Symmetry Energy
Determination of the dipole polarizability of 208Pb strongly constrain model parameters
Calc. for 208Pb dipole polarizabilityby J. Piekarewicz
CREX WS, March 17-19, 2013
Relativistic Quasiparticle Time Blocking Approximation
Quasiparticle Phonon Model
up to 130 MeV20.1±0.6 fm3/e2
I. Poltoratska, PhD thesis
Electric Dipole Polarizability
CREX WS, March 17-19, 2013
Thank You
CREX WS, March 17-19, 2013
C. Iwamoto, et al.,
Sn=12.0 MeVSn=11.1 MeV Sn=12.7 MeV
CREX WS, March 17-19, 2013
A. Carbone PRC81, 041301(R) (2010)
Correlation between the TRK sum rule of PDR and L
CREX WS, March 17-19, 2013
Nuclear Equation of State (EOS)
rr
rrr
pn
pn
rrr pn
Ksym is discussed from studies of e.g. isoscalar giant monopole resonances (ISGMRs).Determination of L is becoming important.
...0,, 2 SAE
AE
...183
202
00
0
symKLJS
Symmetry energy
L: Slope Parameter
EOS for Energy per nucleon
:0
Saturation Density~0.16 fm‐3
4starn RPL
(Baryonic Pressure)
CREX WS, March 17-19, 2013
Steiner et al., Phys. Rep. 411 325(2005)
核子
当たりの
エネル
ギー
Nucleon Density (fm‐3)E/A (M
eV)
E/N (M
eV)
Neutron Density (fm‐3)
Nuclear Equation of State (EOS)
Neutron Matter(=1)
Prediction of the neutron matter EOS is much model dependent.
Neutron Matter(=1)
Symmetry Energy(and Coulomb)
Nuclear Matter (=0)
CREX WS, March 17-19, 2013
X. Roca‐Maza et al., PRL106, 252501 (2011)
208Pb
Correlation between the Neutron Skin Thickness of 208Pb and the Slope Parameter (L)
CREX WS, March 17-19, 2013
Neutron density
Proton density
Neutron rms radius
Proton rms radius
Density distribution of protons and neutrons in a nucleus
My “simple explanation” of the correlation between the neutron skin thickness and the slope parameter (L)
CREX WS, March 17-19, 2013
Smaller S2 at higher
Larger S2 at lower
larger skin
My “simple explanation” of the correlation between the neutron skin thickness and the slope parameter (L)
CREX WS, March 17-19, 2013
My “simple explanation” of the correlation between the neutron skin thickness and the slope parameter (L)
Larger S2 at higher
Smaller S2 at lower
smaller skin
CREX WS, March 17-19, 2013
Neutron skin thickness
Density dependence of the symmetry energy
My “simple explanation” of the correlation between the neutron skin thickness and the slope parameter (L)
Larger S2 at higher
Smaller S2 at lower
smaller skin
Energy minimization= equilibrium condition
CREX WS, March 17-19, 2013
PREX at J-Lab: Z0 of weak interaction : sees the neutrons
proton neutron
Electric charge 1 0
Weak charge 0.08 1
Neutron form factor
)()(41)( 0
32 rqrjrdQF NN
Parity Violating Asymmetry
)()(sin41
22 2
22
2
QFQFQGA
P
NW
F
0
T.W. Donnelly, J. Dubach, I. Sick
C.J. Horowitz
NPA503, 589, 1989
6/16
)(sin41
22 22
2
QFQG
dd
dd
dd
dd
AP
WF
LR
LR
Model Independent Determination of Neutron Skin Thickness
Neutron Skin Thickness Measurement by Electroweak Interaction
C. J. Horowitz, S. J. Pollock, P. A. Souder, R. Michaels
PRC 63, 025501, 2001
measurement at q=0.475 fm‐1
CREX WS, March 17-19, 2013Neutron Skin Thickness Measurement by Electroweak Interaction
PREX at J-labS. Abrahamyan et al., PRL108, 112502 (2012)
CREX WS, March 17-19, 2013Neutron Skin Thickness Measurement by Electroweak Interaction
PREX
PREX Result: S. Abrahamyan et al., PRL108, 112502 (2012)
Theor. Calc.: X. Roca‐Maza et al., PRL106, 252501 (2011)
•Alternative approach at RCNP by using electromagnectic interaction
•The model independent determination of Rnp by PREX and futureprojects is quite important.
CREX WS, March 17-19, 2013My “very simplified picture” of the correlation between neutron skin thickness and dipole polarizability
One dimensional nucleus without surface diffuseness
E1
larger skin thickness smaller restoring force
E1
larger dipole polarizability
With finite diffuseness the relation becomes smoother.
CREX WS, March 17-19, 2013
PREX : Z0 of weak interaction : sees the neutrons
proton neutron
Electric charge 1 0
Weak charge 0.08 1
Neutron form factor
)()(41)( 0
32 rqrjrdQF NN
Parity Violating Asymmetry
)()(sin41
22 2
22
2
QFQFQGA
P
NW
F
0
T.W. Donnelly, J. Dubach, I. Sick
C.J. Horowitz
Nucl. Phys. A 503, 589, 1989
C. J. Horowitz, S. J. Pollock, P. A. Souder, R. Michaels
Phys. Rev. C 63, 025501, 2001
6/16Talk by C. Horowitz
)(sin41
22 22
2
QFQG
dd
dd
dd
dd
AP
WF
LR
LR
Model Independent Determination of Neutron Skin Thickness
CREX WS, March 17-19, 2013
Neutron Skin = RN - RP = 0.33 + 0.16 - 0.18 fm
Establishing a neutron skin at ~95 % CL Asymmetry leads to RN
proposed
published
Also considering a new 48Ca proposal
Spokespersons
K. Kumar R. Michaels K. PaschkeP. A. Souder G. Urciuoli
9/16
S. Abrahamyan et al. Phys. Rev. Lett. 108, 112502 (2012)
CREX WS, March 17-19, 2013
•Missing Mass Measurement
•insensitive to the decay property of the excited states and to the decay threshold.
•no feeding from upper excited states
•measure of the total (not partial) width
•At 0 deg, E1 states are dominantly excited by Coulomb interaction.Coulomb interaction is well known and is model independent.
•High‐resolution (20‐30keV). High (~100%) and uniform detection efficiency.
• Single shot measurement in a broad excitation energy region of 5‐25MeV.
• Cross section is high. We need thin (a few mg/cm2) target.
• E1/M1 decomposition by two methods: polarization transfer and angular distribution of the C.S. (MDA)
Proton Inelastic Scattering at Forward Angles