Atomic nuclei: from fundamental interactions to structure and stars - - PowerPoint PPT Presentation
Atomic nuclei: from fundamental interactions to structure and stars - - PowerPoint PPT Presentation
Atomic nuclei: from fundamental interactions to structure and stars Kai Hebeler Mainz, April 7, 2016 New Vistas in Low-Energy Precision Physics (LEPP) The theoretical nuclear landscape several years ago... Ab initio nuclear structure theory
The theoretical nuclear landscape several years ago...
nuclear structure and reaction observables Quantum Chromodynamics
Ab initio nuclear structure theory
Lattice QCD
- requires extreme amounts
- f computational resources
- currently limited to 1- or 2-nucleon systems
- current accuracy insufficient for
precision nuclear structure
nuclear structure and reaction observables Quantum Chromodynamics
Ab initio nuclear structure theory
Chiral effective field theory
nuclear interactions and currents
nuclear structure and reaction observables Quantum Chromodynamics
Ab initio nuclear structure theory
Chiral effective field theory
nuclear interactions and currents
nuclear structure and reaction observables ab initio many-body frameworks
Faddeev, Quantum Monte Carlo, no-core shell model, coupled cluster ...
Quantum Chromodynamics
Ab initio nuclear structure theory
Chiral effective field theory
nuclear interactions and currents
nuclear structure and reaction observables Quantum Chromodynamics Renormalization Group methods
Ab initio nuclear structure theory
ab initio many-body frameworks
Faddeev, Quantum Monte Carlo, no-core shell model, coupled cluster ...
- choose relevant degrees of
freedom: here nucleons and pions
- operators constrained by
symmetries of QCD
- short-range physics captured in
few short-range couplings
- separation of scales: Q << Λb,
breakdown scale Λb~500 MeV
- power-counting:
expand in powers Q/Λb
- systematic: work to desired
accuracy, obtain error estimates
Chiral effective field theory for nuclear forces
NN 3N 4N 2006 1994 2011
NN 3N 4N
long (2π) intermediate (π) short-range
c1, c3, c4 terms
cD term cE term
Many-body forces in chiral EFT
2006 1994 2011
NN 3N 4N
long (2π) intermediate (π) short-range
c1, c3, c4 terms
cD term cE term
first incorporation in calculations of neutron and nuclear matter
Tews, Krueger, KH, Schwenk, PRL 110, 032504 (2013) Krueger, Tews, KH, Schwenk, PRC 88, 025802 (2013)
Many-body forces in chiral EFT
2006 1994 2011
all terms predicted
NN 3N 4N
long (2π) intermediate (π) short-range
c1, c3, c4 terms
cD term cE term
first incorporation in calculations of neutron and nuclear matter
Tews, Krueger, KH, Schwenk, PRL 110, 032504 (2013) Krueger, Tews, KH, Schwenk, PRC 88, 025802 (2013)
2006 1994 2011
first calculation of matrix elements for ab initio studies of matter and nuclei
KH, Krebs, Epelbaum, Golak, Skibinski, PRC 91, 044001(2015)
Many-body forces in chiral EFT
Chiral effective field theory
nuclear interactions and currents
nuclear structure and reaction observables
Development of nuclear interactions predictions validation
- ptimization
power counting
LENPIC
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
Hλ = UλHU †
λ
λ
dHλ dλ = [ηλ, Hλ]
The Similarity Renormalization Group
- generate unitary transformation which decouples low- and high momenta
- basic idea: change resolution successively in small steps:
with the resolution parameter
- observables are preserved due to unitarity of transformation
- generator can be chosen and tailored to different applications
ηλ
1 2 3 4 r [fm] −100 100 200 V(r) [MeV] λ = 20 fm
−1
1 2 3 4 r [fm] λ = 4 fm
−1
1 2 3 4 r [fm] λ = 3 fm
−1
1 2 3 4 r [fm] λ = 2 fm
−1
1 2 3 4 r [fm] λ = 1.5 fm
−1
AV18 N
3LO
V λ(r) = Z dr0r02Vλ(r, r0)
Systematic decoupling of high-momentum physics: The Similarity Renormalization Group
- elimination of coupling between low- and high momentum components,
simplified many-body calculations, smaller required model spaces
- observables unaffected by resolution change (for exact calculations)
- residual resolution dependences can be used as tool to test calculations
Not the full story: RG transformation also changes three-body (and higher-body) interactions.
Systematic decoupling of high-momentum physics: The Similarity Renormalization Group
Recent advances in ab-initio many-body theory
- 10
- 9
- 8
- 7
- 6
NN+3N-induced
N3LO N2LOopt
(a) exp
- 0.5
0.5 (b)
- 10
- 9
- 8
- 7
. E/A [MeV] NN+3N-full
Λ3N = 400 MeV/c Λ3N = 350 MeV/c
(c) exp
16O 24O 36Ca 40Ca 48Ca 52Ca 54Ca 48Ni 56Ni 60Ni 62Ni 66Ni 68Ni 78Ni 88Sr 90Zr 100Sn 106Sn 108Sn 114Sn 116Sn 118Sn 120Sn 132Sn
- 0.5
0.5 (d)
Binder et al. , Phys. Lett B 736, 119 (2014)
Recent advances in ab-initio many-body theory
- spectacular increase in range of applicability
- f ab initio many body frameworks
- significant overbinding in heavy nuclei
for presently used nuclear interactions
- 10
- 9
- 8
- 7
- 6
NN+3N-induced
N3LO N2LOopt
(a) exp
- 0.5
0.5 (b)
- 10
- 9
- 8
- 7
. E/A [MeV] NN+3N-full
Λ3N = 400 MeV/c Λ3N = 350 MeV/c
(c) exp
16O 24O 36Ca 40Ca 48Ca 52Ca 54Ca 48Ni 56Ni 60Ni 62Ni 66Ni 68Ni 78Ni 88Sr 90Zr 100Sn 106Sn 108Sn 114Sn 116Sn 118Sn 120Sn 132Sn
- 0.5
0.5 (d)
Binder et al. , Phys. Lett B 736, 119 (2014) Hagen et al., Nature Physics 12, 186 (2016)
0.8 1.0 1.2 1.4 1.6
kF [fm
−1]
−30 −25 −20 −15 −10 −5
Energy/nucleon [MeV]
Λ = 1.8 fm
−1 NN only
Λ = 2.8 fm
−1 NN only
Vlow k NN from N
3LO (500 MeV)
3NF fit to E3H and r4He Λ3NF = 2.0 fm
−1
3rd order pp+hh
NN only
- ¯
lS
“Very soft potentials must be excluded because they do not give saturation; they give too much binding and too high density. In particular, a substantial tensor force is required.” Hans Bethe (1971)
KH, Bogner, Furnstahl, Nogga, PRC(R) 83, 031301 (2011)
1 2 3 4 r [fm] −100 100 200 V(r) [MeV] λ = 20 fm
−1
4 1 2 3 4 r [fm] λ = 1.5 fm
−1
AV18 N
3LO
Fitting the 3NF LECs at low resolution scales
0.8 1.0 1.2 1.4 1.6
kF [fm
−1]
−30 −25 −20 −15 −10 −5
Energy/nucleon [MeV]
Λ = 1.8 fm
−1
Λ = 2.8 fm
−1
Λ = 1.8 fm
−1 NN only
Λ = 2.8 fm
−1 NN only
Vlow k NN from N
3LO (500 MeV)
3NF fit to E3H and r4He Λ3NF = 2.0 fm
−1
3rd order pp+hh
NN + 3N NN only
“Very soft potentials must be excluded because they do not give saturation; they give too much binding and too high density. In particular, a substantial tensor force is required.” Hans Bethe (1971)
KH, Bogner, Furnstahl, Nogga, PRC(R) 83, 031301 (2011)
- ¯
lS
1 2 3 4 r [fm] −100 100 200 V(r) [MeV] λ = 20 fm
−1
4 1 2 3 4 r [fm] λ = 1.5 fm
−1
AV18 N
3LO
Fitting the 3NF LECs at low resolution scales
intermediate (cD) and short-range (cE) 3NF couplings fitted to few-body systems at different resolution scales:
E3H = −8.482 MeV r4He = 1.464 fm
c1, c3, c4 terms
cD term cE term
0.8 1.0 1.2 1.4 1.6
kF [fm
−1]
−30 −25 −20 −15 −10 −5
Energy/nucleon [MeV]
Λ = 1.8 fm
−1
Λ = 2.8 fm
−1
Λ = 1.8 fm
−1 NN only
Λ = 2.8 fm
−1 NN only
Vlow k NN from N
3LO (500 MeV)
3NF fit to E3H and r4He Λ3NF = 2.0 fm
−1
3rd order pp+hh
NN + 3N NN only
“Very soft potentials must be excluded because they do not give saturation; they give too much binding and too high density. In particular, a substantial tensor force is required.” Hans Bethe (1971)
KH, Bogner, Furnstahl, Nogga, PRC(R) 83, 031301 (2011)
- ¯
lS
1 2 3 4 r [fm] −100 100 200 V(r) [MeV] λ = 20 fm
−1
4 1 2 3 4 r [fm] λ = 1.5 fm
−1
AV18 N
3LO
Fitting the 3NF LECs at low resolution scales
Drischler, KH, Schwenk, arXiv:1510.06728
2 8 20 28 Z N 2 8
s t a b i l i t y l i n e
O 1970 F 1999 N 1985 C 1986 B 1984 Be 1973 Li 1966 H 1934 He 1961 Ne 2002 Na 2002 Mg2007 Al 2007 Si 2007
unstable oxygen isotopes unstable fluorine isotopes stable isotopes unstable isotopes neutron halo nuclei
- remarkable agreement between different many-body frameworks
- excellent agreement between theory and experiment for masses of
- xygen and calcium isotopes based on specific chiral interactions
- need to quantify theoretical uncertainties
Gallant et al. PRL 109, 032506 (2012) Wienholtz et al. Nature 498, 346 (2013)
Studies of neutron-rich nuclei
S2n (MeV) Neutron number, N 2 6 10 14 18 22
[S2n(theo) – S2n(exp)] (MeV) 2.0 1.0 0.0 –1.0 –2.0 30 31 32 33 34
a
28 30 32 34 36 38
Neutron number, N
ISOLTRAP Experiment NN+3N (MBPT) CC (ref. 5) KB3G GXPF1A
Ca isotopes
16 18 20 22 24 26 28
Mass Number A
- 180
- 170
- 160
- 150
- 140
- 130
Energy (MeV)
MR-IM-SRG IT-NCSM SCGF Lattice EFT CC
- btained in large many-body spaces
AME 2012
O isotopes
KH et al. , Ann. Rev. Nucl. Part. Sci.165, 457 (2015)
- 10
10 20 30 40
S2n (MeV)
- 10
10 20 30 40 10 20 30 40 50 10 12 14 16 18 20 10 12 14 16 18 20 10 20 30 40 50 10 12 14 16 18 20 10 20 30 40 50 10 12 14 16 18 20 10 12 14 16 18 20
Neutron Number N
10 20 30 40 50
2nd order 3rd order AME 2012 8O 9F 11Na 13Al 10Ne 14Si 12Mg 15P 19K 18Ar 16S 17Cl 20Ca
Towards theoretical uncertainty quantification
- calculations based on NN+3N interactions fitted to NN, 3N and 4N systems
- reasonable reproduction of experimental trends
- uncertainties dominated by differences in nuclear Hamiltonians
Simonis, KH, Holt, Menendez, Schwenk,
- Phys. Rev. C93, 011302(R) (2016)
- 10
10 20 30 40
S2n (MeV)
- 10
10 20 30 40 10 20 30 40 50 10 12 14 16 18 20 10 12 14 16 18 20 10 20 30 40 50 10 12 14 16 18 20 10 20 30 40 50 10 12 14 16 18 20 10 12 14 16 18 20
Neutron Number N
10 20 30 40 50
2nd order 3rd order AME 2012 8O 9F 11Na 13Al 10Ne 14Si 12Mg 15P 19K 18Ar 16S 17Cl 20Ca
Towards theoretical uncertainty quantification
- calculations based on NN+3N interactions fitted to NN, 3N and 4N systems
- reasonable reproduction of experimental trends
- uncertainties dominated by differences in nuclear Hamiltonians
Simonis, KH, Holt, Menendez, Schwenk,
- Phys. Rev. C93, 011302(R) (2016)
2 4 6
2
+ Energy (MeV)
8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 2 4 6 8 10 12 14 16 18 20 8 10 12 14 16 18 20
Neutron Number N
2 4 6
2nd order 3rd order exp.
8O 10Ne 12Mg 14Si 16S 18Ar 20Ca
Results for the neutron matter equation of state
c1, c3, c4 terms
cD term cE term
- nly long-range 3NF
contribute in leading order neutron matter is a unique system for chiral EFT: pure neutron matter
0.2 0.4 0.6 0.8 1.0
[
0]
0.5 1.0 1.5 2.0 2.5
P [1033dyne / cm2]
NN only, EM NN only, EGM
KH and Schwenk PRC 82, 014314 (2010)
0.05 0.10 0.15
[fm-3]
5 10 15 20
Energy/nucleon [MeV]
ENN+3N,eff+c3+c1 uncertainties ENN+3N,eff+c3 uncertainty ENN
(1) + ENN (2)
3N neutron star matter
KH, Lattimer, Pethick, Schwenk, PRL 105, 161102 (2010)
ENN+3N,eff
(1)
ENN+3N,eff 2.0 <
3N < 2.5 fm-1
- 0. 05
- 0. 10
0.15
[fm-3]
5 10 15 20
Energy/nucleon [MeV]
- 0. 05
- 0. 10
- 0. 15
[fm-3]
= 1.8 fm-1 = 2.0 fm-1 = 2.4 fm-1 = 2.8 fm-1
KH and Schwenk PRC 82, 014314 (2010)
Symmetry energy and neutron skin constraints
- neutron matter give tightest constraints
- in agreement with all other constraints
Sv = ∂2E/N ∂2x
- ρ=ρ0,x=1/2
L = 3 8 ∂3E/N ∂ρ∂2x
- ρ=ρ0,x=1/2
1303.4662
KH, Lattimer, Pethick, Schwenk, ApJ 773,11 (2013)
rskin[208Pb] = 0.14 − 0.2 fm
KH, Lattimer, Pethick, Schwenk, PRL 105, 161102 (2010)
neutron skin constraint from neutron matter results:
S(208Pb) (fm) slope of neutron EOS 0.0 0.1 0.2 0.3
- 50
50 100 150 200
!"#$ "%&!
Brown, PRL 85, 5296 (2000) Piekarewicz, PRC 85, 041302 (2012)
Hagen et al., Nature Physics 12, 186 (2016)
Predictions for the neutron skin of 48Ca
- microscopic coupled cluster results based on a set of different
nuclear NN+3N interactions (see also Phys. Rev. C91, 051301 (2015))
- correlations between different observables and the precisely measured Rp
- prediction of significantly smaller neutron skin compared to EDF results:
0.12 . Rskin . 0.15 fm
Charge radii of calcium isotopes
Garcia Ruiz at al., Nature Physics (advanced online, 2016)
- novel precise measurements of Ca isotope shifts
- unexpectedly large radii of neutron-rich isotopes
- reasonable theoretical reproduction of radius trends
in coupled cluster calculations based on chiral EFT interactions
- radius increase quantitatively underestimated in all theoretical studies
Constraints on the nuclear equation of state (EOS)
A two-solar-mass neutron star measured using Shapiro delay
- P. B. Demorest1, T. Pennucci2, S. M. Ransom1, M. S. E. Roberts3 & J. W. T. Hessels4,5
a b
–40 –30 –20 –10 10 20 30 –40 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Orbital phase (turns)
Timing residual (μs)
Demorest et al., Nature 467, 1081 (2010)
Mmax = 1.65M → 1.97 ± 0.04 M
Calculation of neutron star properties require EOS up to high densities. Strategy: Use observations to constrain the high-density part of the nuclear EOS. New constraints from recent observations:
A Massive Pulsar in a Compact Relativistic Binary
Antoniadis et al., Science 340, 448 (2013)
→ 2.01 ± 0.04 M
Neutron star radius constraints
incorporation of beta-equilibrium: neutron matter neutron star matter parametrize piecewise high-density extensions of EOS:
- use polytropic ansatz
- range of parameters
p ∼ ρΓ
13.0 13.5 14.0
log 10 [g / cm3]
31 32 33 34 35 36 37
log 10 P [dyne / cm2]
1 2 3
with ci uncertainties
crust
crust EOS (BPS) neutron star matter
12 23 1
Γ1, ρ12, Γ2, ρ23, Γ3 limited by physics
KH, Lattimer, Pethick, Schwenk, ApJ 773, 11 (2013) KH, Lattimer, Pethick, Schwenk, PRL 105, 161102 (2010)
Constraints on the nuclear equation of state
use the constraints:
vs(ρ) =
- dP/dε < c
Mmax > 1.97 M
causality recent NS observations constraints lead to significant reduction of EOS uncertainty band
KH, Lattimer, Pethick, Schwenk, ApJ 773,11 (2013)
vs(ρ) =
- dP/dε < c
causality fictitious NS mass
Mmax > 2.4 M
increased systematically reduces width of band
Mmax
use the constraints:
Constraints on the nuclear equation of state
KH, Lattimer, Pethick, Schwenk, ApJ 773,11 (2013)
- current radius prediction for typical neutron star:
- low-density part of EOS sets scale for allowed high-density extensions
14.2 14.4 14.6 14.8 15.0 15.2 15.4
log 10 [g / cm3]
33 34 35 36
log 10 P [dyne / cm2]
WFF1 WFF2 WFF3 AP4 AP3 MS1 MS3 GM3 ENG PAL GS1 GS2
14.2 14.4 14.6 14.8 15.0 15.2 15.4 33 34 35 36
PCL2 SQM1 SQM2 SQM3 PS
Constraints on neutron star radii
KH, Lattimer, Pethick, Schwenk, ApJ 773, 11 (2013) see also KH, Lattimer, Pethick, Schwenk, PRL 105, 161102 (2010)
1.4 M
8 10 12 14 16
Radius [km]
0.5 1 1.5 2 2.5 3
Mass [Msun]
8 10 12 14 16
Radius [km]
0.5 1 1.5 2 2.5 3
Mass [Msun]
causality
9.7 − 13.9 km
- current radius prediction for typical neutron star:
- low-density part of EOS sets scale for allowed high-density extensions
14.2 14.4 14.6 14.8 15.0 15.2 15.4
log 10 [g / cm3]
33 34 35 36
log 10 P [dyne / cm2]
WFF1 WFF2 WFF3 AP4 AP3 MS1 MS3 GM3 ENG PAL GS1 GS2
14.2 14.4 14.6 14.8 15.0 15.2 15.4 33 34 35 36
PCL2 SQM1 SQM2 SQM3 PS
Constraints on neutron star radii
KH, Lattimer, Pethick, Schwenk, ApJ 773, 11 (2013) see also KH, Lattimer, Pethick, Schwenk, PRL 105, 161102 (2010)
1.4 M
8 10 12 14 16
Radius [km]
0.5 1 1.5 2 2.5 3
Mass [Msun]
8 10 12 14 16
Radius [km]
0.5 1 1.5 2 2.5 3
Mass [Msun]
causality
- radius measurements could significantly improve constraints
9.7 − 13.9 km
Large
- bservatory
for X-ray timing
Summary
- recent advances allow ab initio studies of medium-mass nuclei
- remarkable agreement between different methods for given interaction,
uncertainties dominated by differences in nuclear interactions
- results presented for properties of neutron-rich nuclei and matter based
- n sets of current chiral EFT NN+3N interactions
LENPIC
Future directions
- derivation of systematic uncertainty estimates for many-body observables,
- rder-by-order convergence studies
- exploration of different fitting strategies, include bayesian analysis for
statistical interpretation of uncertainties?
- role of regulators, clean separation of short- and long-range physics,
naturalness of coupling constants, power counting schemes, inclusion of delta excitations...
In collaboration with: computing support:
JUROPA
- C. Pethick
- C. Drischler, T. Krüger, R. Roth,
- A. Schwenk
- J. Lattimer
- S. Bogner
- R. Furnstahl, S. More
- A. Nogga
- E. Epelbaum, H. Krebs
- J. Golak, R. Skibinski
- A. Gezerlis
international collaborator in
LENPIC
- G. Hagen, T. Papenbrock
Thank you!
Backup slides
VNN V3N V3N V3N
Equation of state: Many-body perturbation theory
E = + + + +
central quantity of interest: energy per particle E/N
- “hard” interactions require non-perturbative summation of diagrams
- with low-momentum interactions much more perturbative
- inclusion of 3N interaction contributions crucial!
+
. . .
Hartree-Fock
VNN VNN
+ + +
V3N V3N V3N VNN VNN V3N
2nd-order kinetic energy 3rd-order and beyond H(λ) = T + VNN(λ) + V3N(λ) + ...
First application to isospin asymmetric nuclear matter
- uncertainty bands determined
by set of 7 Hamitonians
Drischler, KH, Schwenk, in preparation
x = np np + nn
- many-body framework allows
treatment of any decomposed 3N interaction
Equation of state of symmetric nuclear matter, nuclear saturation
- ¯
lS
“Very soft potentials must be excluded because they do not give saturation; they give too much binding and too high density. In particular, a substantial tensor force is required.” Hans Bethe (1971)
1 2 3 4 5 −25 −24 −23 −22 −21
f [kHz] log(h+(f)f1/2/Hz1/2)
5 10 15 20 −2 2 x 10
−22
h+ at 50 Mpc t [ms]
eosUU fpeak Shen
Bauswein and Janka, PRL 108, 011101 (2012), Bauswein, Janka, KH, Schwenk, PRD 86, 063001 (2012)
- simulations of NS binary mergers show strong correlation between between
- f the GW spectrum and the radius of a NS
- measuring is key step for constraining EOS systematically at large
fpeak fpeak
ρ
10 11 12 13 14 15 16 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 fpeak [kHz] R1.6 [km]
Gravitational wave signals from neutron star binary mergers
Representation of 3N interactions in momentum space
|pqα⇥i |piqi; [(LS)J(lsi)j] J Jz(Tti)T Tz⇥
p
q
p
q
p
q
|pqα1 |pqα2 |pqα3
1 2 3 2 2 1 1 3 3
Due to the large number of matrix elements, the traditional way of computing matrix elements requires extreme amounts of computer resources.
Np ' Nq ' 15
Nα ' 30 180
dim[hpqα|V123|p0q0α0i] ' 107 1010
Number of matrix elements was so far not sufficient for studies of systems.
A ≥ 4
First Quantum Monte Carlo based on local chiral EFT interactions
0.05 0.1 0.15
n [fm-3]
5 10 15
E/N [MeV]
QMC (2010) AFDMC N2LO 0.8 fm (2nd order) 0.8 fm (3rd order) 1.2 fm (2nd order) 1.2 fm (3rd order)
perfect agreement for soft interactions, first direct validation
- f perturbative calculations
Gezerlis, Tews, Epelbaum, Gandolfi, KH, Nogga, Schwenk PRL 111, 032501 (2013)
0.05 0.1 0.15
n [fm-3]
- 4
- 2
2 4
E/N [MeV] Two-pion-exchange 3N
0.05 0.1 0.15
n [fm-3] Two-pion−one-pion-exchange 3N
0.05 0.1 0.15
n [fm-3] Pion-ring 3N
0.05 0.1 0.15 0.2
n [fm-3]
- 4
- 2
2 4 EM 500 MeV EGM 450/700 MeV EGM 450/500 MeV
Two-pion-exchange−contact 3N
Contributions of many-body forces at N3LO in neutron matter
Tews, Krüger, KH, Schwenk PRL 110, 032504 (2013)
NN 3N 4N
- first calculations of N3LO 3NF and 4NF
contributions to EOS of neutron matter
- found large contributions in Hartree Fock appr.,
comparable to size of N2LO contributions
0.05 0.1 0.15
n [fm-3]
- 4
- 2
2 4
E/N [MeV] Two-pion-exchange 3N
0.05 0.1 0.15
n [fm-3] Two-pion−one-pion-exchange 3N
0.05 0.1 0.15
n [fm-3] Pion-ring 3N
0.05 0.1 0.15 0.2
n [fm-3]
- 4
- 2
2 4 EM 500 MeV EGM 450/700 MeV EGM 450/500 MeV
Two-pion-exchange−contact 3N
Tews, Krüger, KH, Schwenk PRL 110, 032504 (2013)
NN 3N 4N
- first calculations of N3LO 3NF and 4NF
contributions to EOS of neutron matter
- found large contributions in Hartree Fock appr.,
comparable to size of N2LO contributions
- 4NF contributions small
0.05 0.1 0.15
n [fm-3]
- 0.4
- 0.3
- 0.2
- 0.1
0.1 0.2 0.3 0.4
E/N [MeV] Three-pion-exchange 4N V
a
0.05 0.1 0.15
n [fm-3] Three-pion-exchange 4N V
e
0.05 0.1 0.15
n [fm-3] Pion-pion-interaction 4N V
f
0.05 0.1 0.15 0.2
n [fm-3]
- 0.4
- 0.3
- 0.2
- 0.1
0.1 0.2 0.3 0.4 EGM 450/500 MeV EGM 450/700 MeV EM 500 MeV
pRelativistic-corrections 3Np
Contributions of many-body forces at N3LO in neutron matter
N3LO contributions in nuclear matter (Hartree Fock)
0.05 0.1 0.15
n [fm-3]
- 10
- 8
- 6
- 4
- 2
2 4
E/N [MeV] Two-pion-exchange 3N
0.05 0.1 0.15
n [fm-3] Two-pion-
- one-pion-exchange 3N
0.05 0.1 0.15
n [fm-3] Pion-ring 3N
0.05 0.1 0.15
n [fm-3]
- 10
- 8
- 6
- 4
- 2
2 4 EM 500 MeV1 1 EGM 450/700 MeV EGM 450/500 MeV1 1
Two-pion-exchange-
- contact 3N
0.05 0.1 0.15
n [fm-3]
- 0.6
- 0.4
- 0.2
0.2 0.4
E/N [MeV]
EGM 450/500 MeV1 1 EM 500 MeV EGM 450/700 MeV1 1
Relativistic-corrections 3N
0.05 0.1 0.15
n [fm-3] Three-pion-exchange 4N Va
0.05 0.1 0.15
n [fm-3] Three-pion-exchange 4N Vc
0.05 0.1 0.15 0.2
n [fm-3]
- 0.6
- 0.4
- 0.2
0.2 0.4
Three-pion-exchange 4N Ve
0.05 0.1 0.15
n [fm-3]
- 0.2
- 0.1
0.1 0.2 0.3 0.4 0.5
E/N [MeV] Pion-pion-interaction 4N Vf
0.05 0.1 0.15
n [fm-3]
EM 500 MeV11 EGM 450/700 MeV EGM 450/500 MeV1 1
Two-pion-exchange-contact 4N Vk
0.05 0.1 0.15
n [fm-3]
EGM 500 MeV11 EGM 450/700 MeV EGM 450/500 MeV1 1
Two-pion-exchange-
- contact 4N Vl
0.05 0.1 0.15 0.2
n [fm-3]
- 0.2
- 0.1
0.1 0.2 0.3 0.4 0.5 EM 500 MeV11 EGM 450/700 MeV EGM 450/500 MeV1 1
Pion-exchange-
- two-contact 4N Vn
Krüger, Tews, KH, Schwenk PRC88, 025802 (2013)
N3LO contributions in nuclear matter (Hartree Fock)
0.05 0.1 0.15
n [fm-3]
- 10
- 8
- 6
- 4
- 2
2 4
E/N [MeV] Two-pion-exchange 3N
0.05 0.1 0.15
n [fm-3] Two-pion-
- one-pion-exchange 3N
0.05 0.1 0.15
n [fm-3] Pion-ring 3N
0.05 0.1 0.15
n [fm-3]
- 10
- 8
- 6
- 4
- 2
2 4 EM 500 MeV1 1 EGM 450/700 MeV EGM 450/500 MeV1 1
Two-pion-exchange-
- contact 3N
0.05 0.1 0.15
n [fm-3]
- 0.6
- 0.4
- 0.2
0.2 0.4
E/N [MeV]
EGM 450/500 MeV1 1 EM 500 MeV EGM 450/700 MeV1 1
Relativistic-corrections 3N
0.05 0.1 0.15
n [fm-3] Three-pion-exchange 4N Va
0.05 0.1 0.15
n [fm-3] Three-pion-exchange 4N Vc
0.05 0.1 0.15 0.2
n [fm-3]
- 0.6
- 0.4
- 0.2
0.2 0.4
Three-pion-exchange 4N Ve
0.05 0.1 0.15
n [fm-3]
- 0.2
- 0.1
0.1 0.2 0.3 0.4 0.5
E/N [MeV] Pion-pion-interaction 4N Vf
0.05 0.1 0.15
n [fm-3]
EM 500 MeV11 EGM 450/700 MeV EGM 450/500 MeV1 1
Two-pion-exchange-contact 4N Vk
0.05 0.1 0.15
n [fm-3]
EGM 500 MeV11 EGM 450/700 MeV EGM 450/500 MeV1 1
Two-pion-exchange-
- contact 4N Vl
0.05 0.1 0.15 0.2
n [fm-3]
- 0.2
- 0.1
0.1 0.2 0.3 0.4 0.5 EM 500 MeV11 EGM 450/700 MeV EGM 450/500 MeV1 1
Pion-exchange-
- two-contact 4N Vn
Krüger, Tews, KH, Schwenk PRC88, 025802 (2013)
Conclusions/Indications:
- N3LO 3N contributions significant
- N3LO 4N contributions small