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Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook Precision Calculation of Electromagnetic Observables for Light Nuclei Laura Mertes, Thomas H¨ uther, Robert Roth 1 / 18
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Page 1: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Precision Calculation of ElectromagneticObservables for Light Nuclei

Laura Mertes, Thomas Huther, Robert Roth

1 / 18

Page 2: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Outline

1 Motivation

2 Ab initio calculationsSimilarity Renormalization Group (SRG)No-Core Shell Model (NCSM)

3 Electromagnetic Observables

4 ResultsElectromagnetic Observables of DeuteronM1 Observables of 6LiE2 Observables of 12CM1 Observables of Light Nuclei

5 Summary and Outlook

1 / 18

Page 3: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Motivation

precision calculation of electromagnetic observables

→ provide information about structure of nuclei

→ accessible in experiments

→ examples: electromagnetic moments, transition strengths

ab initio calculations from first principles

→ consistent treatment of electromagnetic observables

→ neglected contributions

2 / 18

Page 4: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Motivation

precision calculation of electromagnetic observables

→ provide information about structure of nuclei

→ accessible in experiments

→ examples: electromagnetic moments, transition strengths

ab initio calculations from first principles

→ consistent treatment of electromagnetic observables

→ neglected contributions

2 / 18

Page 5: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Motivation

precision calculation of electromagnetic observables

→ provide information about structure of nuclei

→ accessible in experiments

→ examples: electromagnetic moments, transition strengths

ab initio calculations from first principles

→ consistent treatment of electromagnetic observables

→ neglected contributions

2 / 18

Page 6: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Motivation

precision calculation of electromagnetic observables

→ provide information about structure of nuclei

→ accessible in experiments

→ examples: electromagnetic moments, transition strengths

ab initio calculations from first principles

→ consistent treatment of electromagnetic observables

→ neglected contributions

2 / 18

Page 7: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Ab initio nuclear-structure calculations

Chiral Effective Field Theory (χEFT)

→ construct consistent interaction and electromagneticoperator

Similarity Renormalization Group (SRG)

→ accelerate convergence

Importance-Truncated No-Core Shell Model (IT-NCSM)

→ solve many-body Schrodinger equation

3 / 18

Page 8: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Ab initio nuclear-structure calculations

Chiral Effective Field Theory (χEFT)

→ construct consistent interaction and electromagneticoperator

Similarity Renormalization Group (SRG)

→ accelerate convergence

Importance-Truncated No-Core Shell Model (IT-NCSM)

→ solve many-body Schrodinger equation

3 / 18

Page 9: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Ab initio nuclear-structure calculations

Chiral Effective Field Theory (χEFT)

→ construct consistent interaction and electromagneticoperator

Similarity Renormalization Group (SRG)

→ accelerate convergence

Importance-Truncated No-Core Shell Model (IT-NCSM)

→ solve many-body Schrodinger equation

3 / 18

Page 10: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Similarity Renormalization Group (SRG)

Similarity Renormalization Group (SRG)

initial Hamiltonian induces short-range correlations

idea: prediagonalization of H

→ decoupling of high- and low-energy physics

→ accelerate convergence

Continuous unitary transformation and flow equation

Hα = U†αH0Uα ⇒ d

dαHα = [ηα,Hα]

with initial conditions Hα=0 = H

Uα=0 = 1

antihermitian generator ηα = m2N [Trel,Hα]

4 / 18

Page 11: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Similarity Renormalization Group (SRG)

Similarity Renormalization Group (SRG)

initial Hamiltonian induces short-range correlations

idea: prediagonalization of H

→ decoupling of high- and low-energy physics

→ accelerate convergence

Continuous unitary transformation and flow equation

Hα = U†αH0Uα ⇒ d

dαHα = [ηα,Hα]

with initial conditions Hα=0 = H

Uα=0 = 1

antihermitian generator ηα = m2N [Trel,Hα]

4 / 18

Page 12: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Similarity Renormalization Group (SRG)

Similarity Renormalization Group (SRG)

initial Hamiltonian induces short-range correlations

idea: prediagonalization of H

→ decoupling of high- and low-energy physics

→ accelerate convergence

Continuous unitary transformation and flow equation

Hα = U†αH0Uα ⇒ d

dαHα = [ηα,Hα]

with initial conditions Hα=0 = H

Uα=0 = 1

antihermitian generator ηα = m2N [Trel,Hα]

4 / 18

Page 13: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Similarity Renormalization Group (SRG)

Similarity Renormalization Group (SRG)

initial Hamiltonian induces short-range correlations

idea: prediagonalization of H

→ decoupling of high- and low-energy physics

→ accelerate convergence

Continuous unitary transformation and flow equation

Hα = U†αH0Uα ⇒ d

dαHα = [ηα,Hα]

with initial conditions Hα=0 = H

Uα=0 = 1

antihermitian generator ηα = m2N [Trel,Hα]

4 / 18

Page 14: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Similarity Renormalization Group (SRG)

Similarity Renormalization Group (SRG)

initial Hamiltonian induces short-range correlations

idea: prediagonalization of H

→ decoupling of high- and low-energy physics

→ accelerate convergence

Continuous unitary transformation and flow equation

Hα = U†αH0Uα ⇒ d

dαHα = [ηα,Hα]

with initial conditions Hα=0 = H

Uα=0 = 1

antihermitian generator ηα = m2N [Trel,Hα]

4 / 18

Page 15: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Similarity Renormalization Group (SRG)

SRG for arbitrary operators

evolved eigenstates of Hamiltonian |ψα〉 = U†α |ψ〉

expectation value of operator with eigenstates |ψ〉

Differential equation

d

dαUα = −Uαηα

so far: bare operator with evolved eigenstates

5 / 18

Page 16: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Similarity Renormalization Group (SRG)

SRG for arbitrary operators

evolved eigenstates of Hamiltonian |ψα〉 = U†α |ψ〉

expectation value of operator with eigenstates |ψ〉

Differential equation

d

dαUα = −Uαηα

so far: bare operator with evolved eigenstates

5 / 18

Page 17: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Similarity Renormalization Group (SRG)

SRG for arbitrary operators

evolved eigenstates of Hamiltonian |ψα〉 = U†α |ψ〉

expectation value of operator with eigenstates |ψ〉

〈ψ|O |ψ〉= 〈ψ|UαU†αOUαU†α |ψ〉

Differential equation

d

dαUα = −Uαηα

so far: bare operator with evolved eigenstates

5 / 18

Page 18: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Similarity Renormalization Group (SRG)

SRG for arbitrary operators

evolved eigenstates of Hamiltonian |ψα〉 = U†α |ψ〉

expectation value of operator with eigenstates |ψ〉

〈ψ|O |ψ〉 = 〈ψ|UαU†αOUαU†α |ψ〉

Differential equation

d

dαUα = −Uαηα

so far: bare operator with evolved eigenstates

5 / 18

Page 19: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Similarity Renormalization Group (SRG)

SRG for arbitrary operators

evolved eigenstates of Hamiltonian |ψα〉 = U†α |ψ〉

expectation value of operator with eigenstates |ψ〉

〈ψ|O |ψ〉 = 〈ψ|Uα︸ ︷︷ ︸〈ψα|

U†αOUα U†α |ψ〉︸ ︷︷ ︸|ψα〉

Differential equation

d

dαUα = −Uαηα

so far: bare operator with evolved eigenstates

5 / 18

Page 20: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Similarity Renormalization Group (SRG)

SRG for arbitrary operators

evolved eigenstates of Hamiltonian |ψα〉 = U†α |ψ〉

expectation value of operator with eigenstates |ψ〉

〈ψ|O |ψ〉 = 〈ψ|Uα︸ ︷︷ ︸〈ψα|

U†αOUα︸ ︷︷ ︸|O(α)

α 〉

U†α |ψ〉︸ ︷︷ ︸|ψα〉

Differential equation

d

dαUα = −Uαηα

so far: bare operator with evolved eigenstates

5 / 18

Page 21: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Similarity Renormalization Group (SRG)

SRG for arbitrary operators

evolved eigenstates of Hamiltonian |ψα〉 = U†α |ψ〉

expectation value of operator with eigenstates |ψ〉

〈ψ|O |ψ〉 = 〈ψ|Uα︸ ︷︷ ︸〈ψα|

U†αOUα︸ ︷︷ ︸|O(α)

α 〉

U†α |ψ〉︸ ︷︷ ︸|ψα〉

Differential equation

d

dαUα = −Uαηα

so far: bare operator with evolved eigenstates

5 / 18

Page 22: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Similarity Renormalization Group (SRG)

SRG for arbitrary operators

evolved eigenstates of Hamiltonian |ψα〉 = U†α |ψ〉

expectation value of operator with eigenstates |ψ〉

〈ψ|O |ψ〉 = 〈ψ|Uα︸ ︷︷ ︸〈ψα|

U†αOUα︸ ︷︷ ︸|O(α)

α 〉

U†α |ψ〉︸ ︷︷ ︸|ψα〉

Differential equation

d

dαUα = −Uαηα

so far: bare operator with evolved eigenstates

5 / 18

Page 23: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

No-Core Shell Model (NCSM)

No-Core Shell Model (NCSM)

solve time-independent many-body Schrodinger equation

H |ψ〉 = Em |ψ〉

model space is spanned by Slaterdeterminants of single-particle HOstates |Φν〉

truncation via unperturbedexcitation energy Nmax~Ω

convergence with increasing Nmax

as result obtain energies and

eigenstates |ψ(m)〉 =∑

ν C(m)ν |Φν〉

limited by model space size

[S. Schulz, modified]

6 / 18

Page 24: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

No-Core Shell Model (NCSM)

No-Core Shell Model (NCSM)

solve time-independent many-body Schrodinger equation

H |ψ〉 = Em |ψ〉

model space is spanned by Slaterdeterminants of single-particle HOstates |Φν〉

truncation via unperturbedexcitation energy Nmax~Ω

convergence with increasing Nmax

as result obtain energies and

eigenstates |ψ(m)〉 =∑

ν C(m)ν |Φν〉

limited by model space size

[S. Schulz, modified]

6 / 18

Page 25: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

No-Core Shell Model (NCSM)

No-Core Shell Model (NCSM)

solve time-independent many-body Schrodinger equation

H |ψ〉 = Em |ψ〉

model space is spanned by Slaterdeterminants of single-particle HOstates |Φν〉

truncation via unperturbedexcitation energy Nmax~Ω

convergence with increasing Nmax

as result obtain energies and

eigenstates |ψ(m)〉 =∑

ν C(m)ν |Φν〉

limited by model space size

[S. Schulz, modified]

6 / 18

Page 26: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

No-Core Shell Model (NCSM)

No-Core Shell Model (NCSM)

solve time-independent many-body Schrodinger equation

H |ψ〉 = Em |ψ〉

model space is spanned by Slaterdeterminants of single-particle HOstates |Φν〉

truncation via unperturbedexcitation energy Nmax~Ω

convergence with increasing Nmax

as result obtain energies and

eigenstates |ψ(m)〉 =∑

ν C(m)ν |Φν〉

limited by model space size

[S. Schulz, modified]

6 / 18

Page 27: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

No-Core Shell Model (NCSM)

No-Core Shell Model (NCSM)

solve time-independent many-body Schrodinger equation

H |ψ〉 = Em |ψ〉

model space is spanned by Slaterdeterminants of single-particle HOstates |Φν〉

truncation via unperturbedexcitation energy Nmax~Ω

convergence with increasing Nmax

as result obtain energies and

eigenstates |ψ(m)〉 =∑

ν C(m)ν |Φν〉

limited by model space size

[S. Schulz, modified]

6 / 18

Page 28: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

No-Core Shell Model (NCSM)

No-Core Shell Model (NCSM)

solve time-independent many-body Schrodinger equation

H |ψ〉 = Em |ψ〉

model space is spanned by Slaterdeterminants of single-particle HOstates |Φν〉

truncation via unperturbedexcitation energy Nmax~Ω

convergence with increasing Nmax

as result obtain energies and

eigenstates |ψ(m)〉 =∑

ν C(m)ν |Φν〉

limited by model space size

[S. Schulz, modified]

6 / 18

Page 29: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

No-Core Shell Model (NCSM)

Importance Truncated No-Core Shell Model (IT-NCSM)

starting point: approximation of target state

|ψ(m)ref 〉 =

∑νεMref

C(m)ref,ν |Φν〉

importance measure from 1st order perturbation theory

κ(m)ν = − 〈Φν |H|ψ(m)

ref 〉εν−εref

IT-model space is spanned by basis states |Φν〉 with|κν | ≥ κmin

κmin is importance threshold

solve EV problem in new model space

7 / 18

Page 30: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

No-Core Shell Model (NCSM)

Importance Truncated No-Core Shell Model (IT-NCSM)

starting point: approximation of target state

|ψ(m)ref 〉 =

∑νεMref

C(m)ref,ν |Φν〉

importance measure from 1st order perturbation theory

κ(m)ν = − 〈Φν |H|ψ(m)

ref 〉εν−εref

IT-model space is spanned by basis states |Φν〉 with|κν | ≥ κmin

κmin is importance threshold

solve EV problem in new model space

7 / 18

Page 31: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

No-Core Shell Model (NCSM)

Importance Truncated No-Core Shell Model (IT-NCSM)

starting point: approximation of target state

|ψ(m)ref 〉 =

∑νεMref

C(m)ref,ν |Φν〉

importance measure from 1st order perturbation theory

κ(m)ν = − 〈Φν |H|ψ(m)

ref 〉εν−εref

IT-model space is spanned by basis states |Φν〉 with|κν | ≥ κmin

κmin is importance threshold

solve EV problem in new model space

7 / 18

Page 32: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

No-Core Shell Model (NCSM)

Importance Truncated No-Core Shell Model (IT-NCSM)

starting point: approximation of target state

|ψ(m)ref 〉 =

∑νεMref

C(m)ref,ν |Φν〉

importance measure from 1st order perturbation theory

κ(m)ν = − 〈Φν |H|ψ(m)

ref 〉εν−εref

IT-model space is spanned by basis states |Φν〉 with|κν | ≥ κmin

κmin is importance threshold

solve EV problem in new model space

7 / 18

Page 33: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

No-Core Shell Model (NCSM)

Importance Truncated No-Core Shell Model (IT-NCSM)

starting point: approximation of target state

|ψ(m)ref 〉 =

∑νεMref

C(m)ref,ν |Φν〉

importance measure from 1st order perturbation theory

κ(m)ν = − 〈Φν |H|ψ(m)

ref 〉εν−εref

IT-model space is spanned by basis states |Φν〉 with|κν | ≥ κmin

κmin is importance threshold

solve EV problem in new model space

7 / 18

Page 34: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Magnetic Dipole Moment

interaction between external field and nucleus

caused by orbital motion of protons and spins of nucleons

Magnetic dipole operator

M10 =

√3

4πµN

A∑i=1

[gpsz(i) + lz(i)Πp(i) + gnsz(i)Πn(i)]

magnetic moments are defined as expectation values of M10

Magnetic dipole moment

µ =

√4π

3〈J,MJ = J|M10|J,MJ = J〉

8 / 18

Page 35: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Magnetic Dipole Moment

interaction between external field and nucleus

caused by orbital motion of protons and spins of nucleons

Magnetic dipole operator

M10 =

√3

4πµN

A∑i=1

[gpsz(i) + lz(i)Πp(i) + gnsz(i)Πn(i)]

magnetic moments are defined as expectation values of M10

Magnetic dipole moment

µ =

√4π

3〈J,MJ = J|M10|J,MJ = J〉

8 / 18

Page 36: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Magnetic Dipole Moment

interaction between external field and nucleus

caused by orbital motion of protons and spins of nucleons

Magnetic dipole operator

M10 =

√3

4πµN

A∑i=1

[gpsz(i) + lz(i)Πp(i) + gnsz(i)Πn(i)]

magnetic moments are defined as expectation values of M10

Magnetic dipole moment

µ =

√4π

3〈J,MJ = J|M10|J,MJ = J〉

8 / 18

Page 37: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Magnetic Dipole Moment

interaction between external field and nucleus

caused by orbital motion of protons and spins of nucleons

Magnetic dipole operator

M10 =

√3

4πµN

A∑i=1

[gpsz(i) + lz(i)Πp(i) + gnsz(i)Πn(i)]

magnetic moments are defined as expectation values of M10

Magnetic dipole moment

µ =

√4π

3〈J,MJ = J|M10|J,MJ = J〉

8 / 18

Page 38: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Electromagnetic Observables of Deuteron

Electromagnetic Observables of Deuteron

Magnetic dipole moment

0 0.02 0.04 0.06 0.08 0.10.82

0.84

0.86

0.88

0.9

2H

SRG evolved M1 operator

bare M1 operator

α[fm4]

µgs(M1)[µ

N]

Electric quadrupole moment

0 0.02 0.04 0.06 0.08 0.10.26

0.27

0.28

0.29

2H

SRG evolved E2 operator

bare E2 operator

α[fm4]

Qgs(E2)[efm

2]

expectation value of bare operators is α dependent

consistent SRG changes moments by a few percent

9 / 18

Page 39: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Electromagnetic Observables of Deuteron

Electromagnetic Observables of Deuteron

Magnetic dipole moment

0 0.02 0.04 0.06 0.08 0.10.82

0.84

0.86

0.88

0.9

2H

SRG evolved M1 operator

bare M1 operator

α[fm4]

µgs(M1)[µ

N]

Electric quadrupole moment

0 0.02 0.04 0.06 0.08 0.10.26

0.27

0.28

0.29

2H

SRG evolved E2 operator

bare E2 operator

α[fm4]

Qgs(E2)[efm

2]

expectation value of bare operators is α dependent

consistent SRG changes moments by a few percent

9 / 18

Page 40: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

M1 Observables of 6Li

M1 Observables of 6Li

bare M1 operators

experiment

6Li

μ(1+) [μN]

B(M

1,0+->

1+)[μ

N2]

0.81 0.82 0.83 0.84 0.85 0.8614.5

15

15.5

16

16.5

SRG evolved M1 operators

experiment

6Li

μ(1+) [μN]

B(M

1,0+->

1+)[μ

N2]

0.81 0.82 0.83 0.84 0.85 0.8614.5

15

15.5

16

16.5

IT-NCSMhω 16 MeVα 0.08fm4

(open) NN+3Nind

(filled) NN+3Nfull

EM+500EGM(450/500)(600/500)(550/600)(450/700)(600/700)

Nmax

2

4

6

8

10

12

contributions to µ by using consistent SRG transformation

small contributions to transition strength

10 / 18

Page 41: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

M1 Observables of 6Li

M1 Observables of 6Li

bare M1 operators

experiment

6Li

μ(1+) [μN]

B(M

1,0+->

1+)[μ

N2]

0.81 0.82 0.83 0.84 0.85 0.8614.5

15

15.5

16

16.5

SRG evolved M1 operators

experiment

6Li

μ(1+) [μN]

B(M

1,0+->

1+)[μ

N2]

0.81 0.82 0.83 0.84 0.85 0.8614.5

15

15.5

16

16.5

IT-NCSMhω 16 MeVα 0.08fm4

(open) NN+3Nind

(filled) NN+3Nfull

EM+500EGM(450/500)(600/500)(550/600)(450/700)(600/700)

Nmax

2

4

6

8

10

12

contributions to µ by using consistent SRG transformation

small contributions to transition strength

10 / 18

Page 42: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

M1 Observables of 6Li

M1 Observables of 6Li

bare M1 operators

experiment

6Li

μ(1+) [μN]

B(M

1,0+->

1+)[μ

N2]

0.81 0.82 0.83 0.84 0.85 0.8614.5

15

15.5

16

16.5

SRG evolved M1 operators

experiment

6Li

μ(1+) [μN]

B(M

1,0+->

1+)[μ

N2]

0.81 0.82 0.83 0.84 0.85 0.8614.5

15

15.5

16

16.5

IT-NCSMhω 16 MeVα 0.08fm4

(open) NN+3Nind

(filled) NN+3Nfull

EM+500EGM(450/500)(600/500)(550/600)(450/700)(600/700)

Nmax

2

4

6

8

10

12

contributions to µ by using consistent SRG transformation

small contributions to transition strength

10 / 18

Page 43: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

M1 Observables of 6Li

M1 Observables of 6Li

bare M1 operators

experiment

6Li

μ(1+) [μN]

B(M

1,0+->

1+)[μ

N2]

0.81 0.82 0.83 0.84 0.85 0.8614.5

15

15.5

16

16.5

SRG evolved M1 operators

experiment

6Li

μ(1+) [μN]

B(M

1,0+->

1+)[μ

N2]

0.81 0.82 0.83 0.84 0.85 0.8614.5

15

15.5

16

16.5

IT-NCSMhω 16 MeVα 0.08fm4

(open) NN+3Nind

(filled) NN+3Nfull

EM+500EGM(450/500)(600/500)(550/600)(450/700)(600/700)

Nmax

2

4

6

8

10

12

contribution of chiral currents: [S. Pastore et al., Phys.Rev.C87, 035503(2013)]

→ to magnetic-dipole moment: weak→ to transition strength: not negligible

11 / 18

Page 44: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

E2 Observables of 12C

E2 Observables of 12C

bare E2 operators

experiment

12C

Q(2+) [efm2]

B(E

2,2+->

0+)[e

2fm

4]

3 4 5 6 7 8 94

5

6

7

8

9

SRG evolved E2 operators

experiment

12C

Q(2+) [efm2]

B(E

2,2+->

0+)[e

2fm

4]

3 4 5 6 7 8 94

5

6

7

8

9

IT-NCSMhω 16 MeVα 0.08fm4

(open) NN+3Nind

(filled) NN+3Nfull

EM+500EGM(450/500)(600/500)(550/600)(450/700)(600/700)

Nmax

2

4

6

8

description of strong correlation by rotor model

contributions from consistent SRG are small

12 / 18

Page 45: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

E2 Observables of 12C

E2 Observables of 12C

bare E2 operators

experiment

12C

Q(2+) [efm2]

B(E

2,2+->

0+)[e

2fm

4]

3 4 5 6 7 8 94

5

6

7

8

9

SRG evolved E2 operators

experiment

12C

Q(2+) [efm2]

B(E

2,2+->

0+)[e

2fm

4]

3 4 5 6 7 8 94

5

6

7

8

9

IT-NCSMhω 16 MeVα 0.08fm4

(open) NN+3Nind

(filled) NN+3Nfull

EM+500EGM(450/500)(600/500)(550/600)(450/700)(600/700)

Nmax

2

4

6

8

description of strong correlation by rotor model

contributions from consistent SRG are small

12 / 18

Page 46: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

E2 Observables of 12C

E2 Observables of 12C

bare E2 operators

experiment

12C

Q(2+) [efm2]

B(E

2,2+->

0+)[e

2fm

4]

3 4 5 6 7 8 94

5

6

7

8

9

SRG evolved E2 operators

experiment

12C

Q(2+) [efm2]

B(E

2,2+->

0+)[e

2fm

4]

3 4 5 6 7 8 94

5

6

7

8

9

IT-NCSMhω 16 MeVα 0.08fm4

(open) NN+3Nind

(filled) NN+3Nfull

EM+500EGM(450/500)(600/500)(550/600)(450/700)(600/700)

Nmax

2

4

6

8

description of strong correlation by rotor model

contributions from consistent SRG are small

12 / 18

Page 47: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

E2 Observables of 12C

E2 Observables of 12C

bare E2 operators

experiment

12C

Q(2+) [efm2]

B(E

2,2+->

0+)[e

2fm

4]

3 4 5 6 7 8 94

5

6

7

8

9

SRG evolved E2 operators

experiment

12C

Q(2+) [efm2]

B(E

2,2+->

0+)[e

2fm

4]

3 4 5 6 7 8 94

5

6

7

8

9

IT-NCSMhω 16 MeVα 0.08fm4

(open) NN+3Nind

(filled) NN+3Nfull

EM+500EGM(450/500)(600/500)(550/600)(450/700)(600/700)

Nmax

2

4

6

8

description of strong correlation by rotor model

contributions from consistent SRG are small

12 / 18

Page 48: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

M1 Observables of Light Nuclei

Magnetic Dipole Moments of Light Nuclei

IT-NCSMNN+3Nfull

EM+500

~ω 16 MeV(open) 0.04 fm4

(filled) 0.08 fm4

bare

SRG evolved

experiment

contribution by performing a consistent SRG depends onnucleus

13 / 18

Page 49: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

M1 Observables of Light Nuclei

Magnetic Dipole Moments of Light Nuclei

IT-NCSMNN+3Nfull

EM+500

~ω 16 MeV(open) 0.04 fm4

(filled) 0.08 fm4

bare

SRG evolved

experiment

contribution by performing a consistent SRG depends onnucleus

13 / 18

Page 50: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

M1 Observables of Light Nuclei

Magnetic Dipole Moments of Light Nuclei

IT-NCSMNN+3Nfull

EM+500

~ω 16 MeV(open) 0.04 fm4

(filled) 0.08 fm4

bare

SRG evolved

experiment

contribution by performing a consistent SRG depends onnucleus

13 / 18

Page 51: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

M1 Observables of Light Nuclei

Magnetic Dipole Moments of Light Nuclei

IT-NCSMNN+3Nfull

EM+500

~ω 16 MeV(open) 0.04 fm4

(filled) 0.08 fm4

bare

SRG evolved

experiment

contribution by performing a consistent SRG depends onnucleus

14 / 18

Page 52: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

M1 Observables of Light Nuclei

M1 Transition Strengths of Light Nuclei

IT-NCSMNN+3Nfull

EM+500

~ω 16 MeV(open) 0.04 fm4

(filled) 0.08 fm4

bare

SRG evolved

experiment

small contributions through consistent SRG

15 / 18

Page 53: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

M1 Observables of Light Nuclei

M1 Transition Strengths of Light Nuclei

IT-NCSMNN+3Nfull

EM+500

~ω 16 MeV(open) 0.04 fm4

(filled) 0.08 fm4

bare

SRG evolved

experiment

small contributions through consistent SRG

15 / 18

Page 54: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

M1 Observables of Light Nuclei

M1 Transition Strengths of Light Nuclei

IT-NCSMNN+3Nfull

EM+500

~ω 16 MeV(open) 0.04 fm4

(filled) 0.08 fm4

bare

SRG evolved

experiment

small contributions through consistent SRG

15 / 18

Page 55: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

M1 Observables of Light Nuclei

M1 Transition Strengths of Light Nuclei

IT-NCSMNN+3Nfull

EM+500

~ω 16 MeV(open) 0.04 fm4

(filled) 0.08 fm4

bare

SRG evolved

experiment

underestimation of M1 transition strengths

16 / 18

Page 56: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Summary and Outlook

contribution of consistent SRG evolution depends on

→ nuclei

→ observable

for 6Li: consistent SRG evolution of M1-operator

→ adds contributions to magnetic moment

→ has small effect on transition strength

Outlook

next step to improve consistency → include two-body currentsfrom chiral EFT

Mlm ∝∫ (

~r × ~j (~r))~∇r lYlm(θ, φ) d3r

17 / 18

Page 57: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Summary and Outlook

contribution of consistent SRG evolution depends on

→ nuclei

→ observable

for 6Li: consistent SRG evolution of M1-operator

→ adds contributions to magnetic moment

→ has small effect on transition strength

Outlook

next step to improve consistency → include two-body currentsfrom chiral EFT

Mlm ∝∫ (

~r × ~j (~r))~∇r lYlm(θ, φ) d3r

17 / 18

Page 58: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Summary and Outlook

contribution of consistent SRG evolution depends on

→ nuclei

→ observable

for 6Li: consistent SRG evolution of M1-operator

→ adds contributions to magnetic moment

→ has small effect on transition strength

Outlook

next step to improve consistency → include two-body currentsfrom chiral EFT

Mlm ∝∫ (

~r × ~j (~r))~∇r lYlm(θ, φ) d3r

17 / 18

Page 59: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Summary and Outlook

contribution of consistent SRG evolution depends on

→ nuclei

→ observable

for 6Li: consistent SRG evolution of M1-operator

→ adds contributions to magnetic moment

→ has small effect on transition strength

Outlook

next step to improve consistency → include two-body currentsfrom chiral EFT

Mlm ∝∫ (

~r × ~j (~r))~∇r lYlm(θ, φ) d3r

17 / 18

Page 60: Precision Calculation of Electromagnetic Observables for ...chimera.roma1.infn.it/OMAR/ECTSTAR_DTP/seminars/... · Similarity Renormalization Group (SRG) initial Hamiltonian induces

Motivation Ab initio calculations Electromagnetic Observables Results Summary and Outlook

Epilog

Thanks to my group

S. Alexa, E. Gebrerufael, T. Huther, R. Roth,S. Schulz, H. Spielvogel, C. Stumpf, A. Tichai,K. Vobig, R. WirthInstitut fur Kernphysik, TU Darmstadt

Thank you for your attention!

Verwendete Schriften

Schriftzug oben:Frutiger light regularKerning 0 % Geviert

Schriftzug unten:DFG TTF regularKerning 1 % Geviert

JURECA LOEWE-CSC LICHTENBERG

COMPUTING TIME

18 / 18


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