Radiative capture study by combining EFT with ab initio ...

Radiative capture study by combining EFT with ab initio calculations:

Xilin Zhang (Ohio University)

( ) ( ) Bγp,Beand Liγn,Li 8787

Nuclear Theory Group Seminar, LANL, Jan 15, 2014

X. Z, K. M. Nollett and D. R. Phillips, arXiv:1311.6822; 1401.xxxx

Outline

• Motivations • A toy model: spinless nucleon and core • Li7 capture: spins, core excitation, leading order

(LO) results • Be7 capture: nonperturbative Coulomb, LO

results • Outlook: Next-to-LO • My other works: neutrino-nucleus, jet quenching

in heavy ion collision, cold nuclear matter

Motivations

Astrophysics

W. C. Haxton et.al., arXiv:1208.5723

Solar neutrino generation

Not experimentally accessible

Li7 capture is used to constrain models of Be7 capture.

A toy model

n

c

cn −

γ

Gross features: p-wave

1/17/2014 7

Shallow p-wave bound state 5.0~

MeV 8.572~MeV 100~2~

871

743

Λ

=Λ

γγ Li

Li

BMBM

Gross features: s-wave

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MeV 100≈Λ

Large s-wave scattering length

L. Koester, K. Knopf, and W. Waschkowski, Z. Phys. A 312, 81 (1983)

S-wave in EFT

Effective range expansion (ERE):

Natural

ΛΛ1~ and 1~ 00 ra

S-wave in EFT

Effective range expansion (ERE):

Natural

Unnatural

Λ1~but 1~ 00 ra

γ

ΛΛ1~ and 1~ 00 ra

S-wave in EFT

+= ...+

One parameter: g (or a0)

P-wave in EFT

Shallow p-wave bound state:

ΛΛ

~ and 1~ 121 raγ

Natural Unnatural

0211 42

11

=++ γγra

P-wave in EFT

P-wave in EFT

= +

P-wave in EFT

= +

Two parameters: Delta and h (or a1 and r1)

P-wave in EFT

Asymptotic normalization coefficient (ANC)

P-wave in EFT

0211

32

321

1

1

22

=++

+−

=

γγ

γγ

ra

rC

) and (or and 11 ∆hra

K. M. Nollett et.al., PRC 83, 041001 (2011)

Asymptotic normalization coefficient (ANC)

Radiative capture: LO

Halo-EFT parameters

S wave scattering length

Radiative capture: LO

Halo-EFT parameters

S wave scattering length

C ~ 1~ ,1~ 1~

Λ⇒

Λ⇒

γγ

XaXa

( ) Liγn,Li 87

G. Rupak and R. Higa, Phys. Rev. Lett. 106, 222501 (2011)

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Scales, spins, core excitations

*E

1/17/2014 23


*E

,: nLi7 IS , , :n Li7 IS

1*3

0*1*

25

13

SSDSS

++

1/17/2014 24


*E

2*3*

25

23

:n Li7 )FS(2 , :n Li7 )FS(2

PPP

++

+

+


1*3

0*1*

25

13

SSDSS

++

1/17/2014 25


*E

1*3

1*1*

15

13

, :n Li7 )FS(1 , :n Li7 )FS(1

PPPP

++

+

+

2*3*

25

23

:n Li7 )FS(2 , :n Li7 )FS(2

PPP

++

+

+


1*3

0*1*

25

13

SSDSS

++


1/17/2014 26

MeV 300100−≈Λ

L. Koester, K. Knopf, and W. Waschkowski, Z. Phys. A 312, 81 (1983)

EFT

>>2=iS 1=iS 1=iS

One fine tuning in S wave

++ 1 ,2++ 1 ,2

= + +++ 1 ,2

EFT

>>

~

2=iS 1=iS 1=iS

One fine tuning in S wave

One fine tuning in P wave

P-wave = + +

+2

L. Trache,et.al., Phys. Rev. C 67, 062801(R) (2003)

P-wave = + +

+2


4 parameters: 3 h + 1 Delta, or 3 C + gamma

P-wave = + +

+2



5 parameters

Radiative captures: LO


>>


>>

~ 1~ ,1~ 1~Λ

⇒Λ

⇒γ

γXaXa

Initial total spin Si=2

LO results on Li7(n,gamma)Li8(Li8*)

1/17/2014 40

N. K. Timofeyuk et.al., PRL 91, 232501 (2003); D. Howell et.al., PRC 88, 025804 (2013); D. Gul’ko et.al., SJNP 6, 477 (1968); E. Lynn et.al., PRC 44, 764 (1991); Y. Nagai et. al., PRC 71, 055803 (2005); J. C. Blackmon et. al., PRC 54, 383 (1996); J. E. Lynn et. al., PRC 44, 764 (1991); M. Heil et.al., Astro. J. 507, 997 (1998); W. L. Imhof et.al., PR 114, 1037 (1959).

1/17/2014 41

0.86][>

A. D. Gul’ko, S. S. Trostin, and A. Hudoklin, Sov. J. Nucl. Phys. 6, 477 (1968); J. E. Lynn, E. T. Jurney, and S. Raman, Phys. Rev. C 44, 764 (1991); Y. Nagai et. al., Phys. Rev. C 71, 055803 (2005).


1/17/2014 42

0.86][>



1/17/2014 43

0.86][>

0.89(1)][



( ) Bγp,Be 87

• It is considered as isospin mirror of Li7 capture on the nucleon level • From EFT/core+proton picture, they are quite different due to strong Coulomb effect

Nonperturbative Coulomb effect

1~kkC≡η

Nonperturbative Coulomb effect

1~kkC≡η

Kummer function

Coulomb barrier, and phase

ERE in EFT

ERE in EFT

One parameter: g (or a0)

Two parameters: Delta and h (or a1 and r1)

1/17/2014 51

2.0

*E Shallow bound state

1~kkC=η


1/17/2014 52

*E

2*3*

25

23

: pBe7 )FS(2 , : pBe7 )FS(2

PPP

++

+

+

,: pBe7 IS , , : pBe7 IS

1*3

0*1*

25

13

SSDSS

++

Repeat

= + +

P-wave



hWnGjF

→→→


×

1/17/2014 60

LO results on Be7(p,gamma)B8

P. Navratil, R. Roth and S. Quaglioni, Phys. Lett. B 704, 379 (2011); C. Angulo et. al., Nucl. Phys. A 716, 211 (2003); G. Tabacaru, et. al., Phys. Rev. C 73, 025808 (2006)

1/17/2014 61


One standard deviation in S-wave scattering lengths

P. Navratil, R. Roth and S. Quaglioni, Phys. Lett. B 704, 379 (2011)

1/17/2014 62


One standard deviation in S-wave scattering lengths

Need better measurement of S-wave scattering lengths and/or effective ranges to extrapolate data to zero energy

P. Navratil, R. Roth and S. Quaglioni, Phys. Lett. B 704, 379 (2011)


L. T. Baby, et. al., [ISOLDE Collaboration], Phys. Rev.Lett. 90, 022501 (2003); F. Hammache, et. al., Phys. Rev. Lett. 86, 3985 (2001); F. Strieder, et. al., Nucl. Phys. A 696, 219 (2001); B. W. Filippone, et. al., Phys. Rev. C 28, 2222 (1983); A. R. Junghans, et. al., Phys. Rev. C 68, 065803 (2003); A. R. Junghans, et. al., Phys. Rev. C 81, 012801 (2010).

Fit to 0<E<50 keV

E. G. Adelberger, et al., Rev. Mod. Phys. 83, 195 (2011)

Summary

• EFT (power counting)+ab initio works as expected at LO

• LO need s-wave scattering length, p-wave ANCs, and binding momentum

• The p-wave is a coupled-channel problem

• For Be7 capture, improving s-wave measurement is important for extrapolating data to stellar energies.

Outlook: NLO

Outlook: NLO

• Need to fix higher order couplings, i.e., need more “observables”. • Extract from ab initio calculations? • Change the boundary conditions? • Change the background fields?

Outlook: NLO

• Need to fix higher order couplings, i.e., need more “observables”. • Extract from ab initio calculations? • Change the boundary conditions? • Change the background fields? • Another approach by using data?

Other works

• Neutrino-nucleus interactions (GeV): neutral-current induced photon (motivated by MiniBooNE low energy excess), pion productions, nuclear effects [with Brian Serot]

• Jet quenching in heavy ion collisions: initial state fluctuation, different phenomenological jet energy loss models, possible near-Tc enhancement [with Jinfeng Liao]

• Two-loop contributions: nuclear matter, neutron matter, finite temperature [With Madappa Prakash]

https://sites.google.com/site/xilinzhangphysics/

MiniBooNE

69

New hadronic interactions?

γ

ρω,

Z

70

J.A. Harvey, C.T. Hill, R.J. Hill, Phys. Rev. Lett. 99, 261601 (2007), Phys. Rev. D 77, 085017(2008). R.J. Hill, Phys. Rev. D 81, 013008 (2010), 84 017501(2011).

NOMAD exp.

73

NC photon production off the nucleon

74

75

γρω,

Z

M1~ state teintermedia N

These terms are small

R. J. Hill, Phys. Rev. D 81, 013008 (2010) W. Peters l, H. Lenske, U. Mosel, Nucl. Phy. A640,89 (1998)

8.05.1

1

1

==

ec

γρω,

π

MiniBooNE NC photon events

76

Xection needs to be doubled at least.

77

•Incoherent one is small at Enu~ 1 GeV •Coherent one is zero

backup

• Capture cross section

• 20 keV ~ fb

• 1MeV ~mb

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