Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
Proton Compton Scattering In Unified Proton- + Theory ZHANG Yun - - PowerPoint PPT Presentation
Proton Compton Scattering In Unified Proton- + Theory ZHANG Yun - - PowerPoint PPT Presentation
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary 2011 Cross Strait Meeting on Particle Physics and Cosmology Proton Compton Scattering In Unified Proton- + Theory ZHANG Yun (Collaboration
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
1
Background and Motivation
2
The Model
3
Proton Compton Scattering
4
Vertex Structure
5
Summary
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
∆+(1232MeV, JP = 3
2 +) freedom must be taken into
account in proton Compton scattering
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
∆+(1232MeV, JP = 3
2 +) freedom must be taken into
account in proton Compton scattering Previously p is treated as spin 1/2 Dirac spinor and ∆+ in a different theory
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
∆+(1232MeV, JP = 3
2 +) freedom must be taken into
account in proton Compton scattering Previously p is treated as spin 1/2 Dirac spinor and ∆+ in a different theory Our innovation: We treat p and ∆+ in a unified spin 3/2 field theory
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
∆+(1232MeV, JP = 3
2 +) freedom must be taken into
account in proton Compton scattering Previously p is treated as spin 1/2 Dirac spinor and ∆+ in a different theory Our innovation: We treat p and ∆+ in a unified spin 3/2 field theory How Motivated
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
∆+(1232MeV, JP = 3
2 +) freedom must be taken into
account in proton Compton scattering Previously p is treated as spin 1/2 Dirac spinor and ∆+ in a different theory Our innovation: We treat p and ∆+ in a unified spin 3/2 field theory How Motivated Proton and ∆+ are both comprised of the same quarks.
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
∆+(1232MeV, JP = 3
2 +) freedom must be taken into
account in proton Compton scattering Previously p is treated as spin 1/2 Dirac spinor and ∆+ in a different theory Our innovation: We treat p and ∆+ in a unified spin 3/2 field theory How Motivated Proton and ∆+ are both comprised of the same quarks. Three spin 1/2 particles results in 8 spin states, that for a spin 3/2 particle and two spin 1/2 particles.
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Generalized Rarita-Schwinger Theory
The Lagrangian Konstantin G. Savvidy, arXiv:1005.3455: L = ¯ ψµ[Dµν − mΘµν]ψν, Dµν = γρpρδµν + ξ(γµpν + γνpµ) + ζγµγρpργν, Θµν = δµν − zγνγν,ζ = 3ξ2+2ξ+1
2
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Generalized Rarita-Schwinger Theory
The Lagrangian Konstantin G. Savvidy, arXiv:1005.3455: L = ¯ ψµ[Dµν − mΘµν]ψν, Dµν = γρpρδµν + ξ(γµpν + γνpµ) + ζγµγρpργν, Θµν = δµν − zγνγν,ζ = 3ξ2+2ξ+1
2
L invariant under point transformation: ψµ → ψµ + λγµγνψν ξ′ = ξ(1 − 4λ) − 2λ
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Generalized Rarita-Schwinger Theory
The Lagrangian Konstantin G. Savvidy, arXiv:1005.3455: L = ¯ ψµ[Dµν − mΘµν]ψν, Dµν = γρpρδµν + ξ(γµpν + γνpµ) + ζγµγρpργν, Θµν = δµν − zγνγν,ζ = 3ξ2+2ξ+1
2
L invariant under point transformation: ψµ → ψµ + λγµγνψν ξ′ = ξ(1 − 4λ) − 2λ ξ = 2z − 1 = ⇒ pµψµ(p) = 0.
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Generalized Rarita-Schwinger Theory
The Lagrangian Konstantin G. Savvidy, arXiv:1005.3455: L = ¯ ψµ[Dµν − mΘµν]ψν, Dµν = γρpρδµν + ξ(γµpν + γνpµ) + ζγµγρpργν, Θµν = δµν − zγνγν,ζ = 3ξ2+2ξ+1
2
L invariant under point transformation: ψµ → ψµ + λγµγνψν ξ′ = ξ(1 − 4λ) − 2λ ξ = 2z − 1 = ⇒ pµψµ(p) = 0. mass spectrum: m3/2 = m,m1/2 =
m 6z−2.
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Generalized Rarita-Schwinger Theory
The Lagrangian Konstantin G. Savvidy, arXiv:1005.3455: L = ¯ ψµ[Dµν − mΘµν]ψν, Dµν = γρpρδµν + ξ(γµpν + γνpµ) + ζγµγρpργν, Θµν = δµν − zγνγν,ζ = 3ξ2+2ξ+1
2
L invariant under point transformation: ψµ → ψµ + λγµγνψν ξ′ = ξ(1 − 4λ) − 2λ ξ = 2z − 1 = ⇒ pµψµ(p) = 0. mass spectrum: m3/2 = m,m1/2 =
m 6z−2.
Original Rarita-Schwinger Theory: z = (1+3ξ)2+3(1+ξ)2
4
.
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Generalized Rarita-Schwinger Theory
The Lagrangian Konstantin G. Savvidy, arXiv:1005.3455: L = ¯ ψµ[Dµν − mΘµν]ψν, Dµν = γρpρδµν + ξ(γµpν + γνpµ) + ζγµγρpργν, Θµν = δµν − zγνγν,ζ = 3ξ2+2ξ+1
2
L invariant under point transformation: ψµ → ψµ + λγµγνψν ξ′ = ξ(1 − 4λ) − 2λ ξ = 2z − 1 = ⇒ pµψµ(p) = 0. mass spectrum: m3/2 = m,m1/2 =
m 6z−2.
Original Rarita-Schwinger Theory: z = (1+3ξ)2+3(1+ξ)2
4
. no spin 1/2 on shell component.
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Generalized Rarita-Schwinger Theory
The Lagrangian Konstantin G. Savvidy, arXiv:1005.3455: L = ¯ ψµ[Dµν − mΘµν]ψν, Dµν = γρpρδµν + ξ(γµpν + γνpµ) + ζγµγρpργν, Θµν = δµν − zγνγν,ζ = 3ξ2+2ξ+1
2
L invariant under point transformation: ψµ → ψµ + λγµγνψν ξ′ = ξ(1 − 4λ) − 2λ ξ = 2z − 1 = ⇒ pµψµ(p) = 0. mass spectrum: m3/2 = m,m1/2 =
m 6z−2.
Original Rarita-Schwinger Theory: z = (1+3ξ)2+3(1+ξ)2
4
. no spin 1/2 on shell component. superluminal propagation
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
L = ¯ ψµ[Dµν − mΘµν]ψν, Dµν = γρpρδµν + ξ(γµpν + γνpµ) + ζγµγρpργν, Θµν = δµν − zγνγν
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
L = ¯ ψµ[Dµν − mΘµν]ψν, Dµν = γρpρδµν + ξ(γµpν + γνpµ) + ζγµγρpργν, Θµν = δµν − zγνγν Spin 1/2 component wave function:
u2(0, + 1
2) = 1 3z−1(0, 0, 0, 0, 0, 1 2 √ 3, 0, − 1 2 √ 3, 0, i 2 √ 3, 0, − i 2 √ 3, 1 2 √ 3, 0, − 1 2 √ 3, 0)T
u2(0, − 1
2) = 1 3z−1(0, 0, 0, 0, 1 2 √ 3, 0, − 1 2 √ 3, 0, − i 2 √ 3, 0, i 2 √ 3, 0, 0, − 1 2 √ 3, 0, 1 2 √ 3)T
uµ
2 α(k, σ) = Lµναβ(k, M)uν 2 β(0, σ)
Lµναβ = LV µν ⊗ LSαβ LV, LS: boost matrix for vector and dirac spinor fields respectively.
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
L = ¯ ψµ[Dµν − mΘµν]ψν, Dµν = γρpρδµν + ξ(γµpν + γνpµ) + ζγµγρpργν, Θµν = δµν − zγνγν LV =
E M k1 M k2 M k3 M k1 M
1 + ( E
M − 1) k2
1
| k|2
( E
M − 1) k1k2 | k|2
( E
M − 1) k1k3 | k|2 k2 M
( E
M − 1) k2k1 | k|2
1 + ( E
M − 1) k2
2
| k|2
( E
M − 1) k2k3 | k|2 k3 M
( E
M − 1) k3k1 | k|2
( E
M − 1) k3k2 | k|2
( E
M − 1) k2
3
| k|2
LS =
1
√
2M(E+M)
- E + M −
k · σ E + M + k · σ
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
L = ¯ ψµ[Dµν − mΘµν]ψν, Dµν = γρpρδµν + ξ(γµpν + γνpµ) + ζγµγρpργν, Θµν = δµν − zγνγν Electrodynamic Interaction pµ → pµ − Aµ ⇒ LI = AµJµ = e ¯ ψνΓµνρψρAµ, pµJµ = 0 Γµνρ = γµδνρ + ξ(γνδµρ + γρηνµ) + ζγνγµγρ
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
L = ¯ ψµ[Dµν − mΘµν]ψν, Dµν = γρpρδµν + ξ(γµpν + γνpµ) + ζγµγρpργν, Θµν = δµν − zγνγν Electrodynamic Interaction pµ → pµ − Aµ ⇒ LI = AµJµ = e ¯ ψνΓµνρψρAµ, pµJµ = 0 Γµνρ = γµδνρ + ξ(γνδµρ + γρηνµ) + ζγνγµγρ Comparison
- V. Pascalutsa and O. Scholten, Nucl. Phys. A591, 658 (1995)
L1
I = iG1 2m ¯
ψαΘαµ(zf)γνγ5T3NF νµ + h.c. L2
I = −G2 (2m)2 ¯
ψαΘαµ(zf)γ5T3∂µNF νµ + h.c. L3
I = −G3 (2m)2 ¯
ψαΘαµ(zf)γ5T3N∂νF νµ + h.c.
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
In L = ¯ ψµ[Dµν − mΘµν]ψν,we identify spin 3/2 component as ∆+ and spin 1/2 component as proton. Proton Compton Scattering Feynman Diagrams
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
In L = ¯ ψµ[Dµν − mΘµν]ψν,we identify spin 3/2 component as ∆+ and spin 1/2 component as proton. Feynman Rules Out line: u2(k1), ¯ u2(k4) Vertex: Γµνρ = γµδνρ + ξ(γνδµρ + γρηνµ) + ζγνγµγρ Propogator: [Dµν − mΘµν]−1
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
In L = ¯ ψµ[Dµν − mΘµν]ψν,we identify spin 3/2 component as ∆+ and spin 1/2 component as proton. Feynman Rules Out line: u2(k1), ¯ u2(k4) Vertex: Γµνρ = γµδνρ + ξ(γνδµρ + γρηνµ) + ζγνγµγρ Propogator: [Dµν − mΘµν]−1 Two poles in propogator: p2 = m2: ∆+ pole p2 = M2: proton pole(M =
m 6z−2)
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
In L = ¯ ψµ[Dµν − mΘµν]ψν,we identify spin 3/2 component as ∆+ and spin 1/2 component as proton.
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
In L = ¯ ψµ[Dµν − mΘµν]ψν,we identify spin 3/2 component as ∆+ and spin 1/2 component as proton. Amplitude and Differential Cross Section Mσ1,σ4,λ2,λ3 = ie2(¯ u2η(k4, σ4)ΓµηρSργ(k1 − k3)Γνγκu2
κ(k1, σ1)
+¯ u2η(k4, σ4)ΓνηρSργ(k1 + k2)Γµγκu2
κ(k1, σ1))
ǫµ(k2, λ2)ǫ∗
ν(k3, λ3)
dσ dΩ = 1 64π2 (ω′ ω )2
- σ1,σ4,λ2,λ3
|M|2
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
Low energy expansion agrees with F .E.Low,PR96,1428(1954): dσ dΩ = α2(1+cos2 θ)
2M2
− α2(1−cos θ)(1+cos2 θ)
M3
ω + O(ω2)
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
Low energy expansion agrees with F .E.Low,PR96,1428(1954): dσ dΩ = α2(1+cos2 θ)
2M2
− α2(1−cos θ)(1+cos2 θ)
M3
ω + O(ω2) Difference at O(ω2) from Dirac theory affects the extraction of polarizability parameters(¯ α,¯ β) from experiment(δ¯ α,δ ¯ β = O(1)) dσ dΩ = ( dσ dΩ)Born − αω2
M ( ¯ α+¯ β 2 (1 + cos θ)2 + ¯ α−¯ β 2 (1 − cos θ)2)
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
Low energy expansion agrees with F .E.Low,PR96,1428(1954): dσ dΩ = α2(1+cos2 θ)
2M2
− α2(1−cos θ)(1+cos2 θ)
M3
ω + O(ω2) Difference at O(ω2) from Dirac theory affects the extraction of polarizability parameters(¯ α,¯ β) from experiment(δ¯ α,δ ¯ β = O(1)) dσ dΩ = ( dσ dΩ)Born − αω2
M ( ¯ α+¯ β 2 (1 + cos θ)2 + ¯ α−¯ β 2 (1 − cos θ)2)
50 100 150 200 250 Ω 2.1011 4.1011 6.1011 8.1011
θ = 0 Blue: current theory Red: Dirac theory
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
Low energy expansion agrees with F .E.Low,PR96,1428(1954): dσ dΩ = α2(1+cos2 θ)
2M2
− α2(1−cos θ)(1+cos2 θ)
M3
ω + O(ω2) Difference at O(ω2) from Dirac theory affects the extraction of polarizability parameters(¯ α,¯ β) from experiment(δ¯ α,δ ¯ β = O(1)) dσ dΩ = ( dσ dΩ)Born − αω2
M ( ¯ α+¯ β 2 (1 + cos θ)2 + ¯ α−¯ β 2 (1 − cos θ)2)
50 100 150 200 250 Ω 5.1012 1.1011 1.51011 2.1011 2.51011 3.1011 3.51011
θ = π
2
Blue: current theory Red: Dirac theory
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
Low energy expansion agrees with F .E.Low,PR96,1428(1954): dσ dΩ = α2(1+cos2 θ)
2M2
− α2(1−cos θ)(1+cos2 θ)
M3
ω + O(ω2) Difference at O(ω2) from Dirac theory affects the extraction of polarizability parameters(¯ α,¯ β) from experiment(δ¯ α,δ ¯ β = O(1)) dσ dΩ = ( dσ dΩ)Born − αω2
M ( ¯ α+¯ β 2 (1 + cos θ)2 + ¯ α−¯ β 2 (1 − cos θ)2)
50 100 150 200 250 Ω 1.1011 2.1011 3.1011 4.1011 5.1011 6.1011
θ = π Blue: current theory Red: Dirac theory
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
Low energy expansion agrees with F .E.Low,PR96,1428(1954): dσ dΩ = α2(1+cos2 θ)
2M2
− α2(1−cos θ)(1+cos2 θ)
M3
ω + O(ω2) Difference at O(ω2) from Dirac theory affects the extraction of polarizability parameters(¯ α,¯ β) from experiment(δ¯ α,δ ¯ β = O(1)) dσ dΩ = ( dσ dΩ)Born − αω2
M ( ¯ α+¯ β 2 (1 + cos θ)2 + ¯ α−¯ β 2 (1 − cos θ)2)
50 100 150 200 250 Ω 1.1011 2.1011 3.1011 4.1011 5.1011 6.1011
We are not ready to fit experimental data yet, since proton is not a fundamental particle.
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Vertex Structure
Reminiscence Dirac spinor electrodynamic interaction: ¯ u(p′)[ (p+p′)µ
2m
F1(q2) + iσµνqν
2m F2(q2)]u(p)Aµ
q = p′ − p F1, F2: form factors.
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
Reminiscence Dirac spinor electrodynamic interaction: ¯ u(p′)[ (p+p′)µ
2m
F1(q2) + iσµνqν
2m F2(q2)]u(p)Aµ
q = p′ − p F1, F2: form factors. Our Task Find (all) possible Γµνρ(p, p′) in ¯ ψν(p′)Γµνρ(p, p′)ψρ(p)Aµ Gauge Invariance: qµ ¯ ψν(p′)Γµνρ(p, p′)ψρ(p) = 0
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
Our Task Find (all) possible Γµνρ(p, p′) in ¯ ψν(p′)Γµνρ(p, p′)ψρ(p)Aµ Gauge Invariance: qµ ¯ ψν(p′)Γµνρ(p, p′)ψρ(p) = 0 Structures We Have Found Γµνρ(p, p′) = Scalar Type ηνρ(p + p′)µ γνγρ(p + p′)µ × ηνργ5(p + p′)µ × γνγργ5(p + p′)µ
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
Our Task Find (all) possible Γµνρ(p, p′) in ¯ ψν(p′)Γµνρ(p, p′)ψρ(p)Aµ Gauge Invariance: qµ ¯ ψν(p′)Γµνρ(p, p′)ψρ(p) = 0 Structures We Have Found Γµνρ(p, p′) = Vector Type ηνργµ γνγµγρ γνηµρ + γρηµν × γνηµρ − γρηµν × γ5(· · · )
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
Our Task Find (all) possible Γµνρ(p, p′) in ¯ ψν(p′)Γµνρ(p, p′)ψρ(p)Aµ Gauge Invariance: qµ ¯ ψν(p′)Γµνρ(p, p′)ψρ(p) = 0 Structures We Have Found Γµνρ(p, p′) = Tensor Type τ µλνρqλ σµληνρqλ σµλσνρqλ τ µλνκσκρqλ τ µλκρσνκqλ × γ5(· · · )
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary
Structures We Have Found Scalar Type: ηνρ(p + p′)µ γνγρ(p + p′)µ Vector Type: ηνργµ γνγµγρ γνηµρ + γρηµν Tensor Type: τ µλνρqλ σµληνρqλ σµλσνρqλ τ µλνκσκρqλ τ µλκρσνκqλ Our Claim The scalar, vector and tensor type vertexes we have found comprise the most general set of vertexes that are at most first
- rder in q, and dominate the low energy Compton scattering
amplitude.
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Summary
Summary Motivation for unifying proton and ∆+ in a generalized Rarita-Schwinger theory, and the model
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Summary
Summary Motivation for unifying proton and ∆+ in a generalized Rarita-Schwinger theory, and the model
* Lagrangian;
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Summary
Summary Motivation for unifying proton and ∆+ in a generalized Rarita-Schwinger theory, and the model
* Lagrangian; * spin 1/2 solution;
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Summary
Summary Motivation for unifying proton and ∆+ in a generalized Rarita-Schwinger theory, and the model
* Lagrangian; * spin 1/2 solution; * electrodynamic interaction
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Summary
Summary Motivation for unifying proton and ∆+ in a generalized Rarita-Schwinger theory, and the model
* Lagrangian; * spin 1/2 solution; * electrodynamic interaction
Proton Compton scattering amplitude and cross section
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Summary
Summary Motivation for unifying proton and ∆+ in a generalized Rarita-Schwinger theory, and the model
* Lagrangian; * spin 1/2 solution; * electrodynamic interaction
Proton Compton scattering amplitude and cross section
* Low energy limit;
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Summary
Summary Motivation for unifying proton and ∆+ in a generalized Rarita-Schwinger theory, and the model
* Lagrangian; * spin 1/2 solution; * electrodynamic interaction
Proton Compton scattering amplitude and cross section
* Low energy limit; * comparison with Dirac theory calculation
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Summary
Summary Motivation for unifying proton and ∆+ in a generalized Rarita-Schwinger theory, and the model
* Lagrangian; * spin 1/2 solution; * electrodynamic interaction
Proton Compton scattering amplitude and cross section
* Low energy limit; * comparison with Dirac theory calculation
Constructing general electrodynamic interaction vertexes
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Summary
Summary Motivation for unifying proton and ∆+ in a generalized Rarita-Schwinger theory, and the model
* Lagrangian; * spin 1/2 solution; * electrodynamic interaction
Proton Compton scattering amplitude and cross section
* Low energy limit; * comparison with Dirac theory calculation
Constructing general electrodynamic interaction vertexes
* Scalar, vector and tensor type vertexes;
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary Summary
Summary Motivation for unifying proton and ∆+ in a generalized Rarita-Schwinger theory, and the model
* Lagrangian; * spin 1/2 solution; * electrodynamic interaction
Proton Compton scattering amplitude and cross section
* Low energy limit; * comparison with Dirac theory calculation
Constructing general electrodynamic interaction vertexes
* Scalar, vector and tensor type vertexes; * claiming that other vertexes are higher order in q
Outline Background and Motivation The Model Proton Compton Scattering Vertex Structure Summary