Pr Ps trt rsss - PowerPoint PPT Presentation

Pr♦❜✐♥❣ ●P❉s ✐♥ ♣❤♦t♦♣r♦❞✉❝t✐♦♥ ♣r♦❝❡ss❡s ❛t ❤❛❞r♦♥ ❝♦❧❧✐❞❡rs ❉♠✐tr② ■✈❛♥♦✈ ❙♦❜♦❧❡✈ ■♥st✐t✉t❡ ♦❢ ▼❛t❤❡♠❛t✐❝s P❍❖❚❖◆ ✷✵✶✺✱ ◆♦✈♦s✐❜✐rs❦ t✐♠❡❧✐❦❡✲❉❱❈❙ ✭r❡✈✐❡✇ ♦❢ ✇♦r❦✮✿ ❇✳ P✐r❡✱ ▲✳ ❙③②♠❛♥♦✇s❦✐✱ ❏✳ ❲❛❣♥❡r J/ Ψ ♣❤♦t♦♣r♦❞✉❝t✐♦♥ ✭✐♥ ♣r♦❣r❡ss✮✿ ❉✳ ■✈❛♥♦✈✱ ▲✳❙③②♠❛♥♦✇s❦✐✱ ❏✳ ❲❛❣♥❡r ✶ ✴ ✸✵

❉❱❈❙ ❚❤❡ s✐♠♣❧❡st ❛♥❞ ❜❡st ❦♥♦✇♥ ♣r♦❝❡ss ✐s ❉❡❡♣❧② ❱✐rt✉❛❧ ❈♦♠♣t♦♥ ❙❝❛tt❡r✐♥❣✿ e p → e p γ e e γ ∗ γ p p ❋❛❝t♦r✐③❛t✐♦♥ ✐♥t♦ ●P❉s ❛♥❞ ♣❡rt✉r❜❛t✐✈❡ ❝♦❡✣❝✐❡♥t ❢✉♥❝t✐♦♥ ✲ ♦♥ t❤❡ ❧❡✈❡❧ ♦❢ ❛♠♣❧✐t✉❞❡✳ ❉■❙ : σ = P❉❋ ⊗ ♣❛rt♦♥✐❝ ❝r♦ss s❡❝t✐♦♥ ❉❱❈❙ : M = ●P❉ ⊗ ♣❛rt♦♥✐❝ ❛♠♣❧✐t✉❞❡ ✷ ✴ ✸✵

●P❉s ◮ ●P❉s ❡♥t❡r ❢❛❝t♦r✐③❛t✐♦♥ t❤❡♦r❡♠s ❢♦r ❤❛r❞ ❡①❝❧✉s✐✈❡ r❡❛❝t✐♦♥s ✭❉❱❈❙✱ ❞❡❡♣❧② ✈✐rt✉❛❧ ♠❡s♦♥ ♣r♦❞✉❝t✐♦♥✱ ❚❈❙ ❡t❝✳✮✱ ✐♥ ❛ s✐♠✐❧❛r ♠❛♥♥❡r ❛s P❉❋s ❡♥t❡r ❢❛❝t♦r✐③❛t✐♦♥ t❤❡♦r❡♠s ❢♦r ✐♥❝❧✉s✐✈❡ ✭❉■❙✱ ❡t❝✳✮ ◮ ●P❉s ❛r❡ ❢✉♥❝t✐♦♥s ♦❢ x, t, ξ, µ 2 F ◮ ❋✐rst ♠♦♠❡♥t ♦❢ ●P❉s ❡♥t❡rs t❤❡ ❏✐✬s s✉♠ r✉❧❡ ❢♦r t❤❡ ❛♥❣✉❧❛r ♠♦♠❡♥t✉♠ ❝❛rr✐❡❞ ❜② ♣❛rt♦♥s ✐♥ t❤❡ ♥✉❝❧❡♦♥✱ ◮ ✷✰✶ ✐♠❛❣✐♥❣ ♦❢ ♥✉❝❧❡♦♥✱ ◮ ❉❡❡♣❧② ❱✐rt✉❛❧ ❈♦♠♣t♦♥ ❙❝❛tt❡r✐♥❣ ✭❉❱❈❙✮ ✐s ❛ ❣♦❧❞❡♥ ❝❤❛♥♥❡❧ ❢♦r ●P❉s ❡①tr❛❝t✐♦♥✱ ✸ ✴ ✸✵

❉❱❈❙✱ ❉❱▼P ◮ ❉✐✣❝✉❧t✿ ❡①❝❧✉s✐✈✐t②✱ ✸ ✈❛r✐❛❜❧❡s✱ ●P❉ ❡♥t❡r t❤r♦✉❣❤ ❝♦♥✈♦❧✉t✐♦♥s✱ ♦♥❧② ●P❉ ( ξ, ξ, t ) ❛❝❝❡s✐❜❧❡ t❤r♦✉❣❤ ❉❱❈❙ ❛t ▲❖✦ ◮ ✉♥✐✈❡rs❛❧✐t②✱ ◮ ✢❛✈♦✉r s❡♣❛r❛t✐♦♥✱ ξ ∼ Q 2 x ′ = x − ξ , W 2 ✹ ✴ ✸✵

❙♦✱ ✐♥ ❛❞❞✐t✐♦♥ t♦ s♣❛❝❡❧✐❦❡ ❉❱❈❙ ✳✳✳ e e γ q N’ N GPD ( a ) ❋✐❣✉r❡✿ ❉❡❡♣❧② ❱✐rt✉❛❧ ❈♦♠♣t♦♥ ❙❝❛tt❡r✐♥❣ ✭❉❱❈❙✮ ✿ lN → l ′ N ′ γ ✺ ✴ ✸✵

✇❡ ❝❛♥ ❛❧s♦ st✉❞② t✐♠❡❧✐❦❡ ❉❱❈❙ ❇❡r❣❡r✱ ❉✐❡❤❧✱ P✐r❡✱ ✷✵✵✷ e − e+ γ q N’ N GPD ( b ) ❋✐❣✉r❡✿ ❚✐♠❡❧✐❦❡ ❈♦♠♣t♦♥ ❙❝❛tt❡r✐♥❣ ✭❚❈❙✮✿ γN → l + l − N ′ ❲❤② ❚❈❙✿ ◮ ✉♥✐✈❡rs❛❧✐t② ♦❢ t❤❡ ●P❉s ◮ ❛♥♦t❤❡r s♦✉r❝❡ ❢♦r ●P❉s ◮ s♣❛❝❡❧✐❦❡✲t✐♠❡❧✐❦❡ ❝r♦ss✐♥❣ ◮ ❝♦✉❧❞ ❜❡ st✉❞✐❡❞ ❜♦t❤ ✐♥ ep ❛♥❞ pp ✻ ✴ ✸✵

●❡♥❡r❛❧ ❈♦♠♣t♦♥ ❙❝❛tt❡r✐♥❣✿ γ ∗ ( q in ) N ( p ) → γ ∗ ( q out ) N ′ ( p ′ ) ✈❛r✐❛❜❧❡s✱ ❞❡s❝r✐❜✐♥❣ t❤❡ ♣r♦❝❡ss❡s ♦❢ ✐♥t❡r❡st ✐♥ t❤✐s ❣❡♥❡r❛❧✐③❡❞ ❇❥♦r❦❡♥ ❧✐♠✐t✱ ❛r❡ t❤❡ s❝❛❧✐♥❣ ✈❛r✐❛❜❧❡ ξ ❛♥❞ s❦❡✇♥❡ss η > 0 ✿ ξ = − q 2 out + q 2 q 2 out − q 2 in in η , η = ( p + p ′ ) · ( q in + q out ) . q 2 out − q 2 in ◮ ❉❉❱❈❙✿ q 2 q 2 in < 0 , out > 0 , η � = ξ x − x ′ = η = ξ > 0 ◮ ❉❱❈❙✿ q 2 q 2 in < 0 , out = 0 , x ′ − x = η = − ξ > 0 ◮ ❚❈❙✿ q 2 q 2 in = 0 , out > 0 , ✼ ✴ ✸✵

❈♦❡✣❝✐❡♥t ❢✉♥❝t✐♦♥s ❛♥❞ ❈♦♠♣t♦♥ ❋♦r♠ ❋❛❝t♦rs ❈❋❋s ❛r❡ t❤❡ ●P❉ ❞❡♣❡♥❞❡♥t q✉❛♥t✐t✐❡s ✇❤✐❝❤ ❡♥t❡r t❤❡ ❛♠♣❧✐t✉❞❡s✳ ❚❤❡② ❛r❡ ❞❡✜♥❡❞ t❤r♦✉❣❤ r❡❧❛t✐♦♥s✿ � � � H ( ξ, η, t ) γ + + E ( ξ, η, t ) iσ + ρ ∆ ρ 1 A µν ( ξ, η, t ) = − e 2 g µν u ( P ′ ) ( P + P ′ ) + ¯ T 2 M � � � E ( ξ, η, t ) ∆ + γ 5 + iǫ µν H ( ξ, η, t ) γ + γ 5 + � � u ( P ) , T 2 M ❋❆❈❚❖❘■❩❆❚■❖◆✿ �� � � 1 T q ( x, ξ, η ) H q ( x, η, t ) + T g ( x, ξ, η ) H g ( x, η, t ) H ( ξ, η, t ) = + dx − 1 q �� � � 1 � T q ( x, ξ, η ) � � H q ( x, η, t ) + � T g ( x, ξ, η ) � H g ( x, η, t ) H ( ξ, η, t ) = dx . − − 1 q ✽ ✴ ✸✵

▲❖ ❛♥❞ ◆▲❖ ❈♦❡✣❝✐❡♥t ❢✉♥❝t✐♦♥s ◮ ❉❱❈❙ ✈s ❚❈❙ ❛t ▲❖ ❛r❡ s✐♠♣❧② r❡❧❛t❡❞✿ DV CS T q ( T CS T q ) ∗ = − e 2 1 x + η − iε − ( x → − x ) = q DV CS ˜ − ( T CS ˜ T q = − e 2 T q ) ∗ 1 x + η − iε + ( x → − x ) = q � 1 DV CS Re ( H ) ∼ P x ± η H q ( x, η, t ) , DV CS Im ( H ) ∼ iπH q ( ± η, η, t ) ◮ ❉❉❱❈❙ ❛t ▲❖ 1 DDV CS T q = − e 2 x + ξ − iε − ( x → − x ) q � 1 DDV CS Re ( H ) ∼ P x ± ξ H q ( x, η, t ) , DV CS Im ( H ) ∼ iπH q ( ± ξ, η, t ) ❇✉t t❤✐s ✐s ♦♥❧② tr✉❡ ❛t ▲❖✳ ❆t ◆▲❖ ❛❧❧ ●P❉s ❤✐❞❞❡♥ ✐♥ t❤❡ ❝♦♥✈♦❧✉t✐♦♥s✳ ✾ ✴ ✸✵

❚❈❙ ❛♥❞ ❇❡t❤❡✲❍❡✐t❧❡r ❝♦♥tr✐❜✉t✐♦♥ t♦ ❡①❝❧✉s✐✈❡ ❧❡♣t♦♥ ♣❛✐r ♣❤♦t♦♣r♦❞✉❝t✐♦♥✳ q in l − l + − ∆ p ′ p ❋✐❣✉r❡✿ ❚❤❡ ❋❡②♥♠❛♥ ❞✐❛❣r❛♠ ❢♦r t❤❡ ❇❡t❤❡✲❍❡✐t❧❡r ❛♠♣❧✐t✉❞❡✳ l + l − q out q in p ′ p ❋✐❣✉r❡✿ ❚❤❡ ❋❡②♥♠❛♥ ❞✐❛❣r❛♠ ❢♦r t❤❡ ❈♦♠♣t♦♥ ❛♠♣❧✐t✉❞❡✳ ✶✵ ✴ ✸✵

❚❈❙ e (2) e (1) ϕ ϕ q e’ (2) k k e (3) (1) e’ ∆ T q’ θ (3) e’ p’ p’ boost k’ k’ p γ p c.m. + − l l c.m. ❋✐❣✉r❡✿ ❑✐♥❡♠❛t✐❝❛❧ ✈❛r✐❛❜❧❡s ❛♥❞ ❝♦♦r❞✐♥❛t❡ ❛①❡s ✐♥ t❤❡ γp ❛♥❞ ℓ + ℓ − ❝✳♠✳ ❢r❛♠❡s✳ ❇✲❍ ❞♦♠✐♥❛♥t ❢♦r ♥♦t ✈❡r② ❤✐❣❤ ❡♥❡r❣✐❡s✳ ❚❤❡r❡❢♦r❡ ✇❡ ♥❡❡❞ t❤❡ ✐♥t❡r❢❡r❡♥❝❡ ♣❛rt ♦❢ t❤❡ ❝r♦ss✲s❡❝t✐♦♥✳ ❋♦r ✉♥♣♦❧❛r✐③❡❞ ♣r♦t♦♥s ❛♥❞ ♣❤♦t♦♥s✿ dσ INT dQ ′ 2 dt d cos θ dϕ ∼ cos ϕ · Re H ( η, t ) ✶✶ ✴ ✸✵

❏▲❆❇ ✻ ●❡❱ ❞❛t❛ ❘❛❢❛②❡❧ P❛r❡♠✉③②❛♥ P❤❉ t❤❡s✐s ❋✐❣✉r❡✿ e + e − ✐♥✈❛r✐❛♥t ♠❛ss ❞✐str✐❜✉t✐♦♥ ✈s q✉❛s✐✲r❡❛❧ ♣❤♦t♦♥ ❡♥❡r❣②✳ ❋♦r ❚❈❙ ❛♥❛❧②s✐s M ( e + e − ) > 1 . 1 GeV ❛♥❞ s γp > 4 . 6 GeV 2 r❡❣✐♦♥s ❛r❡ ❝❤♦s❡♥✳ ▲❡❢t ❣r❛♣❤ r❡♣r❡s❡♥ts ❡✶✲✻ ❞❛t❛ s❡t✱ r✐❣❤t ♦♥❡ ✐s ❢r♦♠ ❡✶❢ ❞❛t❛ s❡t✳ ✶✷ ✴ ✸✵

❚❤❡♦r② ✈s ❡①♣❡r✐♠❡♥t ❘✳P❛r❡♠✉③②❛♥ ❛♥❞ ❱✳●✉③❡②✿ � � dφ cos φ dθ dσ � � R = dφ dθ dσ 2 2 Q = 1.3 GeV E = 3.536 GeV γ 1 R’ 0.8 0.6 0.4 0.2 0 -0.2 SC_D= 0.00 -0.4 SC_D= 1.00 SC_D= 2.00 -0.6 BH Dual -0.8 Data -1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 2 -t GeV ❋✐❣✉r❡✿ ❚❤♦❡r❡t✐❝❛❧ ♣r❡❞✐❝t✐♦♥ ♦❢ t❤❡ r❛t✐♦ R ❢♦r ✈❛r✐♦✉s ●P❉s ♠♦❞❡❧s✳ ❉❛t❛ ♣♦✐♥ts ❛❢t❡r ❝♦♠❜✐♥✐♥❣ ❜♦t❤ ❡✶✲✻ ❛♥❞ ❡✶❢ ❞❛t❛ s❡ts✳ ✶✸ ✴ ✸✵

❆♣♣r♦✈❡❞ ❡①♣❡r✐♠❡♥t ❛t ❍❛❧❧ ❇✱ ❛♥❞ ▲❖■ ❢♦r ❍❛❧❧ ❆✳ ✶✹ ✴ ✸✵

❯❧tr❛♣❡r✐♣❤❡r❛❧ ❝♦❧❧✐s✐♦♥s � � dk A dn A dk B dn B σ AB = dk A σ γB ( W A ( k A )) + dk B σ γA ( W B ( k B )) √ s ✳ ✇❤❡r❡ k A,B = 1 2 x A,B ✶✺ ✴ ✸✵