L. F avart I.I.H.E. Université Libre de Bruxelles H Collaboration HERA at DESY CLAS Workshop Genova - 4-8 th of Feb. 9 CLAS workshop Feb. 9 - L.Favart p./8
e p Integrated luminosity 96- + 3-7 (high energy) e + p : 3pb e p : 85pb H Integrated Luminosity / pb - 4 3 Status: -July-7 electrons positrons low E HERA- HERA- 5 5 Days of running CLAS workshop Feb. 9 - L.Favart p./8
e p GeV e (k ) e (k) γ * (q) 3 } p (p) X 4 5 ep ex s x = q = (k k ) x = /(p q) = x y s y = p q/(p e) W = (p + q) γ p CLAS workshop Feb. 9 - L.Favart p.3/8
e CLAS workshop Feb. 9 - L.Favart p.4/8
HERA Fixed Target Experiments xf 3 5 4 3 y= F F L - -6-5 -4-3 - - x CLAS workshop Feb. 9 - L.Favart p.5/8 (GeV ) x
F σ r (x, ) x i 7 6 5 4 3 - - -3 HERA I e + p Neutral Current Scattering - H and x =.3, i= x =.5, i= x =.8, i= x =.3, i=9 x =., i=8 x =.3, i=7 x =.5, i=6 x =.8, i=5 x =.3, i=4 x =., i=3 x =.3, i= x =.5, i= x =.8, i= x =.3, i=9 x =., i=8 x =.3, i=7 x =.5, i=6 x =.8, i=5 HERA I (prel.) Fixed Target H PDF -JETS x =.3, i=4 x =.8, i=3 x =.5, i= x =.4, i= x =.65, i= 3 4 5 / GeV HERA Structure Functions Working Group e (k) p (p) { e (k) p (p) x. γ * (q) γ * (q) q q x e (k ) e (k ) } X } X CLAS workshop Feb. 9 - L.Favart p.6/8
F ( q(x, Q ) P qq + g(x, ) Pqg) dx x dq(x, ) dlog αs H and Combined PDF Fit HERA Structure Functions Working Group April 8 = GeV Q xf HERAPDF. (prel.) x.8 exp. uncert. xu v model uncert..6 xd v xg (.5).4. xs (.5) - - -3-4 x H Collaboration CLAS workshop Feb. 9 - L.Favart p.7/8
CLAS workshop Feb. 9 - L.Favart p.8/8
QCD in Breit frame e e J/ψ γ * x ξ x + ξ p p GP D(x, ξ, Q ) dx Ψ (x, ξ, t; µ) t CLAS workshop Feb. 9 - L.Favart p.9/8 Colour Dipole -z q r z q γ * σ dipole p p q q + q qg +... γ dr ψ in (r, z, ) σ d ψ out (r, z, ) σ = ψ in σd r q q
z ρ, φ, J/ψ,γ r z b p p q AL q q γ t = q Ψγ γ mpx fm E EI m σdip(r, z, b) q q MV r µ = z( z)( + M V ) z / µ ( + M V )/4 AL z =, µ AT CLAS workshop Feb. 9 - L.Favart p./8
MY t W σt Q 8 σ( ) σl Q 6 αs( ) Naive R = σl/σt /M V modified. W σ W δ x g(x, µ ) W δ = 4(α(t) ) = 4(α() + α t ) σt σl Hard scale: δ, α() : universal with Q +M X 4 t dσ/dt e b t b = bdip bexch by bt > bl Hard scale: b: universal with Q +M X 4 MY W CLAS workshop Feb. 9 - L.Favart p./8
M V ρ, φ, ω = J/ψ υ Υ CLAS workshop Feb. 9 - L.Favart p./8
σ [nb] 4 3 γ p ρ p H HERA- prel. H SV σ [nb] γ p φ p H HERA- prel. H SV γ p ρ Y H HERA- prel. (x.5) γ p φ Y H HERA- prel. (x.5) - W = 75 GeV M Y < 5 GeV - W = 75 GeV M Y < 5 GeV +M [GeV ] φ +M [GeV ] σ γ p ρy / σ γ p ρp.8.6.4 H ρ electroproduction (preliminary) H HERA- prel. σ γ p φy / σ γ p φp.8.6.4 H φ electroproduction (preliminary) H HERA- prel. i.e.. W = 75 GeV M Y < 5 GeV 3 4 [GeV ]. W = 75 GeV M Y < 5 GeV 5 5 [GeV ] CLAS workshop Feb. 9 - L.Favart p.3/8
α IP () σ(γ*p ρ p) (nb).6.4 3 - W ρ Φ J/Ψ pb - 4 6 8 4 6 8 γ p ρ p H HERA- prel. H SV γ p J/ψ p H W (GeV) γ p φ p σ γ p φp [nb] H HERA- prel. H φ electroproduction (preliminary) H HERA- prel. [GeV ] 3.3 6.5 6.5 Fit W δ W [GeV] σ(γ * p J/ψp) (nb) p) (nb) - - (a) // Photoproduction DIS 98- H DIS α IP () = + δ/4 + α IP / t α IP =.5 GeV + M α IP () Fit with W δ (GeV ). ( ).4 (.) 3. (.) 6.8 (.5) 6. (.3) W (GeV). H DVCS α IP ()=.8 +M [GeV ] + M GeV σ T CLAS workshop Feb. 9 - L.Favart p.4/8
e e γ * γ p p α IP ().6 γ p ρ p H HERA- prel. H SV γ p φ p H HERA- prel. α IP ().6 γ p ρ p H HERA- prel. H SV γ p φ p H HERA- prel..4 γ p J/ψ p γ p J/ψ p DVCS H H.4 H.. H DVCS α IP ()=.8 4 6 8 +M [GeV ] µ [GeV ] µ = + M X µ = Q +MX 4 µ = CLAS workshop Feb. 9 - L.Favart p.5/8
b [GeV - ] dσ/d t (nb/gev ) dσ/d t (nb/gev ) dσ/d t (nb/gev ) 8 t ρ Φ 5 H HERA- preliminary J/Ψ γ p φ p pb - t (GeV ) t (GeV ) t (GeV ) dσ/d t (nb/gev ) dσ/d t (nb/gev ) dσ/d t (nb/gev ) e p ρ p H HERA- prel. H SV t (GeV ) t (GeV ) t (GeV ) dσ/d t [nb/gev ] e p φ p 4 H HERA- prel. H 96 ep J/Ψp H < > [GeV ] 3.5 (x ) 6.8 (x ) 6. (x ) Fit e bt - MRS (Sat)...3.4.5.6.7.8 t t [GeV ] e b t + M dσ(γ * p J/ψp)/dt (nb/gev ) Fit < < GeV e bt, b = 4.7 ±.5 ±. GeV - ( - t/m g ) - 4, m g =.55 ±. GeV.5.5.75 -t (GeV ) < < 5 GeV (b) 5 < < GeV (c).5.5 (a) < < GeV (d).5 -t (GeV ) 6 4 a) 5 5 5 3 35 4 45 +M [GeV ] + M CLAS workshop Feb. 9 - L.Favart p.6/8
b [GeV - ] 4 e p ρ p H HERA- prel. H SV H 94 e p φ p H HERA- prel. ep J/Ψp H b [GeV - ] 4 e p ρ p H HERA- prel. H SV e p φ p H HERA- prel. ep J/Ψp H 8 DVCS H 8 DVCS H 6 6 4 a) 4 a) 5 5 5 3 35 4 45 5 5 5 +M [GeV ] µ [GeV ] µ = + M X µ = Q +MX 4 µ = CLAS workshop Feb. 9 - L.Favart p.7/8
θ Φ ϕ r ij kl T λ ρ λ γ T λ ρ λ γ T λρ λ γ. hadronic centre of mass ϕ e VM M+ T : γ L ρ L e γ φ p decay plane M T : γ T ρ T T : γ T ρ L electron scattering plane production plane VM direction in the hadronic centre of mass system. θ M VM rest frame M+ T : γ L ρ T T : γ T ρ T s T = T = T = t t t < ) T > T > T > T > T CLAS workshop Feb. 9 - L.Favart p.8/8
ρ.8.6.4. -.. -. -. r 4 Re r 4 r 4. -. -...5 -.5 -.. -.. -. r Re r r - Im r.3.5.... -.5 -. - r.5 -.5 -. Im r - r 5 r 5 Re r 5..5.4.5..5..5 r 4 r 5 r r 6 r 5 r r 5 - Im r 6 Im r 6 - -.5.4.5. -. -. -.5 -.4 -.5 -. [GeV ] H ρ electroproduction (preliminary) H HERA- prel. GK (GPD) CLAS workshop Feb. 9 - L.Favart p.9/8
R = σ L /σ T R = σ L / σ T R SCHC = ɛ 5 γ p ρ Y H HERA- prel. H r 4 ɛr 4 H ρ and φ electroproduction (preliminary) = T T R = σ L / σ T 5 4 3 H ρ electroproduction (preliminary) γ p ρ Y H HERA- prel..6.8 m ππ [GeV] γ p φ Y H HERA- prel. H 4 [GeV ] R=σ L /σ T 5 4.5 4 3.5 3.5 pb - < >=3 GeV < >= GeV R /M R φ ρ ρ.5.5.6.7.8.9...3 M ππ (GeV) CLAS workshop Feb. 9 - L.Favart p./8
T / T M Q +γ γ T / T M t γ T / T t Q γ γ.75.5.5 T / T H ρ prel. H φ prel. [GeV ].4. T / T H ρ prel. H φ prel. [GeV ].. -. -. T / T H ρ prel. H φ prel. [GeV ].. -. -. T - / T H ρ prel. H φ prel. [GeV ] T / T T / T > T / T T / T σ L /σ T T > T > T > T, T CLAS workshop Feb. 9 - L.Favart p./8
t T / T M Q +γ γ T / T M t γ T / T t Q γ γ.75.5.5 T / T H ρ prel. H φ prel. t [GeV ].4. T / T H ρ prel. H φ prel. t [GeV ].. -. -. T / T H ρ prel. H φ prel. t [GeV ].. -. -. T - / T H ρ prel. H φ prel. t [GeV ] T / T T / T T / T T / T t t T / T t T / T t σ L /σ T CLAS workshop Feb. 9 - L.Favart p./8
RSCHC+T = T t R = σl/σt T+T r 4 = σl / σ tot H ρ HERA- prelim..8 = 3.4 GeV 8 = 9. GeV 6 R = σl / σ T.6 4 pb - < > = 3 GeV < > = GeV.4..4.6.8 t (GeV ) t [GeV ] σt σl bl < bt t R ρ CLAS workshop Feb. 9 - L.Favart p.3/8
ρ φ σ L [nb] 3 H ρ and φ electroproduction (preliminary) γ L p ρ p H HERA- prel. σ T [nb] 3 H ρ and φ electroproduction (preliminary) γ T p ρ p H HERA- prel. GK (GPD) INS (k t fact) MPS (Sat) γ L p φ p γ T p φ p - - H HERA- prel. W = 75 GeV GK (GPD) INS (k t fact) MPS (Sat) - - H HERA- prel. W = 75 GeV +M [GeV ] +M [GeV ] + M σ L σ L σ T σ T σ L = CLAS workshop Feb. 9 - L.Favart p.4/8
J/ψ 4 r.5 H.5.5.5.5 4 r - SCHC r - H Photoproduction H Electroproduction Photoproduction Electroproduction 5 5 r +r r +r. J/ψ J/ψ a) b) c) d) e) [GeV ] J/ψ 4 r 4 r - r - 5 5 r +r r +r R t. f) g) h) i) j) t [GeV ].5.5.5.5.5 σ [nb] R = σ L / σ T 8 6 4 - - b) σ T σ L γ p ρ Y H HERA- prel. H SV E665 NMC γ p φ Y - QM ρ /M V M H HERA- prel. H SV γ p J/Ψ Y H.M /M [GeV ] ρ V. MRT(CTEQ6M) MRT(MRST) MRT(H QCD Fit) H [GeV ] CLAS workshop Feb. 9 - L.Favart p.5/8
H H HERA II e - p H HERA I GPD model S( ) b 8 6 4 σdv CS Q 4 b( ) ( + ρ ) S = H HERA II e - p H HERA I GPD model GPD model (only kinematical skewing) 6 5 R( ) 4 3 R = Im A(γ Im A(γ p γ p) p γp) 4 π σdv CS b( ) = [GeV ] σt (γ p X) ( + ρ ) σt (γ p X) CLAS workshop Feb. 9 - L.Favart p.6/8
e e + pb BCA σ(e+ p) σ(e p) σ(e + p) + σ(e p) p cos(φ) H data (prelim.) p cos(φ bel. ) H DVCS Analysis HERA II H.3 ) -. + σ. - σ - )/(σ + -. -. -.3 4 6 8 4 6 8 Φ bel. (degrees) BCA = (σ + φ.5 < t < CLAS workshop Feb. 9 - L.Favart p.7/8
ρ, φ, J/ψ, Υ, γ, W, t t W L/T CLAS workshop Feb. 9 - L.Favart p.8/8
CLAS workshop Feb. 9 - L.Favart p.9/8
% $ " $ '. kt "!#! F σq q p ' * ) ' ( ( &' & %-,!$! +! kt kt F(x, κ) kt σq q p σq q p = 4π/3 d κ/κ 4 F(x, κ) αs(µ ) [ exp(i κ r)] ) )) / ( A = 9 µ = A/(z( z) + m q ) σq q p π /3 r αs(µ ) G(x, µ ) σt ( + M V ) 4 [αs(µ ) G(x, µ )] σl /M V (Q + M V ) 4 [αs(µ ) G(x, µ )] CLAS workshop Feb. 9 - L.Favart p.3/8
% -, $, $ )) W )) +, "! Q / ) Hij / W dz dx f i/p (x, x x, t, µ) A γ ( ) p V p = i,j (z, µ) Hij( x /x,, z, µ) Ψ V j x x x f i/p Ψ V j Hij γt γl ' ) %! CLAS workshop Feb. 9 - L.Favart p.3/8
± T / T T / T T / T T / T r 4 = B (ε + β ) Re r 4 = B/ (εδ + βα βη) r 4 = B (αη εδ ) r = B β r = B αη Re r = B/ β(η α) r = B/ (α + η ) Im r = B/ β(α + η) Im r = B/ (η α ) r 5 = B β r 5 = B/ δ(α η) Re r 5 = B/( ) (βδ + α η) r 5 = B/ δ(η α) Im r 6 = B/( ) (α + η) Im r 6 = B/ δ(α + η) α = T / T β = T / T δ = T / T η = T / T B = = R N T +εn L +εr N T = α + β + η N L = + δ CLAS workshop Feb. 9 - L.Favart p.3/8
$ α IP ] p) [µb/gev dσ/dt (γp ρ ρ - H PRELIMINARY ρ Elastic Photoproduction -t [GeV ] 3 4 5 6 7 H PRELIMINARY.,..35,..69.3.89.6.38.58 H 5 Preliminary H 5 fit 94 94 LPS 95 W [GeV] dσ dt (W ) eb t W 4(α IP (t) ) α IP [GeV ] W W δ α IP (t) = + δ/4 α IP (t) α IP (t) = α IP () + α IP t.4. γ p ρ p H HERA- prel. H HERA- prel. γ p φ p t α(t)..5..5. H 5 Preliminary H 5 fit Zeus 95 Zeus 95 fit Donnachie-Landshoff γ p J/ψ p H -. 4 6 8 4 6 8.95.9 Elastic ρ Photoproduction α IP +M [GeV ] p p -. -. -.8 -.6 -.4 -. -.. t [GeV ] IP CLAS workshop Feb. 9 - L.Favart p.33/8
Events/(.3 GeV) 6 4 pb -.5.6.7.8.9...3.4 M ππ (GeV) CLAS workshop Feb. 9 - L.Favart p.34/8