Searching saturation effects in inclusive and exclusive e

Searching saturation effects in inclusive and exclusive e. A processes Victor P. Goncalves Theory High Energy Physics – Lund University - Sweden and High and Medium Energy Group – UFPel - Brazil Palaiseau – France 08 Sept 20151

Motivation • Deep inelastic scattering with nuclear targets Partons distributions in the nuclei are different from the scaled proton parton distributions 2

Motivation • Deep inelastic scattering with nuclear targets Partons distributions in the nuclei are different from the scaled proton parton distributions 3

Motivation 4

Motivation Nuclei are an efficient amplifier of the nonlinear effects. 5

The color dipole picture: 6

The color dipole picture: 7

The color dipole picture: In what follows: Sums all multiple elastic rescatterings of the dipole. 8

The nuclear structure functions: (*) Cazaroto, Carvalho, VPG, Navarra, PLB 671, 233 (2009). 9

The nuclear structure functions: (*) Cazaroto, Carvalho, VPG, Navarra, PLB 671, 233 (2009). 10

The nuclear structure functions: EPS and DS results, which are solutions of the DGLAP equations, represent an upper and a lower bound for the magnitude of the nuclear effects. (*) Cazaroto, Carvalho, VPG, Navarra, PLB 671, 233 (2009). 11

The nuclear structure functions: The difference between the collinear predictions is so large at small-x that it is not possible to extract information about the presence or not of new dynamics effects. (*) Cazaroto, Carvalho, VPG, Navarra, PLB 671, 233 (2009). 12

The nuclear structure functions: (*) Cazaroto, Carvalho, VPG, Navarra, PLB 671, 233 (2009). 13

The logarithmic Q 2 slope of F 2 A (*) Gay Ducati, VPG, PLB 466, 375 (1999). 14

The logarithmic Q 2 slope of F 2 A Linear (*) Gay Ducati, VPG, PLB 466, 375 (1999). 15

The logarithmic Q 2 slope of F 2 A Linear Nonlinear (*) Gay Ducati, VPG, PLB 466, 375 (1999). 16

The logarithmic Q 2 slope of F 2 A (*) VPG, PLB 495, 303 (2000). 17

The logarithmic Q 2 slope of F 2 A The turnover occurs at larger Q 2 when we increase the energy and the atomic number, as expected from the behavior of the saturation scale. (*) VPG, PLB 495, 303 (2000). 18

Diffraction in e. A processes: (*) Cazaroto, Carvalho, VPG, Navarra, PLB 671, 233 (2009). 19

Nuclear Deep Virtual Compton Scattering • Coherent production 20

Nuclear Deep Virtual Compton Scattering • Coherent production • Incoherent production 21

Nuclear Deep Virtual Compton Scattering: Coherent production (*) • Dependence on W (*) VPG, Pires, PRC 91, 055207 (2015). • Dependence on Q 2 22

Nuclear. Deep. Virtual Compton Nuclear Compton. Scattering: Scattering Incoherent production (*) • Dependence on W (*) VPG, Pires, PRC 91, 055207 (2015). • Dependence on Q 2 23

Nuclear. Deep. Virtual Compton Nuclear Compton. Scattering: Scattering t - dependence (*) • Dependence on W (*) VPG, Pires, PRC 91, 055207 (2015). • Dependence on A 24

Nuclear. Deep. Virtual Compton Nuclear Compton. Scattering: Scattering t - dependence (*) • Dependence on the dipole – proton scattering amplitude (*) VPG, Pires, PRC 91, 055207 (2015). 25

Vector meson production in exclusive e. A processes: the case • Coherent production • Incoherent production 26

Vector meson production in exclusive Photon – Induced Interactions: e. A processes: the case (*) • Energy dependence of the normalized coherent cross sections (*) VPG, Navarra, Pires, in preparation. 27

Vector meson production in exclusive Photon – Induced Interactions: e. A processes: the case (*) • Energy dependence of the normalized incoherent cross sections (*) VPG, Navarra, Pires, in preparation. 28

Vector meson production in exclusive Photon – Induced Interactions: e. A processes: the case (*) • Dependence on A (*) VPG, Navarra, Pires, in preparation. • Dependence on Q 2 29

Vector meson production in exclusive Photon – Induced Interactions: e. A processes: A comparison (*) VPG, Navarra, Pires, in preparation. 30

Summary ü The future e. A collider is the ideal laboratory to search the nonlinear QCD dynamics effects; ü The search of these effects in inclusive observables is not an easy task due to the large uncertainty present in the collinear predictions using the DGLAP dynamics; ü An alternative: the study of the F 2 A slope; ü The nonlinear effects implies a large amount of difractive processes in e. A collisions; ü The study of exclusive processes, e. g. DVCS or vector meson production, allow us to constrain the magnitude and the main characteristics of the nonlinear QCD dynamics. 31

Summary ü The future e. A collider is the ideal laboratory to search the nonlinear QCD dynamics effects; ü The search of these effects in inclusive observables is not an easy task due to the large uncertainty present in the collinear DGLAP predictions; ü An alternative: the study of the F 2 A slope; ü The nonlinear effects implies a large amount of difractive processes in e. A collisions; ü The study of exclusive processes, e. g. DVCS or vector meson production, allow us to constrain the magnitude and the main characteristics of the nonlinear QCD dynamics. 32

Summary ü The future e. A collider is the ideal laboratory to search the nonlinear QCD dynamics effects; ü The search of these effects in inclusive observables is not an easy task due to the large uncertainty present in the collinear DGLAP predictions; ü An alternative: the study of the F 2 A slope; ü The nonlinear effects implies a large amount of difractive processes in e. A collisions; ü The study of exclusive processes, e. g. DVCS or vector meson production, allow us to constrain the magnitude and the main characteristics of the nonlinear QCD dynamics. 33

Summary ü The future e. A collider is the ideal laboratory to search the nonlinear QCD dynamics effects; ü The search of these effects in inclusive observables is not an easy task due to the large uncertainty present in the collinear DGLAP predictions; ü An alternative: the study of the F 2 A slope; ü The nonlinear effects implies a large amount of difractive processes in e. A collisions; ü The study of exclusive processes, e. g. DVCS or vector meson production, allow us to constrain the magnitude and the main characteristics of the nonlinear QCD dynamics. 34

Summary ü The future e. A collider is the ideal laboratory to search the nonlinear QCD dynamics effects; ü The search of these effects in inclusive observables is not an easy task due to the large uncertainty present in the collinear DGLAP predictions; ü An alternative: the study of the F 2 A slope; ü The nonlinear effects implies a large amount of difractive processes in e. A collisions; ü The study of exclusive processes, e. g. DVCS or vector meson production, allow us to constrain the magnitude and the main characteristics of the nonlinear QCD dynamics. 35

Summary ü The future e. A collider is the ideal laboratory to search the nonlinear QCD dynamics effects; ü The search of these effects in inclusive observables is not an easy task due to the large uncertainty present in the collinear DGLAP predictions; ü An alternative: the study of the F 2 A slope; ü The nonlinear effects implies a large amount of difractive processes in e. A collisions; ü The study of exclusive processes, e. g. DVCS or vector meson production, allow us to constrain the magnitude and the main characteristics of the nonlinear QCD dynamics. Thank you for your attention ! 36

Extras 37

Constraining the nuclear gluon distribution in the collinear formalism (*) Cazaroto, Carvalho, VPG, Navarra, PLB 669, 331 (2008). 38

Constraining the nuclear gluon distribution in the collinear formalism The measurement of RL gives a direct access to the xg. A and, consequently, allow us to discriminate between the distinct DGLAP predictions. (*) Cazaroto, Carvalho, VPG, Navarra, PLB 669, 331 (2008). 39

Probing Pomeron Loop effects in e. A processes (*) Amaral, VPG, Kugeratski, NPA 930, 104 (2014). 40

Probing Pomeron Loop effects in e. A processes (*) Amaral, VPG, Kugeratski, NPA 930, 104 (2014). 41