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

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

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5 Nuclei are an efficient amplifier of the nonlinear effects.

66 The color dipole picture:

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88 In what follows: Sums all multiple elastic rescatterings of the dipole.

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

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

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

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

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

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

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

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

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

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

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

Nuclear Deep Virtual Compton Scattering 20 Coherent production

Nuclear Deep Virtual Compton Scattering 21 Incoherent production Coherent production

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

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

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

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

Vector meson production in exclusive eA processes: the  case 26 Incoherent production Coherent production

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

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

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

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

Summary The future eA collider is the ideal laboratory to search the nonlinear QCD dynamics effects; 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; An alternative: the study of the F2A slope; The nonlinear effects implies a large amount of difractive processes in eA collisions; 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 The future eA collider is the ideal laboratory to search the nonlinear QCD dynamics effects; The search of these effects in inclusive observables is not an easy task due to the large uncertainty present in the collinear DGLAP predictions; An alternative: the study of the F2A slope; The nonlinear effects implies a large amount of difractive processes in eA collisions; 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 The future eA collider is the ideal laboratory to search the nonlinear QCD dynamics effects; The search of these effects in inclusive observables is not an easy task due to the large uncertainty present in the collinear DGLAP predictions; An alternative: the study of the F 2 A slope; The nonlinear effects implies a large amount of difractive processes in eA collisions; 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 The future eA collider is the ideal laboratory to search the nonlinear QCD dynamics effects; The search of these effects in inclusive observables is not an easy task due to the large uncertainty present in the collinear DGLAP predictions; An alternative: the study of the F 2 A slope; The nonlinear effects implies a large amount of difractive processes in eA collisions; 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 The future eA collider is the ideal laboratory to search the nonlinear QCD dynamics effects; The search of these effects in inclusive observables is not an easy task due to the large uncertainty present in the collinear DGLAP predictions; An alternative: the study of the F 2 A slope; The nonlinear effects implies a large amount of difractive processes in eA collisions; 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 The future eA collider is the ideal laboratory to search the nonlinear QCD dynamics effects; The search of these effects in inclusive observables is not an easy task due to the large uncertainty present in the collinear DGLAP predictions; An alternative: the study of the F 2 A slope; The nonlinear effects implies a large amount of difractive processes in eA collisions; 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. 36 Thank you for your attention !

Extras 37

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

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

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

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