The VII-th International Conference on the Initial Stages of High-Energy Nuclear Collisions : Initial Stages 2023

Inferring the initial condition for the BK evolution

Not scheduled

2h

Københavns Universitetsbibliotek Nord

Poster Physics at low-x and gluon saturation Reception and poster session

Speaker

Carlisle Aurabelle Casuga (University of Jyväskylä)

Description

In the dipole picture of Deep Inelastic Scattering (DIS) at high energy, the virtual photon fluctuates into a quark-antiquark dipole that interacts with the target color field. This interaction at small-x is naturally described within the Color Glass Condensate (CGC) framework, and one can derive a perturbative Balitsky - Kovchegov (BK) evolution equation that describes the dependence of the dipole-target scattering amplitude on the Bjorken-x.

The initial condition required for the BK evolution describes the dipole-proton scattering at initial Bjorken-x and is as such sensitive to non-perturbative proton structure. In this study, we present an ongoing work where Bayesian inference is used to extract this initial condition with realistic uncertainty estimates from the HERA total cross section data. Extracted posterior distributions of the model parameters describing the initial condition can then be used to calculate predictions and realistic estimates of model uncertainty for any other observable sensitive to the proton small-x structure (such as particle production at the LHC). In the future, the analysis will be extended to include massive quarks and next-to-leading order correction. These future applications require a computationally efficient Bayesian inference setup which is presented in this talk.