Searching for the gluon saturation scale at 𝑥∼10^{−5} with the LHCb detector using direct photons.

Because of the increasing gluon density towards small-𝑥, a regime where these densities reach a saturation (𝑄sat) is expected. The observation of this gluon saturated matter has several consequences to particle production and is a matter of an entire effective field theory, the Color Glass Condensate. The Large Hadron Collider beauty (LHCb) experiment has a privileged geometry for the search of the gluon saturation achieving an unprecedent small-𝑥 coverage. The most direct measurement of gluon densities and kinematics in hadronic collisions is the inverse Compton process (𝑞+𝑔→𝛾+𝑞). The LHCb experiment measured pairs of isolated photons correlated with hadrons from the quark fragmentation in pPb and Pbp collisions at 8.16 TeV probing a Bjorken-𝑥 between 10^{-5}