Gluon density fluctuations in dilute hadrons

Laura Dominé , Giuliano Giacalone (1) , Cédric Lorcé (2) , Stéphane Munier (2) , Simon Pekar

1 IPHT - Institut de Physique Théorique - UMR CNRS 3681
2 CPHT - Centre de Physique Théorique [Palaiseau]

Motivated by the relation existing between the gluon density in a hadron and the multiplicity of the particles measured in the final state of hadron-nucleus collisions, we study systematically the fluctuations of the gluon density in onia, which are the simplest dilute hadrons, of different sizes and at various rapidities. We argue that the small and the large-multiplicity tails of the gluon distributions present universal features, which should translate into properties of the multiplicity of the particles measured in the final state of high-energy proton-nucleus collisions, or of deep-inelastic scattering at a future electron-ion collider. We propose simple physical pictures of the rare events populating the tails of the multiplicity distribution that allow us to derive analytical formulas describing these universal behaviors, and we compare them to the results of Monte Carlo simulations.

Mots clés: Strong Interactions; gluon: density; particle: multiplicity; density: fluctuation; numerical calculations: Monte Carlo; electron nucleon: colliding beams; deep inelastic scattering; electron nucleus: scattering; hadron nucleus: scattering; p nucleus: scattering; energy: high; rapidity

Domaines: Physique des Hautes Energies - Phénoménologie [hep-ph]

Laura Dominé, Giuliano Giacalone, Cédric Lorcé, Stéphane Munier, Simon Pekar. Gluon density fluctuations in dilute hadrons. Physical Review D, 2018, 98 (11), pp.114032. ⟨10.1103/PhysRevD.98.114032⟩. ⟨hal-01909175⟩