A simple model for nuclear structure functions at small x in the dipole picture

Abstract

A simple model for nuclear structure functions in the region of small x and small and moderate Q 2 , is presented. It is a parameter-free extension, in the Glauber-Gribov approach to nuclear collisions, of a saturation model for the nucleon. A reasonable agreement with experimental data on ratios of nuclear structure functions is obtained. Nuclear effects in the longitudinal-to-transverse cross section ratios are found to be small. Predictions of the model for values of x smaller than those available to present experiments are given. The unintegrated gluon distribution and the behaviour of the saturation scale which result from this model are shown and discussed.

Gluon shadowing in the Glauber–Gribov model

“…The authors of [8] make their calculations within a similar framework as the presented model. For x ≤ 10 −3 our model predicts stronger gluon shadowing compared to [21] (dashed-dotted line) and [8] (dotted line), while [23] (dashed line) predicts the strongest effect down to x ∼ 10 −4 . Our calculations are close to the predictions of [8] for x > 10 −3 for this choice of x max IP , while we are consequently below the predictions of [21].…”

Nuclear exclusive vector meson photoproduction

“…The agreement with the proton data is consistent and the extension to Ca and Pb targets is suitable since it is constrained by the DESY-HERA data and validity of the model in the energy range considered. Furthermore, the present investigation is complementary to those ones on heavy quark production [24] and nuclear structure functions [23] using the saturation model for nuclear targets.…”

“…In fact, for light mesons the nuclear shadowing in the scattering amplitude is stronger than a simple A 1/3 ansatz, as discussed in Ref. [23] when computing the nuclear structure functions. Namely, the saturation scale, which drives the A-dependence, between the proton and central nucleus is not simply ∝ A 1/3 , but has a prefactor which makes the result smaller.…”

“…The latter one is characterized by a typical momentum scale Q sat (saturation scale) and it has been constrained by experimental results in deep inelastic scattering (DIS) and diffractive DIS [22]. Here, we will use an extension of the phenomenological saturation model for nuclear targets [23]. This model reasonably describes the experimental data for the nuclear structure function and has been used to predict the nuclear inclusive and diffractive cross sections for heavy quark photoproduction [24].…”

Heavy Quarks and Meson Production in Ultraperipheral Heavy Ion Collisions

“…In this model the cross section for the heavy quark photoproduction on nuclei targets is given by 6,7 ,…”