arXiv subjects

Yan B. Bandeira

Publications and source records attributed to Yan B. Bandeira.

4 recordsLinked to original sources

arXiv2025

Dilepton angular distributions in the color-dipole $S$-matrix framework

The dilepton production at forward rapidities in hadronic collisions at the LHC energies is considered and the helicity density matrix elements of gauge bosons that enter the Drell--Yan angular coefficients associated with the gauge boson decay ($G = γ^*, Z^0, W$) are derived using the color-dipole $S$ - matrix framework. We show results for $pp$ collisions at $\sqrt{s} = 14$ TeV for the nonvanishing helicity density matrix elements in the rapidity range of $2.0 \le y \le 4.0$ of the gauge boson. We consider different models for the proton unintegrated gluon distributions, among others a solution of the Balitsky--Kovchegov equation. We compare the associated predictions with those obtained disregarding the non-linear term in the evolution equation. In addition, the Lam--Tung relation is discussed.

hep-ph↗

arXiv2025

Associated jet + electroweak gauge boson production in hadronic collisions at forward rapidities in the color-dipole $S$-matrix framework

The cross-section for the associated production of a jet with an electroweak gauge boson ($G = W^{\pm}, Z^0, γ$) at forward rapidities in $pp$ and $pA$ collisions is derived within the color - dipole $S$ - matrix framework. We present the full expressions for the differential cross-section of the $q p \rightarrow G q X$ process in the transverse momentum space, considering the longitudinal and transverse polarizations of the gauge boson. We demonstrate that the final formulae can be expressed in terms of the unintegrated gluon distribution and reproduce previous results for the associated jet + $γ$ and jet + $Z^0$ production, derived using other frameworks. Moreover, we derive the back - to - back correlation limit of the spectra and show that it can be expressed in terms of the unpolarized and linearly polarized transverse momentum gluon distributions. Our results improve the description of the inclusive jet plus color neutral particle production at forward rapidities, not far from the proton fragmentation region, in $pp$ or $pA$ collisions, and are the main ingredient to study the impact of nonlinear QCD effects in two - particle correlations.

hep-ph↗

arXiv2024

Production of electroweak gauge bosons at forward rapidities in the color - dipole $S$ - matrix framework

The cross-section for the production of an electroweak gauge boson ($G = W^{\pm}, Z^0, γ$) at forward rapidities in $pp$ collisions is derived within the color - dipole $S$ - matrix framework. We present the full expressions for the differential cross-section of the $q p \rightarrow G X$ process in the impact parameter and transverse momentum spaces, considering the longitudinal and transverse polarizations of the gauge boson. The particular cases associated with the Drell - Yan process and real photon production are discussed. We demonstrate that the final formulae are expressed in terms of the dipole - proton cross-section or the unintegrated gluon distribution, and can be used to estimate the impact of the saturation effects in the gauge boson production at the LHC and future colliders.

hep-ph↗

arXiv2023

Higher twists effects in DIS on nuclei at the EIC and LHeC: A phenomenological analysis

In this paper we investigate the impact of the higher - twist effects, resummed by the non - linear approaches for the QCD dynamics, on the inclusive observables that will be measured in future electron - ion colliders. We assume a phenomenological model for the dipole - nucleus scattering amplitude which takes into account the non - linear corrections and estimate the contribution of the different twists for $F_2^A(x,Q^2)$, $F_L^A(x,Q^2)$ and $\partial F_2^A /\partial ln Q^2$ considering different values of the Bjorken - $x$ variable, photon virtuality $Q^2$ and atomic number $A$. A comparison with the full predictions is performed and the impact of the distinct twists is estimated. Our results indicate that a future analysis of the logarithmic $Q^2$ slope and longitudinal structure function will allow us to probe the presence of the non - linear effects on the QCD dynamics.

hep-ph↗