Related papers: Testing the meson cloud in the nucleon in Drell-Ya…
We provide an experimental and theoretical perspective on the behavior of unpolarized distribution functions for the nucleon and pion on the valence-quark domain; namely, Bjorken-x \gtrsim 0.4. This domain is key to much of hadron physics;…
We study the phenomenology of Drell-Yan processes at the Large Hadron Collider for the case of both the neutral and charged current channels within a recently proposed 4-Dimensional formulation of the Minimal Composite Higgs Model. We…
We investigate the role of the flavor asymmetry of the nucleon's polarized antiquark distributions in Drell-Yan lepton pair production in polarized nucleon-nucleon collisions at HERA (fixed-target) and RHIC energies. It is shown that the…
We discuss the flavor asymmetry of the nucleon in an unquenched quark model for baryons in which the effects of quark-antiquark pairs (u anti-u, d anti-d and s anti-s) are taken into account in an explicit form. It is shown that the…
Parton distributions derived from a chiral quark model that generates an excess of down quarks and antiquarks in the proton's sea satisfactorily describe the measured yields of muon pairs produced in proton-nucleus collisions. Comparison of…
We study the possible contribution of the nucleon's virtual meson cloud to the sea quark distribution as observed in deep inelastic lepton scattering. We adjust the meson-nucleon cut-offs to the large-x tails of the antiquark distributions,…
The recent progress on our understanding of the flavor structure of unpolarized and polarized nucleon sea is reviewed. The large flavor asymmetry between the up and down sea quark distributions is now well established. This asymmetry…
We discuss the nuclear parton distribution functions on the basis of our recently developed semi-microscopic model, which takes into account a number of nuclear effects including Fermi motion and nuclear binding, nuclear meson-exchange…
We address the question whether the nucleon's antiquark sea can be attributed entirely to its virtual meson cloud and, in essence, whether there exists a smooth transition between hadronic and quark-gluon degrees of freedom. We take into…
The lepton helicity distributions in the polarized Drell-Yan process at RHIC energy are investigated. In the absence of the weak interaction, only the measurement of lepton helicity can prove the antisymmetric part of the hadronic tensor.…
We perform a global analysis of Drell-Yan production of charged leptons and dineutrinos, the latter in missing energy plus jet events, in proton-proton collisions within the Standard Model Effective Field Theory (SMEFT). The combination…
A short summary of results of recent simulations of (un)polarized Drell-Yan experiments is presented here. Dilepton production in $pp$, $\bar{p}p$, $\pi^-p$ and $\pi^+p$ scattering is considered, for several kinematics corresponding to…
We investigate the flavour and quark-antiquark structure of the polarized nucleon by calculating the parton distribution functions of the nucleon sea using the meson cloud model. We find that the SU(2) flavor symmetry in the light antiquark…
Modifications of baryon properties due to the restoration of the chiral symmetry in an external hot and dense baryon medium are investigated in an effective chiral quark-meson theory. The nucleon arises as a soliton of the Gell-Mann -…
We explore the possibility of measuring nuclear gluon distributions at the Relativistic Heavy-Ion Collider (RHIC) with $\sqrt{s}=200 \, {\rm GeV}$ proton-nucleus collisions. In addition to measurements at central rapidity, we consider also…
Asymmetries in the quark momentum distributions in the proton reveal fundamental aspects of strong interaction physics. Differences between u-bar and d-bar quarks in the proton sea provide insight into the dynamics of the pion cloud around…
The potential of the Compact Muon Solenoid (CMS) experiment to measure Drell-Yan muon pairs is discussed. Muon pairs can be measured in CMS with high precision up to very high invariant masses. The systematic errors are considered. The…
The discovery of a sizeable asymmetry in the $\bar u$ and $\bar d$ distributions in the proton was one of the more consequential experimental findings in hadron physics last century. Although widely believed to be related to the fundamental…
COMPASS at CERN is preparing for a new series of measurements on the nucleon structure comprising deep virtual Compton scattering and hard exclusive meson production using muon beams, as well as Drell-Yan reactions using a polarised proton…
It is now widely recognized that a key to unravel the nonperturbative chiral-dynamics of QCD hidden in the deep-inelastic-scattering observables is the flavor structure of sea-quark distributions in the nucleon. We analyze the flavor…