相关论文: Constraining the pion distribution amplitude using…
The reaction ${n} {p} \to {p} {p} \pi^{-}$ has been studied in a kinematically complete measurement with a large acceptance time-of-flight spectrometer for incident neutron energies between threshold and 570 MeV. The proton-proton invariant…
The leading twist parametrization of dipion mass distribution in hard exclusive reactions is proposed. Its parameters are related to quark distributions (usual and skewed) in the pion and to distributions amplitudes of mesons ($\pi$,…
This article presents the review of the current understanding on the pion-nucleon Drell-Yan process from the point of view of the TMD factorization. Using the evolution formalism for the unpolarized and polarized TMD distributions developed…
We study hadronic polarization and the related anisotropy of the dilepton angular distribution for the reaction $\pi N \to Ne^+e^-$. We employ consistent effective interactions for baryon resonances up to spin-5/2 to compute their…
The first study of the angular distribution of $\mu^+ \mu^-$ pairs produced in the forward rapidity region via the Drell-Yan reaction $pp \rightarrow \gamma^{*}/Z +X \rightarrow l^+ l^- + X$ is presented, using data collected with the LHCb…
At leading twist the transverse-momentum dependent parton distributions of the pion consist of two functions, the unpolarized $f_{1,\pi}(x,\boldsymbol k^{\, 2}_\perp)$ and the Boer-Mulders function $h_{1,\pi}^{\perp}(x,\boldsymbol k^{\,…
We investigate the single transverse-spin asymmetry with a $\sin (2\phi-\phi_S)$ modulation in the pion-induced Drell-Yan process within the theoretical framework of the transverse momentum dependent factorization. The asymmetry is…
A first measurement of longitudinal as well as transverse spin correlation coefficients for the reaction $\vec{p}\vec{p}\to pn\pi^+$ was made using a polarized proton target and a polarized proton beam. We report kinematically complete…
We evaluate the threshold matrix-element for the reaction $pp \to pp\pi^0$ in a fully relativistic Feynman diagrammatic approach. We employ a simple effective range approximation to take care of the S-wave $pp$ final-state interaction. The…
Values of the proton analysing power in the $pd\to{}^{3}\textrm{He}\,\pi^0/^{3}\textrm{H}\,\pi^+$ reactions at 350-360~MeV per nucleon were obtained by using a polarised proton beam incident on a deuterium cluster-jet target and with a…
We calculate the non-zero (na\"{i}ve) T-odd transverse momentum dependent transversity distribution $h_1^{\perp}(x,\kp^2)$ of the pion in a quark-spectator-antiquark model. The final-state interaction is modelled by the approximation of one…
Existing pion+nucleus Drell-Yan and electron+pion scattering data are used to develop ensembles of model-independent representations of the pion generalised parton distribution (GPD). Therewith, one arrives at a data-driven prediction for…
We extend earlier investigations of charge symmetry violation in the valence quark distributions of the nucleon, and make similar estimates for the pion. The sensitivity of pion-induced Drell-Yan measurements to such effects is then…
We calculate the two leading-twist transverse momentum dependent distribution functions of the pion meson, the unpolarized distribution $f_{1\pi}(x,\bm{k}^2_T)$ and the Boer-Mulders function $h_{1\pi}^\perp (x,\bm{k}^2_T)$, using the pion…
Results are presented of an analysis of proton and charged pion azimuthal distributions measured with respect to the reaction plane in Au + Au collisions at a beam momentum of about 11 AGeV/c. The azimuthal anisotropy is studied as a…
Intermediate energy (p,p$'$x) reaction is studied with antisymmetrized molecular dynamics (AMD) in the cases of $^{58}$Ni target with $E_p = 120$ MeV and $^{12}$C target with $E_p = $ 200 and 90 MeV. Angular distributions for various…
Pion photoproduction reactions are investigated in a dynamical coupled-channel approach based on the Juelich pi-N model, which presently includes the hadronic pi-N and eta-N stable channels as well as the pi-Delta, sigma-N and rho-N…
The quasi-free pn->dphi reaction has been studied at the Cooler Synchrotron COSY-Juelich, using the internal proton beam incident on a deuterium cluster-jet target and detecting a fast deuteron in coincidence with the K+K- decay of the…
A new partial wave analysis of pion photoproduction has been obtained in the framework of fixed-t dispersion relations valid form threshold up to 500 MeV. It is based on new Mainz data for \pi^{0} and \pi^{+} production off the proton and…
The positively charged pions produced in proton-proton collisions at a beam momentum of 1640 MeV/c were measured in the forward direction with a high resolution magnetic spectrograph. The missing mass distribution shows the bound state…