相关论文: Probing factorization violation with vector angula…
We discuss the possible factorization of the tensor asymmetry $A^T_d$ measured for polarized deuteron targets within a relativistic framework. We define a reduced asymmetry and find that factorization holds only in plane wave impulse…
Transverse $\Lambda$ polarization observed over four decades ago contradicted expectations from early leading-order perturbative QCD calculations. Measurements of $\Lambda$ polarization from unpolarized $pp$ and $p$A collisions have been…
We investigate Drell-Yan pair production in a QCD inspired model, which takes into account all relevant hard processes up to $O(\alpha_s)$. To address the known shortfalls of such a fixed order calculation we introduce phenomenological…
In a recent paper (arXive:hep-ph/0406125) entitled {\em Parity violation in hot QCD: why it can happen, and how to look for it}, D. Kharzeev argues for the possibility of P- and/or CP- violation effects in heavy-ion collisions, the effects…
We discuss the Drell-Yan production of dileptons at high energies in the forward rapidity region of proton-proton collisions in a hybrid high-energy approach. This approach uses unintegrated gluon distributions in one proton and collinear…
Different exclusive processes have been proposed to access the generalized transverse momentum dependent distributions (GTMDs) with no proof of factorization, which allows to rigorously define the GTMDs. Using Soft Collinear Effective…
Two-particle angular correlation is one of the most powerful tools to study the mechanism of particle production in proton--proton (pp) collision systems by relating the difference between the azimuthal angle ($\Delta\varphi$) and the…
The asymmetry in the angular distribution of Drell--Yan dilepton pairs generated in collisions where just one nucleon is transversely polarised has been examined in the literature with a variety of results, mainly differing by factors of…
The transversity was recently extracted from data on the production of hadron pairs in semi-inclusive deep-inelastic scattering. This analysis can be conveniently performed in the framework of collinear factorization where the elementary…
We present results for a complete set of polarization observables for jet production in lepton proton collision, where the final state lepton is not observed. The calculations are carried out in collinear factorization at the level of Born…
Understanding the internal spin structure of the nucleon still remains a challenge in strong interaction physics. Transversity, which describes the transverse spin structure of quarks in a transversely polarized proton, is poorly…
An essential part of any factorisation proof is the demonstration that the exchange of Glauber gluons cancels for the considered observable. We show this cancellation at all orders for double Drell-Yan production (the double parton…
Recent BELLE measurements provide the cross section for single hadron production in $e^+e^-$ annihilations, differential in thrust and in the hadron transverse momentum with respect to the thrust axis. Universality breaking effects due to…
We study the production of forward di-jets in proton-lead and proton-proton collisions at the Large Hadron Collider. Such configurations, with both jets produced in the forward direction, impose a dilute-dense asymmetry which allows to…
We study the cross section for vector boson ($W^{\pm}/Z^0/\gamma^*$) production in polarized nucleon-nucleon collisions for low transverse momentum of the observed vector boson. For the case where one measures the transverse momentum and…
We present the first measurements at a hadron collider of differential cross sections for Z+jet+X production in delta phi(Z, jet), |delta y(Z, jet)| and |y_boost(Z, jet)|. Vector boson production in association with jets is an excellent…
In the heavy quark limit inclusive production rate of a heavy meson can be factorized, in which the nonperturbative effect related to the heavy meson can be characterized by matrix elements defined in the heavy quark effective theory. Using…
We present an extraction of unpolarised Transverse-Momentum-Dependent Parton Distribution Functions based on Drell-Yan production data from different experiments, including those at the LHC, and spanning a wide kinematic range. We deal with…
The algebraic theory of third-order tensors under the $t$-product is naturally formulated over the complex field via Fourier block diagonalization. However, many applications require real-valued representations. In this paper, we…
Soft threshold factorization has been used extensively to study hadronic collisions. It is derived in the limit where the momentum fractions $x_{a,b}$ of both incoming partons approach $x_{a,b}\to 1$. We present a generalized threshold…