Related papers: Transversity Measurements at COMPASS
The aim of the COMPASS hadron programme is to study the light-quark hadron spectrum, and in particular, to search for evidence of hybrids and glueballs. COMPASS is a fixed-target experiment at the CERN SPS and features a two-stage…
Single-spin asymmetries in the semi-inclusive production of charged pions in deep-inelastic scattering from transversely and longitudinally polarized proton targets are combined to evaluate the subleading-twist contribution to the…
Fragmentation functions represent a key ingredient to address the proton spin structure in semi-inclusive deep-inelastic scattering and proton-proton collisions. They can not be determined from perturbative Quantum Chromodynamics and have…
We study the beam single spin asymmetry in semi-inclusive hadron production in deep inelastic scattering in at order 1/Q. There are two competing contributions: the leading order transverse momentum dependent parton distribution…
The Collins and Sivers asymmetries for charged hadrons produced in deeply inelastic scattering on transversely polarised protons have been extracted from the data collected in 2007 with the CERN SPS muon beam tuned at 160 GeV/c. At large…
The state of the art concerning transverse-spin and transverse-momentum phenomena in hard hadronic reactions is reviewed. An account is given of single-spin and azimuthal asymmetries in semiinclusive deep inelastic scattering, e^+ e^-…
The COMPASS Collaboration performed measurements of the Drell-Yan process in 2015 and 2018 using a 190 GeV/c $\pi^{-}$ beam impinging on a transversely polarised ammonia target. Combining the data of both years, we present final results on…
The COMPASS experiment at CERN has collected a large sample of events of inelastic scattering of longitudinally polarised muons off longitudinally polarised protons in the non-perturbative region (four-momentum transfer squared $Q^2<1$…
We review the information on the spin and orbital angular momentum structure of the nucleon encoded in the T-even transverse momentum dependent parton distributions within light-cone quark models. Model results for azimuthal spin…
We use a new set of Collins functions to update a previous prediction on the azimuthal asymmetries of pion productions in semi-inclusive deep inelastic scattering (SIDIS) process on a transversely polarized nucleon target. We find that the…
The measurement of transverse single-spin asymmetries for baryon production in the target fragmentation region of semi-inclusive deep-inelastic scattering (SIDIS), can produce important insight into those nonperturbative aspects of QCD…
A review is given on single spin asymmetries in deep inelastic semi-inclusive scattering (SIDIS) and their possible theoretical understanding in the framework of QCD-induced factorization approach, wherefore predictions for transversity…
A comprehensive collection of results on longitudinal double-spin asymmetries is presented for charged pions and kaons produced in semi-inclusive deep-inelastic scattering of electrons and positrons on the proton and deuteron, based on the…
We calculate, in a model, the beam spin asymmetry in semi-inclusive jet production in deep inelastic scattering. This twist-3, $T$-odd observable is non-zero due to final state strong interactions. With reasonable choices for the…
We review what is currently known about the transverse spin structure of hadrons, in particular from observables that can be analyzed within a collinear framework. These effects have been around for 40 years and represent a critical test of…
We study single spin asymmetries at one-loop accuracy in semi-inclusive DIS with a transversely polarized hadron in the initial state. Two measurable spin observables are predicted in the framework of QCD collinear factorization. One of the…
Accounting for transverse momenta of the quarks, a longitudinal quark spin asymmetry exists in a transversely polarized nucleon target. The relevant leading quark distribution $g_{1T}(x,k_T^2)$ can be measured in the semi-inclusive…
A first measurement of beam spin asymmetries for $\pi^+\pi^0$ and $\pi^-\pi^0$ pairs in semi-inclusive deep inelastic scattering is reported. The asymmetries in the dihadron angular distributions were measured from the scattering of a 10.6…
COMPASS is a fixed-target experiment at the CERN SPS for the investigation of the structure and the dynamics of hadrons. The experimental setup features a large acceptance and high momentum resolution spectrometer including particle…
The STAR Collaboration reports measurements of the transverse single-spin asymmetries, $A_N$, for inclusive jets and identified `hadrons within jets' production at midrapidity from transversely polarized $pp$ collisions at $\sqrt{s}$ = 200…