Related papers: Transversity and $\Lambda$ polarization at COMPASS
Following a previous description of Lambda and Lambda-bar polarization in unpolarized p-p interactions, within a perturbative QCD factorization scheme with new polarizing fragmentation functions, here we investigate the transverse…
Since 2005, measurements of Collins and Sivers asymmetries from the HERMES and COMPASS experiments have allowed to assess that the transversity and the Sivers PDFs are different from zero and measurable in semi-inclusive DIS on transversely…
Transversely polarized Lambda production in hard scattering processes is discussed in terms of a leading twist T-odd fragmentation function which describes the fragmentation of an unpolarized quark into a transversely polarized Lambda. We…
The production of vector mesons in SIDIS is a particularly interesting channel to study the polarized fragmentation and related phenomena. Preliminary COMPASS results for the first measurement of inclusive $\rho^0$ Collins and Sivers…
Measuring single spin asymmetries in semi-inclusive deep-inelastic scattering (SIDIS) on a transversely polarized target gives a handle to investigate the transversity distribution and transverse momentum dependent distribution functions.…
We study the transverse-momentum distribution of hadrons produced in semi-inclusive deep-inelastic scattering (SIDIS). We consider cross sections for various combinations of polarizations of the initial lepton and nucleon or the produced…
The transverse polarization observed in the inclusive production of Lambda hyperons in the high energy collisions of unpolarized hadrons is tackled by considering a new set of spin and kT dependent quark fragmentation functions. Simple…
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 analyse the role of partonic transverse motion in unpolarized Semi-Inclusive Deep Inelastic Scattering (SIDIS) processes. Imposing appropriate kinematical conditions, we find some constraints which fix an upper limit to the range of…
The transversity distribution for $u$ and $d$ quarks is usually extracted from data on spin asymmetries in Semi Inclusive Deep Inelastic Scattering (SIDIS): however, due to its chiral odd nature, it has to be coupled to another chiral odd…
The polarization of $\Lambda$ hyperons is preserved in the angular distribution of their decay products. This property allows one to study the spin structure of the $\Lambda$. In Semi-Inclusive Deep Inelastic Scattering where a high energy…
Spontaneous polarization of $\Lambda/\bar{\Lambda}$ in unpolarized hadron interactions has been observed experimentally for nearly half a century and still eludes a definitive explanation. One possible origin is the effect arising from…
The transverse polarization of $\Lambda$ hyperons within unpolarized jets originates from the transverse-momentum-dependent (TMD) fragmentation function $D_{1T}^\perp (z, p_T, \mu^2)$. In the vacuum environment, the QCD evolution of this…
In semi-inclusive deep inelastic scattering of polarized leptons on a transversely polarized target eight target transverse spin-dependent azimuthal modulations are allowed. In the QCD parton model half of these asymmetries can be…
Measurements of transverse polarization of Lambda hyperons produced in high energy pp collisions may help to address several open issues about Lambda production and polarization mechanisms, such as the amount of SU(3) breaking, the…
The target fragmentation region of semi-inclusive deep inelastic scattering is described at leading twist, taking beam and target polarizations into account. The formalism of polarized and transverse-momentum dependent fracture functions is…
We analyse the role of partonic transverse motion in unpolarized Semi-Inclusive Deep Inelastic Scattering (SIDIS) processes. Imposing appropriate kinematical conditions, we find some constraints which fix an upper limit to the range of…
The description of the polarized quark hadronization process is one of the most challenging problems in the physics of strong interactions. The various single hadron and dihadron fragmentation functions, that quantify this process, are…
We study the production of transversely polarized Lambda hyperons in high-energy collisions of protons with large nuclei. The large gluon density of the target at saturation provides an intrinsic semi-hard scale which should naturally allow…
We study the polarization of the anti-Lambda particle in polarized high energy pp collisions at large transverse momenta. The anti-Lambda polarization is found to be sensitive to the polarization of the anti-strange sea of the nucleon. We…