相关论文: Single spin asymmetries in ultra-peripheral $p^\up…
Transverse single-spin asymmetries in inclusive deep inelastic lepton-nucleon scattering can be generated through multiphoton exchange between the leptonic and the hadronic part of the process. Here we consider the two-photon exchange, and…
We investigate the single-spin asymmetries in inclusive and exclusive processes of electron-proton scattering and electron-positron annihilation. In the decomposition of hadronic tensor, a Lorentz symmetric spin-dependent term is generally…
We present a calculation of single and double spin asymmetries for inclusive hadron production in hadronic collisions. Our approach is based on Leading Order (LO) perturbative QCD and generalized factorization theorems, with full account of…
The first measurements of $x_F$-dependent single spin asymmetries of identified charged hadrons, $\pi^{\pm}$, $K^{\pm}$, and protons, from transversely polarized proton-proton collisions at 62.4 GeV at RHIC are presented. The measurements…
The PHENIX experiment at BNL-RHIC recently reported the single transverse spin asymmetry $A_N$ for forward neutrons measured in polarized proton-nucleus collisions at $\sqrt{s_{NN}} = 200\,$GeV; $A_N$ in proton-aluminum and proton-gold…
Understanding the origin and mechanism of the transverse polarization of hyperons produced in unpolarized proton-proton collision, $pp\to \Lambda^\uparrow X$, has been one of the long-standing issues in high-energy spin physics. In the…
We report the first measurement of the opening angle distribution between pairs of jets produced in high-energy collisions of transversely polarized protons. The measurement probes (Sivers) correlations between the transverse spin…
We extend the analysis of two-hadron fragmentation functions to the subleading twist, discussing also the issue of color gauge invariance. Our results can be used anywhere two unpolarized hadrons are semi-inclusively produced in the same…
We derive a general framework for describing semi-inclusive deep-inelastic lepton-nucleon scattering in terms of the unintegrated parton distributions and other higher twist parton correlations. Such a framework provides a consistent…
Motivated by a novel origin of transverse single spin asymmetry (SSA) in semi-inclusive Deep Inelastic Scattering (SIDIS) uncovered by some of us, we quantitatively investigate its impact on the theoretical understanding of the mechanism…
We have measured the cross section and single spin asymmetries from forward $W^{\pm}\rightarrow\mu^{\pm}\nu$ production in longitudinally polarized $p$$+$$p$ collisions at $\sqrt{s}=510$ GeV using the PHENIX detector at the Relativistic…
Ultra-peripheral collisions (UPC) are events characterised by large impact parameters between the two projectiles, larger than the sum of their radii. In UPCs, the protons and ions accelerated by the LHC do not interact via the strong…
We present recent results of single-spin asymmetry $A_N$ measurements in $\pi^0$ inclusive production. Asymmetry was measured in $\pi^-p$ and $pp$ interactions at 40 and 70 GeV correspondingly. Significant asymmetry was observed in the…
We consider the single-spin azimuthal asymmetries recently measured at the HERMES experiment for charged pions produced in semi-inclusive deep inelastic scattering of leptons off longitudinally polarized protons. Guided by the experimental…
At the leading twist, the transversity distribution function, $h^{q}_{1}(x)$, where $x$ is the longitudinal momentum fraction of the proton carried by quark $q$, encodes the transverse spin structure of the nucleon. Extraction of it is…
We consider forward pion production in p p collisions at RHIC energies,which probes the so-called Extended Geometric Scaling region. Upon inclusion of small-x effects via an anomalous dimension within the Color Glass Condensate formalism at…
The most recent data on the weighted transverse single spin asymmetry $A_{UT}^{\sin(\phi_h-\phi_S)}$ from HERMES and COMPASS collaborations are analysed within LO parton model with unintegrated parton distribution and fragmentation…
The study of the Sivers effect, describing correlations between the transverse polarization of the nucleon and its constituent (unpolarized) parton's transverse momentum, has been the topic of a great deal of experimental, phenomenological…
We calculate the single transverse spin asymmetry (STSA) in polarized proton-proton ($p^{\uparrow}+p$) and polarized proton-nucleus ($p^{\uparrow}+A$) collisions ($A_N$) generated by a partonic lensing mechanism. The polarized proton is…
We prove that twist-3 soft-gluon-pole (SGP) cross section for single spin asymmetries is determined by a certain ``primordial'' twist-2 cross section up to kinematic and color factors in the leading order perturbative QCD. This unveils…