Parton intrinsic motion: suppression of the Collins mechanism for transverse single spin asymmetries in p(transv. polarised) p --> pion + X

Abstract

We consider a general formalism to compute inclusive polarised and unpolarised cross sections within pQCD and the factorisation scheme, taking into account parton intrinsic motion in distribution and fragmentation functions, as well as in the elementary dynamics. Surprisingly, the intrinsic partonic motion, with all the correct azimuthal angular dependences, produces a strong suppression of the transverse single spin asymmetry arising from the Collins mechanism. As a consequence, and in contradiction with earlier claims, the Collins mechanism is unable to explain the large asymmetries found in p(transv. polarised) p --> pion + X at moderate to large Feynman x_F. The Sivers effect is not suppressed.

arXiv commentLaTeX, 21+1 pages, 1 ps figure

References in corpus (30)

• Fragmentation of Transversely Polarized Quarks Probed in Transverse Momentum Distributions
• Time-reversal odd distribution functions in leptoproduction
• The complete tree-level result up to order $1/Q$ for polarized deep-inelastic leptoproduction
• Universality of T-odd effects in single spin and azimuthal asymmetries
• Fragmentation Functions for Pions, Kaons, and Protons at Next-to-Leading Order
• Transverse Polarisation of Quarks in Hadrons
• NNLO global parton analysis
• QCD Factorization for Spin-Dependent Cross Sections in DIS and Drell-Yan Processes at Low Transverse Momentum
• Fragmentation Functions from Flavour-inclusive and Flavour-tagged e^+e^- Annihilations
• Observation of a Single-Spin Azimuthal Asymmetry in Semi-Inclusive Pion Electro-Production
• Positivity Constraints for Spin-Dependent Parton Distributions
• Mid-Rapidity Neutral Pion Production in Proton-Proto Collisions at sqrt(s_NN) = 200 GeV
• Cross Sections and Transverse Single-Spin Asymmetries in Forward Neutral-Pion Production from Proton Collisions at \sqrt{s} = 200 GeV
• Investigating the origins of transverse spin asymmetries at RHIC
• Single spin asymmetry for $p^{\uparrow }p\to \pi X$ in perturbative QCD
• Systematic Study of High p_T Hadron Spectra in pp, pA and AA Collisions from SPS to RHIC Energies
• Measuring transversity densities in singly polarized hadron-hadron and lepton-hadron collisions
• Single-spin Azimuthal Asymmetries in Electroproduction of Neutral Pions in Semi-inclusive Deep-inelastic Scattering
• Bounds on transverse momentum dependent distribution and fragmentation functions
• Parton intrinsic motion in inclusive particle production: unpolarized cross sections, single spin asymmetries and the Sivers effect
• Single spin asymmetries in transversely polarized proton(antiproton) - proton inclusive processes
• High-p_T pion and kaon production in relativistic nuclear collisions
• Lambda polarization from unpolarized quark fragmentation
• Phenomenology of single spin asymmetries in p(transv. polarized)-p -> pion + X
• A New Evaluation of Polarized Parton Densities in the Nucleon
• Effects of Parton Intrinsic Transverse Momentum on Photon Production in Hard-Scattering Processes
• NLO QCD Analysis of Polarized Deep Inelastic Scattering
• Hard Scattering in QCD with Polarized Beams
• Reassessment of the Collins Mechanism for Single-spin Asymmetries and the behavior of Delta d(x) at large x
• On the non-vanishing of the Collins mechanism for single spin asymmetries

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• The Spin Structure of the Proton
• Single-Transverse Spin Asymmetries: From DIS to Hadronic Collisions
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• General partonic structure for hadronic spin asymmetries
• High transverse momentum eta meson production in p+p, d+Au and Au+Au collisions at sqrt(s_NN) = 200 GeV
• Next-to-leading Order Calculation of the Single Transverse Spin Asymmetry in the Drell-Yan Process
• QCD Evolution of the Transverse Momentum Dependent Correlations
• Collins effect in semi-inclusive deeply inelastic scattering and in electron positron annihilation
• Reviewing model calculations of the Collins fragmentation function
• Sivers effect and the single spin asymmetry A_N in p(transv. pol.) p --> h X processes
• Sivers effect in Drell Yan at RHIC
• Process dependent Sivers function and implications for single spin asymmetry in inclusive hadron production
• On the role of Collins effect in the single spin asymmetry A_N in p(transv. polarized) p --> h X processes
• Azimuthal asymmetries for hadron distributions inside a jet in hadronic collisions
• The Sivers single-spin asymmetry in photon-jet production
• Single Spin Asymmetry Scaling in the Forward Rapidity Region at RHIC
• Constraints on the gluon Sivers distribution via transverse single spin asymmetries at midrapidity in p(transv. polarized) p -> pi^0 X processes at BNL RHIC
• Testing the process dependence of the Sivers function via hadron distributions inside a jet
• TMDs and SSAs in hadronic interactions
• Monte-Carlo simulation of events with Drell-Yan lepton pairs from antiproton-proton collisions
• Single transverse-spin asymmetries in forward pion production at high energy: incorporating small-x effects in the target
• Feasibility Studies for Single Transverse-Spin Asymmetry Measurements at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC)
• Transverse Spin Structure of the Nucleon
• Phenomenology of transverse spin: past, present and future
• Single spin asymmetries in l p --> h X processes: a test of factorization
• Collins Asymmetry at Hadron Colliders
• Single transverse spin asymmetry of prompt photon production
• Monte Carlo simulation of events with Drell-Yan lepton pairs from antiproton-proton collisions: the fully polarized case
• Spin asymmetries in jet-hyperon production at LHC
• Double spin asymmetry A_{LT} in direct photon production
• Single-Spin Observables and Orbital Structures in Hadronic Distributions
• Monte Carlo simulation of the Sivers effect in high-energy proton-proton collisions
• Transverse single-spin asymmetries in proton-proton collisions at the AFTER@LHC experiment in a TMD factorisation scheme
• Collins Effect in Single Spin Asymmetries of the $p^{\uparrow }p\to \pi X$ Process
• Transverse single-spin asymmetries in $\ell p^{\uparrow }\to hX$ within a TMD approach: Role of quasireal photon exchange
• Single Spin Asymmetry at Large x_F and k_T
• Sivers and Collins Single Spin Asymmetries
• Single Spin Asymmetry in Inclusive Hadron Production in pp Scattering from Collins Mechanism
• Left-right asymmetry in semi-inclusive deep inelastic scattering process
• Analogies between hadron-in-jet and dihadron fragmentation
• Spin physics with antiprotons
• Measurement of the Transverse Single-Spin Asymmetry for Mid-rapidity Production of Neutral Pions in Polarized p+p Collisions at 200 GeV Center-of-Mass Energy
• Left-right asymmetry for pion and kaon production in the semi-inclusive deep inelastic scattering process
• Hyperon Polarization in Unpolarized Scattering Processes
• Sivers effect in semi-inclusive DIS and in the Drell-Yan process
• Anti-hyperon Polarization in $pA$ and ${\Sigma }^{-}A$ Collisions and Intrinsic Antidiquark State in Incident Baryon
• Transverse momentum dependent quark distributions and polarized Drell-Yan processes
• On the Relation Between Mechanisms for Single-Transverse-Spin Asymmetries