scholarly journals KANE-PUMPLIN-REPKO FACTORIZATION: ITS APPLICATION TO PRECISION MEASUREMENTS OF TRANSVERSE SPIN ASYMMETRIES AND TO THE STUDY OF TMD EVOLUTION

2014 ◽  
Vol 25 ◽  
pp. 1460002 ◽  
Author(s):  
DENNIS SIVERS
Keyword(s):  
Transverse Momentum ◽  
Inelastic Scattering ◽  
Precision Measurements ◽  
Transverse Spin ◽  
Transverse Momentum Dependent ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Hadronic Structure ◽  
Single Spin Asymmetries ◽  
Fundamental Understanding

This article presents a summary of overlapping presentations by the author to the QCD Evolution 2013 Workshop (Jefferson Lab, May 6-10, 2013) and to the Opportunities for Polarized Physics at Fermilab workshop (Fermilab, May 20-22, 2013). It contains an introduction to the concept of Kane-Pumplin-Repko (KPR) factorization and describes how this concept can be used in the analysis of high precision measurements of parity-conserving transverse single-spin asymmetries. The discussion demonstrates that such measurements can not only probe directly for specific mechanisms that enhance our fundamental understanding of nonperturbative QCD dynamics but, because transverse spin asymmetries are unambiguously parameterized by a spin-directed momentum shift, 〈δkTN (x, μ2)〉 such measurements can also be used to calibrate other phenomenological applications of transverse momentum dependent distributions (TMDs) and of TMD evolution. The calibration supplied by these measurements can thus enable the use of TMD factorization for the exploration of a broad range of other aspects of hadronic structure. KPR factorization ensures that 〈δkTN (x, μ2)〉 remains invariant under TMD evolution and this invariance can be used in the precision comparison of transverse single-spin asymmetries in the Drell-Yan process with those in Semi-inclusive deep inelastic scattering.

scholarly journals Single spin asymmetries in ℓp↑→hX processes and transverse momentum dependent factorization

2014 ◽  
Vol 89 (11) ◽  
Author(s):  
M. Anselmino ◽  
M. Boglione ◽  
U. D’Alesio ◽  
S. Melis ◽  
F. Murgia ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Transverse Momentum Dependent ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Single Spin Asymmetries

QCD EVOLUTION FOR TRANSVERSE MOMENTUM DEPENDENT OBSERVABLES

2014 ◽  
Vol 25 ◽  
pp. 1460008
Author(s):  
PENG SUN ◽  
FENG YUAN
Keyword(s):  
Transverse Momentum ◽  
Inelastic Scattering ◽  
Deep Inelastic Scattering ◽  
Cross Sections ◽  
Lepton Pair ◽  
Transverse Spin ◽  
Transverse Momentum Dependent ◽  
Spin Asymmetries ◽  
Hadronic Physics

In this talk, we presented our recent studies of the QCD evolution effects on the transverse momentum dependent observables in semi-inclusive deep inelastic scattering and Drell-Yan lepton pair productions. The evolution is first tested for the spin average cross sections, and then applied to the Sivers single transverse spin asymmetries. The latter are among the important topics in hadronic physics research in recent years.

scholarly journals AN of Single Heavy Flavor Decay Muon in the PHENIX Experiment at RHIC

2016 ◽  
Vol 40 ◽  
pp. 1660043 ◽  
Author(s):  
Xiaorong Wang ◽  
Feng Wei
Keyword(s):  
Transverse Momentum ◽  
Spin Asymmetry ◽  
Single Spin Asymmetry ◽  
Transverse Spin ◽  
Heavy Flavor ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Phenix Experiment ◽  
Single Spin Asymmetries ◽  
Heavy Flavor Production

Transverse single-spin asymmetries provide valuable information about the spin structure of the nucleon. At RHIC energies, heavy-flavor production is dominated by gluon-gluon fusion, and the subsequent decay into high [Formula: see text] electrons or muons can be observed statistically in a collider detector like PHENIX. The transverse single-spin asymmetry in heavy-flavor production originates from the initial state correlation between the internal transverse momentum of the parton and the transverse spin of the nucleon (similar with the known Sivers effect). The measurement of transverse single-spin asymmetry of single muons from heavy flavor decay at RHIC serves as a clean probe and would provide important information on the gluon Sivers function. In 2012, the PHENIX experiment collected 9.2 [Formula: see text] integrated luminosity in transversely polarized [Formula: see text] collisions at [Formula: see text] = 200 GeV with a polarization of [Formula: see text]. The signal-to-background ratio was improved by a factor of two compared to the previous RHIC 2006 and 2008 results in high transverse momentum region ([Formula: see text]GeV). The recent PHENIX preliminary results of transverse single-spin asymmetries of single heavy flavor decay muon at forward-rapidity will be shown and the possible improvement on this measurement in 2015 with the help of the FVTX detector will be discussed.

Transverse Single-Spin Asymmetries in Proton-Proton Collisions Within Collinear Factorization

2015 ◽  
Vol 37 ◽  
pp. 1560033
Author(s):  
Daniel Pitonyak ◽  
Koichi Kanazawa ◽  
Yuji Koike ◽  
Andreas Metz
Keyword(s):  
Transverse Momentum ◽  
Heavy Ion ◽  
High Transverse Momentum ◽  
Relativistic Heavy Ion Collider ◽  
Collinear Factorization ◽  
Transverse Momentum Dependent ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Single Spin Asymmetries ◽  
Azimuthal Asymmetries

We provide a new analysis within collinear factorization of transverse single-spin asymmetries (TSSAs) in high transverse momentum charged and neutral pion production in pp collisions at the Relativistic Heavy Ion Collider (RHIC). This study incorporates the so-called twist-3 fragmentation term and shows that one can describe RHIC data through this mechanism. Moreover, by fixing other non-perturbative inputs through extractions of transverse momentum dependent functions in e+e- → h1h2X and semi-inclusive deep-inelastic scattering (SIDIS), we provide for the first time a consistency between certain spin/azimuthal asymmetries in all three reactions (i.e., pp, e+e-, and SIDIS).

Predictions on the Transverse Single-Spin Asymmetries at Subleading Twist of Pion Production in Semi-Inclusive DIS

2016 ◽  
Vol 40 ◽  
pp. 1660030
Author(s):  
Wenjuan Mao ◽  
Zhun Lu ◽  
Bo-Qiang Ma
Keyword(s):  
Transverse Momentum ◽  
Pion Production ◽  
Diquark Model ◽  
Transverse Momentum Dependent ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Single Spin Asymmetries ◽  
Fragmentation Functions

We estimate the single-spin asymmetries with [Formula: see text] and [Formula: see text] angular dependencies for electroproduction of pions in transversely polarized semi-inclusive DIS process. We consider the effect of the twist-3 transverse momentum dependent distributions which convoluted with twist-2 fragmentation functions. We calculate these distributions in a spectator-diquark model, and predict the corresponding single-spin asymmetries at the kinematics of HERMES, JLab and COMPASS. We find that the numerical estimates show that the asymmetries are sizable, and the T-odd twist-3 TMDs play an important role in these asymmetries.

TRANSVERSE SPIN AND TRANSVERSE MOMENTUM EFFECTS AT COMPASS

2009 ◽  
Vol 24 (35n37) ◽  
pp. 3015-3024 ◽  
Author(s):  
FRANCO BRADAMANTE
Keyword(s):  
Transverse Momentum ◽  
Muon Beam ◽  
Transverse Spin ◽  
Fixed Target ◽  
Deuteron Target ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Polarized Target ◽  
Single Spin Asymmetries ◽  
Target Experiment

The study of transverse spin and transverse momentum effects is part of the scientific program of COMPASS, a fixed target experiment at the CERN SPS. For these studies, a 160 GeV/c momentum muon beam is scattered on a transversely polarized nucleon target, and the scattered muon and the forward going hadrons produced in DIS processes are reconstructed and identified in a magnetic spectrometer. The measurements have been performed on a deuteron target in 2002, 2003 and 2004, and on a proton target in 2007. The main results obtained measuring single spin asymmetries are reviewed, with particular emphasis on the most recent proton measurements. After two years of spectroscopy measurements with hadron beams, in 2008 and 2009, the Collaboration will resume measurements with the muon beam and a transversely polarized target in 2010.

scholarly journals MEASUREMENT OF FORWARD JETS AT RHIC

2014 ◽  
Vol 25 ◽  
pp. 1460022 ◽  
Author(s):  
◽  
L. C. BLAND
Keyword(s):  
Angular Momentum ◽  
Transverse Momentum ◽  
Orbital Angular Momentum ◽  
Initial State ◽  
Spin Asymmetries ◽  
Jet Production ◽  
Single Spin ◽  
Single Spin Asymmetries ◽  
Forward Jets

We present first measurements of forward jet production from p↑ + p collisions at [Formula: see text] GeV, including transverse single spin asymmetries. These asymmetries are expected to be sensitive to spin-correlated transverse momentum in the initial state, which is particularly interesting because it is related to orbital angular momentum in the proton.

scholarly journals Introduction to the Transverse-Momentum-Weighted Technique in the Twist-3 Collinear Factorization Approach

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Hongxi Xing ◽  
Shinsuke Yoshida
Keyword(s):  
Transverse Momentum ◽  
Leading Order ◽  
Precise Description ◽  
Collinear Factorization ◽  
Factorization Approach ◽  
Hard Part ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Single Spin Asymmetries ◽  
Successful Approach

The twist-3 collinear factorization framework has drawn much attention in recent decades as a successful approach in describing the data for single spin asymmetries (SSAs). Many SSAs data have been experimentally accumulated in a variety of energies since the first measurement was done in the late 1970s and it is expected that the future experiments like Electron-Ion-Collider will provide us with more data. In order to perform a consistent and precise description of the data taken in different kinematic regimes, the scale evolution of the collinear twist-3 functions and the perturbative higher-order hard part coefficients are mandatory. In this paper, we introduce the techniques for next-to-leading order (NLO) calculation of transverse-momentum-weighted SSAs, which can be served as a useful tool to derive the QCD evolution equation for twist-3 functions and to verify the QCD collinear factorization for twist-3 observables at NLO, as well as obtain the finite NLO hard part coefficients.

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