scholarly journals Transversity distribution in spin asymmetries in semi-inclusive DIS and in the Drell-Yan process

2005 ◽  
Vol 55 (S1) ◽  
pp. A189-A208 ◽  
Author(s):  
A. V. Efremov ◽  
K. Goeke ◽  
P. Schweitzer
Keyword(s):  
Transversity Distribution ◽  
Spin Asymmetries

scholarly journals Exploring nucleon structure and hadronization with dihadrons and hadrons in jets at STAR

2020 ◽  
Vol 1643 (1) ◽  
pp. 012188
Author(s):  
J. L. Drachenberg
Keyword(s):  
Transverse Spin ◽  
Nucleon Structure ◽  
Model Calculations ◽  
Transversity Distribution ◽  
Transverse Momentum Dependent ◽  
Spin Asymmetries ◽  
Proton Collisions ◽  
Dihadron Correlations ◽  
Polarized Proton ◽  
200 Gev

Abstract Over the last decade, theoretical and experimental engagement of transverse-spin phenomena has unlocked tantalizing opportunities for new insights into nucleon structure and hadronization. Observables such as hadrons in jets and dihadron correlations from polarized proton collisions provide access to the transversity distribution function at a range of x complementary to existing semi-inclusive deep inelastic scattering (SIDIS) experiments but at a much higher range of Q 2. Moreover, these two observables give access through two different factorization frameworks–transverse-momentum-dependent (TMD) and collinear–enabling a unique path to address questions concerning factorization-breaking and the universality of TMD functions. Data collected by STAR have revealed the first observations of transverse single-spin asymmetries in the azimuthal distributions of dihadron correlations and hadrons within jets from polarized proton collisions at both s = 500 GeV and 200 GeV. The STAR 200 GeV dihadron data have recently been included in global analyses that for the first time include SIDIS, e + e −, and p + p data to extract the transversity distribution. The STAR hadron-in-jet data provide a unique opportunity to illuminate longstanding questions: Do factorization and universality extend to the TMD picture in proton-proton collisions, e.g. through the Collins mechanism? How do TMD functions evolve with changing kinematics? The STAR dihadron and hadron-in-jet data will be presented and discussed in context with the recent global analyses and model calculations.

scholarly journals Gluon Sivers function and transverse single spin asymmetries in e+p↑→γ+X

2021 ◽  
Vol 103 (3) ◽  
Author(s):  
Siddhesh Padval ◽  
Rohini M. Godbole ◽  
Abhiram Kaushik ◽  
Anuradha Misra ◽  
Vaibhav S. Rawoot
Keyword(s):  
Spin Asymmetries ◽  
Single Spin ◽  
Single Spin Asymmetries ◽  
Sivers Function

scholarly journals Global analysis of the Sivers functions at NLO+NNLL in QCD

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Miguel G. Echevarria ◽  
Zhong-Bo Kang ◽  
John Terry
Keyword(s):  
Pair Production ◽  
Global Analysis ◽  
Vector Boson ◽  
Lepton Pair ◽  
Transverse Spin ◽  
Dglap Evolution ◽  
Spin Asymmetries ◽  
Lepton Pair Production ◽  
Asymmetry Data ◽  
The Impact

Abstract We perform global fit to the quark Sivers function within the transverse momentum dependent (TMD) factorization formalism in QCD. We simultaneously fit Sivers asymmetry data from Semi-Inclusive Deep Inelastic Scattering (SIDIS) at COMPASS, HERMES, and JLab, from Drell-Yan lepton pair production at COMPASS, and from W/Z boson at RHIC. This extraction is performed at next-to-leading order (NLO) and next-to-next-to leading logarithmic (NNLL) accuracy. We find excellent agreement between our extracted asymmetry and the experimental data for SIDIS and Drell-Yan lepton pair production, while tension arises when trying to describe the spin asymmetries of W/Z bosons at RHIC. We carefully assess the situation, and we study in details the impact of the RHIC data and their implications through different ways of performing the fit. In addition, we find that the quality of the description of W/Z vector boson asymmetry data could be strongly sensitive to the DGLAP evolution of Qiu-Sterman function, besides the usual TMD evolution. We present discussion on this and the implications for measurements of the transverse-spin asymmetries at the future Electron Ion Collider.

Effect of the number of layers on determination of spin asymmetries in current-perpendicular-to-plane giant magnetoresistance

2011 ◽  
Vol 98 (4) ◽  
pp. 042503 ◽  
Author(s):  
Tomohiro Taniguchi ◽  
Hiroshi Imamura ◽  
Tomoya M. Nakatani ◽  
Kazuhiro Hono
Keyword(s):  
Giant Magnetoresistance ◽  
Spin Asymmetries ◽  
Number Of Layers ◽  
Current Perpendicular To Plane

scholarly journals Comparison of transverse single-spin asymmetries for forward π0 production in polarized pp , pAl and pAu collisions at nucleon pair c.m. energy sNN=200  GeV

2021 ◽  
Vol 103 (7) ◽  
Author(s):  
J. Adam ◽  
L. Adamczyk ◽  
J. R. Adams ◽  
J. K. Adkins ◽  
G. Agakishiev ◽  
...  
Keyword(s):  
Nucleon Pair ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Single Spin Asymmetries ◽  
200 Gev

scholarly journals Theoretical aspects of single-spin asymmetries studies

1995 ◽  
Author(s):  
S. M. Troshin ◽  
N. E. Tyurin
Keyword(s):  
Spin Asymmetries ◽  
Single Spin ◽  
Single Spin Asymmetries

Spin asymmetries in lepton-hadron scattering

1987 ◽  
Vol 36 (1) ◽  
pp. 55-60
Author(s):  
Sajjad Mahmood ◽  
Khalid Nadeem
Keyword(s):  
Spin Asymmetries

MEASUREMENT OF POLARIZED QUARK DISTRIBUTIONS AT HERMES

2003 ◽  
Vol 18 (08) ◽  
pp. 1185-1192
Author(s):  
◽  
STEFAN BERNREUTHER
Keyword(s):  
Cross Section ◽  
Kinematic Range ◽  
Spin Asymmetries ◽  
Double Spin ◽  
Hermes Experiment ◽  
Down Quark ◽  
Up Quark ◽  
Rich Detector ◽  
The Individual ◽  
Quark Flavors

The HERMES experiment has measured double spin asymmetries in the cross section for deep–inelastic scattering of longitudinally polarized positrons on longitudinally polarized 3 He (1995), 1 H (1996/97), and 2 D (1998) targets. A kinematic range of 0.023 < x < 0.6, and 1 GeV 2 < Q2 < 15 GeV 2 has been covered. From these asymmetries, based on inclusive and semi–inclusive measurements, polarized quark distributions are extracted as a function of x for up [Formula: see text] and down [Formula: see text] flavors as well as for valence and sea quarks. In the measured range, the up quark polarization is positive while the down quark polarization is negative. The sea quark polarization is compatible with zero. In this analysis all sea quark polarizations have been assumed to be flavor symmetric. Presently HERMES is analyzing a high statistics 2 D data sample taken in 1999-2000. For these data it is possible to identify pions and kaons with a RICH detector which was installed in 1998. This will enable an extraction of the individual sea quark flavors [Formula: see text], [Formula: see text], and [Formula: see text] without any symmetry assumptions.

scholarly journals Spin asymmetries in jet-hyperon production at LHC

2008 ◽  
Vol 659 (1-2) ◽  
pp. 127-136 ◽  
Author(s):  
D. Boer ◽  
C.J. Bomhof ◽  
D.S. Hwang ◽  
P.J. Mulders
Keyword(s):  
Hyperon Production ◽  
Spin Asymmetries

scholarly journals Transverse single-spin asymmetries in ℓp↑→hX within a TMD approach: Role of quasireal photon exchange

2017 ◽  
Vol 95 (9) ◽  
Author(s):  
Umberto D’Alesio ◽  
Carlo Flore ◽  
Francesco Murgia
Keyword(s):  
Photon Exchange ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Single Spin Asymmetries
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