43 research outputs found
Ideas in transverse spin physics
Three simple ideas about transverse spin observables are presented for the
purpose of stimulating discussion. The manuscript is based on a presentation at
the "Transversity 2014" workshop in Torre Chia, Sardinia, Italy on June 9-13,
2014 where approximately sixty experts on transverse spin physics had gathered
to share recent results in an atmosphere of sun-drenched intensity.Comment: 4 pages no figure
Studying Spin-Orbit Dynamics using Measurements of the Proton's Polarized Gluon Asymmetry
Measurements involving the gluon spin density, Delta G=G++ - G+-, can play an
important role in the quantitative understanding of proton structure. To
demonstrate this, we show that the shape of the gluon asymmetry, A(x,t)=Delta
G(x,t)/G(x,t), contains significant dynamical information about
non-perturbative spin-orbit effects. It is instructive to use a separation
A(x,t)=A_0^epsilon(x)+epsilon(x,t), where A_0^epsilon(x) is an approximately
scale-invariant form that can be calculated within a given factorization
prescription from the measured distributions Delta q(x,t), q(x,t) and G(x,t).
Applying this separation with the J_z=1/2 sum rule provides a convenient way to
determine the total amount of orbital angular momentum generated by mechanisms
associated with confinement and chiral dynamics. The results are consistent
with alternate non-perturbative approaches to the determination of orbital
angular momentum in the proton. Our studies help to specify the accuracy that
future measurements should achieve to constrain theoretical models for nucleon
structure.Comment: 24 pages, 3 figure
A No‐Depolarization Theorem for Rotator‐Aided Resonance Crossing
An rf frequency rotator magnet provides a useful tool for manipulating particle spins in any accelerator or storage ring with polarized beams. This note briefly demonstrates the general idea of the rotator‐aided crossing of spin resonance and sketches the proof of a general theorem about the process. The important question of whether this technique can be useful for a specific spin resonance at a particular accelerator involves a detailed analysis of the impact of the rotator on a range of machine parameters. © 2003 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87295/2/81_1.pd
Constituent description of NN elastic scattering observables at large angles
We suggest that the constituent picture of nucleon-nucleon elastic scattering can be tested by the spin-correlation measurements All, Ass, Ann, and Asl. These measurements provide a means for isolating various reaction mechanisms, including possible quantum-chromodynamic instanton effects. We give specific model calculations to illustrate these ideas