Parton orbital angular momentum and final state interactions

For transversely polarized nucleons the distribution of quarks in the transverse plane is transversely shifted and that shift can be described in terms of Generalized Parton Distributions (GPDs). This observation provides a 'partonic' derivation of the Ji-relation for the quark angular momentum in terms of GPDs. Wigner distributions are used to show that the difference between the Jaffe-Manohar definiton of quark orbital angular momentum and that of Ji is equal to the change of orbital angular momentum due to the final state interactions as the struck quark leaves the target in a DIS experiment.

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Sivers Function in the Quasi-Classical Approximation

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194515600320 ◽

2015 ◽

Vol 37 ◽

pp. 1560032

Author(s):

Matthew D. Sievert

Keyword(s):

Angular Momentum ◽

Orbital Angular Momentum ◽

Essential Role ◽

Orbital Motion ◽

Final State ◽

Quasi Classical Approximation ◽

Sivers Function ◽

Final State Interactions ◽

New Interpretation

In this brief article we summarize the derivation of the Sivers function of a heavy nucleus, which we obtain by generalizing the quasi-classical McLerran-Venugopalan model to incorporate the role of spin and orbital angular momentum. In doing so we obtain a new channel which is capable of generating the Sivers function of the nucleus from the orbital motion of its nucleons. An essential role is played in this channel by the multiple rescatterings on spectator nucleons which screen the distribution function during the initial- or final-state interactions. The combination of orbital angular momentum together with multiple rescattering yields a new interpretation of the sign flip relation between the Sivers function measured in semi-inclusive deep inelastic scattering and the Drell-Yan process.

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PARTONIC PICTURE OF GTMDS

International Journal of Modern Physics Conference Series ◽

10.1142/s201019451460009x ◽

2014 ◽

Vol 25 ◽

pp. 1460009 ◽

Cited By ~ 8

Author(s):

SIMONETTA LIUTI ◽

ABHA RAJAN ◽

AURORE COURTOY ◽

GARY R. GOLDSTEIN ◽

J. OSVALDO GONZALEZ HERNANDEZ

Keyword(s):

Angular Momentum ◽

Compton Scattering ◽

Orbital Angular Momentum ◽

Scattering Amplitude ◽

Final State Interaction ◽

Deeply Virtual Compton Scattering ◽

Virtual Compton Scattering ◽

Matrix Elements ◽

Final State ◽

Wigner Distributions

We argue that due to parity constraints, the helicity combination of the purely momentum space counterparts of the Wigner distributions — the generalized transverse momentum distributions — that describes the configuration of an unpolarized quark in a longitudinally polarized nucleon, can enter the deeply virtual Compton scattering amplitude only through matrix elements involving a final state interaction. The relevant matrix elements in turn involve light cone operators projections in the transverse direction, or they appear in the deeply virtual Compton scattering amplitude at twist three. Orbital angular momentum or the spin structure of the nucleon was a major reason for these various distributions and amplitudes to have been introduced. We show that twist three contributions to deeply virtual Compton scattering provide observables related to orbital angular momentum.

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Quark Orbital Angular Momentum and Final State Interactions

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194515600356 ◽

2015 ◽

Vol 37 ◽

pp. 1560035 ◽

Cited By ~ 1

Author(s):

Matthias Burkardt

Keyword(s):

Angular Momentum ◽

Orbital Angular Momentum ◽

Final State ◽

Spin Asymmetries ◽

Single Spin ◽

Wigner Distributions ◽

Single Spin Asymmetries ◽

Quark Orbital Angular Momentum ◽

The Difference ◽

Definition Of

Definitions of orbital angular momentum based on Wigner distributions are used to discuss the connection between the Ji definition of the quark orbital angular momentum and that of Jaffe and Manohar. The difference between these two definitions can be interpreted as the change in the quark orbital angular momentum as it leaves the target in a DIS experiment. The mechanism responsible for that change is similar to the mechanism that causes transverse single-spin asymmetries in semi-inclusive deep-inelastic scattering.

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QUARK ORBITAL ANGULAR MOMENTUM AND FINAL STATE INTERACTIONS

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194514600295 ◽

2014 ◽

Vol 25 ◽

pp. 1460029 ◽

Cited By ~ 2

Author(s):

MATTHIAS BURKARDT

Keyword(s):

Angular Momentum ◽

Orbital Angular Momentum ◽

Final State ◽

Spin Asymmetries ◽

Single Spin ◽

Wigner Distributions ◽

Single Spin Asymmetries ◽

Quark Orbital Angular Momentum ◽

The Difference ◽

Definition Of

Definitions of orbital angular momentum based on Wigner distributions are used to discuss the connection between the Ji definition of the quark orbital angular momentum and that of Jaffe and Manohar. The difference between these two definitions can be interpreted as the change in the quark orbital angular momentum as it leaves the target in a DIS experiment. The mechanism responsible for that change is similar to the mechanism that causes transverse single-spin asymmetries in semi-inclusive deep-inelastic scattering.

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SPIN EXPANSION FOR HEAD-ON COLLISION OF TWO BLACK HOLES

International Journal of Modern Physics D ◽

10.1142/s0218271811018639 ◽

2011 ◽

Vol 20 (01) ◽

pp. 43-57 ◽

Cited By ~ 4

Author(s):

ZHOUJIAN CAO ◽

CHENZHOU LIU

Keyword(s):

Black Holes ◽

Black Hole ◽

Angular Momentum ◽

Orbital Angular Momentum ◽

New Method ◽

Initial State ◽

Final State ◽

The Third ◽

Binary Black Hole ◽

Expansion Technique

The spin expansion technique proposed in [L. Boyel, M. Kesden and S. Nissanke, Phys. Rev. Lett.100 (2008) 151101] is very powerful to analyze the relation between the initial state of binary black hole and the final state of the merged black hole. But this technique needs orbital angular momentum to determine the third direction of a triad. Without this triad we cannot get the decomposed components of the involved quantities, and the spin expansion breaks down. The head-on collision of two black holes, whose orbital angular momentum vanishes, falls into this case. In this paper we propose a new method to construct a triad for spin expansion technique. With this new method, we get the same set of equations as in the above-mentioned paper. Furthermore, we use numerical simulations to illustrate the validity of our new method for the head-on collision of two black holes.

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