Recent Developments in Nucleon Spin Decomposition

2016 ◽  
Vol 40 ◽  
pp. 1660012
Author(s):  
Yoshitaka Hatta
Keyword(s):  
Nucleon Spin ◽  
Gauge Invariant ◽  
Recent Developments ◽  
Gluon Helicity

I review the recently achieved, complete gauge invariant decomposition of the nucleon spin and clarify its connection to twist-three GPDs. I also discuss how to compute the gluon helicity [Formula: see text] on a lattice.

scholarly journals PHYSICS OF GLUON HELICITY

2014 ◽  
Vol 25 ◽  
pp. 1460028
Author(s):  
XIANGDONG JI ◽  
YONG ZHAO
Keyword(s):  
Matrix Element ◽  
Time Correlation ◽  
Spin Operator ◽  
Large Momentum ◽  
Time Correlation Functions ◽  
Gauge Invariant ◽  
Equal Time ◽  
Polarized Proton ◽  
Gluon Spin ◽  
Gluon Helicity

The total gluon helicity in a polarized proton is shown to be a matrix element of a gauge-invariant but nonlocal, frame-dependent gluon spin operator [Formula: see text] in the large momentum limit. The operator [Formula: see text] is fit for the calculation of the total gluon helicity in lattice QCD. This calculation also implies that parton physics can be studied through the large momentum limit of frame-dependent, equal-time correlation functions of quarks and gluons.

scholarly journals NUCLEON SPIN IN QCD: OLD CRISIS AND NEW RESOLUTION

2012 ◽  
Vol 27 (31) ◽  
pp. 1230032 ◽  
Author(s):  
Y. M. CHO ◽  
MO-LIN GE ◽  
PENGMING ZHANG
Keyword(s):  
Angular Momentum ◽  
Gauge Invariance ◽  
Nucleon Spin ◽  
Gauge Invariant ◽  
Abelian Decomposition ◽  
Invariance Problem

We clarify the on-going confusion on the long-standing gauge invariance problem of the nucleon spin decomposition to the spin and angular momentum of quarks and gluons. We provide two gauge-invariant decompositions of nucleon spin which have different physical meanings, using the gauge independent Abelian decomposition. The first one is based on the assumption that all (binding and valence) gluons contribute to the nucleon spin, but the second one is based on the assumption that only the binding gluons (and the quarks) contribute to it.

scholarly journals ARE THERE INFINITELY MANY DECOMPOSITIONS OF THE NUCLEON SPIN?

2014 ◽  
Vol 25 ◽  
pp. 1460031
Author(s):  
MASASHI WAKAMATSU
Keyword(s):  
Nucleon Spin ◽  
Gauge Invariant ◽  
Decomposition Problem ◽  
Invariant Extension

We argue against the rapidly spreading idea of gauge-invariant-extension (GIE) approach in the nucleon spin decomposition problem, which implies the existence of infinitely many gauge-invariant decomposition of the nucleon spin.

scholarly journals Gauge-Invariant Decomposition of Nucleon Spin

1997 ◽  
Vol 78 (4) ◽  
pp. 610-613 ◽  
Author(s):  
Xiangdong Ji
Keyword(s):  
Nucleon Spin ◽  
Gauge Invariant

scholarly journals NUCLEON SPIN DECOMPOSITION AT TWIST THREE

2014 ◽  
Vol 25 ◽  
pp. 1460032
Author(s):  
YOSHITAKA HATTA
Keyword(s):  
Recent Progress ◽  
Nucleon Spin ◽  
Gauge Invariant ◽  
Twist Structure

I review the recent progress in understanding the complete gauge invariant decomposition of the nucleon spin with particular emphasis on its twist structure.

scholarly journals Second-Order Gauge-Invariant Cosmological Perturbation Theory: Current Status

2010 ◽  
Vol 2010 ◽  
pp. 1-26 ◽  
Author(s):  
Kouji Nakamura
Keyword(s):  
Perturbation Theory ◽  
Scalar Field ◽  
Second Order ◽  
Current Status ◽  
Cosmological Perturbation ◽  
Gauge Invariant ◽  
Cosmological Perturbation Theory ◽  
Theoretical Predictions ◽  
Recent Developments ◽  
The Universe

The current status of the recent developments of the second-order gauge-invariant cosmological perturbation theory is reviewed. To show the essence of this perturbation theory, we concentrate only on the universe filled with a single scalar field. Through this paper, we point out the problems which should be clarified for the further theoretical sophistication of this perturbation theory. We also expect that this theoretical sophistication will be also useful to discuss the theoretical predictions of non-Gaussianity in CMB and comparison with observations.

Sign in / Sign up

Export Citation Format

Share Document