scholarly journals Critique of the angular momentum sum rules and a new angular momentum sum rule

2004 ◽  
Vol 70 (11) ◽  
Author(s):  
B. L. G. Bakker ◽  
E. Leader ◽  
T. L. Trueman
Keyword(s):  
Angular Momentum ◽  
Sum Rules ◽  
Sum Rule

scholarly journals Relativistic spin sum rules and the role of the pivot

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
Cédric Lorcé
Keyword(s):  
Angular Momentum ◽  
Phase Space ◽  
Relativistic Theory ◽  
Sum Rules ◽  
Spin Component ◽  
Sum Rule ◽  
Relativistic Spin ◽  
First Time ◽  
Space Approach

AbstractSpin sum rules depend on the choice of a pivot, i.e. the point about which the angular momentum is defined, usually identified with the center of the nucleon. The latter is however not unique in a relativistic theory and has led to apparently contradictory results in the literature. Using the recently developed phase-space approach, we compute for the first time the contribution associated with the motion of the center of the nucleon, and we derive a general spin sum rule which reduces to established results after appropriate choices for the pivot and the spin component.

scholarly journals QUARK ORBITAL ANGULAR MOMENTUM IN THE BARYON

2001 ◽  
Vol 16 (22) ◽  
pp. 3673-3697 ◽  
Author(s):  
XIAOTONG SONG
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Orbital Motion ◽  
Magnetic Moments ◽  
Sum Rule ◽  
Quark Spin ◽  
Quark Flavor ◽  
Quark Orbital Angular Momentum ◽  
Quark Flavors ◽  
Partition Factor

Analytical and numerical results, for the orbital and spin content carried by different quark flavors in the baryons, are given in the chiral quark model with symmetry breaking. The reduction of the quark spin, due to the spin dilution in the chiral splitting processes, is transferred into the orbital motion of quarks and antiquarks. The orbital angular momentum for each quark flavor in the proton as a function of the partition factor κ and the chiral splitting probability a is shown. The cancellation between the spin and orbital contributions in the spin sum rule and in the baryon magnetic moments is discussed.

scholarly journals INTEGRAL TRANSFORM TECHNIQUE FOR MESON WAVE FUNCTIONS

1996 ◽  
Vol 11 (20) ◽  
pp. 1611-1626 ◽  
Author(s):  
A.P. BAKULEV ◽  
S.V. MIKHAILOV
Keyword(s):  
Wave Function ◽  
Sum Rules ◽  
Integral Transform ◽  
Wave Functions ◽  
Sum Rule ◽  
New Approach ◽  
Exactly Solvable ◽  
The Stability ◽  
The Masses ◽  
Integral Transform Technique

In a recent paper1 we have proposed a new approach for extracting the wave function of the π-meson φπ(x) and the masses and wave functions of its first resonances from the new QCD sum rules for nondiagonal correlators obtained in Ref. 2. Here, we test our approach using an exactly solvable toy model as illustration. We demonstrate the validity of the method and suggest a pure algebraic procedure for extracting the masses and wave functions relating to the case under investigation. We also explore the stability of the procedure under perturbations of the theoretical part of the sum rule. In application to the pion case, this results not only in the mass and wave function of the first resonance (π′), but also in the estimation of π″-mass.

scholarly journals L-edge sum rule analysis on 3d transition metal sites: from d10to d0and towards application to extremely dilute metallo-enzymes

2018 ◽  
Vol 20 (12) ◽  
pp. 8166-8176 ◽  
Author(s):  
Hongxin Wang ◽  
Stephan Friedrich ◽  
Lei Li ◽  
Ziliang Mao ◽  
Pinghua Ge ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Transition Metal ◽  
Metal Complex ◽  
Sum Rules ◽  
Sum Rule ◽  
X Ray ◽  
Metal Site ◽  
Integrated Intensity ◽  
Rule Analysis ◽  
X Ray Absorption

According to L-edge sum rules, the number of 3d vacancies at a transition metal site is directly proportional to the integrated intensity of the L-edge X-ray absorption spectrum (XAS) for the corresponding metal complex.

COMMENTS ON QCD SUM-RULE CALCULATIONS OF EXCLUSIVE TWO-BODY DECAYS OF CHARMED MESONS

1989 ◽  
Vol 04 (09) ◽  
pp. 877-883 ◽  
Author(s):  
LING-LIE CHAU ◽  
HAI-YANG CHENG
Keyword(s):  
Experimental Data ◽  
Sum Rules ◽  
Theoretical Calculations ◽  
Charmed Mesons ◽  
Qcd Sum Rules ◽  
Generic Structure ◽  
Sum Rule ◽  
Quark Diagram ◽  
Model Independent ◽  
Decays Of Charmed Mesons

Exclusive two-body decay amplitudes of charmed mesons evaluated by Blok and Shifman (BS) using QCD sum rules are analyzed using the model-independent quark-diagram scheme, which helps to pin point the generic structure of the BS calculations, and their difficulties when compared with the experimental data. We also point out what experimental improvements on the data and which new data are most helpful in sharpening these comparisons. Some comments on possible ways of further improving the theoretical calculations are given.

scholarly journals REVIEW ON QCD SUM RULES CALCULATIONS FOR EXOTICS CHARMONIUM

2011 ◽  
Vol 02 ◽  
pp. 36-40
Author(s):  
MARINA NIELSEN
Keyword(s):  
Sum Rules ◽  
Mass Region ◽  
Qcd Sum Rules ◽  
Sum Rule ◽  
Rule Approach ◽  
New States

Many new states in the charmonium mass region were recently discovered by the BaBar, Belle and CDF Collaborations. We use the QCD Sum Rule approach to study the possible structure of some of these states.

scholarly journals STATUS OF THE HADRONIC τ DETERMINATION OF Vus

2008 ◽  
Vol 23 (21) ◽  
pp. 3191-3195 ◽  
Author(s):  
K. MALTMAN ◽  
C. E. WOLFE ◽  
S. BANERJEE ◽  
M. RONEY ◽  
I. NUGENT
Keyword(s):  
Sum Rules ◽  
Branching Fractions ◽  
Sum Rule ◽  
Slow Convergence ◽  
Decay Data ◽  
Decay Modes ◽  
Good Agreement

We update the extraction of Vus from hadronic τ decay data in light of recent BaBar and Belle results on the branching fractions of a number of important strange decay modes. A range of sum rule analyses is employed, particular attention being paid to those based on “non-spectral weights”, developed previously to bring the slow convergence of the relevant integrated D = 2 OPE series under improved control. Results from the various sum rules are in good agreement with one another, but ~ 3σ below expectations based on 3-family unitarity.

QCD SUM RULE APPROACH TO THE K→VACUUM WEAK AMPLITUDE

1990 ◽  
Vol 05 (06) ◽  
pp. 1071-1091
Author(s):  
M.A. AHMED ◽  
M.S. RASHEED
Keyword(s):  
Matrix Element ◽  
Sum Rules ◽  
Finite Energy ◽  
The Other ◽  
Sum Rule ◽  
Rule Approach ◽  
The Matrix

We study the kaon-to-vaccum weak matrix element using the method of the QCD duality finite energy sum rules. It is found that the matrix element in question can be expressed as a sum of two terms: one behaving like ms−md and the other like [Formula: see text]. Detailed numerical estimates are also given.

scholarly journals ON THE QCD SUM RULE DETERMINATION OF THE STRANGE QUARK MASS

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 588-590 ◽  
Author(s):  
NELLO PAVER
Keyword(s):  
Spectral Function ◽  
Quark Mass ◽  
Strange Quark ◽  
Sum Rules ◽  
Sum Rule ◽  
Strange Quark Mass ◽  
Current Quark Mass ◽  
Current Quark

I briefly review recent QCD Sum Rules determinations of the strange current quark mass, based on the analysis of the two-point ΔS=1 scalar correlators and discuss, in particular, the role of resonances and non-resonant background in the spectral function.

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