1 / 14

Twist 4 Matrix elements

This paper examines the intricacies of twist-4 matrix elements, focusing on their relevance in Quantum Chromodynamics (QCD) and experimental physics. It delves into operator parameterization, structure functions, and polarization tensors. The study analyzes available experimental data from SLAC and BCDMS to identify constraints on matrix elements pertinent to protons and neutrons. The significance of twist-4 operators is highlighted in relation to multiparticle correlations and low-energy models of QCD, presenting the need for updated experimental measures to deepen our understanding of hadronic structures.

avon
Télécharger la présentation

Twist 4 Matrix elements

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Twist 4 Matrix elements Su Houng Lee 1. S. Choi et al, PLB 312 (1993) 351 2. Su Houng Lee, PRD 49 (1994) 2242

  2. Some basics on matrix elements and moments • DIS e (E’,k’) e (E,k) X P • Polarization Tensors Where w =2pq/q2

  3. OPE P P • Diagrammatic rep of Structure function X P P • Diagrammatic rep of OPE P P

  4. Twist-2 Operators P P • Twist-4 Operators P P P P

  5. Twist-4 Operators • OPE • Operators • mass Operators

  6. Parameterizing F2 (t=4) • For Cp: BCDMSdata and SLAC data +Virchauz,Milsztajin, PLB274 (92) 221 • We fit to • For Cp-Cn: NMC (combining NMC,SLAC, BCDMSdata) • We fit to

  7. Parameterizing FL (t=4) • Parameterization using transverse basis (Ellis, Furmanski, Petronzio 82) P P • SLAC data analyzed by Sanchex Guillen etal. (91)

  8. Constraints for matrix elements from experiments Note that the matrix elements A’s for the proton and neutron data are independent. data MIT Bag

  9. MIT Bag model calculations (Jaffe-Soldate 81) • Definitions • Calculations • operators • Normalizations by Jaffe (75)

  10. Calculations- cont • calculations involve spin and spatial parts

  11. MIT Bag model vs experimental constraint • F2: Q2=5 GeV2 as = 0.5 • FL: Q2=5 GeV2 as = 0.5

  12. A Parameterization based on flavor structure • Flavor structure • 7 Unknowns: F2,FL, proton, neutron target 4 constraints

  13. Summary - i • Twist-4 matrix elements are interesting itself because, • a) First experimental measurements of multiparticle correlation inside proton • b) Need much more correlation than • such as c) Non-trivial test of low energy models of QCD d) QCD sum rules for hadrons in nuclear matter

  14. Summary - ii 2. To answer the questions, need experimental update on

More Related