# Proton spin structure functions and generalized Sullivan processes

## Abstract

We employ the time-ordered perturbation field theory in the infinite momentum limit, as developed extensively by Drell, Levy, and Yan, to derive the convolution formulas for the proton spin structure functions {ital g}{sub 1}({ital x},{ital Q}{sup 2}) and {ital g}{sub 2}({ital x},{ital Q}{sup 2}) suitable for the generalized Sullivan processes, in which the meson in the cloud or the recoiling baryon is struck and smashed by the virtual photon. Following a previous suggestion that the sea quark distributions of a nucleon at low and moderate {ital Q}{sup 2} may be attributed primarily to such Sullivan processes, we use the convolution formulas to obtain the first moments {Gamma}{sub {ital p}}{equivalent_to}{integral}{sub 0}{sup 1}{ital g}{sub 1}{sup {ital p}}({ital x},{ital Q}{sup 2}){ital dx} and {Gamma}{sub {ital n}}{equivalent_to}{integral}{sub 0}{sup 1}{ital g}{sub 1}{sup {ital n}}({ital x},{ital Q}{sup 2}){ital dx}, as well as to investigate {ital g}{sub 1}{sup {ital p}}({ital x},{ital Q}{sup 2}) and {ital g}{sub 1}{sup {ital n}}({ital x},{ital Q}{sup 2}) as a function of {ital x}. Our results indicate that both the data on {ital g}{sub 1}{sup {ital p}}({ital x},{ital Q}{sup 2}) obtained previously by the European Muon Collaboration and the recent data on the deuteron spin structure function {ital g}{sub 1}{sup {ital d}}({ital x},{italmore »

- Authors:

- Department of Physics, National Taiwan University, Taipei, Taiwan 10764 (Taiwan, Province of China)

- Publication Date:

- OSTI Identifier:
- 142702

- Resource Type:
- Journal Article

- Journal Name:
- Physical Review, D

- Additional Journal Information:
- Journal Volume: 49; Journal Issue: 5; Other Information: PBD: 1 Mar 1994

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 66 PHYSICS; PROTONS; STRUCTURE FUNCTIONS; SPIN; PERTURBATION THEORY; EMC EFFECT; SUM RULES

### Citation Formats

```
Chung, C., and Hwang, W.P..
```*Proton spin structure functions and generalized Sullivan processes*. United States: N. p., 1994.
Web. doi:10.1103/PhysRevD.49.2221.

```
Chung, C., & Hwang, W.P..
```*Proton spin structure functions and generalized Sullivan processes*. United States. doi:10.1103/PhysRevD.49.2221.

```
Chung, C., and Hwang, W.P.. Tue .
"Proton spin structure functions and generalized Sullivan processes". United States. doi:10.1103/PhysRevD.49.2221.
```

```
@article{osti_142702,
```

title = {Proton spin structure functions and generalized Sullivan processes},

author = {Chung, C. and Hwang, W.P.},

abstractNote = {We employ the time-ordered perturbation field theory in the infinite momentum limit, as developed extensively by Drell, Levy, and Yan, to derive the convolution formulas for the proton spin structure functions {ital g}{sub 1}({ital x},{ital Q}{sup 2}) and {ital g}{sub 2}({ital x},{ital Q}{sup 2}) suitable for the generalized Sullivan processes, in which the meson in the cloud or the recoiling baryon is struck and smashed by the virtual photon. Following a previous suggestion that the sea quark distributions of a nucleon at low and moderate {ital Q}{sup 2} may be attributed primarily to such Sullivan processes, we use the convolution formulas to obtain the first moments {Gamma}{sub {ital p}}{equivalent_to}{integral}{sub 0}{sup 1}{ital g}{sub 1}{sup {ital p}}({ital x},{ital Q}{sup 2}){ital dx} and {Gamma}{sub {ital n}}{equivalent_to}{integral}{sub 0}{sup 1}{ital g}{sub 1}{sup {ital n}}({ital x},{ital Q}{sup 2}){ital dx}, as well as to investigate {ital g}{sub 1}{sup {ital p}}({ital x},{ital Q}{sup 2}) and {ital g}{sub 1}{sup {ital n}}({ital x},{ital Q}{sup 2}) as a function of {ital x}. Our results indicate that both the data on {ital g}{sub 1}{sup {ital p}}({ital x},{ital Q}{sup 2}) obtained previously by the European Muon Collaboration and the recent data on the deuteron spin structure function {ital g}{sub 1}{sup {ital d}}({ital x},{ital Q}{sup 2}) obtained by the Spin Muon Collaboration can be understood and the Bjorken sum rule is satisfied. A comparison between our prediction on {ital g}{sub 1}{sup {ital n}}({ital x},{ital Q}{sup 2}) and the recent SLAC data is also given.},

doi = {10.1103/PhysRevD.49.2221},

journal = {Physical Review, D},

number = 5,

volume = 49,

place = {United States},

year = {1994},

month = {3}

}