## SciPost Submission Page

# Generalized Parton Distribution Functions of $\rho$ meson

### by Baodong Sun and Yubing Dong

#### This is not the current version.

### Submission summary

As Contributors: | Yubing Dong |

Preprint link: | scipost_201910_00011v1 |

Date submitted: | 2019-10-14 |

Submitted by: | Dong, Yubing |

Submitted to: | SciPost Physics Proceedings |

Proceedings issue: | 24th European Few Body Conference (University of Surrey, U.K.) |

Discipline: | Physics |

Subject area: | High-Energy Physics - Phenomenology |

Approach: | Theoretical |

### Abstract

We report our recent calculations for the generalized parton distribution functions of the $\rho$ meson with the help of a light-front constituent quark model. The electromagnetic form factors and structure functions of the system are given. Moreover, we also show our results for its gravitational form factors (or energy-momentum tensor form factors) and for other mechanical properties, like its mass distributions, pressures, share-forces, and $D-$term.

###### Current status:

### Submission & Refereeing History

## Reports on this Submission

### Anonymous Report 1 on 2019-11-20 Invited Report

### Report

This paper reports on calculations of generalized parton distribution functions, electromagnetic, electro-weak, and energy-momentum tensor form factors and other structure functions for the rho meson. The calculations are based on a phenomenological model for the rho-quark-antiquark vertex function in a constituent quark model. The momentum dependence of the vertex function is assumed to be of a particular functional form, depending on three parameters, one of which is fixed by a normalisation condition, whereas the other two are somehow "optimally selected" (no further details are given). It would clearly be more interesting to see results based on a dynamical calculation of the vertex function, but phenomenological results can still be useful for comparison purposes.

I think this paper merits publication. However, it should be improved in a few aspects:

1. Equation (13) shows the momentum dependence $\Lambda(...)$ of the rho vertex, but the sentences before and after the equation do not explain what the exact structure of the vertex really is. Is it simply $\Gamma^\mu(...)=\gamma^\mu \Lambda(...)$, or are there other Lorentz structures included?

Perhaps the sentence before (13), "... the phenomenological vertex $\Gamma^\mu$ equals to $\gamma^\mu$ plus the momentum-dependent term of the parton..." is misleading, and what is meant is "multiplied by" instead of "plus". This should be clarified.

My remaining comments concern the formatting and grammar of the paper.

Formatting:

2. The figures 2-5 have really tiny labels, which makes them hard to read. If possible, they should be made bigger.

3. All figures consist of a left and a right panel. In the captions, the authors refer to them as "((a), left)" and "((b), right)", respectively. This is quite unusual and rather clumsy, and it could be improved very easily: just give the left and right panels their labels (a) and (b), and then one can refer to them simply as "(a)" and "(b)" instead of "((a), left)", etc.

Grammar:

In general, the text is full of grammatical errors, which are too numerous to list them here (articles, prepositions, ...). Nevertheless, it is possible to understand most of what is written, so I will list here only the cases I find most important.

4. Throughout the text, the authors write "share forces" instead of "shear forces".

5. In the 3rd paragraph of the Introduction,

"It is expected that future Jefferson Lab. would provide a more precise measurement..."

should be changed to something like

"It is expected that future Jefferson Lab experiments would provide a more precise measurement..."

6. The decomposition of the energy-momentum tensor in Eq. (6) contains a mistake: the terms with $A_0(t)$ and $A_1(t)$ appear to be multiplied, but there should be some sign (probably a plus) between them.

7. The sentence "which stands for the fundamental property and is negative characterizing a stable system." after Eq. (10) is confusing. Do they mean "which stands for a fundamental property..."?

8. In the text before and after Eq. (13), the word "employ" is spelled "employe" twice.

I could go on with more examples, but perhaps the authors find somebody for a thorough proofreading of their text.