Publications
Publication Information
| Title | Pion gravitational form factors in the QCD instanton vacuum I |
| Authors | Wei-Yang Liu, Edward Shuryak, Christian Weiss, Ismail Zahed |
| JLAB number | JLAB-THY-24-4067 |
| LANL number | (None) |
| Other number | DOE/OR/23177-7502 |
| Document Type(s) | (Journal Article) |
| Associated with EIC: | No |
| Supported by Jefferson Lab LDRD Funding: | No |
| Funding Source: | Nuclear Physics (NP) |
|
Journal Compiled for Physical Review D Volume 110 Page(s) 054021 | |
| Publication Abstract: | The pion form factors of the QCD energy-momentum tensor (EMT) are studied in the instanton liquid model (ILM) of the QCD vacuum. In this approach the breaking of conformal symmetry is encoded in the form of stronger-than-Poisson fluctuations in the number of instantons. For the trace of the EMT, it is shown that the gluonic trace anomaly term contributes half the pion mass, with the other half coming from the quark-mass-dependent sigma term. The Q2 dependence of the form factors is governed by glueball and scalar meson exchanges. For the traceless EMT, the spin-0 and 2 form factors are computed at next-to-leading order in the instanton density using effective quark operators. Relations between the gluon and quark contributions to the EMT form factors are derived. The form factors are also expressed in terms of the pion light-front wave functions in the ILM. The results at the low resolution scale of the inverse instanton size are evolved to higher scales using the renormalization group equation. The ILM results compare well with those of recent lattice QCD calculations. |
| Experiment Numbers: | other |
| Group: | THEORY CENTER |
| Document: | |
| DOI: | https://doi.org/10.1103/PhysRevD.110.054021 |
| Accepted Manuscript: | PhysRevD.110.054021.pdf |
| Supporting Documents: | |
| Supporting Datasets: | |