Nuclear Theory·nucl-th

Friday·June 7, 2024

7 papers—4 primary·3 cross-listed

05
[Submitted on 5 Jun 2024] (cross-list from hep-ph)
Does the Sun have a Dark Disk?
Gustavo F. S. Alves🇺🇸 · Susan Gardner🇺🇸 · Pedro Machado🇺🇸 · Mohammadreza Zakeri🇺🇸
The Sun is not quite a perfect sphere, and its oblateness, thought to be induced through its rotation, has been measured using optical observations of its radius. Its gravitational quadrupole moment can then be deduced using solar models, or through helioseismology, and it can also be determined from measurements of its gravitational effects on Mercury's orbit. The various assessments do not appear to agree, with the most complete and precise orbital assessments being in slight excess of other determinations. This may speak to the existence of a non-luminous disk or ring, where we also note evidence for a circumsolar dust ring within Mercury's orbit from the Solar TErrestrial RElations Observatory (STEREO) mission. Historically, too, a protoplanetary disk may have been key to reconciling the Sun's metallicity with its neutrino yield. The distribution of the non-luminous mass within Mercury's orbit can modify the relative size of the optical and orbital quadrupole moments in different ways. We develop how we can use these findings to limit the mass of a dark disk, ring, or halo in the immediate vicinity of the Sun, and we note how future observational studies of the inner solar system can not only refine these constraints but also help to identify and to assess the mass of its dark-matter component.
Comments:
18 pages, 2 figures; version accepted for publication in PRD; sections modified for clarity, additional references and acknowledgements added; removing an assumption in a MESSENGER analysis appears to impact the significance of our conclusions
Subjects:
High Energy Physics — Phenomenology (hep-ph); astro-ph.EP (astro-ph.EP); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2406.03607 [pdf]
PRD(2025)·1 citation
06
[Submitted on 6 Jun 2024] (cross-list from hep-ph)
Light quark mass dependence of nucleon mass to two-loop order
Long-Bin Chen🇨🇳 · Siwei Hu🇨🇳 · Yu Jia🇨🇳 · Zhewen Mo🇨🇳
We investigate the nucleon self energy through the sixth chiral order in the covariant $S U (2)$ chiral perturbation theory ( $χ$ PT) in the single baryon sector. The validity of the extended on-mass-shell (EOMS) renormalization scheme is explicitly verified to two-loop order, manifested by the miraculous cancellation of all nonlocal divergences and power-counting-breaking (PCB) terms that are nonanalytic in pion mass. Using the $σ_{π N}$ term determined from the latest lattice simulation to constrain some unknown higher-order low energy constants (LECs), we predict the nucleon mass in the chiral limit to be $856.6 \pm 1.7$ MeV. It is found that the EOMS scheme exhibits quite satisfactory convergence behavior through $O (q^{6})$ around physical point. We also predict the pion mass dependence of the nucleon mass to the accuracy of $O (q^{6})$ , which is in satisfactory agreement with the recent lattice results over a wide range of pion mass.
Comments:
13 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2406.04124 [pdf]
10 citations
07
[Submitted on 6 Jun 2024] (cross-list from hep-ph)
Evolution of the transverse-momentum dependent gluon distribution at small $x$
Paul Caucal🇫🇷 · Edmond Iancu🇫🇷
Using the colour dipole picture for photon-nucleus interactions at small $x$ together with the Color Glass Condensate (CGC) effective theory, we demonstrate that the next-to-leading (NLO) order corrections to the cross-section for the inclusive production of a pair of hard jets encode not only the JIMWLK evolution with decreasing $x$ , but also the DGLAP evolution of the gluon distribution function and the CSS evolution of the gluon transverse momentum dependent (TMD) distribution. The emergent CSS equation takes the form of a rate equation describing the evolution of the dijet distribution in the transverse momentum imbalance $K_{⊥}$ when increasing the dijet relative momentum $P_{⊥}$ . All three types of evolution become important when both $P_{⊥}$ and $K_{⊥}$ are much larger than the nuclear saturation momentum $Q_{s} (x)$ and we propose a framework which encompasses all of them. The solution to the JIMWLK equation provides the source term for the DGLAP evolution with increasing $K_{⊥}$ , which in turn generates the initial condition for the CSS evolution with increasing $P_{⊥}$ .
Comments:
8 pages, 2 figures, accepted for publication in PRD; for more clarity, the Supplemental Material has been merged within the main text
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2406.04238 [pdf]
PRD(2025)·27 citations

Affiliations

first authorsco-authorsvia INSPIRE

Does the Sun have a Dark Disk?

Light quark mass dependence of nucleon mass to two-loop order

Evolution of the transverse-momentum dependent gluon distribution at small x

Affiliations

Evolution of the transverse-momentum dependent gluon distribution at small $x$