PreprintCC BY 4.0arXiv
Hybrid neutron stars among mass gap objects are excluded by twin stars at 1.4 M⊙
Abstract
We investigate the question whether compact objects in the so-called mass gap (2.5 < M/M⊙ < 5.0) can be neutron stars or hybrid stars. Using a generic hybrid star equation of state with a first-order deconfinement transition, we map the allowed parameter space in a Seidov-type diagram and confront it with modern mass-radius constraints. We find that mass-gap hybrid stars require an extremely early onset of deconfinement and very stiff quark matter. The Bayesian analysis, however, favors equations of state with deconfinement at typical neutron-star masses around 1.4 M⊙ with mass-twin stars that, if confirmed, would rule out hybrid stars as candidates for observed mass-gap compact objects.
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BibTeX
@misc{ayriyan2026hybrid,
title = {{Hybrid neutron stars among mass gap objects are excluded by twin stars at $1.4\,M_\odot$}},
author = {Alexander Ayriyan and David Blaschke and Marcin Dubaj and Oleksandr Vitiuk and Adrian Wojcik},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2606.02593},
eprint = {2606.02593},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.02593},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Hybrid neutron stars among mass gap objects are excluded by twin stars at 1.4 M_⊙
AU - Alexander Ayriyan
AU - David Blaschke
AU - Marcin Dubaj
AU - Oleksandr Vitiuk
AU - Adrian Wojcik
PY - 2026
DA - 2026/10/08
PB - arXiv
DO - 10.48550/arxiv.2606.02593
UR - https://arxiv.org/abs/2606.02593
AB - We investigate the question whether compact objects in the so-called mass gap (2.5 < M/M_⊙ < 5.0) can be neutron stars or hybrid stars. Using a generic hybrid star equation of state with a first-order deconfinement transition, we map the allowed parameter space in a Seidov-type diagram and confront it with modern mass-radius constraints. We find that mass-gap hybrid stars require an extremely early onset of deconfinement and very stiff quark matter. The Bayesian analysis, however, favors equations of state with deconfinement at typical neutron-star masses around 1.4 M_⊙ with mass-twin stars that, if confirmed, would rule out hybrid stars as candidates for observed mass-gap compact objects.
ER -