Hyperon Puzzle: Hints from Quantum Monte Carlo Calculations

Abstract

The onset of hyperons in the core of neutron stars and the consequent softening of the equation of state have been questioned for a long time. Controversial theoretical predictions and recent astrophysical observations of neutron stars are the grounds for the so-called hyperon puzzle. We calculate the equation of state and the neutron star mass-radius relation of an infinite systems of neutrons and $\Lambda$ particles by using the auxiliary field diffusion Monte Carlo algorithm. We find that the three-body hyperon-nucleon interaction plays a fundamental role in the softening of the equation of state and for the consequent reduction of the predicted maximum mass. We have considered two different models of three-body force that successfully describe the binding energy of medium mass hypernuclei. Our results indicate that they give dramatically different results on the maximum mass of neutron stars, not necessarily incompatible with the recent observation of very massive neutron stars. We conclude that stronger constraints on the hyperon-neutron force are necessary in order to properly assess the role of hyperons in neutron stars.

6 pages, 2 figures

References in corpus (14)

• Shapiro delay measurement of a two solar mass neutron star
• A Massive Pulsar in a Compact Relativistic Binary
• An Eccentric Binary Millisecond Pulsar in the Galactic Plane
• Quantum Monte Carlo calculation of the equation of state of neutron matter
• Estimation of the effect of hyperonic three-body forces on the maximum mass of neutron stars
• Hyperon mixing and universal many-body repulsion in neutron stars
• Constraining hypernuclear density functional with $\Lambda$-hypernuclei and compact stars
• Cold neutrons trapped in external fields
• Five-body cluster structure of double-$\Lambda$ hypernucleus ${}_{\Lambda \Lambda }^{11}$Be
• Large-mass neutron stars with hyperonization
• From the lightest nuclei to the equation of state of asymmetric nuclear matter with realistic nuclear interactions
• Massive Neutron Stars with Antikaon Condensates in a Density Dependent Hadron Field Theory
• Maximum mass of a hybrid star having a mixed phase region in the light of pulsar PSR J1614-2230
• Behaviour of the $\Lambda N$ and $\Lambda NN$ potential strengths in the ${}_{\Lambda }^5$He hypernucleus

Cited by in corpus (3)

• From asymmetric nuclear matter to neutron stars: a functional renormalization group study
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• Neutron stars and supernova explosions in the framework of Landau's theory