Ab initio approach to s-shell hypernuclei 3lambdaH, 4lambdaH, 4lambdaHe, and 5lambdaHe with a lambdaN-sigmaN...

Area of Science:

• Nuclear Physics
• Hypernuclear Physics
• Quantum Mechanics

Background:

• Hypernuclei are atomic nuclei containing hyperons, such as Lambda (Λ) or Sigma (Σ) particles.
• Understanding the interactions within hypernuclei is crucial for nuclear physics.
• Previous studies have explored hypernuclear structures, but explicitly including Sigma degrees of freedom requires further investigation.

Purpose of the Study:

• To perform variational calculations for s-shell hypernuclei by including Sigma degrees of freedom.
• To investigate the influence of different YN (hyperon-nucleon) interactions on hypernuclear properties.
• To analyze the impact of the tensor $\Lambda$N-$\Sigma$N transition potential on the internal energy of hypernuclei.

Main Methods:

• Employed variational calculations to model s-shell hypernuclei.
• Explicitly incorporated Sigma degrees of freedom into the calculations.
• Utilized four distinct sets of YN interactions: SC97d(S), SC97e(S), SC97f(S), and SC89(S).

Main Results:

• Successfully obtained the bound-state solution for Lambda-5Helium (⁵ΛHe).
• Observed a large energy expectation value for the tensor $\Lambda$N-$\Sigma$N transition component.
• Demonstrated that the internal energy of the Helium-4 subsystem is significantly affected by the Lambda particle and the strong tensor $\Lambda$N-$\Sigma$N transition potential.

Conclusions:

• The inclusion of Sigma degrees of freedom and tensor interactions is essential for accurate hypernuclear calculations.
• The Lambda particle plays a critical role in determining the internal structure and energy of light hypernuclei.
• The employed YN interactions provide insights into the complex dynamics within s-shell hypernuclei.