Study of the Strong Interaction Among Hadrons with Correlations at the LHC

The strong interaction among hadrons has been measured in the past by scattering experiments. Although this technique has been extremely successful in providing information about the nucleon–nucleon and pion–nucleon interactions, when unstable hadrons are considered the experiments become more challenging. In the last few years, the analysis of correlations in the momentum space for pairs of stable and unstable hadrons measured in pp and p+Pb collisions by the ALICE Collaboration at the LHC has provided a new method to investigate the strong interaction among hadrons. In this article, we review the numerous results recently achieved for hyperon–nucleon, hyperon–hyperon, and kaon–nucleon pairs, which show that this new method opens the possibility of measuring the residual strong interaction of any hadron pair.

Bounds on gravitational parity violation using a rotating torsion pendulum with chiral masses

In this letter we employ recent results on gravitationally induced parity violation with a rotating torsion pendulum whose test bodies are quartz enantiomers (Zhu et al. in Phys Rev Lett 121:261101, 2018) in order to estimate, using a simple model, Hari Dass’s $$\alpha _{2}$$ α 2 constant which parametrizes the strength of parity violation in the gravitational interaction. The result here obtained, $$\alpha _{2}\sim 10^{17}$$ α 2 ∼ 10 17 , is in agreement with estimations based on high resolution experiments performed using chiral molecules, showing that the Hari-Dass’s framework for spin-dependent gravity, together with our simple model, are versatile enough in order to be applied to the analysis of other experimental results involving spin-dependent gravitational effects. Interestingly, it can also be used to constrain indirectly parity-violating effects in macroscopic samples of quartz crystals due to electron–nucleon interactions.

Impurity lattice Monte Carlo for hypernuclei

We consider the problem of including $$\varLambda $$ Λ hyperons into the ab initio framework of nuclear lattice effective field theory. In order to avoid large sign oscillations in Monte Carlo simulations, we make use of the fact that the number of hyperons is typically small compared to the number of nucleons in the hypernuclei of interest. This allows us to use the impurity lattice Monte Carlo method, where the minority species of fermions in the full nuclear Hamiltonian is integrated out and treated as a worldline in Euclidean projection time. The majority fermions (nucleons) are treated as explicit degrees of freedom, with their mutual interactions described by auxiliary fields. This is the first application of the impurity lattice Monte Carlo method to systems where the majority particles are interacting. Here, we show how the impurity Monte Carlo method can be applied to compute the binding energies of the light hypernuclei. In this exploratory work we use spin-independent nucleon–nucleon and hyperon–nucleon interactions to test the computational power of the method. We find that the computational effort scales approximately linearly in the number of nucleons. The results are very promising for future studies of larger hypernuclear systems using chiral effective field theory and realistic hyperon–nucleon interactions, as well as applications to other quantum many-body systems.