Ground-state energy shift of n pions and m kaons in a finite volume

The ground state energy of a collection of n pions and m kaons with short range interactions is calculated for a volume with finite spatial extent L and periodic boundary conditions. This calculation is accomplished to order L^-6 in the large volume expansion. With this result one can extract the various two- and three-body interactions between pions and kaons from lattice QCD data

Ground-state energy shift of n pions and m kaons in a finite volume

The ground state energy of a collection of n pions and m kaons with short range interactions is calculated for a volume with finite spatial extent L and periodic boundary conditions. This calculation is accomplished to order L^-6 in the large volume expansion. With this result one can extract the various two- and three-body interactions between pions and kaons from lattice QCD data

S-wave scattering of strangeness -3 baryons

We explore the interactions of two strangeness -3 baryons in multiple spin channels with lattice QCD. This system provides an ideal laboratory for exploring the interactions of multi-baryon systems with minimal dependence on light quark masses. Model calculations of the two-$\Omega^-$ system in two previous works have obtained conflicting results, which can be resolved by lattice QCD. The lattice calculations are performed using two different volumes with $L\sim2.5$ and 3.9 fm on anisotropic clover lattices at $m_\pi \sim 390$ MeV with a lattice spacing of $a_s \sim 0.123$ fm in the spatial direction and $a_t\sim{a}_s/3.5$ in the temporal direction. Using multiple interpolating operators from a non-displaced source, we present scattering information for two ground state $\Omega^-$ baryons in both the S=0 and S=2 channels. For S=0, $k\cot\delta$ is extracted at two volumes, which lead to an extrapolated scattering length of $a^{\Omega\Omega}_{S=0}=0.16 \pm 0.22 \ \text{fm}$, indicating a weakly repulsive interaction. Additionally, for S=2, two separate highly repulsive states are observed. We also present results on the interactions of the excited strangeness -3, spin-1/2 states with the ground spin-3/2 states for the spin-1 and spin-2 channels. Results for these interactions are consistent with attractive behavior.Comment: 21 pages, 10 fig

On-fiber high-resolution photonic nanojets via high refractive index dielectrics

In this manuscript, we present high spatial resolution focusing of electromagnetic waves at telecommunication wavelengths ({\lambda}0 = 1.55 {\mu}m) by using high-refractive index mesoscale dielectrics placed at the end of an optical fiber. Our approach exploits photonic nanojets (PNJs) to achieve high-intensity, spatially narrow focal spots. The response of the device is evaluated in detail considering 2-dimensional (2D) and 3-dimensional (3D) configurations using high-index mesoscale cylindrical and spherical dielectrics, respectively, placed on top of an optical fiber. It is shown how the PNJs can be shifted towards the output surface of the mesoscale high-index dielectric by simply truncating its 2D/3D cylindrical/spherical output profile. With this setup, a PNJ with a high transversal resolution is obtained using the 2D/3D engineered mesoscale dielectric particles achieving a Full-Width at Half-Maximum of FWHM = 0.28{\lambda}0 (2D truncated dielectric), and FWHMy = 0.17{\lambda}0 and FWHMx = 0.21{\lambda}0 (3D truncated dielectric). The proposed structure may have potential in applications where near-field high spatial resolution is required, such as in sensing and imaging systems.Comment: 13 pages. 6 figure

Impact of Neutron Energy on Asteroid Deflection Performance

In the future, a hazardous asteroid will find itself on a collision course with Earth. For asteroids of moderate size or larger, a nuclear device is one of humanity\u27s only technologies capable of mitigating this threat via deflection on a timescale of less than a decade. This work examined how the output neutron energy from a nuclear device standoff detonation affects the deflection of a notional asteroid that is 300 meters in diameter and composed of silicon dioxide at a bulk density of 1.855 g/cm3. 14.1 MeV and 1 MeV neutron energy sources were modeled in MCNP to quantify the energy deposition in the asteroid target. The asteroid\u27s irradiated region was discretized in angle by tracing the rays emanating from the point of detonation and in depth by considering the neutron mean-free-paths. This high-fidelity approach was shown to deviate from previous analytic approximations commonly used for asteroid energy deposition. 50 kt and 1 Mt neutron yields of the energy deposition mappings were imported into a hydrodynamic asteroid model in ALE3D to simulate the deflective response due to blow-off ejecta. Underexplored in literature, changing the neutron energy was found to have up to a 70% impact on deflection performance due to induced differences in the energy deposition profile and in the energy coupling efficiency. The magnitude of energy deposition accounted for most of the observed variation in the asteroid velocity change, making the coupling efficiency more significant than the spatial profile characteristics. These findings are vital for determining the optimal source neutron energy spectrum for asteroid deflection applications