EPJ A Highlight - Emergence of nuclear rotation from elementary interactions between the nucleons

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Published on 16 October 2020

Nuclei are quantum many-body systems which exhibit emergent degrees of freedom, from shell structure and clustering to collective rotations and vibrations. Such emergent phenomena are traditionally the domain of phenomenological models, yet their description can now be placed on a more fundamental footing in terms of microscopic theory. The nature and emergence of rotational bands are presently investigated in light nuclei through ab initio nuclear many-body calculations. Beyond simply analyzing spectroscopic signatures, the structural insight are investigated in terms of angular momentum coupling schemes and group theoretical correlations as underpinnings for the rotational structure.

EPJ D Highlight - Slowing light in an optical cavity with mechanical resonators and mirrors

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Published on 15 October 2020

Theoretical physicists Kamran Ullah and Hameed Ullah have shown how a position-dependent mass optomechanical system involving a cavity between two mirrors, one attached to a resonator, can enhance induced transparency and reduce the speed of light.

We are all taught at high school that the speed of light through a vacuum is about 300000 km/s, which means that a beam from Earth takes about 2.5 seconds to reach the Moon. It naturally moves more slowly through transparent objects, however, and scientists have found ways to slow it dramatically. Optomechanics, or the interaction of electromagnetic radiation with mechanical systems, is a relatively new and effective way of approaching this. Theoretical physicists Kamran Ullah from Quaid-i-Azam University, Islamabad, Pakistan and Hameed Ullah from the Institute of Physics, Porto Alegre, Brazil have now demonstrated how light is slowed in a position-based mass optomechanical system. This work has been published in EPJ D.

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EPJ D Topical review - Crystal-based intensive gamma-ray light sources

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Published on 06 October 2020

In a Topical review just published in EPJD, A.V. Korol and A.V. Solov'yov (MBN Research Center, Germany) discuss possibilities for designing and practical realization of novel intensive gamma-ray Crystal-based LSs (CLS) operating at photon energies from 102 keV and above that can be constructed exposing oriented crystals to beams of ultrarelativistic particles. CLSs can generate radiation in the photon energy range where the technologies based on the fields of permanent magnets become inefficient or incapable.

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