Results from the Large Hadron Collider (LHC) at CERN point show that the rare B-meson to a muon and antimuon decays are consistent with the standard model. It was hoped that the details of these rare events would provide evidence of supersymmetry, at least for energies up to 8 TeV.

Researchers working on the LHCb experiment announced their results on Monday at the Hadron Collider Conference in Kyoto. A preprint is available on the arXiv.

However, this is not actually inconsistent with supersymmetry, the measurements are still compatible with some supersymmetric theories. For example, Prof. Gordon Kane argues that models based on superstring compactifications are quite compatible with the LHCb results. You can read more about this here.

The energy of the collisions at the LHC will be increased from the current 8 TeV to 14 TeV, which will be engineered over the 2013–2014 shutdown. It is possible that signals of supersymmetry may be found at this higher energy.

Right now it seems that the standard model has again passed at the tests, which include he discovery of the Higgs and the details of the rare B-meson decays.

Invisibility cloaking devices have been the subject of science fiction for a long time; for example the famous Klingon and Romulan devices of Star Trek.

Image courtesy of http://en.memory-alpha.org

This started to become reality in two papers in 2006. John Pendry of Imperial College London and David Schurig & David Smith of Duke University laid out the theory of “transformation optics” in [1]. Shortly after the principle was demonstrated using microwaves [2].

Perfect cloaking?

No-one so far has created a perfect cloaking device that works in a range of frequencies. Although one can make an object invisible, reflections from the cloak make the scene a little darker and the presence of the object is clear.

Now Nathan Landy & David R. Smith [3] have developed a diamond-shaped cloak, with properties carefully matched at the diamond’s corners, so that light passes around the cloak completely with no reflections.

Here, we design and experimentally characterize a two-dimensional, unidirectional cloak that makes no approximations to the underlying transformation optics formulation, yet is capable of reducing the scattering of an object ten wavelengths in size. We demonstrate that this approximation-free design regains the performance characteristics promised by transformation optics.

Extracted from the abstract of [3]

It would be very difficult to extend this technique to visible light, so hiding large objects from our view is a little way off. However, microwaves are important in telecommunications and it is possible that cloaking devices could be applied here.

Reference

[1] J. B. Pendry, D. Schurig, D. R. Smith, Controlling Electromagnetic Fields, Science 23 June 2006:
Vol. 312 no. 5781 pp. 1780-1782.

[2] D. Schurig, J. J. Mock, B. J. Justice, S. A. Cummer, J. B. Pendry, A. F. Starr, D. R. Smith, Metamaterial Electromagnetic Cloak at Microwave Frequencies, Science 10 November 2006: Vol. 314 no. 5801 pp. 977-980

[3] Nathan Landy & David R. Smith, A full-parameter unidirectional metamaterial cloak for microwaves, Nature Materials (2012) doi:10.1038/nmat3476

Dimensional regularization, that is compute in “4 + ε space-time dimensions” and take the limit ε→0 at the end, is a powerful tool in quantum field theory. In fact, Veltman and ’t Hooft won the 1999 Physics Nobel Prize, for dimensional regularization and its application to Yang-Mills theory. The work of Veltman and ‘t Hooft dates back to 1971 and was published in 1972 [3].

However, the original idea may have come from two physicist working in Argentina. According to Wolfgang Bietenholz & Lilian Prado, it was Juan Jose Giambiagi and Carlos Guido Bollini [1] in a paper submitted before Veltman and ‘t Hooft, who first proposed dimensional regularization [2].

The paper of Giambiagi and Bollini, although submitted for publication earlier, was actually published after the paper of Veltman and ‘t Hooft.

Juan José Giambiagi (1924 – 1996)

Read the short preprint by Bietenholz & Prado, which is available on the arXiv, for more details.

Carlos Guido Bollini

Links

Juan José Giambiagi (ICTP biography)

Carlos Guido Bollini (Fundación Konex)

References
[1]Wolfgang Bietenholz & Lilian Prado,40 Years of Calculus in 4 + epsilon Dimensions,(2012) arXiv:1211.1741v1 [physics.hist-ph]

[2]C.G. Bollini and J.J. Giambiagi, Lowest order ‘divergent’ graphs in n-dimensional space, Phys. Lett. 40B (1972) 566-568.

[3] G. ’t Hooft & M. Veltman, Regularization and renormalization of gauge fields Nucl. Phys. B44 (1972) 189-213.