- Alejandro Rivero, "Unbroken Supersymmetry Without New Particles", 0910.4793: Alejandro is a friend and he already wrote in this blog about his "sbootstrap" theory. To tell you in two words what this is about, he moves from a startling numerical coincidence between the masses of charged leptons (the Koide' mass formula) to hypothesize that the role of Supersymmetrical particles in the Standard Model is taken by composite mesons. It is a bold speculation, and it is certainly worth ten minutes of your time, if you can read English and know the basics of group theory.
- Gautam Bhattacharyya, "A Pedagogical Review of Electroweak Symmetry Breaking Scenarios", 0910.5095: a quite well-written and comprehensive summary of the theory of electroweak symmetry breaking in the standard model, with explanations of models involving little Higgs or Higgless breakings. I found it a very useful resource, especially for experimentalists wishing to refresh their memory; but beware, the math is only as simple as possible, not simpler.
- Tilman Plehn, Gavin Salam, Michael Spannowsky, "Fat Jets for a Light Higgs", 0910.5472: a recipe for looking for the Higgs boson at the LHC, using the associated production
- H. Pessard, "Status of the OPERA Neutrino Experiment", 0910.5701: a short review of the status of OPERA, a really cool experiment which aims to detect oscillations of muon neutrinos (from a CERN beam shot underground in the direction of the Gran Sasso underground facility) into tau neutrinos. Tau neutrinos are notoriously hard to detect: technically it is the last standard model fermion to have been directly discovered, although nobody could really doubt of their existence after the tau lepton discovery and the LEP measurement of the Z boson width. OPERA uses photographic emulsions to reach micrometric precision in the tracking of charged particles emitted when tau neutrinos hit nuclei, produce tau leptons, and the latter decays after a path of few microns in the emulsion. Have a look at a typical picture (this one shows acharmed meson decay though) on the right. I think OPERA is cool because of its concept: bricks of emulsions where neutrino interactions are captured get removed from the detector progressively, and analyzed as data taking proceeds. It reminds me of HAL, the supercomputer in "2001, the Space Odyssey", being disassembled bit by bit by the vindictive astronaut the machine had tried to kill. For a previous account of OPERA, read here.
Yes, the paper is mainly an update of the comments in this blog, time ago. Perhaps I should quote the blog too ;-). Actually I should add some bibliography, as I am selling it as a conjecture of mine, while it happens that the proposal to interpret the Ramond sector as a quark sector and the bosonic sector as mesons was already in the papers of Schwarz in 1971; it was forgotten after the discovery of supergravity, where the whole mess was upgraded to Planck scale. Reading between lines, I guess that the idea was received with skepticism; in a graduate lecture in 1974, Mandelstam suggests that it is better to forget about the fermionic sector and see the whole as a "quark theory of the meson, without quarks". The problem, of course, is that you need to explain how a theory can include composites and elementary, or alternatively if you want the fermions to be composite, explain why they are point like.
I am also thinking about removing or rebuilding a point appearing first time in this paper, and needing more substance to be discussed seriously: The argument of the existence of two natural divisions of the standard model on 84+12. That of the top quark and that of the neutrino. This split appears when you consider descending from D=11 or 10 down to 10 or 9 (still weak, the argument here), and then in dimension 9 one should build the SU(3)xU(1)_EM part of the standard model. Moreover, one of the splits needs chirality (for the neutrinos), the other doesn't. Moreover, one of splits involves the most massive particle, the other the lightest. I invite your readers, even without reading the paper, to guess what I am after, here.