Naturalness 2014-Weizmann Institute of Science

Information about the event was blogged by Professor Matt Strassler at, At the Naturalness 2014 Conference. See also his explanation on Naturalness and the Standard Model

Information about the event itself.

The discovery of a Higgs boson, with a mass around 125 GeV, at the LHC is a great victory for the Standard Model (SM). With its minimal scalar sector of electroweak symmetry breaking, the SM at short distances, well below the proton radius, is a complete weakly coupled theory. Even though the SM cannot explain several experimental observations such as neutrino masses, the baryon asymmetry of the universe and the origin of dark matter, one cannot deduce an energy scale at which the SM would be forced to be extended (with the exceptions of the Planck scale and the Landau pole of the hypercharge force). See: Naturalness 2014

***

 

In physics, naturalness is the property that the free parameters or physical constants appearing in a physical theory should take relative values "of order 1". That is, a natural theory would have parameters with values like 2.34 rather than 234,000 or 0.000234. This is in contrast to current theory like the standard model, where there are a number of parameters that vary by many orders of magnitude, and require extensive "fine-tuning" of those values in order for the theory to predict a universe like the one we live in.

The requirement that satisfactory theories should be "natural" in this sense is a current of thought initiated around the 1960s in particle physics. It is an aesthetic criterion, not a physical one, that arises from the seeming non-naturalness of the standard model and the broader topics of the hierarchy problem, fine-tuning, and the anthropic principle.

It is not always compatible with Occam's razor, since many instances of "natural" theories have more parameters than "fine-tuned" theories such as the Standard Model.

 ***

  Now that naturalism has become an accepted component of philosophy, there has recently been interest in Kuhn's work in the light of developments in the relevant sciences, many of which provide corroboration for Kuhn's claim that science is driven by relations of perceived similarity and analogy. It may yet be that a characteristically Kuhnian thesis will play a prominent part in our understanding of science http://plato.stanford.edu/entries/thomas-kuhn/

***

A non-technical discussion of the naturalness criterion and its implications for new physics searches at the LHC. To be published in the book "LHC Perspectives", edited by G. Kane and A. Pierce. See: Naturally Speaking: The Naturalness Criterion and Physics at the LHC

(PDF)