The "What If?" machine

Which models of Beyond Standard Model (BSM) physics do physicists “prefer” and why? How do these opinions change over time, especially in the light of the LHC results? These were the questions asked and answered by philosopher Arianna Borrelli at her recent presentation: “A philosophical experiment: empirical study of knowledge production at the LHC”.


Physicist-turned-philosopher Arianna Borrelli set out to examine the interplay of theory and experiment at CERN, and how developments in science influence changes in physicists’ opinions. Instead of relying on data taken “after the fact”, Arianna made use of the LHC’s first run to live-monitor physicists at work at CERN.

She began in 2011, conducting interviews with CERN theorists and experimentalists, both in person and using a targeted online survey. Then, one year later, she did it all again - only this time, it was after the news of the Higgs-like particle discovery. The preliminary results of this research were presented, for the first time, at a CERN colloquium on 14 February. In the audience were the primary source: the CERN physicists involved in both the study and the research that affected the study.

Arianna’s in-person interviews were held with well-known experimentalists and theorists, including Fabiola Gianotti, Guido Tonelli, John Ellis and Michelangelo Mangano. Among the experimentalists she spoke to, she found there was a preference to remain “unbiased” toward different physics models, and that they had a strong appreciation for model-independent searches. And while theorists did discuss their preferences for certain models, they seemed to consider them as “exploratory tools rather than serious candidates”.

Meanwhile, the online survey looked at the views of the wider high-energy physics community. The first survey had over 1400 respondents, and there were over 900 in the second. While Arianna highlighted that this survey was not “statistically significant” (and that no one quite knew what a “statistically relevant” group of high-energy physicists would look like), the results of the survey did present a “qualitative picture of opinions”. Arianna’s preliminary conclusions showed that while the discovery of the Higgs-like particle does seem to have eroded the general belief in certain BSM-models, the respondents remained strongly motivated to invest resources in the search for new physics.

For further results from the study, including a look at how theorists and experimentalists view each other, see Arianna’s full presentation, available here.

by Katarina Anthony