Theory driven experimentation in particle physics

Abstract

J. Woodward and S. Schindler agree that experimentation being motivated / driven by the theory it tests (Tt) is an epistemically benign form of theory-ladenness (TL). Despite their agreement, they describe two distinct forms of tested- theory drivenness (TD). I argue that TD Schindler describes is a particularly severe form of TL. I label it strong TD. It kicks in early in the measurement during the operation of the apparatus, preceding the stages at which inferences on the status of the observed phenomena are made. I briefly present a classical toy-case as an instance. The elimination of strong TD by calibrating the instrument based on a different operational theory is arguably accomplishable in the toy-case. Strong TD, however, is ubiquitous in particle physics where, contrary to what A. Franklin and Woodward argue, the experimental environment prevents calibration from eliminating it. Instead, a strategy of incrementally widening experimental loop confronts the problem, e.g. in the discovery of J/Ψ particle. I discuss why the context of the particle physics experiments is conducive to this strategy, whether it eliminates strong TD, and whether it remains a genuine epistemic problem within such a context. Weak TD as sketched by Woodward involves P being predicted by Tt or P being deemed an important physical value as the motivation for performing measurement of P. It is not a form of TL in a traditional sense, but in the context of experimentation in particle physics, I argue that it is an acute socio-epistemic problem, perhaps more acute than the possibility of TL.