On the Nature of Hinge Commitments

This is a critical commentary on Pritchard's book Epistemic Angst. In Section 2, I present the closure-based radical skeptical paradox. Then in Section 3, I sketch Pritchard’s undercutting response to this paradox. Finally, in Section 4, I put forward two concerns about Pritchard’s response and I also propose a reading of hinge commitments, the ability reading, that might put some pressure on Pritchard’s own reading of these commitments

Socially extending the mind through social affordances

The extended mind thesis claims that at least some cognitive processes extend beyond the organism’s brain in that they are constituted by the organism’s actions on its surrounding environment. A more radical move would be to claim that social actions performed by the organism could at least constitute some of its mental processes. This can be called the socially extended mind thesis. Based on the notion of affordance as developed in the ecological psychology tradition, I defend the position that perception extends to the environment. Then I will expand the notion of affordance to encompass social affordances. Thus, perception can in some situations also be socially extended

One-Loop Right-Handed Neutrino Threshold Corrections for Two-Loop Running in Supersymmetric Type I Seesaw Models

The renormalization group (RG) running of the neutrino mass operator is required for comparing the predictions of neutrino models at high energy with the experimental data at low energies. In the type I seesaw scenario with n_G right-handed neutrinos, the RG running is also performed in the effective theories above and between the thresholds given by the masses of the right-handed neutrinos. At these thresholds, the effective theories are matched. When calculating the two-loop RG running, the matching has to be performed at the one-loop level. In this work, we calculate the one-loop matching formulae in the MSSM extended by n_G right-handed neutrinos using supergraph techniques. Moreover we present a general formula for one-loop matching of superpotential operators which can readily be applied to any supersymmetric theory where chiral superfields are integrated out.Comment: 15 pages, 4 figures; version to appear in JHE

Displaced vertex searches for sterile neutrinos at future lepton colliders

We investigate the sensitivity of future lepton colliders to displaced vertices from the decays of long-lived heavy (almost sterile) neutrinos with electroweak scale masses and detectable time of flight. As future lepton colliders we consider the FCC-ee, the CEPC, and the ILC, searching at the Z-pole and at the center-of-mass energies of 240, 350 and 500 GeV. For a realistic discussion of the detector response to the displaced vertex signal and the Standard Model background we consider the ILC's Silicon Detector (SiD) as benchmark for the future lepton collider detectors. We find that displaced vertices constitute a powerful search channel for sterile neutrinos, sensitive to squared active-sterile mixing angles as small as $10^{-11}$.Comment: 13 pages plus references, 8 figures, 1 table, matches published versio

Sterile neutrino searches via displaced vertices at LHCb

We explore the sensitivity of displaced vertex searches at LHCb for testing sterile neutrino extensions of the Standard Model towards explaining the observed neutrino masses. We derive estimates for the constraints on sterile neutrino parameters from a recently published displaced vertex search at LHCb based on run 1 data. They yield the currently most stringent limit on active-sterile neutrino mixing in the sterile neutrino mass range between 4.5 GeV and 10 GeV. Furthermore, we present forecasts for the sensitivities that could be obtained from the run 2 data and also for the high-luminosity phase of the LHC.Comment: 5 pages, 6 Figures, 1 Table, version to appear in PL