Nuclear Transparency to Intermediate-Energy Protons

Nuclear transparency in the (e,e'p) reaction for 135 < Tp < 800 MeV is investigated using the distorted wave approximation. Calculations using density-dependent effective interactions are compared with phenomenological optical potentials. Nuclear transparency is well correlated with proton absorption and neutron total cross sections. For Tp < 300 MeV there is considerable sensitivity to the choice of optical model, with the empirical effective interaction providing the best agreement with transparency data. For Tp > 300 MeV there is much less difference between optical models, but the calculations substantially underpredict transparency data and the discrepancy increases with A. The differences between Glauber and optical model calculations are related to their respective definitions of the semi-inclusive cross section. By using a more inclusive summation over final states the Glauber model emphasizes nucleon-nucleon inelasticity, whereas with a more restrictive summation the optical model emphasizes nucleon-nucleus inelasticity; experimental definitions of the semi-inclusive cross section lie between these extremes.Comment: uuencoded gz-compressed tar file containing revtex and bbl files and 5 postscript figures, totalling 31 pages. Uses psfi

Harman on Mental Paint and the Transparency of Experience

Harman famously argues that a particular class of antifunctionalist arguments from the intrinsic properties of mental states or events (in particular, visual experiences) can be defused by distinguishing “properties of the object of experience from properties of the experience of an object” and by realizing that the latter are not introspectively accessible (or are transparent). More specifically, Harman argues that we are or can be introspectively aware only of the properties of the object of an experience but not the properties of the experience of an object and hence that the fact that functionalism leaves out the properties of the experience of an object does not show that it leaves out anything mentally relevant. In this paper, I argue that Harman’s attempt to defuse the anti-functionalist arguments in question is unsuccessful. After making a distinction between the thesis of experiencing-act transparency and the thesis of mental-paint transparency, (and casting some doubt on the former,) I mainly target the latter and argue that it is false. The thesis of mental-paint transparency is false, I claim, not because mental paint involves some introspectively accessible properties that are different from the properties of the objects of experiences but because what I call the identity thesis is true, viz. that mental paint is the same as (an array of) properties of the object of experience. The identification of mental paint with properties of the object of experience entails that the antifunctionalist arguments Harman criticizes cannot be rightly accused of committing the fallacy of confusing the two

Daubert’s Naïve Realist Challenge to Husserl

Despite extensive discussion of naïve realism in the wider philosophical literature, those influenced by the phenomenological movement who work in the philosophy of perception have hardly weighed in on the matter. It is thus interesting to discover that Edmund Husserl’s close philosophical interlocutor and friend, the early twentieth-century phenomenologist Johannes Daubert, held the naive realist view. This article presents Daubert’s views on the fundamental nature of perceptual experience and shows how they differ radically from those of Husserl’s. The author argues, in conclusion, that Daubert’s views are superior to those of Husserl’s specifically in the way that they deal with the phenomenon of perceptual constancy

What has Transparency to do with Husserlian Phenomenology?

This paper critically evaluates Amie Thomasson’s (2003; 2005; 2006) view of the conscious mind and the interpretation of Husserl’s phenomenological reduction that it adopts. In Thomasson’s view, the phenomenological method is not an introspectionist method, but rather a “transparent” or “extrospectionist” method for acquiring epistemically privileged self-knowledge. I argue that Thomasson’s reading of Husserl’s phenomenological reduction is correct. But the view of consciousness that she pairs with it—a view of consciousness as “transparent” in the sense that first-order, world-oriented experience is in no way given to itself—is not compatible with it. Rather, Thomasson’s view is, from a Husserlian vantage point, self-undermining in the same way that any genuinely skeptical view is self-undermining: it undermines the conditions of its own possibility. This is one of the motives Husserl has for developing a same-order view of self-consciousness as the complement to his transparent method for self-knowledge acquisition

The Evil Demon Inside

This paper examines how new evil demon problems could arise for our access to the internal world of our own minds. I start by arguing that the internalist/externalist debate in epistemology has been widely misconstrued---we need to reconfigure the debate in order to see how it can arise about our access to the internal world. I then argue for the coherence of scenarios of radical deception about our own minds, and I use them to defend a properly formulated internalist view about our access to our minds. The overarching lesson is that general epistemology and the specialized epistemology of introspection need to talk---each has much to learn from each other

A linked cluster expansion for the calculation of the semi-inclusive A(e,e'p)X processes using correlated Glauber wave functions

The distorted one-body mixed density matrix, which is the basic nuclear quantity appearing in the definition of the cross section for the semi-inclusive A(e,e'p)X processes, is calculated within a linked-cluster expansion based upon correlated wave functions and the Glauber multiple scattering theory to take into account the final state interaction of the ejected nucleon. The nuclear transparency for 16O and 40Ca is calculated using realistic central and non-central correlations and the important role played by the latter is illustrated.Comment: 18 pages, RevTeX, 3 ps figures. Final version, to appear in Phys. Rev.

Anomalous superconducting proximity effect and coherent charge transport in semiconducting thin film with spin-orbit interaction

We present a microscopic theory of the superconducting proximity effect in a semiconducting thin film with spin-orbit interaction ($N_{SO}$) in an external magnetic field. We demonstrate that an effective 1D Hamiltonian which describes induced superconductivity in $N_{SO}$ in contact with a usual $s$-wave superconductor possesses not only spin-singlet induced superconducting order parameter term, as commonly adopted, but spin triplet order parameter term also. Using this new effective Hamiltonian we confirm previous results for a normal current across contacts of $N_{SO}$ with a normal metal and for a Josephson current with the same $N_{SO}$ with induced superconductivity, obtained previously in the framework of the phenomenological Hamiltonian without spin-triplet terms. However, a calculated current-phase relation across the transparent contact between $N_{SO}$ with induced superconductivity in magnetic field and usual $s$-wave superconductor differs significantly from previous results. We suggest the experiment which can confirm our theoretical predictions.Comment: 5 pages, 6 figure