Precision Measurement of sin^2 theta_W at a Reactor

This paper presents a strategy for measuring sin^2 theta_W to ~1% at a reactor-based experiment, using antineutrinos electron elastic scattering. This error is comparable to the NuTeV, SLAC E158, and APV results on sin^2 theta_W, but with substantially different contributions to the systematics. An improved method for identifying antineutrino proton events, which serve both as a background and as a normalization sample, is described. The measurement can be performed using the near detector of the presently proposed reactor-based oscillation experiments. We conclude that an absolute error of delta(sin^2 theta_W)=0.0019 may be achieved.Comment: To be Submitted to Phys. Rev.

On the energy deposited by a quark moving in an N=4 SYM plasma

We evaluate the energy momentum tensor of a massive quark as it moves through an N=4 SYM quark gluon plasma at constant velocity. We find that in the near-quark region, where the dynamics is expected to be dominated by dissipative behavior, the energy density may be quantitatively characterized by a transient at velocities above the speed of sound of the plasma.Comment: 19 pages, 1 figure; Typos corrected, references adde

A boundary element regularised Stokeslet method applied to cilia and flagella-driven flow

A boundary element implementation of the regularised Stokeslet method of Cortez is applied to cilia and flagella-driven flows in biology. Previously-published approaches implicitly combine the force discretisation and the numerical quadrature used to evaluate boundary integrals. By contrast, a boundary element method can be implemented by discretising the force using basis functions, and calculating integrals using accurate numerical or analytic integration. This substantially weakens the coupling of the mesh size for the force and the regularisation parameter, and greatly reduces the number of degrees of freedom required. When modelling a cilium or flagellum as a one-dimensional filament, the regularisation parameter can be considered a proxy for the body radius, as opposed to being a parameter used to minimise numerical errors. Modelling a patch of cilia, it is found that: (1) For a fixed number of cilia, reducing cilia spacing reduces transport. (2) For fixed patch dimension, increasing cilia number increases the transport, up to a plateau at $9\times 9$ cilia. Modelling a choanoflagellate cell it is found that the presence of a lorica structure significantly affects transport and flow outside the lorica, but does not significantly alter the force experienced by the flagellum.Comment: 20 pages, 7 figures, postprin

Rescattering in Meson Photoproduction off Few Body Systems

Exclusive reactions induced at high momentum transfer in few body systems provide us with an original way to study the production and propagation of hadrons in cold nuclear matter. In very well defined parts of the phase space, the reaction amplitude develops a logarithmic singularity. It is on solid ground since it depends only on on-shell elementary amplitudes and on low momentum components of the nuclear wave function. This is the best window to study the propagation of exotic configurations of hadrons such as, for instance, the onset of color transparency. It may appear earlier in meson photo-production reactions, more particularly in the strange sector, than in more classical quasi elastic scattering of electrons. More generally, those reactions provide us with the best tool to determine the cross section of the scattering of various hadrons (strange particles, vector mesons) from the nucleon and to access the production of possible exotic states.Comment: 15 pages; 11 figures During the review process of the paper, the following changes have been implemented: 1- The title has been changed, 2- The abstact and the first paragraph of the introduction have been rephrased for consistency; 3- Figure 10 has been added; 4- The Appedix has been considerably expanded: it gives the full expressions of the elementary photoproduction amplitudes in terms of Pauli spinors and matrice

Bosonic Partition Functions at Nonzero (Imaginary) Chemical Potential

We consider bosonic random matrix partition functions at nonzero chemical potential and compare the chiral condensate, the baryon number density and the baryon number susceptibility to the result of the corresponding fermionic partition function. We find that as long as results are finite, the phase transition of the fermionic theory persists in the bosonic theory. However, in case that bosonic partition function diverges and has to be regularized, the phase transition of the fermionic theory does not occur in the bosonic theory, and the bosonic theory is always in the broken phase.Comment: 30 pages, 6 figure