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Alex Wright

Publications and source records attributed to Alex Wright.

42 records · Page 3Linked to original sources

The DarkSide Program at LNGS

DarkSide is a direct detection dark matter program based on two phase time projection chambers with depleted argon targets. The DarkSide detectors are designed, using novel low background techniques and active shielding, to be capable of demonstrating in situ a very low level of residual background. This means that each detector in the DarkSide program should have the ability to make a convincing claim of dark matter detection based on the observation of a few nuclear recoil events. The collaboration is currently operating a 10 kg prototype detector, DarkSide-10, in Laboratori Nazionali del Gran Sasso, Italy, while the first physics detector in the program, DarkSide-50, is expected to be deployed at LNGS at the end of 2012.

physics.ins-det↗

Sums of Adjoint Orbits

Let G be a real compact connected simple Lie group, and g its Lie algebra. We study the problem of determining, from root data, when a sum of adjoint orbits in g, or a product of conjugacy classes in G, contains an open set. Our general methods allow us to determine exactly which sums of adjoint orbits in su(m) and products of conjugacy classes in SU(m) contain an open set, in terms of the highest multiplicities of eigenvalues. For su(m) and SU(m) we show L^2--singular dichotomy: The convolution of invariant measures on adjoint orbits, or conjugacy classes, is either singular to Haar measure or in L^2.

math.GR↗

A Highly Efficient Neutron Veto for Dark Matter Experiments

We present a conceptual design for an active neutron veto, based on boron-loaded liquid scintillator, for use in direct-detection dark matter experiments. The simulated efficiency of a 1 meter thick veto, after including the effects of neutron captures in the inner detector and inefficiencies due to feed-throughs into the veto, is greater than 99.5% for background events produced by radiogenic neutrons, while the background due to externally produced cosmogenic neutrons is reduced by more than 95%. The ability of the veto to both significantly suppress, and provide in situ measurements of, these two dominant sources of background would make the next generation of dark matter experiments much more robust, and dramatically improve the credibility of a dark matter detection claim based on the observation of a few recoil events. The veto would also allow direct extrapolation between the background-free operation of a small detector and the physics reach of a larger detector of similar construction.

nucl-ex↗

Regular Orbital Measures on Lie Algebras

Let H be a regular element of an irreducible Lie Algebra g, and let mu be the orbital measure supported on the Adjoint orbit of H. We show that the k-th power of the Fourier transform of mu is in L^2(g) if and only if k > dim g/(dim g-rank g).

math.FA↗

Operator Algebras with Unique Preduals

We show that every free semigroup algebras has a (strongly) unique Banach space predual. We also provide a new simpler proof that a weak*-closed unital operator operator algebra containing a weak* dense subalgebra of compact operators has a unique Banach space predual.

math.OA↗