Study of multi-nucleon transfer reactions in 58, 64Ni + 207Pb collisions at the velocity filter SHIP

The European Physical Journal A - We investigated multi-nucleon transfer reactions in collisions of 58Ni + 207Pb and 64Ni + 207Pb at Coulomb barrier energies. The new aspect is that we used a...     

InAs/GaSb superlattice focal plane arrays for high-resolution thermal imaging

The first fully operational mid-IR (3–5 μm) 256×256 IR-FPA camera system based on a type-II InAs/GaSb short-period superlattice showing an excellent noise equivalent temperature difference below 10 mK and a very uniform performance has been realized. We report on the development and fabrication of the detecor chip, i.e., epitaxy, processing technology and electro-optical characterization of fully integrated InAs/GaSb superlattice focal plane arrays. While the superlattice design employed for the first demonstrator camera yielded a quantum efficiency around 30%, a superlattice structure grown with a thicker active layer and an optimized V/III BEP ratio during growth of the InAs layers exhibits a significant increase in quantum efficiency. Quantitative responsivity measurements reveal a quantum efficiency of about 60% for InAs/GaSb superlattice focal plane arrays after implementing this design improvement. The paper presented there appears in Infrared Photoelectronics, edited by Antoni Rogalski, Eustace L. Dereniak, Fiodor F. Sizov, Proc. SPIE Vol. 5957, 595707 (2005).     

Spectral properties of random Schrödinger operators with unbounded potentials

We investigate spectral properties of random Schrödinger operators H = - + _n()(1 + |n|) acting onl ²(Z ^d), where _n are independent random variables uniformly distributed on [0, 1].Research partially supported by a Sloan Doctoral Dissertation Fellowship and NSERC under grant OGP-0007901Research partially supported by NSF grant DMS-9101716     

Limit on the electron electric dipole moment in gadolinium-iron garnet

A new method for the detection of the electron electric dipole moment (EDM) using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the sample's magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electron EDM of 5 x 10(-24)e cm, which is a factor of 40 below the limit obtained from the only previous solid-state EDM experiment. The result is limited by the imperfect discrimination of an unexpectedly large voltage that is even upon the reversal of the sample magnetization.     

Construction of the Incipient Infinite Cluster for Spread-out Oriented Percolation Above 4 + 1 Dimensions

 We construct the incipient infinite cluster measure (IIC) for sufficiently spread-out oriented percolation on ℤ ^d × ℤ₊, for d +1 > 4+1. We consider two different constructions. For the first construction, we define ℙ ⁿ (E) by taking the probability of the intersection of an event E with the event that the origin is connected to (x,n)  ℤ ^d × ℤ₊, summing this probability over x  ℤ ^d , and normalising the sum to get a probability measure. We let n → ∞ and prove existence of a limiting measure ℙ_∞, the IIC. For the second construction, we condition the connected cluster of the origin in critical oriented percolation to survive to time n, and let n → ∞. Under the assumption that the critical survival probability is asymptotic to a multiple of n ⁻¹, we prove existence of a limiting measure ℚ_∞, with ℚ_∞ = ℙ_∞. In addition, we study the asymptotic behaviour of the size of the level set of the cluster of the origin, and the dimension of the cluster of the origin, under ℙ_∞. Our methods involve minor extensions of the lace expansion methods used in a previous paper to relate critical oriented percolation to super-Brownian motion, for d+1 > 4+1. Received: 13 December 2001 / Accepted: 11 July 2002 Published online: 29 October 2002 RID="*" ID="*" Present address: Department of Mathematics and Computer Science, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands. E-mail: rhofstad@win.tue.nl     

Observation of D+(s)K- and evidence for D+(s)pi- final states in neutral B decays

We report the first observation of a B meson decay that is not accessible by a direct spectator process. The channel B(0)-->D(+)(s)K- is found in a sample of 85 x 10(6) BB; events, collected with the Belle detector at KEKB, with a branching fraction B(B(0)-->D(+)(s)K-)=(4.6(+1.2)(-1.1)+/-1.3) x 10(-5). We also obtain evidence for the B0-->D(+)(s)pi(-) decay with branching fraction B(B0-->D(+)(s)pi(-))=(2.4(+1.0)(-0.8)+/-0.7) x 10(-5). This value may be used to extract a model-dependent value of |V(ub)|.