The XV-15 tilt rotor research aircraft

The design characteristics of the XV-15 Tilt rotor research aircraft are presented. Particular attention is given to the following: control system; conversion system; and propulsion system. Flight test results are also reported

Hadronic physics with domain-wall valence and improved staggered sea quarks

With the advent of chiral fermion formulations, the simulation of light valence quarks has finally become realistic for numerical simulations of lattice QCD. The simulation of light dynamical quarks, however, remains one of the major challenges and is still an obstacle to realistic simulations. We attempt to meet this challenge using a hybrid combination of Asqtad sea quarks and domain-wall valence quarks. Initial results for the proton form factor and the nucleon axial coupling are presented.Comment: Two Talks presented at Lattice2004(spectrum), LaTex, 6 pages, 6 eps figure

Vitrification and determination of the crystallization time scales of the bulk-metallic-glass-forming liquid Zr58.5Nb2.8Cu15.6Ni12.8Al10.3

The crystallization kinetics of Zr58.5Nb2.8Cu15.6Ni12.8Al10.3 were studied in an electrostatic levitation (ESL) apparatus. The measured critical cooling rate is 1.75 K/s. Zr58.5Nb2.8Cu15.6Ni12.8Al10.3 is the first bulk-metallic-glass-forming liquid that does not contain beryllium to be vitrified by purely radiative cooling in the ESL. Furthermore, the sluggish crystallization kinetics enable the determination of the time-temperature-transformation (TTT) diagram between the liquidus and the glass transition temperatures. The shortest time to reach crystallization in an isothermal experiment; i.e., the nose of the TTT diagram is 32 s. The nose of the TTT diagram is at 900 K and positioned about 200 K below the liquidus temperature

Insight into nucleon structure from generalized parton distributions

The lowest three moments of generalized parton distributions are calculated in full QCD and provide new insight into the behavior of nucleon electromagnetic form factors, the origin of the nucleon spin, and the transverse structure of the nucleon.Comment: 3 pages, Lattice2003(Theoretical developments

Quark Contributions to Nucleon Momentum and Spin from Domain Wall fermion calculations

We report contributions to the nucleon spin and momentum from light quarks calculated using dynamical domain wall fermions with pion masses down to 300 MeV and fine lattice spacing a=0.084 fm. Albeit without disconnected diagrams, we observe that spin and orbital angular momenta of both u and d quarks are opposite, almost canceling in the case of the d quark, which agrees with previous calculations using a mixed quark action. We also present the full momentum dependence of n=2 generalized form factors showing little variation with the pion mass.Comment: 7 pages, 5 figures, NT-LBNL-11-020, MIT-CTP-4323. Presented at the 29th International Symposium on Lattice Field Theory (Lattice 2011), Squaw Valley, California, 10-16 Jul 201

Meson decay constants from Nf=2 clover fermions

We present recent results for meson decay constants calculated on configurations with two flavours of O(a)-improved Wilson fermions. Non-perturbative renormalisation is applied and quark mass dependencies as well as finite volume and discretisation effects are investigated. In this work we also present a computation of the coupling of the light vector mesons to the tensor current using dynamical fermions.Comment: 6 pages, contribution to Lattice2005(Hadron spectrum and quark masses

Attractive Channel Skyrmions and the Deuteron

The deuteron is described as a quantum state on a ten-dimensional manifold $M_{10}$ of Skyrme fields of degree two, which are obtained by calculating the holonomy of $SU(2)$ instantons. The manifold $M_{10}$ includes both toroidal configurations of minimal energy and configurations which are approximately the product of two Skyrmions in the most attractive relative orientation. The quantum Hamiltonian is of the form $-\Delta +V$, where $\Delta$ is the covariant Laplace operator on $M_{10}$ and $V$ is the potential which $M_{10}$ inherits from the Skyrme potential energy functional. Quantum states are complex-valued functions on the double cover of $M_{10}$ satisfying certain constraints. There is a unique bound state with the quantum numbers of the deuteron, and its binding energy is approximately 6 MeV. Some of the deuteron's electrostatic and magnetostatic properties are also calculated and compared with experiment.Comment: 38 pages, latex, 9 figure