Power corrections in heavy-to-light decays at large recoil energy

I briefly present recent work on QCD power corrections in heavy-to-light meson decays, using an effective field theory approach.Comment: 4 pages, 1 figure. Talk given at ICHEP 2002, Amsterdam, July 200

The SCET_II and factorization

We reformulate the soft-collinear effective theory which includes the collinear quark and soft gluons. The quark form factor is used to prove that SCET$_{\rm II}$ reproduces the IR physics of the full theory. We give a factorization proof in deep inelastic lepton-hadron scattering by use of the position space formulation.Comment: 14 pages. The revised version which modifies largely will appear in PL

Nonleptonic B decays into two light mesons in soft-collinear effective theory

We consider nonleptonic B decays into two light mesons at leading order in soft-collinear effective theory, and show that the decay amplitudes are factorized to all orders in alpha_s. The operators for nonleptonic B decays in the full theory are first matched to the operators in SCET_I, which is the effective theory appropriate for sqrt{m_b Lambda} <mu <m_b with Lambda~0.5 GeV. We evolve the operators and the relevant time-ordered products in SCET_I to SCET_II, which is appropriate for mu < sqrt{m_b Lambda}. Using the gauge-invariant operators in SCET_II, we compute nonleptonic B decays in SCET, including the nonfactorizable spectator contributions and spectator contributions to the heavy-to-light form factor. As an application, we present the decay amplitudes for B ->pi,pi in soft-collinear effective theory.Comment: 42 pages, 5 figures, 2 tables Major revision of the manuscript. The idea of using SCET_I, and SCET_II is clearly presented. Some of the calculational steps are explicitly show

Invariant Operators in Collinear Effective Theory

We consider processes which produce final state hadrons whose energy is much greater than their mass. In this limit interactions involving collinear fermions and gluons are constrained by a symmetry, and we give a general set of rules for constructing leading and subleading invariant operators. Wilson coefficients C(mu,P) are functions of a label operator P, and do not commute with collinear fields. The symmetry is used to reproduce a two-loop result for factorization in B -> D pi in a simple way.Comment: 11 pages, 2 figs, journal versio

Factorization, Effective Field Theory, and B-> D^(*) X Decays

In this proceedings I review the soft-collinear effective theory (SCET), an effective theory for energetic particles. I also discuss factorization in exclusive and inclusive B-> D^(*)X decays, and tests which can help distinguish whether factorization is a result of a large energy limit, the large N_c limit, or a combination of the two.Comment: 7 pages, 3 figs, Invited plenary talk at the 5th International Conference on Hyperons, Charm, and Beauty Hadrons, Vancouver, June 200

Graphical amplitudes from SCET

We discuss the relationship between the graphical amplitudes T, C, P, ... used to parameterize nonleptonic B decay amplitudes, and matrix elements of operators in the soft-collinear effective theory (SCET) at leading order in \Lambda/m_b. Using the SU(3) flavor symmetry of the weak Hamiltonian we derive all-order constraints on the electroweak penguin contributions to the Wilson coefficients of SCET operators.Comment: 7 pages; one additional relation included, minor corrections. version published in Physics Letters

Integrating an oscilloscope into a general purpose automatic test system

The General Purpose Automatic Test System was developed for the Air Force as a system to automatically test and fault isolate an electronic unit under test. The Test System is a building block concept and this paper developed the hardware and programming software necessary to integrate an oscilloscope into the system. A Tektronix Type 564 oscilloscope with a Tektronix Type 3A5 Programmable Amplifier and a Tektronix Type 3B5 Programmable Time Base was used. A prototype of the digital and analog interface between the Test System and the Tektronix System was built and demonstrated. The Oscilloscope Building Block displays waveforms only and requires manual intervention in the automatic test program to interpret the presented data --Abstract, Page ii