Interview with Marion Ecker, June 23, 2001

Marion Ecker was interviewed on June 23, 2001 by Michael J. Birkner about her life as a resident of Adams County. Ecker discusses her childhood and education at Shippensburg State, as well as her teaching career in Gettysburg. She also discusses her connections to Gettysburg College, especially the Plank family. Collection Note: This oral history was selected from the Oral History Collection maintained by Special Collections & College Archives. Transcripts are available for browsing in the Special Collections Reading Room, 4th floor, Musselman Library. GettDigital contains the complete listing of oral histories done from 1978 to the present. To view this list and to access selected digital versions please visit -- http://gettysburg.cdmhost.com/cdm/landingpage/collection/p16274coll

Long distance contribution to K+→π+ννˉK^+ \to \pi^+ \nu {\bar \nu} decay and O(p4)O(p^4) terms in CHPT

The long distance contribution to $K^+ \to \pi^+ \nu {\bar \nu}$ is calculated using chiral perturbation theory. The leading contribution comes from $O(p^4)$ tree terms. The branching ratio of the $O(p^4)$ long distance contribution is found to be of order $10_{-3}$ smaller than the short distance contributions.Comment: 12 pages, 1 figure (available upon request

Radiative Semileptonic Kaon Decays

We evaluate the matrix elements for the radiative kaon decays $K^+ \to l^+\nu_l\gamma$, $l^+ \nu_l l'^+ l'^-$ and $K \to \pi l \nu_l\gamma$ \ ($l,\ l' = e,\mu$) to next-to-leading order in chiral perturbation theory. We calculate total rates and rates with several kinematical cuts and confront the results with existing data. Measurements at future kaon facilities will allow for a more detailed comparison between theory and experiment.Comment: LaTeX, 40 pages, 5 figures (not included), CERN-TH 6625/92, BUTP-92/3

Anatomy of Mixing-Induced CP Asymmetries in Left-Right-Symmetric Models with Spontaneous CP Violation

We investigate the pattern of CP violation in K, B_d and B_s mixing in a symmetrical SU(2)_R x SU(2)_L x U(1) model with spontaneous CP violation. We calculate the phases of the left and right quark mixing matrices beyond the small phase approximation and perform a careful analysis of all relevant restrictions on the model's parameters from Delta m_K, Delta m_B, epsilon, epsilon'/epsilon and the CP asymmetry in B->J/psi K_S. We find that, with current experimental data, the mass of the right-handed charged gauge boson, M2, is restricted to be in the range 2.75 to 13 TeV and the mass of the flavour-changing neutral Higgs boson, MH, in 10.2 to 14.6 TeV. This means in particular that the decoupling limit M2, MH -> infinity is already excluded by experiment. We also find that the model favours opposite signs of epsilon and sin 2beta and is excluded if sin 2beta > 0.1.Comment: 33 pages Latex with 11 Postscript-Figures (included

Chiral Perturbation Theory and U(3)_L\times U(3)_R Chiral Theory of Mesons

We examine low energy limit of $U(3)_L\times U(3)_R$ chiral theory of mesons through integrating out fields of vector and axial-vector mesons. The effective lagrangian for pseudoscalar mesons at $O(p^4)$ has been obtained, and five low energy coupling constants $L_i(i=1,2,3,9,10)$ have been revealed. They are in good agreement with the results of CHPT's at $\mu \sim m_\rho$.Comment: 20 pages, Standard LaTex file, no finger

The Design of Mechanically Compatible Fasteners for Human Mandible Reconstruction

Mechanically compatible fasteners for use with thin or weakened bone sections in the human mandible are being developed to help reduce large strain discontinuities across the bone/implant interface. Materials being considered for these fasteners are a polyetherertherketone (PEEK) resin with continuous quartz or carbon fiber for the screw. The screws were designed to have a shear strength equivalent to that of compact/trabecular bone and to be used with a conventional nut, nut plate, or an expandable shank/blind nut made of a ceramic filled polymer. Physical and finite element models of the mandible were developed in order to help select the best material fastener design. The models replicate the softer inner core of trabecular bone and the hard outer shell of compact bone. The inner core of the physical model consisted of an expanding foam and the hard outer shell consisted of ceramic particles in an epoxy matrix. This model has some of the cutting and drilling attributes of bone and may be appropriate as an educational tool for surgeons and medical students. The finite element model was exercised to establish boundary conditions consistent with the stress profiles associated with mandible bite forces and muscle loads. Work is continuing to compare stress/strain profiles of a reconstructed mandible with the results from the finite element model. When optimized, these design and fastening techniques may be applicable, not only to other skeletal structures, but to any composite structure

Vector form factor of the pion : A model-independent approach

We study a model-independent parameterization of the vector pion form factor that arises from the constraints of analyticity and unitarity. Our description should be suitable up to s^(1/2) ~ 1.2 GeV and allows a model-independent determination of the mass of the rho(770) resonance. We analyse the experimental data on tau^- -> pion^- pion^0 nu_tau and e^+ e^- -> pion^+ pion^- in this framework, and its consequences on the low-energy observables worked out by chiral perturbation theory. An evaluation of the two pion contribution to the anomalous magnetic moment of the muon, a_{mu}, and to the fine structure constant, alpha(M_Z^2), is also performed.Comment: 5 pages, 2 figures. To appear in the proceedings of the High-Energy Physics International Conference on Quantum Chromodynamics QCD02, Montpellier (France), 2-9 July (2002

Rare Kaon Decays in the 1/Nc1/N_c-Expansion

We study the unknown coupling constants that appear at order $p^4$ in the Chiral Perturbation Theory analysis of $K \to \pi \gamma^* \to \pi l^+ l^-$, $K^{+-} \to \pi^{+-} \gamma \gamma$ and $K \to \pi \pi \gamma$ decays. To that end, we compute the chiral realization of the $\Delta S \, = \, 1$ Hamiltonian in the framework of the $1/N_c$-expansion of the low-energy action. The phenomenological implications are also discussed.Comment: 18 pages, LaTeX, CPT-92/P.279