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Full-Text Articles in Physics
The Electromagnetic Mass Differences Of Pions And Kaons, John F. Donoghue, Antonio F. Pérez
The Electromagnetic Mass Differences Of Pions And Kaons, John F. Donoghue, Antonio F. Pérez
Physics Department Faculty Publication Series
We use the Cottingham method to calculate the pion and kaon electromagnetic mass differences with as few model dependent inputs as possible. The constraints of chiral symmetry at low energy, QCD at high energy and experimental data in between are used in the dispersion relation. We find excellent agreement with experiment for the pion mass difference. The kaon mass difference exhibits a strong violation of the lowest order prediction of Dashen’s theorem, in qualitative agreement with several other recent calculations.
The Quantum Theory Of General Relativity At Low Energies, John Donoghue
The Quantum Theory Of General Relativity At Low Energies, John Donoghue
Physics Department Faculty Publication Series
In quantum field theory there is now a well developed technique, effective field theory, which allows one to obtain low energy quantum predictions in “non-renormalizable” theories, using only the degrees of freedom and interactions appropriate for those energies. Whether or not general relativity is truly fundamental, at low energies it is automatically described as a quantum effective field theory and this allows a consistent framework for quantum gravity at ordinary energies. I briefly describe the nature and limits of the technique.
Dynamics Of A Suspension Of Spheres And Rigid Polymers: Effect Of Geometrical Mismatch, Radu P. Mondescu, M. Muthukumar
Dynamics Of A Suspension Of Spheres And Rigid Polymers: Effect Of Geometrical Mismatch, Radu P. Mondescu, M. Muthukumar
Physics Department Faculty Publication Series
No abstract provided.
Chiral Anomaly And Gamma 3 Pi, Br Holstein
Chiral Anomaly And Gamma 3 Pi, Br Holstein
Physics Department Faculty Publication Series
Measurement of the γ3π process has revealed a possible conflict with what should be a solid prediction generated by the chiral anomaly. We show that inclusion of appropriate energy-momentum dependence in the matrix element reduces the discrepancy.
Future Lq Oscillation Experiments And Present Data, Jj Gomez-Cadenas, M.C Gonazles-Garcia
Future Lq Oscillation Experiments And Present Data, Jj Gomez-Cadenas, M.C Gonazles-Garcia
Physics Department Faculty Publication Series
Our goal in this paper is to examine the discovery potential of laboratory experiments searching for the oscillation lk(le)Plq, in the light of recent data on solar and atmospheric neutrino experiments, which we analyse together with the most restrictive results from laboratory experiments on neutrino oscillations. In order to explain simultaneously all present results we use a fourneutrino framework, with an additional sterile neutrino. Our predictions are rather pessimistic for the upcoming experiments NOMAD and CHORUS, which, we Þnd, are able to explore only a small area of the oscillation parameter space. On the other hand, the discovery potential of …
Final State Interactions In The Decay Of Heavy Quarks, John Donoghue
Final State Interactions In The Decay Of Heavy Quarks, John Donoghue
Physics Department Faculty Publication Series
I discuss some recent results on the systematic behavior of final state rescattering which makes use of the limit of a heavy B meson. The results suggest that soft final state interactions do not disappear in the large $m_B$ limit. Soft and hard final state phases can both contribute to CP violating asymmetries in B decay. The way that the soft phases occur is interesting theoretically and suggests the violation of local quark-hadron duality.
Nonperturbative Methods In Kaon Physics (Aside From The Lattice), John Donoghue
Nonperturbative Methods In Kaon Physics (Aside From The Lattice), John Donoghue
Physics Department Faculty Publication Series
I discuss the progress in the use of analytic techniques for low energy QCD, in particular as applied to kaon physics. These methods are becoming increasingly powerful and we have gained a good deal of control over the difficult hadronic interactions. There are continuing developments, and I speculate on the ways that these techniques may become yet more sophisticated in the future.
Is B→Xsγ Equal To B→Sγ? Spectator Contributions To Rare Inclusive B Decays, John Donoghue, Alexey A. Petrov
Is B→Xsγ Equal To B→Sγ? Spectator Contributions To Rare Inclusive B Decays, John Donoghue, Alexey A. Petrov
Physics Department Faculty Publication Series
In B→Xsγ, there are perturbative QCD corrections at order αs not only to the single quark line process b→sγ but also coming from a set of diagrams where the weak interaction vertex involves a gluon which interacts with the spectator quark in the B hadron. We discuss the impact of the full set of these diagrams. These can influence the decay rate and also the line shape of the photon spectrum as they favor a softer photon energy than does the pure spectator decay b→sγ. A subset of these diagrams generates differences in the decay rates for charged and neutral …