arXiv subjects

P. M. Hamilton

Publications and source records attributed to P. M. Hamilton.

3 recordsLinked to original sources

arXiv2017

A Challenge to Lepton Universality in B Meson Decays

One of the key assumptions of the Standard Model of fundamental particles is that the interactions of the charged leptons, namely electrons, muons, and taus, differ only because of their different masses. While precision tests comparing processes involving electrons and muons have not revealed any significant violation of this assumption, recent studies involving the higher-mass tau lepton have resulted in observations that challenge lepton universality at the level of four standard deviations. A confirmation of these results would point to new particles or interactions, and could have profound implications for our understanding of particle physics.

hep-ex↗

arXiv2011

Recent Results in Semileptonic B Decays With BaBar

In this note, recent results of studies of semileptonic B meson decays from \babar are discussed and preliminary results given. In particular, a recent measurement of $\mathcal{B}(B \to D^{(*)}τν)$ and the ratio $\mathcal{B}(B \to D^{(*)}τν)/\mathcal{B}(B \to D^{(*)}\ell ν)$ is presented. For the $D^*$ mode, a branching fraction of $1.79\pm0.13\stat\pm0.17\syst$ is found, with a ratio of $0.325\pm0.023\stat\pm0.027\syst$. For the $D$ mode, the results are $1.04\pm0.12\stat\pm0.14\syst$ and $0.456\pm0.053\stat\pm0.056\syst$, respectively. In addition, a study of $B_s$ production and semileptonic decays using data collected in a center-of-mass energy region above the \Y4S resonance is discussed. The semileptonic branching fraction $\mathcal{B}(B_s \to \ell νX)$ is measured to be $9.9{}^{+2.6}_{-2.1}\stat{}^{+1.3}_{-2.0}\syst$.

hep-ex↗

arXiv2008

Linear frictional forces cause orbits to neither circularize nor precess

For the undamped Kepler potential the lack of precession has historically been understood in terms of the Runge-Lenz symmetry. For the damped Kepler problem this result may be understood in terms of the generalization of Poisson structure to damped systems suggested recently by Tarasov[1]. In this generalized algebraic structure the orbit-averaged Runge-Lenz vector remains a constant in the linearly damped Kepler problem to leading order in the damping coe

physics.class-ph↗