Measurement of the D_s leptonic decay constant f_{D_s} and observation of new resonances decaying to D^(*)pi
Abstract/Contents
- Abstract
- The absolute branching fractions for the decays $D^-_s\rightarrow\ell^-\bar{\nu}_{\ell}$ ($\ell=e$, $\mu$, or $\tau$) are measured using a data sample corresponding to an integrated luminosity of 521 fb$^{-1}$ collected at center of mass energies near 10.58 GeV with the BABAR detector at the PEP-II $e^+e^-$ collider at SLAC. The number of $D_s^-$ mesons is determined by reconstructing the recoiling system $DKX\gamma$ in events of the type $e^+e^-{\rightarrow}DKXD^{*-}_s$, where $D^{*-}_s\rightarrow D^-_s\gamma$ and $X$ represents additional pions from fragmentation. The $D^-_s\rightarrow\ell^-\nu_{\ell}$ events are detected by full or partial reconstruction of the recoiling system $DKX\gamma\ell$. The following results are obtained: $B(D^-_s \to \mu^- \nu) = (6.02 \pm 0.38 \pm 0.34) \times 10^{-3}$, $B(D^-_s \to \tau^- \nu) = (5.00 \pm 0.35 \pm 0.49) \times 10^{-2}$, and $B(D^-_s \to e^- \nu) < 2.8 \times 10^{-4} at 90% C.L.$, where the first uncertainty is statistical and the second is systematic. The branching fraction measurements are combined to determine the $D^-_s$ decay constant $f_{D_s} = (258.6 \pm 6.4 \pm 7.5)$ MeV. In addition, a study has been performed of the $D^+\pi^-$, $D^0\pi^+$, and $D^{*+}\pi^-$ systems in inclusive $e^+e^- \rightarrow c\bar{c}$ interactions in a search for excited $D$ meson states. The dataset used consists of $\sim$454 fb$^{-1}$. The mass spectra for these systems show, for the first time, candidates for the radial excitations of the $D^0$, $D^{*0}$, and $D^{*+}$, as well as the $L=2$ excited states of the $D^0$ and $D^+$, where $L$ is the orbital angular momentum of the quarks. Finally, a prototype of a next generation Detector of Internally Reflected Cherenkov radiation (Focusing DIRC) has been tested using a 10 GeV electron beam at SLAC. The Focusing DIRC is based on the DIRC which was used in the BABAR detector, but has new pixel photon detectors which improve the resolution on the single photon time of propagation by about an order of magnitude allowing, for the first time, to correct the chromatic smearing in the Cherenkov angle. The Focusing DIRC may be used in a future Super-B factory.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2011 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Benitez, Jose Feliciano |
|---|---|
| Associated with | Stanford University, Department of Physics |
| Primary advisor | Leith, David W. G. S |
| Thesis advisor | Leith, David W. G. S |
| Thesis advisor | Peskin, Michael Edward, 1951- |
| Thesis advisor | Roodman, Aaron J. (Aaron Jay), 1964- |
| Advisor | Peskin, Michael Edward, 1951- |
| Advisor | Roodman, Aaron J. (Aaron Jay), 1964- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Jose Benitez. |
|---|---|
| Note | Submitted to the Department of Physics. |
| Thesis | Ph.D. Stanford University 2011 |
| Location | electronic resource |
Access conditions
- Copyright
- © 2011 by Jose Feliciano Benitez
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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