arXiv subjects

S. Anderson

Publications and source records attributed to S. Anderson.

27 records · Page 2Linked to original sources

arXiv2000

First Observation of the Decays $B^{0}\to D^{-}p\bar{p}π^{+}$ and B^{0}\to D^{-}p\bar{n}$

We report the first observation of exclusive decays of the type B to D^* N anti-N X, where N is a nucleon. Using a sample of 9.7 times 10^{6} B-Bbar pairs collected with the CLEO detector operating at the Cornell Electron Storage Ring, we measure the branching fractions B(B^0 \to D^{*-} proton antiproton π^+) = ({6.5}^{+1.3}_{-1.2} +- 1.0) \times 10^{-4} and B(B^0 \to D^{*-} proton antineutron) = ({14.5}^{+3.4}_{-3.0} +- 2.7) times 10^{-4}. Antineutrons are identified by their annihilation in the CsI electromagnetic calorimeter.

hep-ex↗

arXiv2000

The Cleo III Ring Imaging Cherenkov Detector

The CLEO detector has been upgraded to include a state of the art particle identification system, based on the Ring Imaging Cherenkov Detector (RICH) technology, in order to take data at the upgraded CESR electron positron collider. The expected performance is reviewed, as well as the preliminary results from an engineering run during the first few months of operation of the CLEO III detector.

hep-ex↗

arXiv1999

Performance of the CLEO III LiF-TEA Ring Imaging Cherenkov Detector in a High Energy Muon Beam

The CLEO III Ring Imaging Cherenkov detector uses LiF radiators to generate Cherenkov photons which are then detected by proportional wire chambers using a mixture of CH$_4$ and TEA gases. The first two photon detector modules which were constructed, were taken to Fermilab and tested in a beam dump that provided high momentum muons. We report on results using both plane and "sawtooth" shaped radiators. Specifically, we discuss the number of photoelectrons observed per ring and the angular resolution. The particle separation ability is shown to be sufficient for the physics of CLEO III.

hep-ex↗

arXiv1999

Hadronic Structure in the Decay $τ^{-}\to π^{-}π^{0}ν_τ$

We report on a study of the invariant mass spectrum of the hadronic system in the decay tau- -> pi- pi0 nu_tau. This study was performed with data obtained with the CLEO II detector operating at the CESR e+ e- collider. We present fits to phenomenological models in which resonance parameters associated with the rho(770) and rho(1450) mesons are determined. The pi- pi0 spectral function inferred from the invariant mass spectrum is compared with data on e+ e- -> pi+ pi- as a test of the Conserved Vector Current theorem. We also discuss the implications of our data with regard to estimates of the hadronic contribution to the muon anomalous magnetic moment.

hep-ex↗

arXiv1999

Observation of a Broad L=1 $c\bar{q}$ State in $B^{-}\to D^{*+}π^{-}π^{-}$ at CLEO

Using 4.7 fb^-1 of data taken at CESR at energies at and near the Upsilon(4S) we have studied the decay B- -> D{*+}pi-pi- (and its conjugate). We observe a new, broad charmed meson state, which we interpret as D_J(j=1/2), in its decay to D{*+}pi-. Our preliminary results indicate the mass and width of this L=1 state to be m = (2461 +41/-3} +/-10 +/-32) MeV and Gamma = (290 +101/-79 +/-26 +/-36) MeV, with the third uncertainty associated with the parameterization of the relative strong phases. In addition we have measured several new branching fractions of charged B mesons. All quoted results are preliminary.

hep-ex↗

arXiv1999

The CLEO-III RICH Detector and Beam Test Results

We are constructing a Ring Imaging Cherenkov detector (RICH) for the CLEO III upgrade for precision charged hadron identification. The RICH uses plane and sawtooth LiF crystals as radiators, MWPCs as photon detectors with TEA as the photo-sensitive material, and low-noise Viking readout electronics. Results of a beam test of the first two out of total 30 sectors are presented.

hep-ex↗

arXiv1999

The CLEO-III Ring Imaging Cherenkov Detector

The CLEO-III Detector upgrade for charged particle identification is discussed. The RICH design uses solid LiF crystal radiators coupled with multi-wire chamber photon detectors, using TEA as the photosensor, and low-noise Viking readout electronics. Results from our beam test at Fermilab are presented.

hep-ex↗

arXiv1998

First Search for CP Violation in Tau Lepton Decay

Using the CLEO II detector we have performed the first search for $CP$ violation in tau lepton decay. CP violation in lepton decay does not occur in the minimal standard model but can occur in extensions such as the multi-Higgs doublet model. It appears as a characteristic difference between the $τ^+$ and $τ^-$ decay angular distributions for the semi-leptonic decay modes such as $τ^- \to K^0 π^- ν$. We define an observable asymmetry to exploit this and find no evidence for any CP violation.

hep-ex↗

arXiv1997

$Λ\barΛ$ Production in Two-Photon Interactions at CLEO

Using the CLEO detector at the Cornell $e^+e^-$ storage ring, CESR, we study the two-photon production of $Λ\barΛ$, making the first observation of $γγ\to Λ\barΛ$. We present the cross-section for $ γγ\to Λ\barΛ$ as a function of the $γγ$ center of mass energy and compare it to that predicted by the quark-diquark model.

hep-ex↗