arXiv subjects

B. I. Eisenstein

Publications and source records attributed to B. I. Eisenstein.

4 recordsLinked to original sources

arXiv2008

Precision Measurement of B(D+ -> mu+ nu) and the Pseudoscalar Decay Constant fD+

We measure the branching ratio of the purely leptonic decay of the D+ meson with unprecedented precision as B(D+ -> mu+ nu) = (3.82 +/- 0.32 +/- 0.09)x10^(-4), using 818/pb of data taken on the psi(3770) resonance with the CLEO-c detector at the CESR collider. We use this determination to derive a value for the pseudoscalar decay constant fD+, combining with measurements of the D+ lifetime and assuming |Vcd| = |Vus|. We find fD+ = (205.8 +/- 8.5 +/- 2.5) MeV. The decay rate asymmetry [B(D+ -> mu+ nu)-B(D- -> mu- nu)]/[B(D+ -> mu+ nu)+B(D- -> mu- nu)] = 0.08 +/- 0.08, consistent with no CP violation. We also set 90% confidence level upper limits on B(D+ -> tau+ nu) < 1.2x10^(-3) and B(D+ -> e+ nu) < 8.8x10^(-6).

hep-ex↗

arXiv2004

Hadronic Branching Fractions of D^0 and D^+, and sigma(e^+e^- --> D bar{D} at E_{cm} = 3.77 GeV

Using nearly 60 pb-1 of data collected with the CLEO-c detector at the psi_prime resonance, we measure absolute branching fractions for three D0 and two D+ Cabibbo-allowed hadronic decay modes, and the cross section for e+e- to D Dbar at Ecm = 3.77 GeV. We report preliminary measurements of the reference branching fractions, B(D0 to K- pi+) = (3.92\pm 0.08\pm 0.23)% and B(D+ to K- pi+ pi+) = (9.8\pm 0.4\pm 0.8)%, and preliminary measurements of other major branching fractions, B(D0 to K- pi+ pi0) = (14.3\pm 0.3\pm 1.0)%, B(D0 to K- pi+ pi- pi+) = (8.1\pm 0.2\pm 0.9)%, and B(D+ to Ks pi+) = (1.61\pm 0.08\pm 0.15)%. We determine preliminary values of the cross sections, sigma(e+ e- to D0 D0bar) = (3.47\pm 0.07\pm 0.15) nb, sigma(e+ e- to D+ D-) = (2.59\pm 0.11\pm 0.11) nb, and sigma(e+ e- to D Dbar) = (6.06\pm 0.13\pm 0.22) nb. We note that the Monte Carlo simulations used in calculating efficiencies in this analysis included final state radiation. However, the branching fractions used in the Particle Data Group averages do not include this effect. If we had not included final state radiation in our simulations, branching fractions would have been 0.5% to 2% lower.

hep-ex↗

arXiv2003

Measurement of the Charge Asymmetry in $B\to K^* (892)^{\pm}π^{\mp}$

We report on a search for a CP-violating asymmetry in the charmless hadronic decay B -> K*(892)+- pi-+, using 9.12 fb^-1 of integrated luminosity produced at \sqrt{s}=10.58 GeV and collected with the CLEO detector. We find A_{CP}(B -> K*(892)+- pi-+) = 0.26+0.33-0.34(stat.)+0.10-0.08(syst.), giving an allowed interval of [-0.31,0.78] at the 90% confidence level.

hep-ex↗

arXiv2001

Experimental Investigation of the Two-Photon Widths of the $χ_{c0}$ and the $χ_{c2}$ Mesons

Using 12.7 $fb^{-1}$ of data collected with the CLEO detector at CESR, we observed two-photon production of the $c \bar c$ states $χ_{c0}$ and $χ_{c2}$ in their decay to $π^+ π^- π^+ π^-$. We measured $Γ_{γγ}(χ_{c}) \times {\mathcal B}(χ_{c} \to π^+π^-π^+π^-)$ to be 75 +- 13 (stat) +- 8 (syst) eV for the $χ_{c0}$ and 6.4 +- 1.8 (stat) +- 0.8 (syst) eV for the $χ_{c2}$, implying $Γ_{γγ}(χ_{c0})$ = 3.76 +- 0.65 (stat) +- 0.41 (syst) +- 1.69 (br) keV and $Γ_{γγ}(χ_{c2})$ = 0.53 +- 0.15 (stat) +- 0.06 (syst) +- 0.22 (br) keV. Also, cancelation of dominant experimental and theoretical uncertainties permits a precise comparison of $Γ_{γγ}(χ_{c0})/Γ_{γγ}(χ_{c2})$, evaluated to be 7.4 +- 2.4 (stat) +- 0.5 (syst) +- 0.9 (br), with QCD-based predictions.

hep-ex↗