Measurement of Orbitally Excited D-Mesons at CDF II

Measurement of Orbitally Excited D-Mesons at CDF II Igor V. Gorelov (For the CDF Collaboration) Talk given on behalf of the CDF Collaboration at the First Meeting of the APS Topical Group on Hadronic Physics, GHP 2004, 24-26 October 2004, FERMILAB. Results on the first measurement of orbitally excited neutral D-meson states, D*_2 and D_1, produced in hadron collisions at Tevatron are presented. Using data from the displaced track trigger, CDF II collects the largest world sample of these states in decay modes D*+ pi-, D+ pi-. Masses and widths of both states have been measured with precision better than or comparable to the world average.Comment: 6 pages, 5 figures, talk given on behalf of the CDF Collaboration at the First Meeting of the APS Topical Group on Hadronic Physics, GHP 2004, Oct 24-26,2004, Fermilab, Batavia, Illinoi

Observation of B→ϕKB\to \phi K and B→ϕK∗B\to \phi K^{*}

We have studied two-body charmless hadronic decays of $B$ mesons into the final states phi K and phi K^*. Using 9.7 million $B\bar{B}$ pairs collected with the CLEO II detector, we observe the decays B- -> phi K- and B0 -> phi K*0 with the following branching fractions: BR(B- -> phi K-)=(5.5 +2.1-1.8 +- 0.6) x 10^{-6} and BR(B0 -> phi K*0)=(11.5 +4.5-3.7 +1.8-1.7) x 10^{-6}. We also see evidence for the decays B0 -> phi K0 and B- -> phi K*-. However, since the statistical significance is not overwhelming for these modes we determine upper limits of <12.3 x 10^{-6} and <22.5 x 10^{-6} (90% C.L.) respectively.Comment: 9 pages postscript, also available through http://w4.lns.cornell.edu/public/CLN

Measurements of B --> D_s^{(*)+} D^{*(*)} Branching Fractions

This article describes improved measurements by CLEO of the $B^0 \to D_s^+ D^{*-}$ and $B^0 \to D_s^{*+} D^{*-}$ branching fractions, and first evidence for the decay $B^+ \to D_s^{(*)+} \bar{D}^{**0}$, where $\bar{D}^{**0}$ represents the sum of the $\bar{D}_1(2420)^0$, $\bar{D}_2^*(2460)^0$, and $\bar{D}_1(j=1/2)^0$ L=1 charm meson states. Also reported is the first measurement of the $D_s^{*+}$ polarization in the decay $B^0 \to D_s^{*+} D^{*-}$. A partial reconstruction technique, employing only the fully reconstructed $D_s^+$ and slow pion $\pi_s^-$ from the $D^{*-} \to \bar{D}^0 \pi^-_s$ decay, enhances sensitivity. The observed branching fractions are ${\mathcal B} (B^0 \to D_s^+ D^{*-}) = (1.10 \pm 0.18 \pm 0.10 \pm 0.28)$, ${\mathcal B} (B^0 \to D_s^{*+} D^{*-}) = (1.82 \pm 0.37 \pm 0.24 \pm 0.46)$, and ${\mathcal B} (B^+ \to D_s^{(*)+} \bar{D}^{**0}) = (2.73 \pm 0.78 \pm 0.48 \pm 0.68)$, where the first error is statistical, the second systematic, and the third is due to the uncertainty in the $D_s^+ \to \phi \pi^+$ branching fraction. The measured $D_s^{*+}$ longitudinal polarization, $\Gamma_L/\Gamma = (50.6 \pm 13.9 \pm 3.6)$, is consistent with the factorization prediction of 54%.Comment: 26 pages (LaTeX), 15 figures. To be submitted to PR

Study of the Decays B0 --> D(*)+D(*)-

The decays B0 --> D*+D*-, B0 --> D*+D- and B0 --> D+D- are studied in 9.7 million Y(4S) --> BBbar decays accumulated with the CLEO detector. We determine Br(B0 --> D*+D*-) = (9.9+4.2-3.3+-1.2)e-4 and limit Br(B0 --> D*+D-) < 6.3e-4 and Br(B0 --> D+D-) < 9.4e-4 at 90% confidence level (CL). We also perform the first angular analysis of the B0 --> D*+D*- decay and determine that the CP-even fraction of the final state is greater than 0.11 at 90% CL. Future measurements of the time dependence of these decays may be useful for the investigation of CP violation in neutral B meson decays.Comment: 21 pages, 5 figures, submitted to Phys. Rev.

Precise Measurement of B^{0}\to \bar{B^{0} Mixing Parameters at the Υ(\Upsilon(S)$

We describe a measurement of B^0-B^0bar mixing parameters exploiting a method of partial reconstruction of the decay chains B0 -> D^{*-}\pi^+ and B0 -> D^{*-}\rho^+. Using 9.6 x 10^6 BBbar pairs collected at the Cornell Electron Storage Ring, we find \chi_d = 0.198 +- 0.013 +- 0.014, |y_d|<0.41 at 95% confidence level, and |Re(\epsilon_B)|<0.034 at 95% confidence level.Comment: 11 pages postscript, also available through http://w4.lns.cornell.edu/public/CLN

Measurement of B(/\c->pKpi)

The /\c->pKpi yield has been measured in a sample of two-jet continuum events containing a both an anticharm tag (Dbar) as well as an antiproton (e+e- -> Dbar pbar X), with the antiproton in the hemisphere opposite the Dbar. Under the hypothesis that such selection criteria tag e+e- -> Dbar pbar (/\c) X events, the /\c->pkpi branching fraction can be determined by measuring the pkpi yield in the same hemisphere as the antiprotons in our Dbar pbar X sample. Combining our results from three independent types of anticharm tags, we obtain B(/\c->pKpi)=(5.0+/-0.5+/-1.2)

Measurement of the Decay Asymmetry Parameters in Λc+→Λπ+\Lambda_c^+ \to \Lambda\pi^+ and Λc+→Σ+π0\Lambda_c^+ \to \Sigma^+\pi^0

We have measured the weak decay asymmetry parameters (\aLC ) for two \LC\ decay modes. Our measurements are \aLC = -0.94^{+0.21+0.12}_{-0.06-0.06} for the decay mode $\Lambda_c^+ \to \Lambda\pi^+$ and \aLC = -0.45\pm 0.31 \pm 0.06 for the decay mode $\Lambda_c \to \Sigma^+\pi^0$. By combining these measurements with the previously measured decay rates, we have extracted the parity-violating and parity-conserving amplitudes. These amplitudes are used to test models of nonleptonic charmed baryon decay.Comment: 11 pages including the figures. Uses REVTEX and psfig macros. Figures as uuencoded postscript. Also available as http://w4.lns.cornell.edu/public/CLNS/1995/CLNS95-1319.p

Dalitz Analysis of the Decay D0→K−π+π0D^{0}\to K^{-}\pi^{+}\pi^{0}

We use data collected with the CLEO II detector to perform a high-statistics measurement of the resonant substructure in $D^0 \to K^-\pi^+\pi^0$ decays. We find the Dalitz Plot is well represented by a combination of seven quasi-two-body decay channels ($\bar{K}^{*0} \pi^0$, $K^- \rho$, $K^{*-} \pi^+$, $K^*_0(1430)^-\pi^+$, $\bar{K}^*_0(1430)^0 \pi^0$, $K^- \rho^+(1700)$, and $K^*(1680)^- \pi^+$), plus a small non-resonant component. Using the amplitudes and phases from this analysis, we calculate an integrated CP asymmetry of $-0.031 \pm 0.086$.Comment: 32 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, Version to appear in Phys. Rev.

Study of B Decays to Charmonium States B→ηcKB\to \eta_{c}K and B→χC0KB\to \chi_{C0}K

In a sample of $9.66\times 10^6 B\bar{B}$ pairs collected with the CLEO detector we make the first observation of B decays to an $\eta_c$ and a kaon. We measure branching fractions $BR(B^+\to\eta_c K^+) = (0.69 + 0.26 - 0.21 +- 0.08 +- 0.20)\times 10^{-3}$ and $BR(B^0\to\eta_c K^0) = (1.09 + 0.55 - 0.42 +- 0.12 +- 0.31)\times 10^{-3}$, where the first error is statistical, the second is systematic and the third is from the $\eta_c$ branching fraction uncertainty. From these we extract the $\eta_c$ decay constant in the factorization approximation, $f_{\eta_c} = 335 +- 75$ MeV. We also search for B decays to a $\chi_{c0}$ and a kaon. No evidence for a signal is found and we set 90% CL upper limits: $BR(B^+\to\chi_{c0} K^+) < 4.8\times 10^{-4}$ and $BR(B^0\to\chi_{c0} K^0) < 5.0\times 10^{-4}$.Comment: 10 pages postscript, also available through http://w4.lns.cornell.edu/public/CLN