Showing papers by "J. S. Lange published in 2004"

Observation ofB+→pp¯π+,B0→pp¯K0, andB+→pp¯K*+

Abstract: We report the first observation of a $b\ensuremath{\rightarrow}u$ type charmless baryonic $B$ decay, ${B}^{+}\ensuremath{\rightarrow}p\overline{p}{\ensuremath{\pi}}^{+}$, as well as $b\ensuremath{\rightarrow}s$ type ${B}^{0}\ensuremath{\rightarrow}p\overline{p}{K}^{0}$ and ${B}^{+}\ensuremath{\rightarrow}p\overline{p}{K}^{*+}$ decays. The analysis is based on a $78\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data sample recorded on the $\ensuremath{\Upsilon}(4S)$ resonance with the Belle detector at KEKB. We find $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}p\overline{p}{\ensuremath{\pi}}^{+})=({3.06}_{\ensuremath{-}0.62}^{+0.73}\ifmmode\pm\else\textpm\fi{}0.37)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}p\overline{p}{K}^{0})=({1.88}_{\ensuremath{-}0.60}^{+0.77}\ifmmode\pm\else\textpm\fi{}0.23)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, and $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}p\overline{p}{K}^{*+})=({10.3}_{\ensuremath{-}2.8\ensuremath{-}1.7}^{+3.6+1.3})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$. We also update $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}p\overline{p}{K}^{+})=({5.66}_{\ensuremath{-}0.57}^{+0.67}\ifmmode\pm\else\textpm\fi{}0.62)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ and present an upper limit on $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}p\overline{p}{K}^{*0})$ at the 90% confidence level. A common feature of the observed decay modes is threshold peaking in baryon pair invariant mass.

Observation of B ->psi(3770)K

Abstract: We report the first observation of the decay B+-->psi(3770)K+ where the psi(3770) is reconstructed in the D-0(D) over bar (0) and D+D- decay channels The obtained branching fraction is B(B+-->psi(3770)K+)=(048+/-011+/-007)x10(-3) We have measured the branching fraction for the decay B+-->D-0(D) over bar K-0(+) to be (117+/-021+/-015)x10(-3) and set a 90% confidence level upper limit of 090x10(-3) for the decay B+-->D+D-K+ We also present the results of a search for possible decays to D (D) over bar and D-0(D) over bar (0)pi(0) of the recently observed X(3872) particle The analysis is based on 88 fb(-1) of data collected at the Y(4S) resonance by the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider

Measurement of the B ! KBranching Fractions and Asymmetries

Abstract: γ decays by CLEO in 1993 [1], this process con-tinues to be a subject of considerable interest. The sizeof the decay rate itself provides only a mild constrainton extensions to the Standard Model (SM), because SMpredictions for exclusive rates suffer from large (∼30%)and model dependent form factor uncertainties [2]. Ofmore interest are asymmetries, where theoretical uncer-tainties largely cancel. The isospin asymmetry betweenthe charged and neutral B → K

Evidence forB+→ωl+ν

Abstract: We have searched for the decay ${B}^{+}\ensuremath{\rightarrow}\ensuremath{\omega}{l}^{+}\ensuremath{ u}$ ($l=e$ or $\ensuremath{\mu}$) in $78\text{ }\text{ }{\mathrm{f}\mathrm{b}}^{\ensuremath{-}1}$ of $\ensuremath{\Upsilon}(4S)$ data ($85\ifmmode\times\else\texttimes\fi{}{10}^{6}$$B\overline{B}$ events) accumulated with the Belle detector. The final state is fully reconstructed using the $\ensuremath{\omega}$ decay into ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$, combined with detector hermeticity to estimate the neutrino momentum. A signal of $414\ifmmode\pm\else\textpm\fi{}125$ events is found in the data, corresponding to a branching fraction of $(1.3\ifmmode\pm\else\textpm\fi{}0.4\ifmmode\pm\else\textpm\fi{}0.2\ifmmode\pm\else\textpm\fi{}0.3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$, where the first two errors are statistical and systematic, respectively. The third error reflects the estimated form-factor uncertainty.

New measurements of time-dependent CP-violating asymmetries in b ---> s transitions at Belle

Abstract: We present new measurements of CP-violation parameters in B0 --> phi K0, K+ K- Ks, f0(980) Ks, eta' Ks, omega Ks, Ks pi0, and K*0 gamma (K*0 --> Ks pi0) decays based on a sample of 275 x 10^6 BBbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. One neutral B meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters for each of the decay modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays. All results are preliminary.

Erratum: Publisher's note: Study of CP violating effects in time dependent B0(B̄0)→ D(*)±Π ± decays (Physical Review Letters (2004) 93 (031802))

Abstract: We report measurements of time dependent decay rates for $B^0(\bar{B}^0) \to D^{(*)\mp}\pi^{\pm}$ decays and extraction of CP violation parameters containing $\phi_3$. Using fully reconstructed $D^{(*)}\pi$ events from a $140 {\rm fb}^{-1}$ data sample collected at the $\Upsilon(4S)$ resonance, we obtain the CP violation parameters for $D^* \pi$ and $D \pi$ decays, $2R_{D^{(*)} \pi} \sin (2\phi_1 + \phi_3 \pm \delta_{D^{(*)} \pi})$, where $R_{D^{(*)} \pi}$ is the ratio of the magnitudes of the doubly-Cabibbo-suppressed and Cabibbo-favoured amplitudes, and $\delta_{D^{(*)} \pi}$ is the strong phase difference between them. Under the assumption of $\delta_{D^{(*)} \pi}$ being close to either 0 or $180^{\circ}$, we obtain $|2R_{D^* \pi} \sin (2\phi_1 + \phi_3)| = 0.060 \pm 0.040(\mathrm{stat}) \pm 0.019(\mathrm{sys})$ and $|2R_{D \pi} \sin (2\phi_1 + \phi_3)| = 0.061 \pm 0.037(\mathrm{stat}) \pm 0.018(\mathrm{sys})$.

Measurement of polarization and triple-product correlations in B ---> phi K* decays

Abstract: We present measurements of decay amplitudes and triple-product correlations in B-->phiK* decays based on 253 fb(-1) of data recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) storage ring. The decay amplitudes for the three different helicity states are determined from the angular distributions of final-state particles. The longitudinal polarization amplitudes are found to be 0.45 +/- 0.05 +/- 0.02 for B0-->phiK(*0) and 0.52 +/- 0.08 +/- 0.03 for B+ -->phiK(*+) decays. CP- and T-odd CP-violating triple-product asymmetries are measured to be consistent with zero.

Improved measurement of the electroweak penguin process B ---> X(s)l+l-

Abstract: We present an improved measurement of the branching fraction for the electroweak penguin process B -> X-sl(l)+(-), where l is an electron or a muon and X-s is a hadronic system containing an s-quark. The measurement is based on a sample of 152x10(6) Upsilon(4S)-> B (B) over bar events collected with the Belle detector at the KEKB energy asymmetric e(+)e(-) collider. The X-s hadronic system is reconstructed from one K+/- or K-S(0) and up to four pions, where at most one pion can be neutral. Averaging over both lepton flavors, the inclusive branching fraction is measured to be B(B -> X-sl(l)+(-))=(4.11 +/- 0.83(stat)(-0.81)(+0.85)(syst))x10(-6) for M-l(l)+(-)> 0.2 GeV/c(2).

Study of double charmonium production in e(+)e(-) annihilation at root s approximate to 10.6 GeV

Abstract: We present a new analysis of double charmonium production in e(+)e(-) annihilation. The observation of the processes e(+)e(-)-->J/psieta(c), J/psichi(c0), and J/psieta(c)(2S) is confirmed using a data set more than 3 times larger than that of Belle's previous report, and no evidence for the process e(+)e(-)-->J/psiJ/psi is found. We perform an angular analysis for J/psieta(c) production and set an upper limit on the production of J/psiJ/psi. Processes of the type e(+)e(-)-->psi(2S)(c (c) over bar)(res) have been observed for the first time; their rates are found to be comparable to those of e(+)e(-)-->J/psi(c (c) over bar)(res) processes.