72 research outputs found
Study of the decays B->D_s1(2536)+ anti-D(*)
We report a study of the decays B -> D_s1(2536)+ anti-D(*), where anti-D(*)
is anti-D0, D- or D*-, using a sample of 657 x 10^6 B anti-B pairs collected at
the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy
e+e- collider. The branching fractions of the decays B+ -> D_s1(2536)+ anti-D0,
B0 -> D_s1(2536)+ D- and B0 -> D_s1(2536)+ D*- multiplied by that of
D_s1(2536)+ -> (D*0K+ + D*+K0) are found to be (3.97+-0.85+-0.56) x 10^-4,
(2.75+-0.62+-0.36) x 10^-4 and (5.01+-1.21+-0.70) x 10^-4, respectively.Comment: 6 pages, 2 figues, submitted to PRD (RC
Evidence for B- -> tau- nu_bar with a Semileptonic Tagging Method
We present a measurement of the decay B- -> tau- nu_bar using a data sample
containing 657 million BB_bar pairs collected at the Upsilon(4S) resonance with
the Belle detector at the KEKB asymmetric-energy e+e- collider. A sample of
BB_bar pairs are tagged by reconstructing one B meson decaying
semileptonically. We detect the B- -> tau- nu_bar candidate in the recoil. We
obtain a signal with a significance of 3.6 standard deviations including
systematic uncertainties, and measure the branching fraction to be Br(B- ->
tau- nu_bar) = [1.54+0.38-0.37(stat)+0.29-0.31(syst)]*10^-4. This result
confirms the evidence for B- -> tau- nu_bar obtained in a previous Belle
measurement that used a hadronic B tagging method.Comment: 7 pages, 3 figures, corrected references, to appear in PRD-R
Studies of the Decay B+- -> D_CP K+-
We report studies of the decay B+- -> D_CP K+-, where D_CP denotes neutral D
mesons that decay to CP eigenstates. The analysis is based on a 29.1/fb data
sample of collected at the \Upsilon(4S) resonance with the Belle detector at
the KEKB asymmetric e+ e- storage ring. Ratios of branching fractions of
Cabibbo-suppressed to Cabibbo-favored processes involving D_CP are determined
to be B(B- -> D_1 K-)/B(B- -> D_1 pi-)=0.125 +- 0.036 +- 0.010 and B(B- -> D_2
K-)/B(B- -> D_2 pi-)=0.119 +- 0.028 +- 0.006, where indices 1 and 2 represent
the CP=+1 and CP=-1 eigenstates of the D0 - anti D0 system, respectively. We
also extract the partial rate asymmetries for B+- -> D_CP K+-, finding A_1 =
0.29 +- 0.26 +- 0.05 and A_2 = -0.22 +- 0.24 +- 0.04.Comment: 10 pages, 2 figures, submitted to Physical Review Letter
Measurements of Branching Fractions for B0 --> Ds+pi- and B0-bar --> Ds+K-
We present improved measurements of the branching fractions for the decays B0
--> Ds+pi- and B0-bar --> Ds+K- using a data sample of 657x10^6 BB-bar events
collected at the Y(4S) resonance with the Belle detector at the KEKB
asymmetric-energy e+e- collider. The results are BF(B0 --> Ds+pi-) = (1.99 +/-
0.26 +/- 0.18)x10^-5 and BF(B0-bar --> Ds+K-) = (1.91 +/- 0.24 +/- 0.17)x10^-5,
where the uncertainties are statistical and systematic, respectively. Based on
these results, we determine the ratio between amplitudes of the doubly Cabibbo
suppressed decay B0 --> D+pi- and the Cabibbo favored decay B0 --> D-pi+, R_Dpi
= [1.71 +/- 0.11(stat) +/- 0.09(syst) +/- 0.02(theo)]%, where the last term
denotes the theory error.Comment: 7 pages, 10 figures, 2 tables, published in PRD(RC
Observation of Ds+K- and evidence for D-s(+)pi(-) final states in neutral B decays
We report the first observation of a B meson decay that is not accessible by a direct spectator process. The channel (B) over bar (0)-->Ds+K- is found in a sample of 85x10(6) B (B) over bar events, collected with the Belle detector at KEKB, with a branching fraction B((B) over bar (0)-->Ds+K-)=(4.6(-1.1)(+1.2)+/-1.3)x10(-5). We also obtain evidence for the B-0-->D(s)(+)pi(-) decay with branching fraction B(B-0-->D(s)(+)pi(-))=(2.4(-0.8)(+1.0)+/-0.7)x10(-5). This value may be used to extract a model-dependent value of \V-ub\
Search for Lepton-number-violating B+->D-l+l'+ Decays
We perform the first search for lepton-number-violating B+->D-l+l'+ decays,
where l and l' stand for e or mu, using 772 x 10^6 BB-bar pairs accumulated at
the Upsilon(4S) resonance with the Belle detector at the KEKB e^+e^- collider.
No evidence for these decays has been found. Assuming uniform three-body phase
space distributions for the D-l+l+ decays, we set the following upper limits on
the branching fractions at 90% confidence level: Br(B+ -> D-e+e+) < 2.6x10^-6,
Br(B+ -> D-e+mu+) D-mu+mu+) < 1.0x10^-6.Comment: 7 pages, 2 figure
European clinical guidelines for Tourette syndrome and other tic disorders. Part II: pharmacological treatment
To develop a European guideline on pharmacologic treatment of Tourette syndrome (TS) the available literature was thoroughly screened and extensively discussed by a working group of the European Society for the Study of Tourette syndrome (ESSTS). Although there are many more studies on pharmacotherapy of TS than on behavioral treatment options, only a limited number of studies meets rigorous quality criteria. Therefore, we have devised a two-stage approach. First, we present the highest level of evidence by reporting the findings of existing Cochrane reviews in this field. Subsequently, we provide the first comprehensive overview of all reports on pharmacological treatment options for TS through a MEDLINE, PubMed, and EMBASE search for all studies that document the effect of pharmacological treatment of TS and other tic disorders between 1970 and November 2010. We present a summary of the current consensus on pharmacological treatment options for TS in Europe to guide the clinician in daily practice. This summary is, however, rather a status quo of a clinically helpful but merely low evidence guideline, mainly driven by expert experience and opinion, since rigorous experimental studies are scarce
Observation of B-0 -> p(Lambda)over-bar pi(-)
We report the first observation of the charmless hyperonic B decay, B-0-->p (&ULambda;) over bar pi(-), using a 78 fb(-1) data sample recorded on the Y(4S) resonance with the Belle detector at KEKB. The measured branching fraction is B(B-0-->p (&ULambda;) over bar pi(-))=(3.97(-0.80)(+1.00)+/-0.56)x10(-6). Searches for B-0-->p (&ULambda;) over barK(-) and p (&USigma;) over bar (0)pi(-) yield no significant signals and we set 90% confidence-level upper limits of B(B-0-->p (&ULambda;) over barK(-))p (&USigma;) over bar (0)pi(-))<3.8x10(-6)
Observation of radiative B -> phi K gamma decays
The radiative decay B-->phiKgamma is observed for the first time. The branching fraction for the charged B--->phiK(-)gamma decay mode is measured to be B(B--->phiK(-)gamma)=(3.4+/-0.9+/-0.4)x10(-6). The photon energy distribution for the B--->phiK(-)gamma decay is presented. The signal for the neutral (B) over bar (0)-->phi(K) over bar (0)gamma decay mode is not statistically significant and an upper limit, B((B) over bar (0)-->phi(K) over bar (0)gamma)<8.3x10(-6) at 90% C.L., is set. The analysis is based on a data set of 90 fb(-1) collected by the Belle experiment at the e(+)e(-) asymmetric collider KEKB
- …