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.
We report the status of the Heavy Flavour Averaging Group (HFLAV) averages of the $τ$ lepton measurements We then update the latest published HFLAV global fit of the $τ$ lepton branching fractions (Spring 2017) with recent results by BABAR. We use the fit results to update the Cabibbo-Kobayashi-Maskawa (CKM) matrix element Vus measurements with the $τ$ branching fractions. We combine the direct $τ$ branching fraction measurements with indirect predictions using kaon branching fractions measurements to improve the determination of Vus using $τ$ branching fractions. The Vus determinations based …
Production of the matter-antimatter asymmetry in the $B$-Mesogenesis mechanism is directly related to the branching fraction of seemingly baryon number violating decays of $B$ mesons into a light Standard Model baryon and missing energy. Achieving the observed baryon asymmetry requires that the branching fraction for such decays be greater than about $10^{-7}-10^{-5}$. Experimental searches at $B$ Factories and Hadron Colliders target specific decay modes. Therefore, computing the exclusive branching fraction for each decay is a critical step towards testing Mesogenesis. In this work we use QC…
This work summarizes the current status of the measured semileptonic branching fractions $B^{0,+} \to X_c μν$. The sum of exclusive measurements is compared with the inclusive determination, accounting for isospin extrapolation. Further derived quantities are computed, taking into account different explanations for the unmeasured components of the total branching fraction. These quantities focus on the charge breakdown of the final states, and are designed for use as inputs or comparisons in future experimental measurements.
We examine the parametrization of the e+e- -> omega pi0 cross section in the vicinity of the phi resonance and the extraction of the branching fraction of the isospin violating process phi -> omega pi0 from experimental data. We found that there are two possible solutions of the branching fraction, one is 4 times 10^{-5}, and the other is 7 times 10^{-3}. The latter is two orders of magnitude higher than the former, which is the commonly accepted one.
We determine the Cabibbo-Kobayashi-Maskawa matrix (CKM) element |Vus| in several different ways using updated preliminary HFAG averages for the tau lepton branching fractions and we compare the results with the determinations obtained from the kaon decays and from the unitarity of the CKM matrix.
We report the first determination of the absolute branching fractions of the X(3872) decays by globally analyzing the measurements provided by the Belle, BaBar, BESIII, and LHCb experiments. The branching fractions of X(3872) to pi^+pi^- J/psi and D*0D0bar+c.c. are found to be (4.1^{+1.9}_{-1.1})% and (52.4^{+25.3}_{-14.3})%, respectively. The branching fractions of the decays X(3872) to gamma J/psi, gamma psi', omega J/psi, and pi^0 chi_{c1} are also determined. The global fit implies that the fraction of X(3872) decays which are not observed in experiments is (31.9_{-31.5}^{+18.1})%, which i…
Current absolute branching fractions of $Λ_c^+$ and $D_s^+$ mesons are limiting the determination of important measurements. They have only been measured at $e^+e^-$ colliders. Here techniques for measuring them at hadron colliders are discussed. The precision determination of $Λ_c^+\to p K^-π^+$ seems possible with current data, however the corresponding determination of $D_s^+\to K^+K^-π^+$ will require more integrated luminosity.
Using the CLEO-II detector at CESR we have measured the ratio of branching fractions, ${\cal B}(D^+\rightarrow K^- π^+ π^+)/{\cal B}(D^0 \rightarrow K^-π^+) = 2.35 \pm 0.16 \pm 0.16$. Our recent measurement of ${\cal B}(D^0 \rightarrow K^-π^+)$ then gives ${\cal B}(D^+\rightarrow K^- π^+ π^+) = (9.3 \pm 0.6 \pm 0.8)\%$.
We investigate the implications of the model with a SU(2)-singlet up-type quark, heavy enough not to be produced at the LHC, namely, the contribution of the new quark to the branching ratios of the K to πν\barν, B to πν\barν and B to K ν\barν decays. We show that the deviation from the Standard Model can be up to 10% in the case of a 5 TeV quark. Precise measurements of these branching ratios at the future experiments will allow to observe the contributions of the new quark or to impose stronger constraints on its mass.
Based on the data of BES and Belle, the production of $D\bar{D}$ in the $e^+e^-\to D\bar{D}$ scattering process is studied in this paper. We analyze the continuum and resonant contributions in the energy region from 3.7 to 4.4 GeV. In the $χ^2$ fit to data, we obtain the resonance parameters of $ψ(3770)$, the branching ratio of $ψ(3770)\to D\bar{D}$ decay by confronting the data to the theoretical formula where both the contributions of the resonances, continuum and interference effects are included. We obtain the branching ratio of $ψ(3770)\to D\bar{D}$ decay is $97.2%\pm 8.9%$, as well as th…
We report the first measurement of the branching fraction f00 for Upsilon(4S) --> B0B0bar. The data sample consists of 81.7 fb^-1 collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy e^+e^- storage ring. Using partial reconstruction of the decay B0bar --> D^{*+} \ell^{-} \barν_{\ell} in which only the charged lepton and the soft pion from the decay D^{*+} --> D0 pi^+ are reconstructed, we obtain f00 = 0.487 \pm 0.010(stat) \pm 0.008(sys). Our result does not depend on the branching fractions of B0bar --> D^{*+} \ell^{-} \barν_{\ell} and D^{*+} --> D0 p…
The measurement of $B_s$-meson branching fractions is a fundamental tool to probe physics beyond the Standard Model. Every measurement of untagged time-integrated $B_s$-meson branching fractions is model-dependent due to the time dependence of the experimental efficiency and the large lifetime difference between the two $B_s$ mass eigenstates. In recent measurements, this effect is bundled in the systematics. We reappraise the potential numerical impact of this effect -- we find it to be close to 10% in real-life examples where new physics is a correction to dominantly Standard-Model dynamics.…
Motivated by the first untagged decay-time-integrated amplitude analysis of $B_s \to K_SK^{\mp}π^{\pm}$ decays performed by LHCb collaboration, where the decay amplitudes are modeled to contain the resonant contributions from intermediate resonances $K^*(892)$, $K_0^*(1430)$ and $K_2^*(1430)$, we comprehensively investigate the quasi-two-body $B_{s} \to K^0/\overline{\kern -0.2em K}^0 K^{\pm}π^{\mp}$ decays, and calculate the branching fractions and the time-dependent $CP$ asymmetries within the perturbative QCD approach based on the $k_T$ factorization. In the quasi-two-body space region the …
We report preliminary measurements of absolute hadronic branching fractions of Ds mesons determined using a double tag technique. These measurements are from 195 pb^{-1} of e+e- collisions recorded at center of mass energies near 4.17 GeV with the CLEO-c detector at CESR. We obtain absolute branching fractions for Ds+ decays to KS0 K+, K- K+ pi+, K- K+ pi+ pi-, pi+ pi+ pi-, pi+ eta, and pi+ etaprime. We discuss the problems inherent in measuring accurately the branching fraction for Ds+ to phi pi+, which is often used as a reference mode for measurement of other Ds+ branching fractions, and pr…
The branching fractions of D_s meson decays serve to normalize many measurements of processes involving charm quarks. Using 298 /pb of e+ e- collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for eight D_s decays with a double tag technique. In particular we determine the branching fraction B(D_s -> K- K+ pi+) = (5.50 +- 0.23 +- 0.16)%, where the uncertainties are statistical and systematic respectively. We also provide partial branching fractions for kinematic subsets of the K- K+ pi+ decay mode.
We describe new measurements of the inclusive and exclusive branching fractions for Psi(2S) transitions to J/Psi using e+e- collision data collected with the CLEO detector operating at CESR. All branching fractions and ratios of branching fractions reported here represent either the most precise measurements to date or the first direct measurements. Indirectly and in combination with other CLEO measurements, we determine B(ChicJ --> gamma J/Psi) and B(Psi(2S) --> light hadrons).
Recent measurements of hadronic branching fractions of D and Ds mesons, performed by the BaBar and Belle experiments at the asymmetric e+e- B factories colliders PEP II and KEKB, are reviewed.
We present measurements of branching fraction, polarization and charge asymmetry in charmless hadronic B decays with eta, eta', omega, and b_1 in the final state. All the results use the final BABAR dataset.
Using 58 million J/psi and 14 million psi' decays obtained by the BESII experiment, the branching fraction of J/psi --> pi+ pi- pi0 is determined. The result is (2.10+/-0.12)X10^{-2}, which is significantly higher than previous measurements.
Non-leptonic charm decays provide insights into both electro-weak and strong dynamics. This includes the study of long-distance hadronic effects, the approximate symmetries of strong interactions, and precision tests of the Standard Model. In these proceedings we summarise recent results in non-leptonic branching fraction measurements of D mesons, including measurements of relative and absolute branching fractions in inclusive and exclusive modes, radiative decays, and measurements of direct CP violation.
The decay branching fractions of the three narrow Upsilon resonances to mu+ mu- have been measured by analyzing about 4.3 1/fb e+e- data collected with the CLEO III detector. The branching fraction B(Y(1S) -> mu+ mu-) = (2.49 +- 0.02 +- 0.07)% is consistent with the current world average but B(Y(2S) -> mu+ mu-) = (2.03 +- 0.03 +- 0.08)% and B(Y(3S) -> mu+ mu-) = (2.39 +- 0.07 +- 0.10)% are significantly larger than prior results. These new muonic branching fractions imply a narrower total decay width for the Y(2S) and Y(3S) resonances and lower other branching fractions that rely on these deca…
Measurements of production cross-sections of inclusive $b$-hadrons pairs, bottom mesons and baryons, and quarkonia at LHC will be shown. Recent measurements of branching fractions of bottom baryons, bottom mesons with baryons in the final state, and a new result about a search for intermediate states in meson decay will also be shown.
This paper reviews semileptonic decays of $B$-mesons to states containing charm mesons, i.e., D, D*, D** and possible non-resonant D^{(*)}npi states as well. The paper covers measurement of branching fractions, form-factors and, most importantly, the magnitude of the CKM matrix element V_cb.
The decay branching fractions of the three narrow Upsilon resonances to mu+mu- have been measured by analyzing about 4.3 1/fb e+e- data collected in the vicinity of the resonances with the CLEO III detector. The branching fraction B(Y(1S) to mu+mu-) = (2.49 +- 0.02 \+- 0.07)% is consistent with the current world average but B(Y(2S) to mu+mu-) = (2.03 +- 0.03 +- 0.08)% and B(Y(3S) to mu+mu-) = (2.39 +- 0.07 +- 0.10)% are significantly larger than prior results. These new muonic branching fractions imply a narrower total decay width for the Y(2S) and Y(3S) resonances and lower other branching fr…
With the first data sample collected by the CLEO-c detector at the psi(3770) resonance we have studied four exclusive semileptonic decays of the D0 meson. Our results include the first observation and absolute branching fraction measurement for D0 --> rho- e+ nu_e and improved measurements of the absolute branching fractions for D0 decays to K- e+ nu_e, pi- e+ nu_e, and K*- e+ nu_e.
We have measured the branching fractions of the colour suppressed decays B^{+} --> ψ(2S) K^{*+}(892) and B^{0} --> psi(2S)K^{*0}(892) using a data sample of 84 million B\bar{B} events recorded by the Belle detector on the Upsilon(4S) resonance. The branching fractions for the charged and neutral mode decays are (8.13 \pm 0.77 \pm 0.89) x 10^{-4}$ and $(7.20 \pm 0.43 \pm 0.65) x 10^{-4}$, respectively.
We present a measurement of the branching fraction and time-dependent CP violation parameters for B0 -> D*+ D*- Ks decays. We also obtain an upper limit on the product branching fraction for the possible two-body decay, B0 -> Ds1+(2536) D*-. These results are obtained from a 414 fb-1 data sample that contains 449e10^6 BBbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e+e- collider.
We present preliminary measurements of the branching fractions for charmless hadronic decays of B mesons into two-body final states with kaons, pions and a phi resonance. The measurements are based on a data sample of approximately 23 million B-anti-B pairs collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC.
The decay psi(2S) --> eta J/psi is used to measure, for the first time, all prominent eta-meson branching fractions with the same experiment in the same dataset, thereby providing a consistent treatment of systematics across branching fractions. We present results for eta decays to gamma gamma, pi+pi-pi0, 3 pi0, pi+ pi- gamma, and e+ e- gamma, accounting for 99.9% of all eta decays. The precisions for several of the branching fractions and their ratios are improved. Two channels, pi+ pi- gamma and e+ e- gamma, show results that differ at the level of three standard deviations from those previo…
The "τ\to 3πην" decay with the "η\to γγ" mode is studied using 384 fb^-1 of data collected by the BaBar detector. The branching fraction is measured to be (1.60+/-0.05+/-0.11)x10^-4. It is found that "τ\to f1 πνto 3πην" is the dominant decay mode with a branching fraction of (1.11+/-0.06+/-0.05)x10^-4. The first error on the branching fractions is statistical and the second systematic. In addition, a 90% confidence level upper limit on the branching fraction of the "τ\to η'(958) πν" decay is measured to be 7.2x10^-6. This last decay proceeds through a second-class current and is expected to be…
We measure the branching fractions of the psi(2S) meson to the leptonic final states e+e- and mu+mu- relative to that for psi(2S)-->J/psi pi+pi-. The method uses psi(2S) mesons produced in the decay of B mesons at the Upsilon(4S) resonance in a data sample collected with the BABAR detector at the Stanford Linear Accelerator Center. Using previous measurements for the psi(2S)-->J/psi pi+pi- branching fraction, we determine the e+e- and mu+mu- branching fractions to be 0.0078+/-0.0009+/-0.0008 and 0.0067+/-0.0008+/-0.0007 respectively.
The B^0 -> D^*-a_1^+ branching fraction has been measured with data collected by the BABAR experiment in 1999 and 2000 corresponding to a total integrated luminosity of 20.6 fb^-1. Signal events have been selected using a partial reconstruction technique, in which only the a_1^+ and the slow pion (pi_s) from the D^*- decay are identified. A signal yield of 18400 +/- 1200 events has been found, corresponding to a preliminary branching fraction of (1.20 +/- 0.07(stat) +/- 0.14 (syst))%.
Using 58$\times 10^{6}$ $\jpsi$ events collected with the Beijing Spectrometer (BESII) at the Beijing Electron Positron Collider (BEPC), the branching fractions of $\jpsi$ to $p\bar{p}η$ and $p\bar{p}\etap$ are determined. The ratio $\frac{Γ(\jpsi\rar\ppbη)}{Γ(\jpsi\rar\ppb)}$ obtained by this analysis agrees with expectations based on soft-pion theorem calculations.
The Ds+- -> K+-K-+pi+- absolute branching fraction is measured using e+e- -> Ds*+- Ds1-+(2536) events collected by the Belle detector at the KEKB e+e- asymmetric energy collider. Using the ratio of yields when either the Ds1 or Ds* is fully reconstructed, we find Br(Ds+- -> K+-K-+pi+-)= (4.0+-0.4(stat)+-0.4(sys))%.
We report determination of branching fractions for the decays psi(2S) --> h + J/psi, where h=any, pi+pi-, pi0pi0, eta, pi0, and gamma gamma through chi_{c0,1,2}. These measurements use 27M psi(2S) decays produced in e+e- collision data collected with the CLEO detector. The resulting branching fractions and ratios thereof improve upon previously achieved precision in all cases, and in combination with other measurements permit determination of B(chi_cJ --> gamma J/psi) and B(psi(2S) --> light hadrons).
We report branching fractions and charge asymmetries for exclusive decays of charged and neutral B mesons to two-body final states containing a charmonium meson, J/psi or psi(2S). This result is based on a 29.4 fb^{-1} data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e+e- collider.
We present an update on total and partial branching fractions and on CP asymmetries in the semi-inclusive decay B -> Xs l+l-. Further, we summarize our results on branching fractions and CP asymmetries for semi-inclusive and fully-inclusive B -> Xs gamma decays. We present the first result on the CP asymmetry difference of charged and neutral B -> Xs gamma$ decays yielding the first constraint on the ratio of Wilson coefficients Im (C8/C7).
We present a measurement of the branching fraction for the decay B^0->a1+(1260)pi- with a1+->pi+pi+pi- using a data sample containing 535x10^6 BBbar pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider operating at the Upsilon(4S) resonance. We measure the branching fraction Br(B^0->a1+pi-)Br(a1+->pi+pi+pi-) = (14.9 +- 1.6 +- 2.3)x10^-6, where the first and second errors are statistical and systematic, respectively.
We present a measurement of the branching fraction for the decay B- --> D0 K*- using a sample of approximately 86 million BBbar pairs collected by the BaBar detector from e+e- collisions near the Y(4S) resonance. The D0 is detected through its decays to K- pi+, K- pi+ pi0 and K- pi+ pi- pi+, and the K*- through its decay to K0S pi-. We measure the branching fraction to be B.F.(B- --> D0 K*-)= (6.3 +/- 0.7(stat.) +/- 0.5(syst.)) x 10^{-4}.
A largely model-independent measurement of the inclusive electron momentum spectrum and branching fraction for semileptonic decays of B mesons is presented based on data recorded at the Upsilon(4S) resonance with the BABAR detector. Backgrounds from secondary charm decays are separated from prompt B decays using charge and angular correlations between the electron from one B meson and a high momentum electron tag from the second B meson. The resulting branching fraction is BR(B -> X e nu) = (10.87 +-0.18(stat)+-0.30(syst))%. Based on this measurement we determine the CKM matrix element |V_cb|.
The CLEO-c experiment at the CESR e+ e- storage ring has collected data with E_cm = 3.77 GeV and E_cm ~ 4.17 GeV to study the decays of charmed mesons. This paper discusses results on the hadronic branching fractions of the D0, D+, and Ds+.
We present a measurement of the branching fraction for the doubly-Cabibbo-suppressed decay D+ to K+ pi0, using 281 pb-1 of data accumulated with the CLEO-c detector on the psi(3770) resonance. We find B(D+ to K+ pi0) = (2.28 +- 0.36 +- 0.15 +- 0.08) times 10^{-4}, where the first uncertainty is statistical, the second is systematic, and the last error is due to the uncertainty in the reference mode branching fraction.
Using data collected at the psi(3770) resonance with the CLEO-c detector at the Cornell e+e- storage ring, we present improved measurements of the absolute branching fractions of D+ decays to K0B e+ nu_e, pi0 e+ nu_e, K0B* e+ nu_e, and rho0 e+ nu_e, and the first observation and absolute branching fraction measurement of D+ --> omega e+ nu_e. We also report the most precise tests to date of isospin invariance in semileptonic D0 and D+ decays.
The angular distributions and the differential branching fraction of the decay B0 to K*(892)0 mu+ mu- are studied using a data sample corresponding to an integrated luminosity of 5.2 inverse femtobarns collected with the CMS detector at the LHC in pp collisions at sqrt(s) = 7 TeV. From more than 400 signal decays, the forward-backward asymmetry of the muons, the K*(892)0 longitudinal polarization fraction, and the differential branching fraction are determined as a function of the square of the dimuon invariant mass. The measurements are in good agreement with standard model predictions.
We present the first observation of the decay $B^+\toρ^+K^0$, using a data sample of 348 fb$^{-1}$ collected at the $Υ(4S)$ resonance with the \babar detector.The branching fraction and charge asymmetry are measured to be $(8.0^{+1.4}_{-1.3}\pm0.6)\times10^{-6}$ and ($-12.2\pm16.6\pm2.0)%$, respectively, where the first uncertainty is statistical and the second is systematic. The significance of the observed branching fraction, including systematic uncertainties, is 7.9 standard deviations.
We present measurements of the branching fraction and time-dependent CP asymmetries in B0 -> JPsi pi0 decays based on (231.8 +/- 2.6) x 10**6 asymmetries Y(4S) -> BBbar decays collected with the BaBar detector at the SLAC PEP-II asymmetric-energy B factory. We obtain a branching fraction B(B0 -> JPsi pi0) = (1.94 +/- 0.22 (stat.) +/- 0.17 (syst.)) x 10**-5. We also measure the CP asymmetry parameters C = -0.21 +/- 0.26 (stat.) +/- 0.06 (syst.) and S = -0.68 +/- 0.30 (stat.) +/- 0.04 (syst.).
We report a measurement of the branching fraction for the decay $B^+ \to ρ^+π^0$ based on a 140 ${\rm fb}^{-1}$ data sample collected with the Belle detector at the KEKB asymmetric $e^+e^-$ collider. We measure the branching fraction ${\cal B}(B^+ \to ρ^+π^0)=(13.2\pm 2.3({\rm stat.})^{+1.4}_{-1.9}({\rm sys.}))\times 10^{-6}$, and the CP-violating asymmetry ${\cal A}_{CP}(B^\mp \to ρ^\mpπ^0)=0.06\pm0.19({\rm stat.})^{+0.04}_{-0.06}({\rm sys.})$.
In this paper we investigate the prospects for measuring the branching fraction of the Standard Model Higgs boson decay into a pair of $Z$ bosons at the future Compact Linear Collider (CLIC) at 350 GeV and 3 TeV centre-of-mass energies. Studies are performed using a detailed simulation of the detector for CLIC, taking into consideration all relevant physics and beam-induced background processes. It is shown that the product of the Higgs production cross-section and the branching fraction BR(${H\rightarrow\thinspace ZZ^\ast}$) can be measured with a relative statistical uncertainty of 20% (3.0%…
We present measurements of the branching fractions for B0 meson decays to eta'K0 and omegaK0, and of the branching fractions and CP-violation charge asymmetries for B+ meson decays to etapi+, etaK+, eta'pi+, eta'K+, omegapi+, and omegaK+. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 383 million BBbar pairs produced in e+e- annihilation. The measurements agree with previous results; we find no evidence for direct CP violation.
By analyzing about 33 $\rm pb^{-1}$ data sample collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, we directly measure the branching fractions for the neutral and charged $D$ inclusive semimuonic decays to be $BF(D^0 \to μ^+ X) =(6.8\pm 1.5\pm 0.7)%$ and $BF(D^+ \to μ^+ X) =(17.6 \pm 2.7 \pm 1.8)%$, and determine the ratio of the two branching fractions to be $\frac{BF(D^+ \to μ^+ X)}{BF(D^0 \to μ^+ X)}=2.59\pm 0.70 \pm 0.25$.
We report a measurement of the branching fraction e^+e^- --> B0B0bar with a data sample of 81.7 fb^-1 collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy e^+e^- storage ring. Using partial reconstruction of the decay B0bar --> D^{*+} \ell^{-} \barν_{\ell} we obtain a preliminary result of f00 = 0.486 +- 0.010(stat.) +- 0.009(sys.). Our result does not depend on branching fractions of the B0bar and the D^{*+} decay chains, on the simulated reconstruction efficiency, on the ratio of the charged and neutral B meson lifetimes, nor on assumption of isospin…
Using $e^+e^-$ annihilation data taken at the CESR collider with the CLEO-c detector, measurements of two main $Ω^-$ branching fractions have been made using the reaction $ψ(2S)\toΩ^-\overlineΩ^+$, hyperon pair production at $\sqrt{s}=3.69$~GeV, the peak of the $ψ(2S)$ resonance. $Ω^-$ decay channels are identified through momentum distributions of charged particles, and systematics of the $Ω^-$ branching fractions have been studied. The result gives: $\mathcal{B}(Ω^- \to Λ^0 K^-) = (68.9\pm9.5\pm4.3)\%$, and $ \mathcal{B}(Ω^- \to Ξ^0 π^-) = (19.0\pm4.0\pm1.2)\%$.
We present improved measurements of the branching fraction and CP asymmetry for the process B+ --> rho+ pi0. The data sample corresponding to 211/fb comprises 232 million Y(4S)-->BBbar decays collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. The yield and CP asymmetry are measured using an extended maximum likelihood fitting method. The branching fraction and CP asymmetry are found to be BR(B+ --> rho+ pi0)= [10.2 +- 1.4(stat) +- 0.9(syst)] x 10^-6 and Acp (B+ --> rho+ pi0) = -0.01 +- 0.13(stat) +- 0.02(syst).
We have observed the rare decay B0->rho+rho- in a sample of 89 million BBbar pairs recorded with the BABAR detector. We measure the branching fraction B(B0->rho+rho-)=(27+7-6+5-7)10^-6 and determine the longitudinal polarization fraction Gamma_L/Gamma=0.99+0.01-0.07+-0.03. Our results are preliminary.
Using data recorded by the CLEO-II detector at CESR, we report new measurements of the branching fractions for the decays of the charmed baryon $Λ_c^+$ into $pK^-π^+π^0$, $p\bar{K}^0$, $p\bar{K}^0π^+π^-$, and $p\bar{K}^0π^0$, all measured relative to $pK^-π^+$. The relative branching fractions are $0.67\pm0.04\pm0.11, 0.46\pm0.02\pm0.04,0.52\pm0.04\pm0.05$, and $0.66\pm0.05\pm0.07$ respectively.
Relative branching fractions of Bd,Bs --> h+ h'- decays (where h,h'= K or pi) and direct CP asymmetry in Bd --> K+ pi- have been measured with 180 pb-1 of data collected by the CDFII detector at the Tevatron collider. This includes the first BR measurement of a charmless Bs-->PP decay (Bs --> K+K-).
From an analysis of the current world averages of the charged kaon and tau to kaon branching fractions, we derive, within the framework of type II Higgs doublets models such as the Minimal Supersymmetric Extension of the Standard Model, $\tanβ/m_H < 0.21$ GeV$^{-1}$ at a 90% confidence limit.
We measure the absolute branching fraction for D0 --> K- pi+ using partial reconstruction of B0bar --> D^{*+} X \ell^{-} \barν_{\ell} decays, in which only the charged lepton and the pion from the decay D^{*+} --> D0 pi^+ are used. Based on a data sample of 230 million B Bbar pairs collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC, we obtain the absolute branching fractions of D0 --> K- pi+ = (4.007 \pm 0.037 \pm 0.072)%, where the first uncertainty is statistical and the second is systematic.
