We report measurements of charmless hadronic B^0 decays into the pi+pi-K+pi+ final state. The analysis uses a sample of 657x10^6 BBbar pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider at the Y(4S) resonance. The decay B^0 -> rho0 Kpi is observed for the first time; the significance is 5.0sigma and the corresponding partial branching fraction for M_Kpi in (0.75,1.20) GeV/c^2 is [2.8 +- 0.5(stat) +-0.5(syst)] x 10^{-6}. We also obtain the first evidence for B^0 -> f0Kpi with 3.5sigma significance and for B^0 -> pi+pi-K*0 with 4.5sigma significance. For the two-body decays B^0 -> rho0K*0 and B^0 -> f0K*0, the significances are 2.7sigma and 2.5sigma, respectively, and the upper limits on the branching fractions are 3.4x10^{-6} and 2.2x10^{-6} at 90% confidence level.
Penguin transitions play a key role in the search of New Physics hints in the heavy flavor sector. During the last decade CDF has been exploring this opportunity with a rich study of two--body charmless decays of neutral B mesons into charged final--state particles. After briefly introducing the aspects of this physics peculiar to the hadron collision environment, I report on two interesting results: the first polarization measurement of the B^0_s --> phi phi decay and the update of the B^0(_s) --> h^+h'^- decays analysis.
Charmless $B$ decays are dominated by contributions from the short distance amplitudes from tree level and penguin loop-level amplitudes. The Tree contribution presents a weak phase $γ$. The relationship between these two amplitudes can generated a CP asymmetry depending from the relative amount among them in a particular decay. In multi-body charmless $B$ decays, these relative contribution can change along the phase space, given a non isotropic distribution of CP asymmetries in the Dalitz plot. Two recent LHCb analyses involving charmless multi-body B decays are discussed: the obsevation of …
We present measurements of time-dependent CP violation parameters in B0 --> K0 PI0, B0 --> Ks Pi+ Pi- and B0 --> Ks K+ K- decays. The latter two are extracted using time-dependent Dalitz plot analyses. These results are obtained from a large data sample that contains 657 x 10^6 BBbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.
We report recent results from the BABAR experiment on semileptonic charmless B-meson decays and electroweak penguin processes. Semileptonic charmless decays are used to determine |Vub| and the exclusive modes considered here also begin to constrain QCD-lattice form factor calculations. Radiative penguin decays are both sensitive to physics beyond the Standard Model and can be used to extract Heavy Quark parameters related to the b-quark mass and its motion inside the hadron.
In the study of two-body charmless B decays as a mean of looking for direct CP-violation and measuring the CKM mixing parameters in the Standard Model, the short-distance penguin contribution with its absorptive part generated by charm quark loop seems capable of producing sufficient $B \to Kπ$ decays rates, as obtained in factorization and QCD-improved factorization models. However there are also long-distance charming penguin contributions which could give rise to a strong phase due to the rescattering $D^{*}D^{*}_{s} \to Kπ$ etc. In this talk, I would like to discuss recent works on the cha…
The BABAR experiment has completed its first year of data-taking during which 21 $fb^{-1}$ of data were accumulated. We present preliminary results on two types of charmless B decays based on this data sample. The first, $B^0 \to K^{*0}γ$, is a so-called electromagnetic penguin. And the second, $B^0 \to h^+h^{'-}$, where $h^{(')}$ can be either a pion or kaon, can come from either penguin diagrams or Cabibbo suppressed tree diagrams.
Two-body charmless hadronic decays of $B$ mesons are important for determining Standard Model parameters and for detecting the presence of new physics. We present recent results from the Belle experiment on the charmless hadronic decays $B\rightarrow ηπ^0$ and $B\rightarrow π^0 π^0$.
We present recent results on time integrated and time dependent CP violation for charmless hadronic B decays using BABAR detector at the PEP-II B-factory.
We present recent results on charmless hadronic B decays using data collected by the BaBar detector at the PEP-II asymmetric-energy e+e- collider at the Stanford Linear Accelerator Center. We report measurements of branching fractions and charge asymmetries in several charmless two-body, three-body, and quasi-two-body decay modes. We also report measurements of polarization in charmless B decays to exclusive final states with two vector mesons.
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.
We report recent measurements of branching fractions and charge asymmetries of charmless hadronic B decays using the data collected with the BABAR detector at the PEP-II asymmetric energy e+e- collider.
Knowing the mass of the b-quark is essential to the study of the structure and decays of B mesons as well as to future tests of the Higgs mechanism of mass generation. We present recent preliminary measurements of the b-quark mass and related nonperturbative parameters from moments of kinematic distributions in charmed and charmless semileptonic and radiative penguin B decays. Their determination from charmless semileptonic B decays is the first measurement in this mode. The data were collected by the BABAR detector at the PEP-II asymmetric-energy e+e- -collider at the Stanford Linear Accelera…
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.
We present experimental measurements of branching fraction and longitudinal polarization fraction in charmless hadronic B decays into vector, axial vector and tensor final states with the final dataset of \babar . Measurements of such kind of decays are a powerful tool both to test the Standard Model and search possible sources of new physics.
We search for CP violating asymmetries in five charmless hadronic B meson decays using the full CLEO II and CLEO II.V data samples totalling 9.7 million BBbar events. The resulting Acp measurements have a precision that varies from +-0.12 to +-0.25 (absolute) depending on mode. No significant nonzero asymmetry is observed in any mode but 90% CL limits are strong and rule out some estimates of Acp.
Charmless hadronic $B$ decays are a good testing ground for the Standard Model (SM) of Particle Physics. The dominant amplitudes are CKM suppressed tree diagrams and/or $ b\to s$ or $b\to d$ loop ("penguin") diagrams. Non-SM particle could appear in the loop, and hence these decays are sensitive to search for New Physics (NP). Some of the recent measurements of two-body charmless hadronic $B$ decays from Belle and their prospects at Belle II are discussed.
There has been much progress in measurements of charmless hadronic B decays during 1997. Building on the previous indications from CLEO and LEP, CLEO now has clear signals in five exclusive final states: K^+π^, K^0π^+, etapr K^+, etapr K^0, and omega K^+. The branching fractions for the etapr K modes are several times larger than the others. A similar strikingly large signal has been seen in the inclusive decay, B->etapr X_S. All of these signals would appear to be dominated by hadronic penguin processes. (Invited talk presented at the Seventh International Symposium On Heavy Flavor Physics, S…
This article summarises measurements of time-dependent CP asymmetries in decays of neutral B mesons to charmonium, open-charm and gluonic penguin-dominated charmless final states. Unless otherwise stated, these measurements are based on a sample of approximately 230 million Y(4S) to BBbar decays collected by the BABAR detector at the PEP-II asymmetric-energy B-factory.
We report results from five analyses based on data taken with the BABAR detector at the PEP-II asymmetric e+e- collider. Included are branching fraction measurements for many B-meson decays involving eta, eta', omega, phi or a0 mesons and the final state Kspi+pi-, and a full angular analysis of the decay B->phiK*0.
We present several searches for charmless hadronic two-body and three-body decays of B mesons from electron-positron annihilation data collected by the BABAR detector near the Upsilon(4S) resonance. We report the preliminary branching fractions BR(B0 --> pi+pi-) = (4.1 +/- 1.0 +/- 0.7) x 10^-6, BR(B0 --> K+pi-) = (16.7 +/- 1.6 +/- 1.3) x 10^-6, BR(B0 --> rho-/+ pi+/-) = (49 +/- 13 +6 -5) x 10^-6, BR(B+ --> eta' K+) = (62 +/- 18 +/- 8) x 10^-6, and present upper limits for nine other decays.
In this paper we present first LHCb results on charmless charged two- and three-body $B$ meson decays. In particular, using the first picobarn of integrated luminosity, LHCb observed the $B^{0}\rightarrow K^{+}π^{-}$ and $B^{+}\rightarrow K^{+}π^{+}π^{-}$ decays. Such decays provide an interesting way to determine the angle $γ$ of the Unitary Triangle, thanks to the possible presence of New Physics in the penguin loops.
We present final measurements of thirteen charmless hadronic B decay modes from the CLEO experiment. The decay modes include the ten pipi, Kpi, and KKbar final states and new limits on dibaryonic final states, ppbar, pLambdabar, and LambdaLambdabar, as well as a new determination of the ratio BR(B-> DK)/BR(B-> Dpi). The results are based on the full CLEO II and CLEO III data samples totalling 15.3 fb-1 at the Upsilon(4S), and supercede previously published results.
We report measurements of Time-Dependent CP asymmetries in several $b\to s$ penguin dominated hadronic B decays, where New Physics contributions may appear. We find no significant discrepancies with respect to the Standard Model expectations.
We report results of searches for charmless hadronic B meson decays to pseudoscalar(pi^+-,K^+-,Pi^0 or Ks^0)-vector(Rho, K* or Omega) final states. Using 9.7 million BBbar pairs collected with the CLEO detector, we report first observation of B^- --> Pi^-Rho^0, B^0 --> Pi^+-Rho^-+ and B^- --> Pi^-Omega, which are expected to be dominated by hadronic b --> u transitions. The measured branching fractions are (10.4+3.3-3.4+-2.1)x10^-6, (27.6+8.4-7.4+-4.2)x10^-6 and (11.3+3.3-2.9+-1.4)x10^-6, respectively. Branching fraction upper limits are set for all the other decay modes investigated.
Based on a sample of approximately 500,000 hadronic Z0 decays accumulated between 1993 and 1998, the SLD experiment has set limits on 24 fully charged two-body and quasi two-body exclusive charmless hadronic decays of B+, B0, and B0_s mesons. The precise tracking capabilities of the SLD detector provided for the efficient reduction of combinatoric backgrounds, yielding the most precise available limits for ten of these modes.
We report recent results in the study of rare hadronic and radiative penguin decays of B mesons. These results are based on a sample of 23 million B B-bar pairs collected by the BaBar Collaboration at the SLAC PEP-II e+e- B Factory.
We search for CP-violating asymmetries (Acp) in the B meson decays to K+- pi-+, K+- pi0, Ks pi+-, K+- eta', and omega pi+-. Using 9.66 million Upsilon(4S) decays collected with the CLEO detector, the statistical precision on Acp is in the range of \pm 0.12 to \pm 0.25 depending on decay mode. While CP-violating asymmetries of up to \pm 0.5 are possible within the Standard Model, the measured asymmetries are consistent with zero in all five decay modes studied.
Based on the most recent data in charmless B decays including the very recently reported large direct CP violations, it is shown that the weak phase gamma can well be extracted without two-fold ambiguity even only from two decay modes pi^+pi^- and pi^+K^-, and its value is remarkably consistent with the global standard model fit at a compatible accuracy. A fit to all the pi pi, pi K data favor both large electroweak penguin and color-suppressed tree amplitude with large strong phases. It is demonstrated that the inclusion of small SU(3)symmetry breaking effects of strong phases and the inelast…
We search for direct CP violation in charmless hadronic B decays observed in a sample of about 22.7 million $B\bar{B}$ pairs collected with the BABAR detector at the PEP-II asymmetric-energy $e^+e^-$ collider. We measure the following charge asymmetries: ${\cal A}_{CP} (B^{\pm}\toη^\prime K^{\pm}) = -0.11\pm 0.11\pm 0.02$, ${\cal A}_{CP} (B^{\pm}\toωπ^{\pm}) = -0.01^{+0.29}_{-0.31}\pm 0.03$, ${\cal A}_{CP} (B^{\pm}\toϕK^{\pm}) = -0.05\pm 0.20\pm 0.03$, ${\cal A}_{CP} (B^{\pm}\toϕK^{*\pm}) = -0.43^{+0.36}_{-0.30}\pm 0.06$, and ${\cal A}_{CP} (B^{0}\toϕK^{*0}) = 0.00\pm 0.27\pm 0.03$.
Using 22.7M BBbar events collected with the BABAR detector at SLAC, we present preliminary measurements of the branching fractions for charmless hadronic decays of B mesons into two-body, quasi two-body and three-body final states with pions, kaons, and rho and a0 resonances. In the search for exclusive $B^0 \to π^+π^-π^0$, we measure ${\cal B}(B^0 \to ρ^{\pm}(770)π^{\mp})=(28.9\pm5.4\pm4.3) \times 10^{-6}$, together with the relative asymmetry ${\cal A}_{\rm phys} = -0.04 \pm 0.18 \pm 0.02$. We also set the upper limits on $B^0 \to ρ^0(770)π^0$, non-resonant $B^0 \to π^+π^-π^0$, $B^0 \to a_0^…
Using a theoretical framework based on the next-to-leading order QCD-improved effective Hamiltonian and a factorization Ansatz for the hadronic matrix elements of the four-quark operators, we reassess branching fractions in two-body non-leptonic decays $B \to PP, PV, VV$, involving the lowest lying light pseudoscalar $(P)$ and vector $(V)$ mesons in the standard model. Using the sensitivity of the decay rates on the effective number of colors, $N_c$, as a criterion of theoretical predictivity, we classify all the current-current (tree) and penguin transitions in five different classes. The rec…
Within the framework of QCD factorization (QCDF), we consider two different types of power correction effects in order to resolve the CP puzzles and rate deficit problems with penguin-dominated two-body decays of B mesons and color-suppressed tree-dominated $π^0π^0$ and $ρ^0π^0$ modes: penguin annihilation and soft corrections to the color-suppressed tree amplitude. We emphasize that the electroweak penguin solution to the $B\to Kπ$ CP puzzle via New Physics is irrelevant for solving the CP and rate puzzles related to tree-dominated decays. While some channels e.g. $K^-π^+,K^-ρ^0,π^+π^-,ρ^\pmπ…
We have studied charmless hadronic decays of B mesons into two-body final states with kaons and pions. We present preliminary results based on 9.66 million $B\bar{B}$ pairs collected with the CLEO detector. We have made the first observation of the decay $B \to π^+π^-$, with the branching fraction of $Br(B \to π^+ π^-) = (4.7^{+1.8}_{-1.5} \pm 0.6) \times 10^{-6}$. We have also observed for the first time the decay $B \to K^0π^0$ with the branching fraction of $Br(B \to K^0 π^0) = (14.8^{+5.9+2.4}_{-5.1-3.3}) \times 10^{-6}$, thus completing the set of four $Kπ$ branching fraction measurements…
A way of circumventing the gauge and infrared problems with effective Wilson coefficients is shown. Implications of experimentally measured charmless $B$ decays are discussed.
Two-body charmless nonleptonic decays of the B_s meson are studied within the framework of generalized factorization in which factorization is applied to the tree level matrix elements while the effective Wilson coefficients are $μ$ and renormalization scheme independent, and nonfactorizable effects are parametrized in terms of N_c(LL) and N_c(LR), the effective numbers of colors arising from (V-A)(V-A) and (V-A)(V+A) four-quark operators, respectively. Branching ratios of $B_s\to PP,PV,VV$ decays are calculated as a function of N_c(LR) with two different considerations for N_c(LL). We find th…
We report the results of a study of two-body B meson decays to the complete set of K pi, pi pi, and K K final states. The study is performed on a data sample of 31.7 +/- 0.3 million B B-bar events recorded on the Upsilon(4S) resonance by the Belle experiment at KEKB. We observe significant signals in all K pi final states and in the pi+ pi- and pi+ pi0 final states. We set limits on the pi0 pi0 and K K final states. A search is performed for partial-rate asymmetries between conjugate states for flavor-specific final states.
We have searched for two-body charmless hadronic decays of $B$ mesons. Final states include $ππ$, $K π$, and $KK$ with both charged and neutral kaons and pions; $πρ$, $K ρ$, and $K^*π$; and $Kϕ$, $ K^*ϕ$, and $ϕϕ$. The data used in this analysis consist of 2.6~million $B\bar{B}$~pairs produced at the $Υ(4S)$ taken with the CLEO-II detector at the Cornell Electron Storage Ring (CESR). We measure the branching fraction of the sum of $B^0 \rightarrow π^+π^-$ and $B^0 \rightarrow K^+π^-$ to be $(1.8^{+0.6+0.2}_{-0.5-0.3}\pm0.2) \times 10^{-5}$. In addition, we place upper limits on individual bran…
We present results of searches for B-meson decays to charmless final states that include a K*, rho, omega, or phi meson accompanied by a second meson. Using the entire data sample of 9.7 million BBbar pairs collected with the CLEO II and CLEO II.V detectors, we observe a signal for the decay B+ -> omega pi+, and measure a branching fraction of B(B+ -> omega pi+) = (11.3^{+3.3}_{-2.9} \pm 1.5) \times 10^{-6}. We also see evidence for the decay B0 -> omega K0, and set limits for the decays B0 -> rho0 pi0 and B0 -> K*0 pi0. In addition to these new results, we also summarize previous CLEO results…
We present a search for B decays to a charged scalar meson a0+ and a pi0 where the a0+ decays to an eta meson and a pi+. The analysis was performed on a data sample consisting of 383x10-6 BBbar pairs collected with the Babar detector at the PEP-II asymmetric-energy B Factory at SLAC. We find no significant signal and set an upper limit on the product branching fraction BF[(B+ -> a0+ pi0) x (a0+ -> eta pi+)] of 1.4x10-6 at the 90% confidence level.
We present preliminary results of several searches for rare charmless hadronic decays of the B meson using data collected by the BABAR detector at the Stanford Linear Accelerator Center's PEP-II storage ring. We search for the decays h^+h^-, h^+h^-h^+, h^+h^-pi^0, X^0h^+, and X^0 K_S^0, where h = pi or K, and X^0 = eta^prime or omega. In a sample of 8.8 million B-anti-B decays we measure the branching fractions: BF(B^0 --> pi^+pi^-) = (9.3^{+2.6}_{-2.3}^{+1.2}_{-1.4}) x 10^{-6}, BF(B^0 --> K^+pi^-) = (12.5^{+3.0}_{-2.6}^{+1.3}_{-1.7}) x 10^{-6}, BF(B^0 --> rho^-pi^+) = (49 +/- 13^{+6}_{-5}) x …
Nonfactorizable effects in hadronic charmless B -> PP, VP decays can be parametrized in terms of the effective number of colors N_c in the effective parameters $a_i^{eff}$ that are linear combinations of Wilson coefficients. It is shown that N_c(V+A) in the penguin amplitudes induced by the (V-A)(V+A) four-quark operators is different from N_c(V-A) in the decay amplitudes arising from the (V-A)(V-A) operators. Central values of the branching ratios of $B^\pm\toωπ^\pm$ and $B\toππ$ decays favor $N_c(V-A)\approx 2$, in accordance with the nonfactorizable effect observed in $B\to D^{(*)}π(ρ)$. Me…
We present preliminary measurements of time-dependent CP-violation parameters in the decays B0->omegaK0S, B0->eta'K0, B0->pi0K0S, B0->phiK0Spi0, and B0->K+K-K0S, which includes the resonant final states phiK0S and f0(980)K0S. The data sample corresponds to the full BABAAR dataset of 467 million BBbar pairs produced at the PEP-II asymmetric-energy e+e- collider at the Stanford Linear Accelerator Center.
We report results of a study of charmless B meson decays to three-body KPiPi, KKPi and KKK final states. Measurements of branching fractions for B decays to K+0Pi+Pi-, K+K+K-, K0K+K-, KsKsK+ and KsKsKs final states are presented. The decays B0=>K0K+K-, B+=>KsKsK+ and B0=>KsKsKs are observed for the first time. We also report evidence for B+=>K+K-Pi+ decay. For the three-body final states K0K+K-, KsKsPi+, K+K+Pi- and K-Pi+Pi+ 90% confidence level upper limits are reported. Finally, we discuss the possibility of using the three-body B0=>KsK+K- decay for CP violation studies. The results are obta…
We present preliminary results from a search for inclusive charmless B->KX decays. These decays occur dominantly via one-loop b->s penguin transitions, and can provide useful information about these processes. Using a sample of 288.5/fb collected with the BABAR detector at the PEP-II asymmetric-energy e+e- B Factory at SLAC, we search for high-energy kaons recoiling against fully reconstructed B decays. We measure the partial branching fractions for kaons with momentum p*(K)>2.34GeV in the B rest frame, and obtain (in units of 10^-6): B(B->K+X, p*>2.34GeV) = 196^{+37}_{-34}(stat.)^{+31}_{-30}(…
The computation of direct CP asymmetries in charmless B decays at next-to-next-to-leading order (NNLO) in QCD is of interest to ascertain the short-distance contribution. Here we compute the two-loop penguin contractions of the current-current operators Q_{1,2} and provide a first estimate of NNLO CP asymmetries in penguin-dominated b -> s transitions.
Preliminary results from the BABAR experiment on charmless B decays to charged pions or kaons, and the measurement of the B -> J/psi K* decay amplitudes are presented. The data sample, collected at the asymmetric-energy B-factory PEP-II at SLAC, comprises a total number of 22.7 million Y(4S) decays, corresponding to an integrated on-resonance luminosity of approximately 21 fb-1. We measure the following CP-averaged branching fractions: BR(B -> pi+pi-) = (4.1 +- 1.0(stat) +- 0.7(sys))xE-6 BR(B -> K+pi-) = (16.7 +- 1.6(stat) +1.2-1.7(sys))xE-6 and an upper limit of BR(B -> K+K-) < 2.5xE-6, at 90…
Two-body charmless hadronic B decays involving a tensor meson in the final state are studied within the framework of QCD factorization (QCDF). Due to the G-parity of the tensor meson, both the chiral-even and chiral-odd two-parton light-cone distribution amplitudes of the tensor meson are antisymmetric under the interchange of momentum fractions of the quark and anti-quark in the SU(3) limit. Our main results are: (i) In the naive factorization approach, the decays such as $B^-\to \bar K_2^{*0}π^-$ and $\bar B^0\to K_2^{*-}π^+$ with a tensor meson emitted are prohibited owing to the fact that …
Hadronic $B$ decays without a charm quark constitute a powerful probe to search for physics beyond the standard model as well as to provide constraints on $CP$ violation parameters. We report final measurements from Belle of the branching fractions and $CP$ asymmetries for the decays $B^{0} \rightarrow π^{0} π^{0}$ and $B^{\pm} \rightarrow K^{+} K^{-} π^{\pm}$. The $B^{0} \rightarrow π^{0} π^{0}$ measurements enable us to improve constraints on the angle $ϕ_{2}$ of the CKM unitarity triangle. For $B^{\pm} \rightarrow K^{+} K^{-} π^{\pm}$ we measure $CP$ asymmetry as a function of the invariant…
Rare charmless hadronic B decays are a good testing ground for QCD. In this paper we describe a selection of new measurements made by the BABAR and BELLE collaborations.
Various new measurements in charmless $B_{u,d,s}\to PP$ modes, where $P$ is a low lying pseudoscalar meson, are reported by Belle and LHCb. These include the rates of $B^0\toπ^0π^0$, $ηπ^0$, $B_s\toη'η'$, $B^0\to K^+K^-$ and $B^0_s\toπ^+π^-$ decays. Some of these modes are highly suppressed and are among the rarest $B$ decays. Direct CP asymmetries on various modes are constantly updated. It is well known that direct CP asymmetries and rates of suppressed modes are sensitive to final state interaction (FSI). As new measurements are reported and more data will be collected, it is interesting an…
We report on recent measurements, from the BaBar and Belle experiments, of B-meson decays to purely hadronic final states that do not contain charm. The studies are based on large samples of BBbar pairs collected at the Upsilon(4S) or B_s(*)B_s(*) pairs collected at the Upsilon(5S) by the BaBar and Belle detectors at the asymmetric energy e+e- colliders at SLAC and KEK-B, respectively. This paper includes the following results: measurements of branching fractions and charge asymmetries of B meson decays to eta' rho, eta' f0, and eta' K*, where the K* stands for a vector, tensor, or scalar stra…
We perform a model dependent fit to recent data on charmless hadronic B decays and determine $γ$, the phase of $V^*_{ub}$. We find $γ= 114^{+25}_{-21}$ degrees, which disfavors the often quoted $γ\sim 60^\circ$ at the two standard deviation level. We also fit for the form factors $F_0^{Bπ}$ and $A_0^{Bρ}$, and the strange-quark mass. They are consistent with theoretical expectations, although $m_s$ is somewhat low. Such agreement and the good $χ^2$ for the fit may be interpreted as a confirmation of the adequacy of our model assumptions.
We report several new and updated results from Belle and BABAR for rare hadronic B decays. These include many new results for B decays to eta'X and omegaX and new measurements of the longitudinal polarisation in the decays B -> rho K*.
We report on recent results on charmless hadronic and radiative rare $B_s^0$ decays, based on the data collected by the Belle experiment at the KEKB $e^+e^-$ collider. These include the studies of $B_s^0\rightarrow K^0\bar{K^0}$, $B_s^0\rightarrowϕγ$ and $B_s^0\rightarrowγγ$.
We study the radiative charmless $B_{(s)}\to V(A)γ$ decays in perturbative QCD (pQCD) approach to the leading order in $α_s$ (here $V$ and $A$ denotes vector mesons and two kinds of axial-vector mesons: $^3P_1$ and $^1P_1$ states, respectively.). Our predictions of branching ratios are consistent with the current available experimental data. We update all $B_{(s)}\to V$ form factors and give the predictions for $B\to A$ form factors using the recent hadronic inputs. In addition to the dominant factorizable spectator diagrams, which is form factor like, we also calculate the so-called ``power s…
Within the factorization-assisted topological-amplitude approach, we studied the 33 charmless $B_{(s)} \to VV$ decays, where $V$ stands for a light vector meson. According to the flavor flows, the amplitude of each process can be decomposed into 8 different topologies. In contrast to the conventional flavor diagrammatic approach, we further factorize each topological amplitude into decay constant, form factors and unknown universal parameters. By $χ^2$ fitting 46 experimental observables, we extracted 10 theoretical parameters with $χ^2$ per degree of freedom around 2. Using the fitted paramet…
We give an overview of the experimental measurements and the theoretical understanding of the branching fractions and CP-violating asymmetries of charmless B-meson decays. Most experimetal results are from the BABAR and Belle experiments during the past decade. The global features of these experimental results are typically well described by the QCD-motivated theories such as QCD factorization, pQCD and soft-collinear effective theory. The agreement between theory and experiment is generally satisfactory, though there remain some unsolved puzzles that pose a great challenge to both theorists a…
