Radiative Penguin Decays of B Mesons: Measurements of B -> K* gamma, B -> K2*(1430) gamma, and Search for B0 -> phi gamma

Electromagnetic radiative penguin decays of the B meson were studied with the BaBar detector at SLAC's PEP-II asymmetric-energy B Factory. Branching fractions and isospin asymmetry of the decay B -> K* gamma, branching fractions of B -> K2*(1430) gamma, and a search for B0 -> phi gamma are presented. The decay rates may be enhanced by contributions from non-standard model processes.Comment: 5 pages, 3 figures, presented at the 2004 Meeting of the Division of Particles and Fields of the American Physical Society, Riverside, CA, USA, August 26-31, 2004, submitted to International Journal of Modern Physics

Observation of B+ ---> a(1)+(1260) K0 and B0 ---> a(1)-(1260) K+

We present branching fraction measurements of the decays B^{+} -> a1(1260)^{+} K^{0} and B^{0} to a1(1260)^{-} K^{+} with a1(1260)^{+} -> pi^{-} pi^{+} pi^{+}. The data sample corresponds to 383 million B B-bar pairs produced in e^{+}e^{-} annihilation through the Y(4S) resonance. We measure the products of the branching fractions: B(B^{+}-> a1(1260)^{+} K^{0})B(a1(1260)^{+} -> pi^{-} pi^{+} pi^{+}) = (17.4 +/- 2.5 +/- 2.2) 10^{-6} B(B^{0}-> a1(1260)^{-} K^{+})B(a1(1260)^{-} -> pi^{+} pi^{-} pi^{-}) = (8.2 +/- 1.5 +/- 1.2) 10^{-6}. We also measure the charge asymmetries A_{ch}(B^{+} -> a1(1260)^{+} K^{0})= 0.12 +/- 0.11 +/- 0.02 and A_{ch}(B^{0} -> a1(1260)^{-} K^{+})= -0.16 +/- 0.12 +/- 0.01. The first uncertainty quoted is statistical and the second is systematic

Search for CP violation in the decays D0 ---> K- K+ and D0 ---> pi- pi+

We measure CP-violating asymmetries of neutral charmed mesons in the modes D0 --> K- K+ and D0 --> pi- pi+ with the highest precision to date by using D0 --> K- pi+ decays to correct detector asymmetries. An analysis of 385.8 fb-1 of data collected with the BaBar detector yields values of aCP(KK) = (0.00 +/- 0.34 (stat.) +/- 0.13 (syst.))% and aCP(pipi) = (-0.24 +/- 0.52 (stat.) +/- 0.22 (syst.))%, which agree with Standard Model prediction

Observation of the semileptonic decays B ---> D* tau- anti-nu(tau) and evidence for B ---> D tau- anti-nu(tau

We present measurements of the semileptonic decays B- --> D0 tau- nubar, B- --> D*0 tau- nubar, B0bar --> D+ tau- nubar, and B0bar --> D*+ tau- nubar, which are potentially sensitive to non--Standard Model amplitudes. The data sample comprises 232x10^6 Upsilon(4S) --> BBbar decays collected with the BaBar detector. From a combined fit to B- and B0bar channels, we obtain the branching fractions B(B --> D tau- nubar) = (0.86 +/- 0.24 +/- 0.11 +/- 0.06)% and B(B --> D* tau- nubar) = (1.62 +/- 0.31 +/- 0.10 +/- 0.05)% (normalized for the B0bar), where the uncertainties are statistical, systematic, and normalization-mode-related

Study of e+ e- ---> Lambda anti-Lambda, Lambda anti-Sigma0, Sigma0 anti-Sigma0 using initial state radiation with BABAR

We study the e+e- --> Lambda anti-Lambda gamma, Lambda anti-Sigma0 gamma, Sigma0 anti-Sigma0 gamma processes using 230 fb-1 of integrated luminosity collected by the BABAR detector at e+e- center-of-mass energy of 10.58 GeV. From the analysis of the baryon-antibaryon mass spectra the cross sections for e+e- --> Lambda anti-Lambda, Lambda anti-Sigma0, Sigma0 anti-Sigma0 are measured in the dibaryon mass range from threshold up to 3 GeV/c^2. The ratio of electric and magnetic form factors, |G_E/G_M|, is measured for e+e- --> Lambda anti-Lambda, and limits on the relative phase between Lambda form factors are obtained. We also measure the J/psi --> Lambda anti-Lambda, Sigma0 anti-Sigma0 and psi(2S) --> Lambda anti-Lambda branching fractions

Measurements of Partial Branching Fractions for anti-B ---> X(u) l anti-nu and Determination of |V(ub)|

We present partial branching fractions for inclusive charmless semileptonic B decays Bbar --> X_u ell nubar, and the determination of the CKM matrix element |V_{ub}|. The analysis is based on a sample of 383 million Y(4S) decays into B Bbar pairs collected with the BaBar detector at the PEP-II e+ e- storage rings. We select events using either the invariant mass M_X of the hadronic system, the invariant mass squared, q^2, of the lepton and neutrino pair, the kinematic variable P_+ or one of their combinations. We then determine partial branching fractions in limited regions of phase space: Delta B = (1.18 +- 0.09_{stat.} +- 0.07_{sys.} +- 0.01_{theo.}) x 10^{-3} (M_X 8 GeV^2/c^4). Corresponding values of |V_{ub}| are extracted using several theoretical calculations

Physics at the B Factories

We review recent progress at the two $e^+ e^-$ B factories. The first measurement of CP violation and the prospects for measuring all the angles of the unitarity triangle are discussed.Comment: To appear in the Proceedings of From the Smallest to the Largest Distances, a conference in honor of Tranh Thanh Van in Moscow, Russi

Nonleptonic charmless two-body B→ATB \to AT decays

In this work we have studied hadronic charmless two-body B decays involving p-wave mesons in final state. We have calculated branching ratios of $B\to AT$ decays (where $A$ and $T$ denotes a $^3P_1$ axial-vector and a tensor meson, respectively), using $B \to T$ form factors obtained in the covariant light-front (CLF) approach, and the full effective Hamiltonian. We have obtained that $\mathcal{B}(B^{0} \to a_{1}^{+}a_{2}^{-}) =42.47 \times10^{-6}$, $\mathcal{B}(B^{+} \to a_{1}^{+}a_{2}^{0}) = 22.71 \times10^{-6}$, $\mathcal{B}(B \to f_{1}K_{2}^{*}) = (2.8-4) \times 10^{-6}$ (with $f_{1}=, f_{1}(1285),f_{1}(1420)$) for $\theta_{^{3}P_{1}} = 53.2^{\circ}$, $\mathcal{B}(B \to f_{1}(1420)K_{2}^{*}) = (5.91-6.42) \times 10^{-6}$ with $\theta_{^{3}P_{1}} = 27.9^{\circ}$, $\mathcal{B}(B \to K_{1}a_{2})= (1.7 - 5.7) [1-9.3] \times10^{-6}$ for $\theta_{K_{1}} = -37^{\circ} [-58^{\circ}]$ where $K_1 = K_1(1270), K_1(1400)$. It seems that these decays can be measured in experiments at $B$ factories. Additionally, we have found that $\mathcal{B}(B \to K_{1}(1270)a_{2})/\mathcal{B}(B \to K_{1}(1400)a_{2})$ and $\mathcal{B}(B \to f_1(1420)K_{2}^{*})/\mathcal{B}(B \to f_1(1285)K_{2}^{*})$ ratios could be useful to determine numerical values of mixing angles $\theta_{K_{1}}$ and $\theta_{^{3}P_{1}}$, respectively.Comment: 12 page

Vast planes of satellites in a high resolution simulation of the Local Group: comparison to Andromeda

We search for vast planes of satellites (VPoS) in a high resolution simulation of the Local Group performed by the CLUES project, which improves significantly the resolution of former similar studies. We use a simple method for detecting planar configurations of satellites, and validate it on the known plane of M31. We implement a range of prescriptions for modelling the satellite populations, roughly reproducing the variety of recipes used in the literature, and investigate the occurence and properties of planar structures in these populations. The structure of the simulated satellite systems is strongly non-random and contains planes of satellites, predominantly co-rotating, with, in some cases, sizes comparable to the plane observed in M31 by Ibata et al.. However the latter is slightly richer in satellites, slightly thinner and has stronger co-rotation, which makes it stand out as overall more exceptional than the simulated planes, when compared to a random population. Although the simulated planes we find are generally dominated by one real structure, forming its backbone, they are also partly fortuitous and are thus not kinematically coherent structures as a whole. Provided that the simulated and observed planes of satellites are indeed of the same nature, our results suggest that the VPoS of M31 is not a coherent disc and that one third to one half of its satellites must have large proper motions perpendicular to the plane

What can we learn from phi_1 and B_d^0 -> pi^+ pi^- ?

We discuss what we can understand from $\phi_1$ and $B^0_d\to \pi^+ \pi^-$ decay mode. Using a convention without weak phases $\phi_2$ and $\phi_3$, we can solve the parameters from the time-depended CP asymmetry. If we can put a condition the contribution from penguin except for the CKM factor including in the diagram is small, then we can lead the allowed region of $R_t$ or $\phi_2$ by using the convention.Comment: 7 pages, 4 figures, references and comments adde