Measurement of the spectral function for the τ^− → K^−K_Sν_τ decay

The decay τ^− → K^−K_Sν_τ has been studied using 430×10^6 e^+e^− → τ^+τ^− events produced at a center-of-mass energy around 10.6 GeV at the PEP-II collider and studied with the BABAR detector. The mass spectrum of the K^−K_S system has been measured and the spectral function has been obtained. The measured branching fraction B(τ^− → K^−K_Sν_τ) = (0.739 ± 0.011(stat) ± 0.020(syst)) × 10^(-3) is found to be in agreement with earlier measurements

Search for lepton-flavor-violating decays D⁰ → X⁰e±μ∓

We present a search for seven lepton-flavor-violating neutral charm meson decays of the type D⁰ → X⁰e±μ∓, where X⁰ represents a π⁰, K⁰_S, K*⁰, ρ⁰, ϕ, ω, or η meson. The analysis is based on 468  fb⁻¹ of e⁺e⁻ annihilation data collected at or close to the Υ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. No significant signals are observed, and we establish 90% confidence level upper limits on the branching fractions in the range (5.0−22.5) × 10⁻⁷. The limits are between 1 and 2 orders of magnitude more stringent than previous measurements

Measurement of the e^+e^− → K^0_sK^±π^∓π^0 and K^0_sK^±π^∓η cross sections using initial-state radiation

The processes e^+e^− → K^0_SK^±π^∓π^0 and e^+e^− → K^0_SK^±π^∓η are studied over a continuum of energies from threshold to 4 GeV with the initial-state photon radiation method. Using 454  fb^(-1) of data collected with the BABAR detector at the SLAC PEP-II storage ring, the first measurements of the cross sections for these processes are obtained. The intermediate resonance structures from K^(*0)(Kπ)^0, K^∗(892)^±(Kπ)^∓ , and K^0_SK^±ρ^∓ are studied. The J/ψ is observed in all of these channels, and corresponding branching fractions are measured

Study of the process e^+e^− → π^+π^−η using initial state radiation

We study the process e^+e^− → π^+π^−ηγ, where the photon is radiated from the initial state. About 8000 fully reconstructed events of this process are selected from the BABAR data sample with an integrated luminosity of 469  fb^(-1). Using the π^+π^−η invariant mass spectrum, we measure the e^+e^− → π^+π^−η cross section in the e^+e^− center-of-mass energy range from 1.15 to 3.5 GeV. The cross section is well described by the Vector-Meson dominance model with four ρ-like states. We observe 49±9 events of the J/ψ decay to π^+π^−η and measure the product Γ_(J/Ψ → e^+e^−)B_(J/Ψ → π^+π^−η) = 2.34 ± 0.43_(stat) ± 0.16_(syst)  eV

SuperB Progress Report for Physics

SuperB is a high luminosity e{sup +}e{sup -} collider that will be able to indirectly probe new physics at energy scales far beyond the reach of any man made accelerator planned or in existence. Just as detailed understanding of the Standard Model of particle physics was developed from stringent constraints imposed by flavour changing processes between quarks, the detailed structure of any new physics is severely constrained by flavour processes. In order to elucidate this structure it is necessary to perform a number of complementary studies of a set of golden channels. With these measurements in hand, the pattern of deviations from the Standard Model behavior can be used as a test of the structure of new physics. If new physics is found at the LHC, then the many golden measurements from SuperB will help decode the subtle nature of the new physics. However if no new particles are found at the LHC, SuperB will be able to search for new physics at energy scales up to 10-100 TeV. In either scenario, flavour physics measurements that can be made at SuperB play a pivotal role in understanding the nature of physics beyond the Standard Model. Examples for using the interplay between measurements to discriminate New Physics models are discussed in this document. SuperB is a Super Flavour Factory, in addition to studying large samples of B{sub u,d,s}, D and {tau} decays, SuperB has a broad physics programme that includes spectroscopy both in terms of the Standard Model and exotica, and precision measurements of sin{sup 2} {theta}{sub W}. In addition to performing CP violation measurements at the {Upsilon}(4S) and {phi}(3770), SuperB will test CPT in these systems, and lepton universality in a number of different processes. The multitude of rare decay measurements possible at SuperB can be used to constrain scenarios of physics beyond the Standard Model. In terms of other precision tests of the Standard Model, this experiment will be able to perform precision over-constraints of the unitarity triangle through multiple measurements of all angles and sides. This report extends and updates the studies presented in both the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008. Together, these three documents detail the Physics case of the SuperB Project

Review of Particle Physics

The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,143 new measurements from 709 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, Probability and Statistics. Among the 120 reviews are many that are new or heavily revised, including a new review on Machine Learning, and one on Spectroscopy of Light Meson Resonances. The Review is divided into two volumes. Volume 1 includes the Summary Tables and 97 review articles. Volume 2 consists of the Particle Listings and contains also 23 reviews that address specific aspects of the data presented in the Listings. The complete Review (both volumes) is published online on the website of the Particle Data Group (pdg.lbl.gov) and in a journal. Volume 1 is available in print as the PDG Book. A Particle Physics Booklet with the Summary Tables and essential tables, figures, and equations from selected review articles is available in print, as a web version optimized for use on phones, and as an Android app.United States Department of Energy (DOE) DE-AC02-05CH11231government of Japan (Ministry of Education, Culture, Sports, Science and Technology)Istituto Nazionale di Fisica Nucleare (INFN)Physical Society of Japan (JPS)European Laboratory for Particle Physics (CERN)United States Department of Energy (DOE