121630940
Heavy quarks and tau
I present some recent experimental results on τ, charm, and bottom physics. CVC test and Michel parameters of the τ; mixing and fDs; and fB, Nc, η'K, ππ and Kπ, Vcb and Vub, lifetime and mixing, and CP violation searches in B decays.
35600922
Measurement of the branching fraction for D+-->K- pi + pi +
Using the CLEO-II detector at CESR we have measured the ratio of branching fractions, B(D+ → K−π+π+)/B(D0 → K−π+) = 2.35 ± 0.16 ± 0.16. Our recent measurement of B(D0 → K−π+) then gives B(D+ → K−π+π+) =
17397470
Inclusive decays of B mesons to charmonium.
We have used the CLEO-II detector at the Cornell Electron Storage Ringe (CESR) to study the inclusive production of charmonium mesons in a sample of 2.15 million {ital B{bar B}} events. We find inclusive branching fractions of (1.12{plus_minus}0.04{plus_minus}0.06)% for {ital B}{r_arrow}{ital J}/{psi}{ital X}, (0.34{plus_minus}0.04{plus_minus}0.03)% for {ital B}{r_arrow}{psi}{prime}{ital X}, and (0.40{plus_minus}0.06{plus_minus}0.04)% for {ital B}{r_arrow}{chi}{sub {ital c}1}{ital X}. We also find some evidence for the inclusive production of {chi}{sub {ital c}2}, and set an upper limit for the branching fraction of the inclusive decay {ital B}{r_arrow}{eta}{sub {ital c}}{ital X} of 0.9% at 90% confidence level. Momentum spectra for inclusive {ital J}/{psi}, {psi}{prime}, and {chi}{sub {ital c}1} production are presented. These measurements are compared to theoretical calculations.
120057201
Testing the Dark Energy Camera on a telescope simulator
The Dark Energy Camera is a new prime-focus instrument to be delivered to the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory (CTIO) in 2011. Construction is in-progress at this time at Fermilab. In order to verify that the camera meets technical specifications for the Dark Energy Survey and to reduce the time required to commission the instrument while it is on the telescope, we are constructing a "Telescope Simulator" and performing full system testing prior to shipping to CTIO. This presentation will describe the Telescope Simulator and how we use it to verify some of the technical specifications.
38939426
Observation of inclusive B decays to the charmed baryons Sigma c++ and Sigma c0.
Using data collected in the region of the [Upsilon](4[ital S]) resonance with the CLEO II detector operating at the Cornell Electron Storage Ring, we report on evidence for the production of [Sigma][sub [ital c]][sup ++] and [Sigma][sub [ital e]][sup 0] baryons in [ital B] decays, with [Sigma][sub [ital c]][r arrow][Lambda][sub [ital c]][sup +][pi]. This observation is based on 77[plus minus]19[Sigma][sub [ital c]][sup ++] and 76[plus minus]21[Sigma][sub [ital c]][sup 0] candidates from [ital B] decays. We find the product branching fractions [ital scrB]([ital [bar B]][r arrow][Sigma][sub [ital c]][ital X])[ital scrB]([Lambda][sub [ital c]][sup +][r arrow][ital pK][sup [minus]][pi][sup +]) for [Sigma][sub [ital c]]=[Sigma][sub [ital c]][sup ++], [Sigma][sub [ital c]][sup 0], and [Sigma][sub [ital c]][sup +] to be (2.1[plus minus]0.8[plus minus]0.7)[times]10[sup [minus]4], (2.3[plus minus]0.8[plus minus]0.7)[times]10[sup [minus]4], and less than 4.8[times]10[sup [minus]4] at 90% confidence level, respectively. A study of the [Sigma][sub [ital c]][sup ++] and [Sigma][sub [ital c]][sup 0] momentum spectra indicates that [ital B] decays to two-body final states with [Sigma][sub [ital c]] are suppressed.
116478167
Study of dalitz-plot distributions of the decays eta ---> pi+ pi- pi0 and eta ---> pi+ pi- gamma
15707893
Strategies to identify boosted tops
We study techniques for identifying highly boosted top jets, where the subsequent top decay products are not isolated. For hadronic boosted tops, we consider variables which probe the jet substructure in order to reduce the background from QCD jets with large invariant mass. Substructure variables related to two-body kinematics are least sensitive to the modeling of parton shower, while those which involve multi-body kinematics may still have discrimination power. For leptonic boosted tops, we consider variables which characterize the separation between the lepton—although not isolated by conventional criterion—and the hadronic activity in the top jet. Such variables are useful in reducing the backgrounds both from heavy-flavor jets and from accidental jet-lepton overlap. We give numerical estimates of the top identification efficiency versus background rejection rate as a functions of cuts on these variables, and find that these variables offer additional useful information above invariant mass alone.
119185991
Dark force detection in low energy e-p collisions
We study the prospects for detecting a light boson X with mass mX ≾ 100 MeV at a low energy electron-proton collider. We focus on the case where X dominantly decays to e+e− as motivated by recent “dark force” models. In order to evade direct and indirect constraints, X must have small couplings to the standard model (αX ≾ 10−8) and a sufficiently large mass (mX ≳ 10 MeV). By comparing the signal and background cross sections for the e−p e+e− final state, we conclude that dark force detection requires an integrated luminosity of around 1 ab−1, achievable with a forthcoming JLab proposal.
118951198
Neutrino constraints on spontaneous Lorentz violation
We study the effect of spontaneous Lorentz violation on neutrinos. We consider two kinds of effects: static effects, where the neutrino acquires a Lorentz-violating dispersion relation, and dynamic effects, which arise from the interactions of the neutrino with the Goldstone boson of spontaneous Lorentz violation. Static effects are well detailed in the literature. Here, special emphasis is given to the novel dynamic effect of Goldstone-Cerenkov radiation, where neutrinos moving with respect to a preferred rest frame can spontaneously emit Goldstone bosons. We calculate the observable consequences of this process and use them to derive experimental bounds from SN1987A and the CMBR. The bounds derived from dynamic effects are complementary to - and in many cases much stronger than - those obtained from static effects.
119475515
Little Technicolor
Inspired by the AdS/CFT correspondence, we show that any G/H symmetry breaking pattern can be described by a simple two-site moose diagram. This construction trivially reproduces the CCWZ prescription in the context of Hidden Local Symmetry. We interpret this moose in a novel way to show that many little Higgs theories can emerge from ordinary chiral symmetry breaking in scaled-up QCD. We apply this reasoning to the simple group little Higgs to see that the same low energy degrees of freedom can arise from a variety of UV complete theories. We also show how models of holographic composite Higgs bosons can turn into brane-localized little technicolor theories by"integrating in"the IR brane.
119290488
Supermodels for early LHC
Abstract We investigate which new physics signatures could be discovered in the first year of the LHC, beyond the expected sensitivity of the Tevatron data by the end of 2010. We construct “supermodels”, for which the LHC sensitivity even with only 10 pb −1 useful luminosity is greater than that of the Tevatron with 10 fb −1 . The simplest supermodels involve s -channel resonances in the quark–antiquark and especially in the quark–quark channels. We concentrate on easily visible final states with small standard model backgrounds, and find that there are simple searches, besides those for Z ′ states, which could discover new physics in early LHC data. Many of these are well-suited to test searches for “more conventional” models, often discussed for multi-fb −1 data sets.