399 research outputs found
Breit-Wigner Enhancement of Dark Matter Annihilation
We point out that annihilation of dark matter in the galactic halo can be
enhanced relative to that in the early universe due to a Breit-Wigner tail, if
the dark matter annihilates through a pole just below the threshold. This
provides a new explanation to the "boost factor" which is suggested by the
recent data of the PAMELA, ATIC and PPB-BETS cosmic-ray experiments.Comment: 4 pages, 4 figure
Family Security Insurance: A New Foundation for Economic Security
A report released by Georgetown Law\u27s Workplace Flexibility 2010 and the Berkeley Center on Health, Economic & Family Security (Berkeley CHEFS) outlining a blueprint for establishing and financing a new national insurance program to provide wage replacement for time off for health and caregiving needs. The report describes the need among working Americans for time off from work to address personal illness, to care for a new child, or to care for a loved one with a serious illness. It argues that the need for time off is no longer an issue for individual families or select industries, but a national priority that has major social and economic implications. Family Security Insurance, the national insurance program proposed in the report, would fundamentally reform social policy to address workers\u27 critical needs, and, at the same time, spread the cost fairly, protect the deficit, and keep people working
Anomaly-Free Sets of Fermions
We present new techniques for finding anomaly-free sets of fermions. Although
the anomaly cancellation conditions typically include cubic equations with
integer variables that cannot be solved in general, we prove by construction
that any chiral set of fermions can be embedded in a larger set of fermions
which is chiral and anomaly-free. Applying these techniques to extensions of
the Standard Model, we find anomaly-free models that have arbitrary quark and
lepton charges under an additional U(1) gauge group.Comment: 21 (+1) page
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Proposal for encoding the Old Turkic script in the SMP of the UCS
This is a proposal to encode the Old Turkic script in the international character encoding standard Unicode. The script was published in Unicode Standard version 5.2 in October 2009. Old Turkic appears in stone inscriptions from the early 8c CE near the Orkhon River in Mongolia, and a slightly different version is found near the Yenisei River in Siberia in the later 8c CE. By the 9c CE, the script had been replaced by the Uyghur script
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Precision measurement of the top quark mass in the lepton + jets channel using a matrix element method with Quasi-Monte Carlo integration
This thesis presents a measurement of the top quark mass obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. The measurement uses a matrix element integration method to calculate a t{bar t} likelihood, employing a Quasi-Monte Carlo integration, which enables us to take into account effects due to finite detector angular resolution and quark mass effects. We calculate a t{bar t} likelihood as a 2-D function of the top pole mass m{sub t} and {Delta}{sub JES}, where {Delta}{sub JES} parameterizes the uncertainty in our knowledge of the jet energy scale; it is a shift applied to all jet energies in units of the jet-dependent systematic error. By introducing {Delta}{sub JES} into the likelihood, we can use the information contained in W boson decays to constrain {Delta}{sub JES} and reduce error due to this uncertainty. We use a neural network discriminant to identify events likely to be background, and apply a cut on the peak value of individual event likelihoods to reduce the effect of badly reconstructed events. This measurement uses a total of 4.3 fb{sup -1} of integrated luminosity, requiring events with a lepton, large E{sub T}, and exactly four high-energy jets in the pseudorapidity range |{eta}| < 2.0, of which at least one must be tagged as coming from a b quark. In total, we observe 738 events before and 630 events after applying the likelihood cut, and measure m{sub t} = 172.6 {+-} 0.9 (stat.) {+-} 0.7 (JES) {+-} 1.1 (syst.) GeV/c{sup 2}, or m{sub t} = 172.6 {+-} 1.6 (tot.) GeV/c{sup 2}
Constitutional Officers, Agencies, Boards and Commissions in California State Government, 1849-1975
This paper is designed primarily to present data on the formal organizational history of governmental units created by statute or constitutional provision by California state government since 1849
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Measurement of the Hadronic Mass Spectrum in B to Xulnu Decaysand Determination of the b-Quark Mass at the BaBar Experiment
I present preliminary results of the measurement of the hadronic mass spectrum and its first three spectral moments in inclusive charmless semileptonic B-meson decays. The truncated hadronic mass moments are used for the first determination of the b-quark mass and the nonperturbative parameters {mu}{sub {pi}}{sup 2} and {rho}{sub D}{sup 3} in this B-meson decay channel. The study is based on 383 x 10{sup 6} B{bar B} decays collected with the BABAR experiment at the PEP-II e{sup +}e{sup -} storage rings, located at the Stanford Linear Accelerator Center. The first, second central, and third central hadronic mass moment with a cut on the hadronic mass m{sub X}{sup 2} < 6.4GeV{sup 2} and the lepton momentum p* > 1 GeV are measured to be: M{sub 1} = (1.96 {+-} 0.34{sub stat} {+-} 0.53{sub syst}) GeV{sup 2}; U{sub 2} = (1.92 {+-} 0.59{sub stat} {+-} 0.87{sub syst}) GeV{sup 4}; and U{sub 3} = (1.79 {+-} 0.62{sub stat} {+-} 0.78{sub syst}) GeV{sup 6}; with correlation coefficients {rho}{sub 12} = 0.99, {rho}{sub 23} = 0.94, and {rho}{sub 13} = 0.88, respectively. Using Heavy Quark Effective Theory-based predictions in the kinetic scheme we extract: m{sub b} = (4.60 {+-} 0.13{sub stat} {+-} 0.19{sub syst} {+-} 0.10{sub theo} GeV); {mu}{sub {pi}}{sup 2} = (0.40 {+-} 0.14{sub stat} {+-} 0.20{sub syst} {+-} 0.04{sub theo}) GeV{sup 2}; {rho}{sub D}{sup 3} = (0.10 {+-} 0.02{sub stat} {+-} 0.02{sub syst} {+-} 0.07{sub theo}) GeV{sup 3}; at {mu} = 1 GeV, with correlation coefficients {rho}{sub m{sub b}{mu}{sub {pi}}{sup 2}} = -0.99, {rho}{sub {mu}{sub {pi}}{sup 2}{rho}{sub D}{sup 3}} = 0.57, and {rho}{sub m{sub b}{rho}{sub D}{sup 3}} = -0.59. The results are in good agreement with earlier determinations in inclusive charmed semileptonic and radiative penguin B-meson decays and have a similar accuracy. Through the comparison of this result to those obtained in other channels, this provides a test of the Heavy Quark Effective Theory predictions that are used for the determination of |V{sub ub}|. In addition, the measured dependence of the hadronic mass moments on the hadronic mass cut is compared to the dependence predicted by Heavy Quark Effective Theory
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R-axion detection at LHC
Supersymmetric models with spontaneously broken approximate R-symmetry contains a light spin 0 particle, the R-axion. The properties of the particle can be a powerful probe of the structure of the new physics. In this paper, we discuss the possibilities of the R-axion detection at the LHC experiments. It is challenge to observe this light particle in the LHC environment. However, for typical values in which the mass of the R-axion is a few hundred MeV, we show that those particles can be detected by searching for displaced vertices from R-axion decay
Nest We Grow
4 glulam larch timber columns are notched with a series of reoccuring moment connections.https://openscholarship.wustl.edu/bcs/1213/thumbnail.jp
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Proposal for a High-Brightness Pulsed Electron Source
We propose a novel scheme for a high-brightness pulsed electron source, which has the potential for many useful applications in electron microscopy, inverse photo-emission, low energy electron scattering experiments, and electron holography. A description of the proposed scheme is presented
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