311 research outputs found

    Three Numerical Puzzles and the Top Quark's Chiral Weak-Moment

    Get PDF
    Versus the standard model's t --> W b decay helicity amplitudes, three numerical puzzles occur at the 0.1 % level when one considers the amplitudes in the case of an additional (f_M + f_E) coupling of relative strength 53 GeV. The puzzles are theoretical ones which involve the t --> W b decay helicity amplitudes in the two cases, the relative strength of this additional coupling, and the observed masses of these three particles. A deeper analytic realization is obtained for two of them. Equivalent realizations are given for the remaining one. An empirical consequence of these analytic realizations is that it is important to search for effects of a large chiral weak-moment of the top-quark, the effective mass-scale is about 53 GeV. A full theoretical resolution would include relating the origin of such a chiral weak-moment and the mass generation of the top-quark, the W-boson, and probably the b-quark.Comment: 18 pages, 1 postscript table (revised to better explain notation, model #1, add a little material...

    Book Reviews

    Get PDF
    Reviews of the following books: The Long Argument: English Puritanism and the Shaping of New England Culture, 1570-1700 by Stephen Foster; The Salem Witch Crisis by Larry Gragg; A Home for Everyman: The Greek Revival and Maine Domestic Architecture by Joyce K. Bibber; The Gunpowder Mills of Maine by Maurice W. Hitten; In the Hands of Providence: Joshua L. Chamberlain And The American Civil War by Alice Rains Trulock; Hurricane Island: The Town That Disappeared by Eleanor Motley Richardson; Home Front On Penobscot Bay: Rockland During The War Years, 1940-1945by Paul G. Merriam, Thomas J. Molloy, and Theodore W. Sylvester, Jr.; The History of Broadcasting in Maine: The First Fifty Yearsby Ellie Thompson; New Compass Points by Roy P. Fairfiel

    Graphical amplitudes from SCET

    Full text link
    We discuss the relationship between the graphical amplitudes T, C, P, ... used to parameterize nonleptonic B decay amplitudes, and matrix elements of operators in the soft-collinear effective theory (SCET) at leading order in \Lambda/m_b. Using the SU(3) flavor symmetry of the weak Hamiltonian we derive all-order constraints on the electroweak penguin contributions to the Wilson coefficients of SCET operators.Comment: 7 pages; one additional relation included, minor corrections. version published in Physics Letters

    A new CP violating observable for the LHC

    Full text link
    We study a new type of CP violating observable that arises in three body decays that are dominated by an intermediate resonance. If two interfering diagrams exist with different orderings of final state particles, the required CP-even phase arises due to the different virtualities of the resonance in each of the two diagrams. This method can be an important tool for accessing new CP phases at the LHC and future colliders.Comment: 22 pages, v2: discussion of charged particle decays and a few references added v3: typos corrected, matches published versio

    Site-Specific Metal Chelation Facilitates the Unveiling of Hidden Coordination Sites in an Fe II/Fe III -Seamed Pyrogallol[4]arene Nanocapsule

    Get PDF
    Under suitable conditions, C-alkylpyrogallol­[4]­arenes (PgCs) arrange into spherical metal–organic nanocapsules (MONCs) upon coordination to appropriate metal ions. Herein we present the synthesis and structural characterization of a novel FeII/FeIII-seamed MONC, as well as studies related to its electrochemical and magnetic behaviors. Unlike other MONCs that are assembled through 24 metal ions, this nanocapsule comprises 32 Fe ions, uncovering 8 additional coordination sites situated between the constituent PgC subunits. The FeII ions are likely formed by the reducing ability of DMF used in the synthesis, representing a novel synthetic route toward polynuclear mixed-valence MONCs

    Rare radiative B decays to orbitally excited K mesons

    Get PDF
    The exclusive rare radiative B meson decays to orbitally excited axial-vector mesons K_1^*(1270), K_1(1400) and to the tensor meson K_2^*(1430) are investigated in the framework of the relativistic quark model based on the quasipotential approach in quantum field theory. These decays are considered without employing the heavy quark expansion for the s quark. Instead the s quark is treated to be light and the expansion in inverse powers of the large recoil momentum of the final K^{**} meson is used to simplify calculations. It is found that the ratio of the branching fractions of rare radiative B decays to axial vector K^*_1(1270) and K_1(1400) mesons is significantly influenced by relativistic effects. The obtained results for B decays to the tensor meson K_2^*(1430) agree with recent experimental data from CLEO.Comment: 17 pages, revte

    Sustainment of the TeleSleep program for rural veterans

    Get PDF
    BackgroundIn fiscal year 2021, the Veterans Health Administration (VHA) provided care for sleep disorders to 599,966 Veterans, including 189,932 rural Veterans. To further improve rural access, the VA Office of Rural Health developed the TeleSleep Enterprise-Wide Initiative (EWI). TeleSleep's telemedicine strategies include tests for sleep apnea at the Veteran's home rather than in a sleep lab; Clinical Video Telehealth applications; and other forms of virtual care. In 2017 and 2020, VHA provided 3-year start-up funding to launch new TeleSleep programs at rural-serving VA medical facilities.MethodsIn early 2022, we surveyed leaders of 24 sites that received TeleSleep funding to identify successes, failures, facilitators, and barriers relevant to sustaining TeleSleep implementations upon expiration of startup funding. We tabulated frequencies on the multiple choice questions in the survey, and, using the survey's critical incident framework, summarized the responses to open-ended questions. TeleSleep program leaders discussed the responses and synthesized recommendations for improvement.Results18 sites reported sustainment, while six were “on track.” Sustainment involved medical centers or regional entities incorporating TeleSleep into their budgets. Facilitators included: demonstrating value; aligning with local priorities; and collaborating with spoke sites serving rural Veterans. Barriers included: misalignment with local priorities; and hiring delays. COVID was a facilitator, as it stimulated adoption of telehealth practices; and also a barrier, as it consumed attention and resources. Recommendations included: longer startup funding; dedicated funding for human resources to accelerate hiring; funders communicating with local facility leaders regarding how TeleSleep aligns with organizational priorities; hiring into job classifications aligned with market pay; and obtaining, from finance departments, projections and outcomes for the return on investment in TeleSleep

    On leptonic models for blazars in the Fermi era

    Full text link
    Some questions raised by Fermi-LAT data about blazars are summarized, along with attempts at solutions within the context of leptonic models. These include both spectral and statistical questions, including the origin of the GeV breaks in low-synchrotron peaked blazars, the location of the gamma-ray emission sites, the correlations in the spectral energy distributions with luminosity, and the difficulty of synchrotron/SSC models to fit the spectra of some TeV blazars.Comment: 9 pages, 1 figure, in "Beamed and Unbeamed Gamma Rays from Galaxies," Muonio, Finland, 11-15 April, 2011, ed. R. Wagner, L. Maraschi, A. Sillanpaa, to appear in Journal of Physics: Conference Serie

    Gamma-ray Activity in the Crab Nebula: The Exceptional Flare of April 2011

    Full text link
    The Large Area Telescope on board the Fermi satellite observed a gamma-ray flare in the Crab nebula lasting for approximately nine days in April of 2011. The source, which at optical wavelengths has a size of ~11 ly across, doubled its gamma-ray flux within eight hours. The peak photon flux was (186 +- 6) 10-7 cm-2 s-1 above 100 MeV, which corresponds to a 30-fold increase compared to the average value. During the flare, a new component emerged in the spectral energy distribution, which peaked at an energy of (375 +- 26) MeV at flare maximum. The observations imply that the emission region was likely relativistically beamed toward us and that variations in its motion are responsible for the observed spectral variability.Comment: 13 pages, 7 figures, accepted for publication in Ap
    corecore