2,004 research outputs found

    New methods for B meson decay constants and form factors from lattice NRQCD

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    We determine the normalisation of scalar and pseudoscalar current operators made from non-relativistic bb quarks and Highly Improved Staggered light quarks in lattice Quantum Chromodynamics (QCD) through O(αs)\mathcal{O}(\alpha_s) and ΛQCD/mb\Lambda_{\text{QCD}}/m_b. We use matrix elements of these operators to extract BB meson decay constants and form factors, then compare to those obtained using the standard vector and axial-vector operators. This provides a test of systematic errors in the lattice QCD determination of the BB meson decay constants and form factors. We provide a new value for the BB and BsB_s meson decay constants from lattice QCD calculations on ensembles that include uu, dd, ss and cc quarks in the sea and those which have the u/du/d quark mass going down to its physical value. Our results are fB=0.196(6)f_B=0.196(6) GeV, fBs=0.236(7)f_{B_s}=0.236(7) GeV and fBs/fB=1.207(7)f_{B_s}/f_B =1.207(7), agreeing well with earlier results using the temporal axial current. By combining with these previous results, we provide updated values of fB=0.190(4)f_B=0.190(4) GeV, fBs=0.229(5)f_{B_s}=0.229(5) GeV and fBs/fB=1.206(5)f_{B_s}/f_B = 1.206(5).Comment: 14 pages, 10 figure

    Mass of the b quark from lattice NRQCD and lattice perturbation theory

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    We present a determination of the b-quark mass accurate through O(alpha(2)(s)) in perturbation theory and including partial contributions at O(alpha(3)(s)). Nonperturbative input comes from the calculation of the Upsilon and B-s energies in lattice QCD, including the effect of u, d and s sea quarks. We use an improved NRQCD action for the b quark. This is combined with the heavy quark energy shift in NRQCD determined using a mixed approach of high-beta simulation and automated lattice perturbation theory. Comparison with experiment enables the quark mass to be extracted: in the (MS) over bar scheme we find (m) over bar (b)((m) over bar (b)) = 4.166(43) GeV. DOI: 10.1103/PhysRevD.87.07401

    The mass of the b-quark from lattice NRQCD and lattice perturbation theory

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    We present a determination of the b-quark mass accurate through O(\alpha_s^2) in perturbation theory and including partial contributions at O(\alpha_s^3). Nonperturbative input comes from the calculation of the Upsilon and B_s energies in lattice QCD including the effect of u, d and s sea quarks. We use an improved NRQCD action for the b-quark. This is combined with the heavy quark energy shift in NRQCD determined using a mixed approach of high-beta simulation and automated lattice perturbation theory. Comparison with experiment enables the quark mass to be extracted: in the MS bar scheme we find m_b(m_b) = 4.166(43) GeV.Comment: v2 - corrected some typos and an error in the summary plo

    B and Bs semileptonic decay form factors with NRQCD/HISQ quarks

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    We discuss our ongoing effort to calculate form factors for several B and Bs semileptonic decays. We have recently completed the first unquenched calculation of the form factors for the rare decay B -> K ll. Extrapolated over the full kinematic range of q^2 via model-independent z expansion, these form factor results allow us to calculate several Standard Model observables. We compare with experiment (Belle, BABAR, CDF, and LHCb) where possible and make predictions elsewhere. We discuss preliminary results for Bs -> K l nu which, when combined with anticipated experimental results, will provide an alternative exclusive determination of |Vub|. We are exploring the possibility of using ratios of form factors for this decay with those for the unphysical decay Bs -> eta_s as a means of significantly reducing form factor errors. We are also studying B -> pi l nu, form factors for which are combined with experiment in the standard exclusive determination of |Vub|. Our simulations use NRQCD heavy and HISQ light valence quarks on the MILC 2+1 dynamical asqtad configurations.Comment: 7 pages, 5 figures, presented at the 31st International Symposium on Lattice Field Theory (Lattice 2013), 29 July - 3 August 2013, Mainz, German

    Preparing the New Law Graduate to Practice Law: A View from the Trenches

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    Most legal educators reject the premise that the primary mission of the law school is to train law students to practice law. Rather, most law professors claim that their primary function is to teach students to think like lawyers. To many commentators, however, the academic community\u27s antipractice attitude has spawned an unhealthy dichotomy between theory and practice, a division within the academic community, and a chasm between law schools and the practicing bar. Moreover, this dissonance or gap between law school and practice significantly contributes to the fact that most law graduates are substantially unprepared to function as lawyers when they enter the profession. The 1992 MacCrate Report reflects a serious effort by some concerned members of the legal community to grapple with the problems of the legal profession and to narrow the gap between law schools and the profession. The article begins by briefly exploring the reality of this perceived gap between law school and practice. Next, the article describes our study of the DPA\u27s New Attorney Training Program and discusses what we have learned from listening to and observing these new graduates struggle to gain competency. The article also compares the preparedness of new graduates in the Kentucky public defender program with that of new graduates who participated in a live-client clinic at the University of Wisconsin Law School or the University of Oklahoma College of Law. In addition, the article focuses on the extent to which the practical skills and fundamental values identified in the MacCrate Report can be readily acquired in a training program such as that offered by the DPA or in a law school clinical program. Based upon the DPA study and our professional experiences, the article concludes that law students and new graduates, if provided a quality, intensive, educational experience, can achieve minimal competence in a reasonable time frame. Finally, the Article examines Barnhizer\u27s proposed changes to legal education and his suggested new institutional approaches. The DPA study and professional experiences convince us that Barnhizer\u27s recommendations are sound and do, in fact, merit serious consideration

    Mechanistic and Treatment Implications of ΔNp63 Expression in a Rare Case of Metastatic Hidradenocarcinoma

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    Hidradenocarcinomas are rare, aggressive adnexal tumors of sweat gland origin that demonstrate a high potential for local recurrence, metastasis and poor outcome. These neoplasms can derive from preexisting clear cell hidradenomas, but more commonly appear de novo with the molecular events responsible for the pathogenesis currently unknown. Molecular markers of pathogenesis as well as effective forms of adjuvant chemotherapy are missing due to the lack of accurate diagnosis, paucity of cases and confusion with other visceral solid tumors. Here, we report a 37-year-old man who presented with a rapidly growing, painful palpable mass located in the right inguinal area. The patient was a nonsmoker, did not consume alcohol and had a medical history remarkable only for a lower abdominal superficial skin lesion in the same area that had been excised 11 years earlier. Although initially slow growing, the lesion eventually expanded, was surgically excised and was diagnosed as a hidradenoma. There was no family history of malignancy and the patient had not experienced any constitutional symptoms. We probed the immunohistochemical status and detected negative staining for the estrogen, progesterone and Her2 receptors, while strong, diffuse nuclear staining was seen in the majority of cells consistent with p53 overexpression. Similarly, strong nuclear reactivity was seen with p63 and p73 antibodies. The p63 gene contains 2 separate promoters which express at least 6 major transcripts that lead to 2 fundamentally different classes of proteins; 3 isoforms (TAp63α, β and γ) encode proteins that induce apoptosis, whereas the other 3 isoforms (ΔNp63α, β and γ) may exert inhibitory effects on p53. Interest in p63 stems from this ‘two genes in one’-concept. Importantly, the nuclear presence of ΔNp63 was detected widespread throughout the tumor. We have identified a subtype of hidradenocarcinomas that express ΔNp63 and uncovered an unforeseen commonality with triple-negative breast tumors. To our knowledge, this is the first report of a sweat gland tumor that displayed expression of both ΔNp63 and p73 and demonstrated a triple-negative receptor status. Such a link between 2 seemingly disparate tumor types indicates a mutual pathway of tumorigenesis and suggests the potential for common therapeutic regimens

    A comparison of vertical drift‐envelopes to conventional drift‐bottles

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109919/1/lno19752010141.pd
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