School of Mathematics: Recent submissions

Now showing items 361-380 of 393

    • Heavy quark physics from lattice QCD 

      RYAN, SINEAD MARIE (Elsevier, 2002)
      I review the current status of lattice calculations of heavy quark quantities. Particular emphasis is placed on leptonic and semileptonic decay matrix elements.

    • Semileptonic decays B-->pi lepton neutrino and D-->pi lepton neutrion from lattice QCD 

      RYAN, SINEAD MARIE (American Physical Society, 2001)
      We present a lattice QCD calculation of the form factors and differential decay rates for semileptonic decays of the heavy-light mesons B and D to the final state pln . The results are obtained with three methodological ...

    • Lattice QCD calculation of anti-B --> D lepton anti-neutrino decay form-factors at zero recoil 

      RYAN, SINEAD MARIE (2008-10-09)
      A lattice QCD calculation of the B? ?Dl?? decay form factors is presented. We obtain the value of the form factor h+(w) at the zero-recoil limit w=1 with high precision by considering a ratio of correlation functions in ...

    • B and D semileptonic decays to light mesons 

      RYAN, SINEAD MARIE (2008-10-09)
      We present an update of our calculation of the form factors and partial widths of semileptonic heavy-to-light meson decays, in the quenched approximation. Our complete data set has now been analysed and our results include ...

    • Quenched QCD with O(a) improvement: The spectrum of light hadrons 

      RYAN, SINEAD MARIE (American Physical Society, 2000)
      We present a comprehensive study of the masses of pseudoscalar and vector mesons, as well as octet and decuplet baryons computed in O(a)-improved quenched lattice QCD. Results have been obtained using the nonperturbative ...

    • Progress in leptonic and semileptonic decays in lattice QCD 

      RYAN, SINEAD MARIE (American Physical Society, 1999)
      The status of lattice calculations of heavy quark phenomenology is reviewed. Particular emphasis is placed on the understanding and control of the calculational uncertainties. The ensuing implications for constraining ...

    • Lattice determinations of the strange quark mass 

      RYAN, SINEAD MARIE (University of Chicago, 1999)
      The importance of the strange quark mass, as a fundamental parameter of the Standard Model (SM) and as an input to many interesting quantities, has been highlighted in many reviews, eg in Ref . A first principles calculation ...

    • Estimated errors in |Vcd|/|Vcs| from semileptonic D decays 

      RYAN, SINEAD MARIE (Elsevier, 1999)
      We estimate statistical and systematic errors in the extraction of the CKM ratio |Vcd|/|Vcs| from exclusive D-meson semileptonic decays using lattice QCD and anticipated new experimental results.

    • B and D meson decay constants in lattice QCD 

      RYAN, SINEAD MARIE (American Physical Society, 1998)
      We have calculated the decay constants of B and D mesons with lattice QCD. We use an O(a)-improved action that takes light quark actions as a starting point, tuned so that it can be directly applied at the physical masses ...

    • Spectroscopy of Bs and Ds mesons 

      RYAN, SINEAD MARIE (Elsevier, 1998)
      We study Bs and Ds spectroscopy in quenched lattice QCD using the Fermilab approach to heavy quarks. We obtain results at four lattice spacings, a, using O(a)-improved Wilson quarks. We compare and contrast the various ...

    • Effect of tree-level and mean-field improvement on the light-hadron spectrum in quenched QCD 

      RYAN, SINEAD MARIE (American Physical Society, 1997)
      We compute the light-hadron mass spectrum at b55.7 using the O(a)-improved Sheikholeslami-Wohlert fermion action with two choices of the clover coefficient: the classical value c51 and a mean-field or tadpole-improved ...

    • Soft covariant gauges on the lattice 

      RYAN, SINEAD MARIE (2008-10-08)
      We present an exploratory study of a one-parameter family of covariant, nonperturbative lattice gauge-fixing conditions that can be implemented through a simple Monte Carlo algorithm. We demonstrate that at the numerical ...

    • Radial and orbital excitations of static-light mesons 

      Ryan, Sinead; Peardon, Michael (2007)
      We present results for the spectrum of static-light mesons from Nf = 2 lattice QCD. These results were obtained using all-to-all light quark propagators on an anisotropic lattice, yielding an improved signal resolution ...

    • Octahedral and dodecahedral monopoles 

      HOUGHTON, CONOR JAMES (IOP, 1996)
      It is shown that there exists a charge five monopole with octahedral symmetry and a charge seven monopole with icosahedral symmetry. A numerical implementation of the ADHMN construction is used to calculate the energy ...

    • Tetrahedral and cubic monopoles 

      HOUGHTON, CONOR JAMES (Springer Science + Business Media, 1996)
      Using a numerical implementation of the ADHMN construction, we compute the fields and energy densities of a charge three monopole with tetrahedral symmetry and a charge four monopole with octahedral symmetry. We then ...

    • SU(N) monopoles and Platonic symmetry 

      HOUGHTON, CONOR JAMES (American Institute of Physics, 1997)
      We discuss the ADHMN construction for SU(N) monopoles and show that a particular simplification arises in studying charge N?1 monopoles with minimal symmetry breaking. Using this we construct families of tetrahedrally ...