다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

https://biblio.ugent.be/publication/685594/file/1130605.pdf

Review of Particle Physics

We discuss the theoretical bases that underpin the automation of the computations of tree-level and next-to-leading order cross sections, of their matching to parton shower simulations, and of the merging of matched samples that differ by light-parton multiplicities. We present a computer program, MadGraph5 aMC@NLO, capable of handling all these computations — parton-level fixed order, shower-matched, merged — in a unified framework whose defining features are flexibility, high level of parallelisation, and human intervention limited to input physics quantities. We demonstrate the potential of the program by presenting selected phenomenological applications relevant to the LHC and to a 1-TeV e + e − collider. While next-to-leading order results are restricted to QCD corrections to SM processes in the first public version, we show that from the user viewpoint no changes have to be expected in the case of corrections due to any given renormalisable Lagrangian, and that the implementation of these are well under way.

/pdf/the-automated-computation-of-tree-level-and-next-to-leading-4etm0g6w46.pdf

The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations

The Pythia program can be used to generate high-energy-physics ''events'', i.e. sets of outgoing particles produced in the interactions between two incoming particles. The objective is to provide as accurate as possible a representation of event properties in a wide range of reactions, within and beyond the Standard Model, with emphasis on those where strong interactions play a role, directly or indirectly, and therefore multihadronic final states are produced. The physics is then not understood well enough to give an exact description; instead the program has to be based on a combination of analytical results and various QCD-based models. This physics input is summarized here, for areas such as hard subprocesses, initial- and final-state parton showers, underlying events and beam remnants, fragmentation and decays, and much more. Furthermore, extensive information is provided on all program elements: subroutines and functions, switches and parameters, and particle and process data. This should allow the user to tailor the generation task to the topics of interest.

/pdf/pythia-6-4-physics-and-manual-3dvwmijpnq.pdf

PYTHIA 6.4 Physics and Manual

Using partially twisted boundary conditions we compute the K->pi semi-leptonic form factors in the range of momentum transfers 0 <~ q^2 <= q^2_{max}=(mK-mpi)^2 in lattice QCD with N_f=2+1 dynamical flavours. In this way we are able to determine f+(0) without any interpolation in the momentum transfer, thus eliminating one source of systematic error. This study confirms our earlier phenomenological ansatz for the strange quark mass dependence of the scalar form factor. We identify and estimate potentially significant NNLO effects in the chiral expansion that guides the extrapolation of the data to the physical point. Our main result is f+(0) = 0.9599(34)(^{+31}_{-43})(14)$, where the first error is statistical, the second error is due to the uncertainties in the chiral extrapolation of the lattice data and the last error is an estimate of potential discretisation effects.

K->pi form factors with reduced model dependence

We present results of a lattice computation of the matrix elements of the vector and axial-vector currents which are relevant for the semileptonic decays D\ensuremath{\rightarrow}K and D\ensuremath{\rightarrow}${\mathit{K}}^{\mathrm{*}}$. The computations are performed in the quenched approximation to lattice QCD on a ${24}^{3}$\ifmmode\times\else\texttimes\fi{}48 lattice at \ensuremath{\beta}=6.2, using an O(a)-improved fermionic action. In the limit of zero lepton masses the semileptonic decays D\ensuremath{\rightarrow}K and D\ensuremath{\rightarrow}${\mathit{K}}^{\mathrm{*}}$ are described by four form factors: ${\mathit{f}}_{\mathit{K}}^{+}$, V, ${\mathit{A}}_{1}$, and ${\mathit{A}}_{2}$, which are functions of ${\mathit{q}}^{2}$, where ${\mathit{q}}^{\mathrm{\ensuremath{\mu}}}$ is the four-momentum transferred in the process. Our results for these form factors at ${\mathit{q}}^{2}$=0 are ${\mathit{f}}_{\mathit{K}}^{+}$(0)=0.${67}_{\mathrm{\ensuremath{-}}8}^{+7}$, V(0)=1.${01}_{\mathrm{\ensuremath{-}}13}^{+30}$, ${\mathit{A}}_{1}$(0)=0.${70}_{\mathrm{\ensuremath{-}}10}^{+7}$, ${\mathit{A}}_{2}$(0)=0.${66}_{\mathrm{\ensuremath{-}}15}^{+10}$, which are consistent with the most recent experimental world average values. We have also determined the ${\mathit{q}}^{2}$ dependence of the form factors, which we find to be reasonably well described by a simple pole-dominance model. Results for other form factors, including those relevant to the decays D\ensuremath{\rightarrow}\ensuremath{\pi} and D\ensuremath{\rightarrow}\ensuremath{\rho}, are also given.

"Improved" lattice study of semileptonic decays of D mesons.

A Hierarchy of Gauge Hierarchies

A lattice study of semileptonic decays of d-mesons

We review the status of the RBC-UKQCD collaborations’ computations of the K L -K S mass difference. After a brief discussion of the theoretical framework which had been developed previously by the collaboration, we describe our latest computation, performed at physical quark masses, and present our preliminary result m KL - m KS = (5.5 ± 1.70) × 10-12 MeV.

/pdf/the-k-l-k-s-mass-difference-5ao39kklzb.pdf

Christopher T. Sachrajda

Papers

K->pi form factors with reduced model dependence

"Improved" lattice study of semileptonic decays of D mesons.

A Hierarchy of Gauge Hierarchies

A lattice study of semileptonic decays of d-mesons

The K L - K S Mass Difference