Publications (29)
Lattice QCD Applications on QPACE
Y. Nakamura, A. Nobile, D. Pleiter +4
QPACE is a novel massively parallel architecture optimized for lattice QCD simulations. A single QPACE node is based on the IBM PowerXCell 8i processor. The nodes are interconnecte…
Branching ratio and direct CP-violating rate asymmetry of the rare decays and
C. Greub, H. Simma, D. Wyler
We calculate CP-violating rate asymmetries in the rare radiative decays and . They arise because of the interference b…
Progress and status of APEmille
APE collaboration, A. Bartoloni, S. Cabasino +19
We report on the progress and status of the APEmille project: a SIMD parallel computer with a peak performance in the TeraFlops range which is now in an advanced development phase.…
Status of the QPACE Project
H. Baier, H. Boettiger, M. Drochner +27
We give an overview of the QPACE project, which is pursuing the development of a massively parallel, scalable supercomputer for LQCD. The machine is a three-dimensional torus of id…
Status of APEmille
APE-Collaboration, :, A. Bartoloni +31
This paper presents the status of the APEmille project, which is essentially completed, as far as machine development and construction is concerned. Several large installations of…
A new simulation algorithm for lattice QCD with dynamical quarks
B. Bunk, K. Jansen, B. Jegerlehner +3
A previously introduced multi-boson technique for the simulation of QCD with dynamical quarks is described and some results of first test runs on a lattice with Wilso…
Topological structure of the SU(3) vacuum and exceptional eigenmodes of the improved Wilson-Dirac operator
D. Smith, H. Simma, M. Teper
We present a study of the instanton size and spatial distributions in pure SU(3) gauge theory using under-relaxed cooling. We also investigate the low-lying eigenmodes of the (impr…
Exclusive Radiative B-Decays in the Light-Cone QCD Sum Rule Approach
A. Ali, V. M. Braun, H. Simma
We carry out a detailed study of exclusive radiative rare -decays in the framework of the QCD sum rules on the light cone, which combines the traditional QCD sum rule technique…
QCD on the Cell Broadband Engine
F. Belletti, G. Bilardi, M. Drochner +16
We evaluate IBM's Enhanced Cell Broadband Engine (BE) as a possible building block of a new generation of lattice QCD machines. The Enhanced Cell BE will provide full support of do…
Decay constants of B-mesons from non-perturbative HQET with two light dynamical quarks
F. Bernardoni, B. Blossier, J. Bulava +8
We present a computation of B-meson decay constants from lattice QCD simulations within the framework of Heavy Quark Effective Theory for the b-quark. The next-to-leading order cor…
CP Violation and Strong Phases from Penguins in and Decays
G. Kramer, W. F. Palmer, H. Simma
We calculate direct CP-violating rate asymmetries in charged and decays arising from the interference of amplitudes with different strong and CKM phases. The pe…
Preparing for N_f=2 simulations at small lattice spacings
M. Della Morte, P. Fritzsch, B. Leder +6
We discuss some large effects of dynamical fermions. One is a cutoff effect, others concern the contribution of multi-pion states to correlation functions and are expected to survi…
QPACE -- a QCD parallel computer based on Cell processors
H. Baier, H. Boettiger, M. Drochner +32
QPACE is a novel parallel computer which has been developed to be primarily used for lattice QCD simulations. The compute power is provided by the IBM PowerXCell 8i processor, an e…
Extraction of the bare form factors for the semi-leptonic decays
F. Bahr, D. Banerjee, M. Koren +2
The computation of the form factors for the decay is presented. The b quark is treated by means of Heavy Quark Effective Theory, currently in the static approxi…
Equations of Motion for Effective Lagrangians and Penguins in Rare B-Decays
H. Simma
We study the application of the classical equations of motion (EOM) within the framework of an effective low-energy Lagrangian treated at the loop level. Gauge-fixing and ghost ter…
The b-quark mass from non-perturbative Heavy Quark Effective Theory at
F. Bernardoni, B. Blossier, J. Bulava +8
We report our final estimate of the b-quark mass from lattice QCD simulations using Heavy Quark Effective Theory non-perturbatively matched to QCD at . Treating s…
apeNEXT: A multi-TFlops Computer for Simulations in Lattice Gauge Theory
F. Bodin, Ph. Boucaud, N. Cabibbo +19
We present the APE (Array Processor Experiment) project for the development of dedicated parallel computers for numerical simulations in lattice gauge theories. While APEmille is a…
CP Violation and Strong Phases from Penguins in Decays
G. Kramer, W. F. Palmer, H. Simma
We calculate direct CP-violating observables in charged decays arising from the interference of amplitudes with different strong and CKM phases. The perturbative strong p…
Low-Lying Eigenvalues of the Wilson-Dirac Operator
K. Jansen, C. Liu, H. Simma +1
An exploratory study of the low-lying eigenvalues of the Wilson-Dirac operator and their corresonding eigenvectors is presented. Results for the eigenvalues from quenched and unque…
B-physics with Wilson fermions
F. Bernardoni, B. Blossier, J. Bulava +8
We report the final results of the ALPHA collaboration for some B-physics observables: , and . We employ CLS configurations with 2 flavors of improved Wi…
The -parameter in 3-flavour QCD and by the ALPHA collaboration
M. Bruno, M. Dalla Brida, P. Fritzsch +6
We present results by the ALPHA collaboration for the -parameter in 3-flavour QCD and the strong coupling constant at the electroweak scale, , in terms of hadronic q…
Quenched -parameter from Osterwalder-Seiler tmQCD quarks and mass-splitting discretization effects
P. Dimopoulos, H. Simma, A. Vladikas
We apply an Osterwalder-Seiler version of twisted mass QCD to a study of the parameter, in which three of the four quark fields making up the relevant operator are m…
Status of the apeNEXT project
R. Ammendola, F. Bodin, Ph. Boucaud +27
We present the current status of the apeNEXT project. Aim of this project is the development of the next generation of APE machines which will provide multi-teraflop computing powe…
B-physics from HQET in two-flavour lattice QCD
F. Bernardoni, B. Blossier, J. Bulava +8
We present our analysis of B physics quantities using non-perturbatively matched Heavy Quark Effective Theory (HQET) in Nf= 2 lattice QCD on the CLS ensembles. Using all-to-all pro…
determination in lattice QCD
F. Bahr, F. Bernardoni, B. Blossier +10
The 2012 PDG reports a tension at the level of between two exclusive determinations of . They are obtained by combining the experimental branching ratios of $B \to…
The apeNEXT project (Status report)
F. Bodin, Ph. Boucaud, J. Micheli +18
We present the current status of the apeNEXT project. Aim of this project is the development of the next generation of APE machines which will provide multi-teraflop computing powe…
The APENEXT project
F. Bodin, P. Boucaud, N. Cabibbo +31
APENEXT is a new generation APE processor, optimized for LGT simulations. The project follows the basic ideas of previous APE machines and develops simple and cheap parallel system…
Quenched QCD with O(a) improvement: I. The spectrum of light hadrons
UKQCD Collaboration, K. C. Bowler, P. Boyle +9
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…
The strong coupling from a nonperturbative determination of the parameter in three-flavor QCD
M. Bruno, M. Dalla Brida, P. Fritzsch +6
We present a lattice determination of the parameter in three-flavor QCD and the strong coupling at the Z pole mass. Computing the nonperturbative running of the coupling in th…