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More than 99% of the mass of the visible universe is made up of protons and neutrons. Both particles are much heavier than their quark and gluon constituents, and the Standard Model of particle physics should explain this difference. We present a full ab initio calculation of the masses of protons, neutrons, and other light hadrons, using lattice quantum(More)
The existence and stability of atoms rely on the fact that neutrons are more massive than protons. The measured mass difference is only 0.14% of the average of the two masses. A slightly smaller or larger value would have led to a dramatically different universe. Here, we show that this difference results from the competition between electromagnetic and(More)
In a previous Letter [Borsanyi et al., Phys. Rev. Lett. 111, 252001 (2013)] we determined the isospin mass splittings of the baryon octet from a lattice calculation based on N_{f}=2+1 QCD simulations to which QED effects have been added in a partially quenched setup. Using the same data we determine here the corrections to Dashen's theorem and the(More)
We describe an atmospheric pressure nanosampling interface for mass spectrometry based on near-field laser ablation. Pulsed laser radiation is delivered to the sample surface through a near-field optical probe, and the ablation plume is sampled through a capillary orifice and analyzed by standard MS methods. A spatial resolution of less than 200 nm and a(More)
We investigate the performance gains from hyper-systolic implementations of n 2-loop problems on the massively parallel computer Quadrics, exploiting its 3-dimensional interprocessor connectivity. For illustration we study the communication aspects of an exact molecular dynamics simulation of n particles with Coulomb (or gravitational) interactions. We(More)
We present the final analysis of the light and strange hadron spectra from a full QCD lattice simulation with two degenerate dynamical sea quark flavours at β = 5.6 on a 16 3 × 32 lattice. Four sets of sea quark masses corresponding to the range .69 ≤ m π /m ρ ≤ .83 are investigated. For reference we also ran a quenched simulation at β eff = 6.0, which is(More)
  • U Gll Assner, S G Usken, +5 authors G Siegert
  • 1995
First results of a recently started simulation of full QCD with two avours of sea-quarks at a coupling of = 5:6 on a 16 3 32 lattice are presented. Emphasis is laid on the statistical signiicance that can be achieved by an \integrated luminosity" of 140 TFlophrs, for Hybrid Monte Carlo simulations at four intermediate values of m m. The simulation takes(More)
Results from two studies of full QCD with two flavours of dynamical Wilson fermions are presented. At β = 5.6, the region 0.83 > mπ mρ > 0.56 at mπa > (0.23L) −1 is explored. The SESAM collaboration has generated ensembles of about 200 statistically independent configurations on a 16 3 × 32-lattice at three different κ-values and is entering the final phase(More)