30,599 research outputs found
Non-perturbative Renormalisation with Domain Wall Fermions
We present results from a study of the renormalisation of both quark bilinear
and four-quark operators for the domain wall fermion action, using the
non-perturbative renormalisation technique of the Rome-Southampton group. These
results are from a quenched simulation, on a 16^3 x 32 lattice, with beta=6.0
and L_s=16.Comment: 4 pages, 6 figures, Lattice 2000 (Improvement and Renormalisation),
RBC collaboration, Typos correcte
Non-Perturbative Renormalisation using Domain Wall Fermions
The viability of the Non-Perturbative Renormalisation (NPR) method of the
Rome/Southampton group is studied, for the first time, in the context of domain
wall fermions. The procedure is used to extract the renormalisation
coefficients of the various quark bilinears, as well as the four-fermion
operators relevant to the effective Hamiltonian. The
renormalisation of the Hamiltonian is also discussed.Comment: LATTICE99(Improvement and Renormalization),3 pages, LaTeX2e; minor
typos correcte
Chiral Corrections to the Hyperon Vector Form Factors
We present the complete calculation of the SU(3)-breaking corrections to the
hyperon vector form factors up to O(p^4) in the Heavy Baryon Chiral
Perturbation Theory. Because of the Ademollo-Gatto theorem, at this order the
results do not depend on unknown low energy constants and allow to test the
convergence of the chiral expansion. We complete and correct previous
calculations and find that O(p^3) and O(1/M_0) corrections are important. We
also study the inclusion of the decuplet degrees of freedom, showing that in
this case the perturbative expansion is jeopardized. These results raise doubts
on the reliability of the chiral expansion for hyperons.Comment: 20 pages, 4 figures, v2: published versio
A universal quantum circuit for two-qubit transformations with three CNOT gates
We consider the implementation of two-qubit unitary transformations by means
of CNOT gates and single-qubit unitary gates. We show, by means of an explicit
quantum circuit, that together with local gates three CNOT gates are necessary
and sufficient in order to implement an arbitrary unitary transformation of two
qubits. We also identify the subset of two-qubit gates that can be performed
with only two CNOT gates.Comment: 3 pages, 7 figures. One theorem, one author and references added.
Change of notational conventions. Minor correction in Theorem
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