Title of article :
Pure QCD bounds and estimates for light quark masses Original Research Article
Author/Authors :
F.J. Yndur?in، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 1998
Pages :
15
From page :
324
To page :
338
Abstract :
We consider bounds on light quark masses that follow from positivity of the pseudoscalar correlator spectral function plus the assumption that perturbative QCD is valid for the correlator and its derivatives up to order N for momenta t ⩾ t̂. We find that the bounds vary a lot depending on the assumed value of t̂ and even, if it is too small (t̂ ∼- 1.5, 1.6, 2.1 GeV2 for respectively N = 0, 1, 2), that there is incompatibility between the asumption of validity of perturbative QCD and positivity. This allows us to establish a criterion for the values of t̂ admissible, and to get upper and lower bounds for m., and upper bounds for md + mu, md − mu. The upper bounds are not particularly interesting, but the lower ones are very tight; specifically we find 240 MeV ⩽ ms; 16 MeV ⩽ md + mu if we assume perturbative QCD to give a valid description of the correlator for t ⩾ 2.2 GeV2; or, if it only holds for t ⩾ 4.5 GeV2, then 150 MeV ⩽ ms; 10 MeV ⩽ md + mu. Here the masses are running masses defined at l GeV. We also show reasonable models where the bounds are saturated. The results suggest that some of the current estimates of the light quark masses are less precise than usually claimed, which is the main outcome of this work.
Journal title :
Nuclear Physics B
Serial Year :
1998
Journal title :
Nuclear Physics B
Record number :
880658
Link To Document :
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