TY - JOUR
T1 - Testing QCD
AU - Farrar, Glennys R.
N1 - Funding Information:
Last year Darrell Jackson and I used QCD in a naive but plausible way to obtain \[1 \] the prediction that the helicity of a quark which carries nearly all of the momentum ofa hadron (x ~ 1) must be the same as the helicity of the hadron itself, which in turn led to the prediction that as x ~ 1 the ratio (u/d) of up to down quarks must approach 5. This is an exciting resuit, if valid, since it is so distinctive: the other possibilities which have been suggested are u/d ~ 2 (exact SU(2)) and u/d ~ 1/(1 -x) -~ o~ \[2\]( corresponding to the pair of "valence" quarks which are at small x being in an isospin singlet state). The validity of such a distinctive prediction deserves to be carefully analyzed, * Work supported in part by the U.S. Energy Research and Development Administration under Contract E-(11-1)-68. 4:1 Furthermore, even if the latter possibility were ruled out by precision experiments at large Q2 and x, it would be very difficult to distinguish the logarithmic Q2 dependence of moments required by asymptotic freedom from the fractional, power dependence on Q2 of a fixed point theory.
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1977/10/10
Y1 - 1977/10/10
N2 - QCD is used to predict that the ratio of up to down quarks → 5 as x → 1 and the rigor of the proof and the underlying assumptions are discussed. Measuring σ v ̄P σvP as x → 1 gives the best experimental test of this prediction.
AB - QCD is used to predict that the ratio of up to down quarks → 5 as x → 1 and the rigor of the proof and the underlying assumptions are discussed. Measuring σ v ̄P σvP as x → 1 gives the best experimental test of this prediction.
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U2 - 10.1016/0370-2693(77)90674-8
DO - 10.1016/0370-2693(77)90674-8
M3 - Article
AN - SCOPUS:0001527383
SN - 0370-2693
VL - 70
SP - 346
EP - 348
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
IS - 3