Flavor-spin Symmetry and the Tensor Charge∗
نویسندگان
چکیده
Investigations of the spin composition of the nucleon have led to surprising insights, beginning with the revelation that the majority of its spin is carried by quark and gluonic orbital angular momenta and gluon spin rather than by quark helicity. In addition, considerable effort has gone into understanding, predicting and measuring the transversity distribution, h1(x), of the nucleon. 3 Transversity, as combinations of helicity states, |⊥/⊤ >∼ ( |+ > ±|− > ), for the moving nucleon is a variable introduced originally by Moravcsik and Goldstein to reveal an underlying simplicity in nucleon–nucleon spin dependent scattering amplitudes. In their analysis of the chiral odd distributions, Jaffe and Ji related the first moment of the transversity distribution to the flavor contributions of the nucleon tensor charge:
منابع مشابه
Flavor-spin symmetry estimate of the nucleon tensor charge.
The axial vector and tensor charge, defined as the first moments of the forward nucleon matrix elements of corresponding quark currents, are essential for characterizing the spin structure of the nucleon. There are no definitive theoretical predictions for the tensor charge, aside from several model-dependent calculations. We present a new approach that exploits the approximate mass degeneracy ...
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The flavor singlet axial and tensor charges of the nucleon are calculated in lattice QCD. We find ∆Σ = ∆u+∆d+∆s = +0.638(54)− 0.347(46)− 0.109(30) = +0.18(10) for the axial charge and δΣ = δu+ δd + δs = +0.839(60)− 0.231(55)− 0.046(34) = +0.562(88) for the tensor charge. The result for the axial charge shows reasonable agreement with the experiment and that for the tensor charge is the first pr...
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