Relativistic and Binding Energy Corrections To Heavy Quark Fragmentation Functions
Withdrawn; originally put in incomplete form without permission
hep-ph↗
arXiv subjects
P. Hoodbhoy
Publications and source records attributed to P. Hoodbhoy.
Beyond The Colour-Singlet Model For Inelastic J/ψPhotoproduction
Bound-state corrections to $J/ψ$ production from almost real photons are calculated in the colour-singlet model. A systematic, gauge-invariant, theory of hard quarkonium processes is used upto $O(v^2)$, where $v$ is the relative velocity of the quarks. The internal structure of the meson is characterised by two parameters, $ε_B/M$ and $\nabla^2 ϕ(0)/M^2 ϕ(0)$, in addition to the usual wavefunction at the origin $ϕ(0)$. These parameters are constrained to be consistent with measured leptonic decay of the $J/ψ$ and hadronic and radiative decays of $η_c$.
hep-ph↗
The Spin Structure of the Nucleon in the Asymptotic Limit
In analogy to the Altarelli-Parisi equation for the quark and gluon helicity contributions to the nucleon spin, we derive an evolution equation for the quark and gluon orbital angular momenta. The solution of the combined equations yields the asymptotic fractions of the nucleon spin carried by quarks and gluons: $3n_f/(16+3n_f)$ and $16/(16+3n_f)$, respectively, where $n_f$ is the number of active quark flavors. These are identical to the well-known asymptotic partitions of the nucleon momentum between quark and gluon contributions. We show that the axial-anomaly contribution to the quark helicity is cancelled by a similar contribution to the quark orbital angular momentum, making the total quark contribution to the nucleon spin anomaly-free.
hep-ph↗