A new implementation of the general PQCD formalism of Collins, including heavy quark mass effects, is described. Important features that contribute to the accuracy and efficiency of the calculation of both neutral current (NC) and charged current (CC) processess are explicitly discussed. This new implementation is applied to the global analysis of the full HERA I data sets on NC and CC cross se...

The forward-backward asymmetry is an important measurable quantity which can enable independent determination of the neutral-current couplings fermions. In this paper, we extend definition from partonic level to hadronic by calculating hadron pair in semi-inclusive electron position annihilation process. Semi-inclusive implies that a back-to-back jet also measured addition pair. Due limitation ...

Current cone jet algorithms, widely used at hadron colliders, take event particles as seeds in an iterative search for stable cones. A longstanding infrared (IR) unsafety issue in such algorithms is often assumed to be solvable by adding extra ‘midpoint’ seeds, but actually is just postponed to one order higher in the coupling. A proper solution is to switch to an exact seedless cone algorithm,...

Hadronic matrix elements of twoand threecurrent correlators encode detailed information on hadron structure such as quark spatial distributions, charge radii and quadrupole moments. In the non-relativistic limit they reduce to the square of the wave function and therefore the shape of the hadron can be extracted. The issue of a deformation in the nucleon and ∆ was first examined in the context ...

We report our light hadron mass calculation in quenched lattice quantum chromodynamics (QCD) with an increased statistics of two hundred gauge configurations. Our lattice size is 48 × 64 and the inverse-squared coupling is β = 6.5. Staggered quark wall sources of quark mass mqa = 0.01, 0.005, 0.0025 and 0.00125 and point sink are used. These parameters roughly correspond to a physical box of (2...