1,397 research outputs found
Target Mass Corrections to Electro-Weak Structure Functions and Perturbative Neutrino Cross Sections
We provide a complete and consistent framework to include subasymptotic
perturbative as well as mass corrections to the leading twist (tau=2)
evaluation of charged and neutral current weak structure functions and the
perturbative neutrino cross sections. We revisit previous calculations in a
modern language and fill in the gaps that we find missing for a complete and
ready-to-use "NLO xi-scaling" formulary. In particular, as a new result we
formulate the mixing of the partonic and hadronic structure function tensor
basis in the operator approach to deep inelastic scattering. As an underlying
framework we follow the operator product expansion a la Georgi & Politzer that
allows the inclusion of target mass corrections at arbitrary order in QCD and
we provide explicit analytical and numerical results at NLO. We compare this
approach with a simpler collinear parton model approach to xi-scaling. Along
with target mass corrections we include heavy quark mass effects as a
calculable leading twist power suppressed correction. The complete corrections
have been implemented into a Monte Carlo integration program to evaluate
structure functions and/or integrated cross sections. As applications, we
compare the operator approach with the collinear approximation numerically and
we investigate the NLO and mass corrections to observables that are related to
the extraction of the weak mixing angle from a Paschos-Wolfenstein-like
relation in neutrino-iron scattering. We expect that the interpretation of
neutrino scattering events in terms of oscillation physics and electroweak
precision physics will benefit from our results.Comment: 26 pages, 5 figures, note added, to appear in PR
Heavy Quark Parton Distribution Functions
We present the CTEQ6HQ parton distribution set which is determined in the
general variable flavor number scheme which incorporates heavy flavor mass
effects; hence, this set provides advantages for precision observables which
are sensitive to charm and bottom quark masses. We describe the analysis
procedure, examine the predominant features of the new distributions, and
compare with previous distributions. We also examine the uncertainties of the
strange quark distribution and how the the recent NuTeV dimuon data constrains
this quantity.Comment: 5 pages, 2 figures; contribution to the XIII International Workshop
on Deep Inelastic Scattering (DIS 2005
On Kaon production in e+e- and Semi-inclusive DIS reactions
We consider semi-inclusive unpolarized DIS for the production of charged
kaons and the different possibilities to test the conventionally used
assumptions s-\bar=0 and D_d^{K^+-K^-}=0. The considered tests have the
advantage that they do not require any knowledge of the fragmentation
functions. We also show that measurements of both charged and neutral kaons
would allow the determination of the kaon FFs D_q^{K^++K^-} solely from SIDIS
measurements, and discuss the comparison of (D_u-D_d)^{K^+-K^-} obtained
independently in SIDIS and e+e- reactions. All analysis are performed in LO and
NLO in QCD. The feasibility of the tests to HERMES SIDIS data is considered.Comment: 7 pages, NLO analysis for all presented tests and feasibility to
HERMES data adde
Fragmentation functions of mesons in the Field-Feynman model
The fragmentation functions of the pion with distinction between
, , and are studied in the
Field-Feynman recursive model, by taking into account the flavor structure in
the excitation of quark-antiquark pairs by the initial quarks. The obtained
analytical results are compatible with available empirical results. The
framework is also extended to predict the fragmentation functions of the kaon
with distinction between , ,
, and . This work gives a significant
modification of the original model, and the predictions can be tested by future
experiments on the fragmentation functions of the kaon.Comment: 6 Latex pages, 10 figures, to appear in EPJ
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