Achim Geiser
(DESY)
25/04/2013, 08:30
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
Measurements of open charm production cross sections in deep-inelastic ep scattering at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross sections sigma_red^{c\bar{c}} for charm production are obtained in the kinematic range of photon virtuality 2.5<Q2<2000 GeV2 and Bjorken scaling variable 0.00003<x<0.05. The combination method accounts for the correlations of the...
Sergey Alekhin
25/04/2013, 08:55
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We present a determination of the running charm-quark mass in the MSbar scheme in framework of global analyses of the proton structure using recent HERA data of charm production cross section measurements. A crucial prerequisite for this task are QCD precision predictions to higher orders which require the choice of a scheme for the description of heavy-quark production in deep-inelastic...
Dr
Aleksander Kusina
(Southern Methodist University)
25/04/2013, 09:20
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We analyze the impact of heavy flavors treatment in parton distribution
functions (PDFs) on measurable quantities like DIS structure functions.
We compare predictions obtained using ACOT scheme PDFs with different
number of active flavors and results of fix-flavor-number scheme.
We propose a correction factor that can be applied to calculations
carried in the fix-flavor-number scheme but...
Oleksandr Zenaiev
25/04/2013, 09:45
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
Charm production in deep inelastic ep scattering was measured with the ZEUS detector using an integrated luminosity of 354 pb-1.
Charm quarks were identified by reconstructing D+ mesons in the D+ --> K- pi+ pi+ decay channel. Lifetime information was used to reduce combinatorial background substantially. Differential cross sections were measured in the kinematic region 5<Q2<1000 GeV2,...
Olena Bachynska
(Deutsches Elektronen-Synchrotron (DESY)), Dr
Olena Bachynska
(DESY)
25/04/2013, 10:05
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
Charm production has been measured with the ZEUS detector
in deep inelastic ep scattering at HERA.
The measurement is based on the full reconstruction of the decay chain
D*->D0pis, D0->Kpi and exploits the full HERA II statistics.
Differential cross sections have been measured.
The kinematic range is 1.5 GeV < pT(D*) < 10GeV, |eta(D*)| < 1.5,
5 < Q2 < 1000GeV2 and 0.02 < y <...
Johannes Bluemlein
(DESY)
25/04/2013, 11:00
Heavy Flavours
Talk in Parallel Session at DIS2013
New results on the 3-loop heavy flavor corrections to DIS are reported.
They concern the case of graphs with 2 massive lines, both of equal and
unequal masses (m_c and m_b), and an extension in the renormalization.
Furthermore, we present results for massive ladder, V-graph and Benz-topologies, as well as new classes of mathematical functions needed in the analytic description of these results.
Dr
Marco Guzzi
(Desy Hamburg)
25/04/2013, 11:25
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
We determine the mass of the charm quark and study its effect
in the next-to-next-to-leading order ${\cal O}(\alpha_s^2)$
CTEQ global analysis of parton distribution functions (PDFs) of the proton. Fits are based on the general-mass variable flavor number scheme S-ACOT-$\chi$ for the treatment of heavy-quark contributions and include the recently published measurements of open charm...
Tzvetalina Stavreva
(LPSC)
25/04/2013, 11:50
Structure functions and Parton Densities
Talk in Parallel Session at DIS2013
The associated production of a direct photon with a heavy quark provides us with the opportunity to test for and constrain the presence of intrinsic charm and bottom in the nucleon. We present comparisons of the theoretical predictions for this process with the initial measurements from D0 and CDF, as well as with the recently updated D0 measurements. Future predictions and possibilities for...
