402 research outputs found
Studying the neutron orbital structure by coherent hard exclusive processes off 3He
Hard exclusive processes, such as Deeply Virtual Compton Scattering (DVCS),
allow to access generalized parton distributions (GPDs). By means of an Impulse
Approximation (IA) calculation, it is shown here how, in the low momentum
transfer region, the sum of the GPDs H and E is dominated by the neutron
contribution. Thanks to this property, 3He could open a new way to access the
neutron structure information. In this work, a simple and efficient extraction
procedure of the neutron GPDs, able to take into account the nuclear effects
included in IA analysis, is proposed.Comment: 4 pages, 3 figures; talk presented by Matteo Rinaldi at 3rd Workshop
On The QCD Structure Of The Nucleon (QCD-N'12), 22-26 Oct 2012, Bilbao, Spai
Parton correlations in same-sign pair production via double parton scattering at the LHC
Same-sign boson pairs production is a promising channel to look for
signatures of double parton interactions at the LHC. The corresponding cross
section has been calculated by using double parton distribution functions,
encoding two parton correlations, evaluated in a Light-Front quark model. The
obtained result is in line with previous estimates which make use of an
external parameter, the so called effective cross section, not necessary in our
approach. The possibility to observe for the first time two-parton
correlations, in the next LHC runs, has been established.Comment: 5 pages, 3 figures, 3 table
Double parton correlations in Light-Front constituent quark model
Double parton distribution functions (dPDF) represent a tool to explore the
3D proton structure. They can be measured in high energy proton-proton and
proton nucleus collisions and encode information on how partons inside a proton
are correlated among each other. dPFDs are studied here in the valence quark
region, by means of a constituent quark model, where two particle correlations
are present without any additional prescription. This framework allows to
understand the dynamical origin of the correlations and to clarify which, among
the features of the results, are model independent. Use will be made of a
relativistic light-front scheme, able to overcome some drawbacks of the
previous calculation. Transverse momentum correlations, due to the exact
treatment of the boosts, are predicted and analyzed. The role of spin
correlations is also shown. Due to the covariance of the approach, some
symmetries of the dPDFs are seen unambigously. For the valence sector, the
study of the QCD evolution of the model results, which can be performed safely
thanks to the property of good support, has been also completed.Comment: 8 pages, 12 figures, invited talk at the "XLIV ISMD Conference",
Bologna, Italy, 8-12 September 2014. Submitted to EPJ Web of Conference
A model calculation of double parton distribution functions of the pion
Two-parton correlations in the pion are investigated in terms of double
parton distribution functions. A Poincar\'e covariant Light-Front framework has
been adopted. As non perturbative input, the pion wave function obtained within
the so-called soft-wall AdS/QCD model has been used. Results show how novel
dynamical information on the structure of the pion, not accessible through
one-body parton distribution, are encoded in double parton distribution
functions.Comment: 14 pages, 8 figure
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