10 research outputs found
Incoherent diffractive photoproduction of and on heavy nuclei in the color dipole approach
We calculate cross sections and transverse momentum distributions for the
incoherent diffractive production of vector mesons and on
heavy nuclei. In distinction to coherent diffraction, the nucleus is allowed to
break up, but except for the vector meson no new particles are produced in the
reaction. Within the color dipole approach, we derive the multiple scattering
expansion of the incoherent diffractive cross section as an expansion over
quasielastic scatterings of the color dipole. We also compare our results to
the measurement of the ALICE collaboration for incoherent production
at and show predictions at
. We also briefly discuss a possible
contribution to production in peripheral collisions in the centrality class.Comment: 18 pages, 8 fig
Unintegrated gluon distributions from the color dipole cross section in the BGK saturation model
We evaluate the unintegrated gluon distribution of the proton starting from a
parametrization of the color dipole cross section including DGLAP evolution and
saturation effects. To this end, we perform the Fourier-Bessel transform of
. At large transverse momentum of gluons we match the
so-obtained distribution to the logarithmic derivative of the collinear gluon
distribution. We check our approach by calculating the proton structure
function finding good agreement with HERA data.Comment: 4 pages, 3 fig
Diffractive production of electroweak vector bosons at the LHC
We analyse diffractive electroweak vector boson production in hadronic
collisions and show that the single diffractive W boson production asymmetry in
rapidity is a particularly good observable at the LHC to test the concept of
the flavour symmetric pomeron parton distributions. It may also provide an
additional constraint for the parton distribution functions in the proton.Comment: 7 pages, 5 figure
Probing proton structure with correlations in ultraperipheral collisions
We study the exclusive diffractive photoproduction in
ultraperipheral collisions. The formalism makes use of off-diagonal
generalizations of the unintegrated gluon distribution, the so-called
generalized transverse momentum dependent distributions (GTMDs). We present two
different formulations. The first one is based directly on gluon GTMD
parametrizations in momentum space. Another option is the calculation of the
GTMD as a Fourier transform of the dipole-nucleon scattering amplitude
. The latter approach requires some extra
regularization discussed in the paper. Different dipole amplitudes from the
literature are used. Compared to previous calculations in the literature, we
integrate over the full phase space and therefore cross sections for realistic
conditions are obtained. We present distributions in rapidity of or , transverse momentum of the pair, four-momentum transfer squared
as well as the azimuthal correlation between a sum and a difference of the
and transverse momenta. The azimuthal correlations are partially due
to the so-called elliptic gluon Wigner distribution. Different models lead to
different modulations in the azimuthal angle. The modulations are generally
smaller than 5%. They depend on the range of transverse momentum selected for
the calculation.Comment: 22 pages, 14 figures, 1 tabl
Probing proton structure with c c ¯ correlations in ultraperipheral pA collisions
Abstract We study the exclusive diffractive c c ¯ photoproduction in ultraperipheral pA collisions. The formalism makes use of off-diagonal generalizations of the unintegrated gluon distribution, the so-called generalized transverse momentum dependent distributions (GTMDs). We present two different formulations. The first one is based directly on gluon GTMD parametrizations in momentum space. Another option is the calculation of the GTMD as a Fourier transform of the dipole-nucleon scattering amplitude N(Y, r → ⊥, b → ⊥). The latter approach requires some extra regularization discussed in the paper. Different dipole amplitudes from the literature are used. Compared to previous calculations in the literature, we integrate over the full phase space and therefore cross sections for realistic conditions are obtained. We present distributions in rapidity of c or c ¯ , transverse momentum of the c c ¯ pair, four-momentum transfer squared as well as the azimuthal correlation between a sum and a difference of the c and c ¯ transverse momenta. The azimuthal correlations are partially due to the so-called elliptic gluon Wigner distribution. Different models lead to different modulations in the azimuthal angle. The modulations are generally smaller than 5%. They depend on the range of transverse momentum selected for the calculation
Baculovirus expression and potential diagnostic application of the gp51 envelope glycoprotein of genetic mutants of the bovine leukaemia virus
Introduction: Field isolates of bovine leukaemia virus (BLV) show the presence of a few amino acid substitutions in major conformational G and H epitopes on surface glycoprotein gp51. Potentially, these substitutions can affect the 3D structure of these epitopes leading to their diminished immunoreactivity. The aim of this study was to express three gp51 glycoproteins carrying mutated epitopes as recombinant baculovirus proteins in insect cells to test their immunoreactivity with bovine sera