References of "Cudell, Jean-René"
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See detailNew analytic unitarization schemes
Cudell, Jean-René ULg; Predazzi, E.; Selyugin, O. V.

in Physical Review. D : Particles and Fields (2009), 79

We consider two well-known classes of unitarization of Born amplitudes of hadron elastic scattering. The standard class, which saturates at the black disk limit includes the standard eikonal ... [more ▼]

We consider two well-known classes of unitarization of Born amplitudes of hadron elastic scattering. The standard class, which saturates at the black disk limit includes the standard eikonal representation, while the other class, which goes beyond the black-disk limit to reach the full unitarity circle, includes the U matrix. It is shown that the basic properties of these schemes are independent of the functional form used for the unitarisation, and that U matrix and eikonal schemes can be extended to have similar properties. A common form of unitarisation is proposed interpolating between both classes. The correspondence with different nonlinear equations are also briefly examined. [less ▲]

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See detailHow precisely will the total cross section be measured at the LHC?
Cudell, Jean-René ULg; Selyugin, O. V.

in Physical Review Letters (2009), 102

It is very likely that hadronic scattering will enter a new regime at the LHC, as the black-disk limit is reached. This will lead to a severe change in the t dependence of the real part and of the slope ... [more ▼]

It is very likely that hadronic scattering will enter a new regime at the LHC, as the black-disk limit is reached. This will lead to a severe change in the t dependence of the real part and of the slope of the elastic scattering amplitude, and in turn this may bias the measurement of the total cross section. We examine this issue, and suggest new strategies to test the reliability of the total cross section measurements. [less ▲]

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See detailCentral exclusive production of dijets at hadronic colliders
Cudell, Jean-René ULg; Dechambre, Alice ULg; Hernandez, O. F. et al

in European Physical Journal C -- Particles & Fields (2009), 61(3), 369

In view of the recent diffractive dijet data from CDF run II, we critically re-evaluate the standard approach to the calculation of central production of dijets in quasi-elastic hadronic collisions. We ... [more ▼]

In view of the recent diffractive dijet data from CDF run II, we critically re-evaluate the standard approach to the calculation of central production of dijets in quasi-elastic hadronic collisions. We find that the process is dominated by the non-perturbative region, and that even perturbative ingredients, such as the Sudakov form factor, are not under theoretical control. Comparison with data allows us to fix some of the uncertainties. Although we focus on dijets, our arguments apply to other high-mass central systems, such as the Higgs boson. [less ▲]

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See detailFeatures of elastic scattering at small t at the LHC
Selyugin, O. V.; Cudell, Jean-René ULg

in AIP Conference Proceedings (2009), 1105

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See detailExclusive central production of dijets at hadronic colliders
Ivanov, Igor ULg; Cudell, Jean-René ULg; Dechambre, Alice et al

in AIP Conference Proceedings (2009), 1105

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See detailAxions & Polarisation of Quasars
Payez, Alexandre ULg; Cudell, Jean-René ULg; Hutsemekers, Damien ULg

Poster (2008, May 21)

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See detailAxions and polarisation of quasars
Payez, Alexandre ULg; Cudell, Jean-René ULg; Hutsemekers, Damien ULg

in AIP Conference Proceedings (2008), 1038

We present results showing that, thanks to axion-photon mixing in external magnetic fields, it is actually possible to produce an effect similar to the one needed to explain the large-scale coherent ... [more ▼]

We present results showing that, thanks to axion-photon mixing in external magnetic fields, it is actually possible to produce an effect similar to the one needed to explain the large-scale coherent orientations of quasar polarisation vectors in visible light that have been observed in some regions of the sky. [less ▲]

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See detailThe spin-flip amplitude in the impact-parameter representation
Selyugin, O. V.; Cudell, Jean-René ULg

in European Physical Journal. Special Topics (2008)

The impact-parameter representation of the spin-flip amplitude of hadron elastic scattering is examined in different unitarisation schemes, taking the Born term of the spin-flip amplitude from the Dubna ... [more ▼]

The impact-parameter representation of the spin-flip amplitude of hadron elastic scattering is examined in different unitarisation schemes, taking the Born term of the spin-flip amplitude from the Dubna Dynamical Model (DDM). It is shown that the basic properties of the unitarisation schemes are independent of the functional form used for unitarisation but heavily depend on the asymptotic value of the unitarised amplitude. [less ▲]

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See detailCentral Exclusive Dijet Production
Dechambre, Alice ULg; Cudell, Jean-René ULg; Ivanov, Igor ULg et al

in AIP Conference Proceedings (2008), 1038

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See detailUnitarisation and black-disk limit at the LHC in the presence of a hard pomeron
Cudell, Jean-René ULg; Selyugin, Oleg Viktorovich

in Physics Letters B (2008), 662(5), 417-423

Recent models of soft diffraction include a hard pomeron pole besides the usual soft term. Such models violate the black-disk limit around Tevatron energies, so that they need to be supplemented by a ... [more ▼]

Recent models of soft diffraction include a hard pomeron pole besides the usual soft term. Such models violate the black-disk limit around Tevatron energies, so that they need to be supplemented by a unitarisation scheme. Two standard schemes are considered in this Letter, and we show that they lead to an uncertainty at the LHC much larger than previously estimated. We also examine the signature of unitarisation on various small-t observables, the slope in t of the elastic cross section, or the ratio of the real to imaginary parts of the scattering amplitude, and show that the existence of a unitarised hard pomeron in soft scattering may be confirmed by LHC data. (C) 2008 Elsevier B.V. All rights reserved. [less ▲]

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See detailAnalytic properties of different unitarization schemes
Selyugin, O. V.; Cudell, Jean-René ULg; Predazzi, E.

in Eur. Phys. J. ST (2008), 162

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See detailExclusive J/psi and Upsilon hadroproduction and the QCD odderon
Bzdak, A.; Motyka, L.; Szymanowski, L. et al

in Physical Review. D (2007), 75(9),

We study pp and pp collisions which lead to the exclusive production of J/psi or Upsilon from the pomeron-odderon and the pomeron-photon fusion. We calculate scattering amplitudes of these processes in ... [more ▼]

We study pp and pp collisions which lead to the exclusive production of J/psi or Upsilon from the pomeron-odderon and the pomeron-photon fusion. We calculate scattering amplitudes of these processes in the lowest-order approximation and in the framework of k(perpendicular to) factorization. We present estimates of cross sections for the kinematic conditions of the Tevatron and of the LHC. [less ▲]

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See detailA dataset for hadron elastic scattering
Cudell, Jean-René ULg; Lenguel, Sasha; Martynov, E.

Textual, factual or bibliographical database (2007)

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See detailSaturation effects in elastic scattering at the LHC
Selyugin, O. V.; Cudell, Jean-René ULg

in Bartels, J.; Borras, K.; Diehl, M. (Eds.) et al 12th International Conference on Elastic and Diffractive Scattering (Blois Workshop) - Forward Physics and QCD (2007)

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See detailThe soft and the hard pomerons: elastic scattering and unitarisation
Cudell, Jean-René ULg; Lengyel, A.; Martynov, E. et al

in Bartels, J. (Ed.) 12th International Conference On Elastic And Diffractive Scattering: Forward Physics And QCD (2007)

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See detailNew contributions to heavy-quarkonium production
Lansberg, Jean-Philippe ULg; Cudell, Jean-René ULg; Kalinovsky, Y. L.

in Physics Letters B (2006), 633(2-3), 301-308

We reconsider quarkonium production in a field-theoretical setting and we show that the lowest-order mechanism for heavy-quarkonium production receives in general contributions from two different cuts ... [more ▼]

We reconsider quarkonium production in a field-theoretical setting and we show that the lowest-order mechanism for heavy-quarkonium production receives in general contributions from two different cuts. The first one corresponds to the usual colour-singlet mechanism. The second one has not been considered so far. We treat it in a gauge-invariant manner, and introduce new 4-point vertices, suggestive of the colour-octet mechanism. These new objects enable us to go beyond the static approximation. We show that the contribution of the new cut can be as large as the usual colour-singlet mechanism at high P-T for J/psi. In the psi' case, theoretical uncertainties are shown to be large and agreement with data is possible. (c) 2005 Elsevier B.V. All rights reserved. [less ▲]

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See detailSoft and hard Pomerons in hadron elastic scattering at small t
Cudell, Jean-René ULg; Lengyel, A.; Martynov, E.

in Physical Review. D (2006), 73(3),

We consider simple-pole descriptions of soft elastic scattering for pp, (p) over barp, pi(+/-)p and K(+/-)p. We work at t and s small enough for rescatterings to be effectively absorbed in a simple-pole ... [more ▼]

We consider simple-pole descriptions of soft elastic scattering for pp, (p) over barp, pi(+/-)p and K(+/-)p. We work at t and s small enough for rescatterings to be effectively absorbed in a simple-pole parametrization, and allow for the presence of a hard Pomeron. After building and discussing an exhaustive dataset, we show that simple poles provide an excellent description of the data in the region -0.5 GeV2<= t <= -0.1 GeV2, 6 GeV <= root s <= 63 GeV. We show that new form factors have to be used, and get information on the trajectories of the soft and hard Pomerons. [less ▲]

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See detailSoft data and the hard pomeron
Cudell, Jean-René ULg; Lengyel, Alexander; Martynov, E. et al

in Nuclear Physics B-Proceedings Supplements (2006, February), 152

We show that the introduction of an additional, hard, singularity in soft forward amplitudes enables one to improve considerably the fits using a simple-pole structure for the soft pomeron.

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See detailAnalytic properties of unitarization schemes
Selyugin, Oleg Viktorovich; Cudell, Jean-René ULg

in Czechoslovak Journal of Physics (2006)

The analytic properties of the elastic hadron scattering amplitude are examined in the impact parameter representation at high energies. Different unitarization procedures and the corresponding non-linear ... [more ▼]

The analytic properties of the elastic hadron scattering amplitude are examined in the impact parameter representation at high energies. Different unitarization procedures and the corresponding non-linear equations are presented. Several unitarisation schemes are presented. They lead to almost identical results at the LHC. [less ▲]

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