arXiv subjects

Cyrille Marquet

Publications and source records attributed to Cyrille Marquet.

69 records · Page 4Linked to original sources

arXiv2008

Azimuthal correlations of forward dijets in d+Au collisions at RHIC

Measuring correlations between forward dijets in deuteron-gold collisions at RHIC will further test the Color Glass Condensate (CGC) picture of the nuclear wavefunction at small-x, which successfully predicted the suppressed production of high-p_T particles at forward rapidities in d+Au collisions: R_dA<1. I present predictions for the correlation in azimuthal angle between forward dijets in the CGC framework, with both multiple scatterings and non-linear QCD evolution at small-x taken into account.

hep-ph↗

arXiv2007

Testing BFKL evolution with Mueller-Navelet jets

We study the correlation in azimuthal angle between Mueller-Navelet jets produced in hadron-hadron collisions. We argue that this observable would test the BFKL approach at next-to-leading logarithmic accuracy. In order to motivate such a measurement, we give predictions for jets separated by large rapidity intervals within the Tevatron and LHC ranges.

hep-ph↗

arXiv2007

Forward inclusive dijet production and azimuthal correlations in pA collisions

We derive forward inclusive dijet production in the scattering of a dilute hadron off an arbitrary dense target, whose partons with small fraction of momentum x are described by a Color Glass Condensate. Both multiple scattering and non-linear QCD evolution at small-x are included. This is of relevance for measurements of two-particle correlations in the proton direction of proton-nucleus collisions at RHIC and LHC energies. The azimuthal angle distribution is peaked back to back and broadens as the momenta of the measured particles gets closer to the saturation scale.

hep-ph↗

arXiv2007

A unified description of diffractive deep inelastic scattering with saturation

We propose a new description of inclusive diffraction in deep inelastic scattering (DIS). The diffractive structure functions are expressed in the dipole picture and contain heavy-quark contributions. The dipole scattering amplitude, a saturation model fitted on inclusive DIS data, features a saturation scale Q_s(x) larger than 1 GeV for x=10^{-5}. The q\bar{q}g contribution to the diffractive final state is modeled in such a way that both the large-Q^2 and small-beta limits are implemented. In the regime xpom<0.01 in which saturation is expected to be relevant, we obtain a parameter-free description of the HERA data with chi^2/points=1.2.

hep-ph↗

arXiv2007

Non-forward Balitsky-Kovchegov equation and Vector Mesons

Considering the Balitsky-Kovchegov QCD evolution equation in full momentum space, we derive the travelling wave solutions expressing the nonlinear saturation constraints on the dipole scattering amplitude at non-zero momentum transfer. A phenomenological application to elastic vector meson production shows the compatibility of data with the QCD prediction: an enhanced saturation scale at intermediate momentum transfer.

hep-ph↗

arXiv2007

Hard diffraction and the Color Glass Condensate

Following the Good-and-Walker picture, hard diffraction in the high-energy/small-x limit of QCD can be described in terms of eigenstates of the scattering matrix off a Color Glass Condensate. From the CGC non-linear evolution equations, it is then possible to derive the behavior of diffractive cross-sections at small $x.$ I discuss recent results, in particular the consequences of the inclusion of Pomeron loops in the evolution.

hep-ph↗

arXiv2006

Mini review on saturation and recent developments

I discuss the saturation regime of QCD: the weak-coupling regime that describes large parton densities inside hadrons and the resulting high-energy behavior of scattering amplitudes. I briefly review past successes in the context of deep inelastic scattering at HERA and forward particle production at RHIC, and I present some recent progresses that significantly improved our understanding of high-energy scattering in QCD.

hep-ph↗

arXiv2006

Inclusive and diffractive deep inelastic scattering in high-energy QCD

In the context of both inclusive and diffractive deep inelastic scattering, we derive the first phenomenological consequences of the inclusion of Pomeron loops in the QCD evolution equations towards high energy. We discuss the transition between the well-known geometric scaling regime and the new diffusive scaling, that emerges for sufficiently high energies and up to very large values of Q^2, well above the proton saturation momentum.

hep-ph↗

arXiv2006

The high-energy limit of inclusive and diffractive deep inelastic scattering in QCD

Following recent progresses in the understanding of high-energy scattering in QCD, we derive the first phenomenological consequences of Pomeron loops, in the context of both inclusive and diffractive deep inelastic scattering. In particular, we discuss diffusive scaling, a new scaling law that emerges for sufficiently high energies and up to very large values of $Q^2,$ well above the proton saturation momentum.

hep-ph↗

arXiv2005

Particle production and saturation at HERA

Perturbative QCD in the high-energy limit describes the evolution of scattering amplitudes with increasing energy towards and into the so-called saturation regime. Comparisons of the predictions with experimental data for a number of observables led to significant progress and understanding. We discuss the case of particle-production cross-sections measured at HERA and argue that these measurements have the potential to provide evidence for the saturation regime of QCD.

hep-ph↗

arXiv2005

Small-x effects in forward-jet production at HERA

We investigate small-x effects in forward-jet production at HERA in the two-hard-scale region kT ~ Q>>Lambda_QCD. We show that, despite describing different energy regimes, both a BFKL parametrization and saturation parametrizations describe well the H1 and ZEUS data for dsigma/dx published a few years ago. This is confirmed when comparing the predictions to the latest data.

hep-ph↗

arXiv2005

Gluon production and diffraction in the dipole picture

Using the eikonal approximation, we show that inclusive gluon production is related to the scattering of a gluon-gluon dipole while diffractive gluon production in DIS is related to a two-$q\bar q$ dipole scattering amplitude. Hence diffractive photon dissociation cross-sections are observables that provide potential information on dipole correlations, which represent an open issue in high-energy QCD.

hep-ph↗

arXiv2004

A QCD dipole formalism for forward-gluon production

We derive inclusive and diffractive forward-gluon production in the scattering of a $q\bar{q}$ dipole off an arbitrary target in the high-energy eikonal approximation, suitable to study the saturation regime. We show how the inclusive cross-section is related to the total cross-section for the scattering of a colorless pair of gluons on the target: the gluon-production cross-section can be expressed as a convolution between this $gg$ dipole total cross-section and a dipole distribution. We then consider as an application the forward-jet production from an incident hadron and describe forward-jet production at HERA and Mueller-Navelet jets at Tevatron or LHC. We show how these measurements are related to the $q\bar{q}-gg$ or $gg-gg$ dipole-dipole cross-sections and why they are therefore well-suited for studying high-energy scattering in QCD.

hep-ph↗

arXiv2004

Saturation in two-hard-scale processes at hadron colliders

A study of saturation effects in two-hard-scale hadronic processes such as Mueller-Navelet jets is presented. The cross-sections are expressed in the dipole framework while saturation is implemented via an extention of the Golec-Biernat and Wusthoff model. The transition to saturation is found to be more abrupt than in gamma*-gamma* cross-sections. Observables with a potentially clear saturation signal are proposed.

hep-ph↗

arXiv2002

Phonon-phonon interactions due to non-linear effects in a linear ion trap

We examine in detail the theory of the intrinsic non-linearities in the dynamics of trapped ions due to the Coulomb interaction. In particular the possibility of mode-mode coupling, which can be a source of decoherence in trapped ion quantum computation, or, alternatively, can be exploited for parametric down-conversion of phonons, is discussed and conditions under which such coupling is possible are derived.

quant-ph↗