I will briefly overview the current status of phenomenological research in exclusive and diffractive photoproduction of excited vector mesons. The talk would cover the formalism and the key results on photo- and electroproduction observables of both heavy quarkonia states and light vector mesons in the color dipole picture. The key challenges in QCD modelling of such reactions including the...
We discuss production of forward charm/anticharm quarks,
$D$ mesons and neutrinos/antineutrinos from their semileptonic decays
in proton-proton collisions at the LHC energies.
The calculation is preformed within $k_t$-factorization
and hybrid model using different unintegrated gluon distribution
functions (UGDFs) from the literature.
We include gluon-gluon fusion, intrinsic charm (IC)...
In this talk I will present analysis of J/ฯ yield and polarization in high multiplicity hadron collisions using the CGC+NRQCD framework. Some predictions for pp and pA collisions at LHC energies will be presented.
We investigate improvements on models of dipole cross-section, one of which was originally proposed by Golec-Biernat and W\"usthoff (GBW), and the other is a DGLAP improved model proposed by Bartels, Golec-Biernar and Kowalski (BGK), which has improved small dipole behaviour.
Both models have been very successful in describing saturation phenomenon in small $x$ DIS.
In this study, we...
There has been much recent progress towards extending the BFKL equation to next-to-next-to-leading logarithmic (NNLL) accuracy. One of the remaining ingredients of the BFKL kernel is the one-loop central-emission vertex (CEV) for two gluons which are not strongly ordered in rapidity. In this talk I will discuss our recent extraction of this vertex in N=4 super Yang-Mills (SYM) theory, which is...
Heavy-flavored emissions have been always considered as an excellent channel to test properties of Quantum chromodynamics (QCD) at present and future colliders. Among different regimes, in which heavy-flavor production can be investigated, we focus our attention on the semi-hard one, where $s \gg Q^2 \gg \Lambda_{QCD}$ (s is the squared center-of-mass energy, $\{Q^2\}$ a (set of) hard scale(s)...
We discuss the production mechanism of a new state,
a fully charm tetraquark, discovered two years ago by the LHCb at
M = 6.9 GeV in the $J/\psi J/\psi$ channel.
Both single parton scattering (SPS) and double parton scattering (DPS)
mechanisms are considered. We calculate the distribution in the invariant
mass of the four-quark system $M_{4c}$ for SPS and DPS production of
$c c \bar...
We review our calculations of $\eta_c$(1S,2S) prompt production in proton-proton collisions at $\sqrt{s}= 7\,, 8\,, 13\,{\rm TeV}$, as well as $\chi_{c0}$(1P) and $\chi_{b0}$(1P). The matrix element of the $g^*g^* \to \mathcal{Q}$ is found by taking into account the proper colour factors and coupling constant to quarkonia electromagnetic form factors for $\gamma^*\gamma^*\to \mathcal{Q}$. The...
We review the recent developments of the QCD shockwave approach at Next-to-Leading Order. The general method of this effective action will be sketched, and several examples, in the case of diffractive processes, will be presented.
The cross-sections of diffractive double hadron photo- or electroproduction with large pT, on a nucleon or a nucleus, are calculated to NLO accuracy.
A hybrid formalism mixing collinear factorization and high energy kt factorization, more precisely the shockwave formalism, is used to derive the results.
The cancellation of divergences is explicitly shown, and the finite parts of the NLO...
In this work, we calculate the double-inclusive gluon production within the framework of the dense-dilute Color Glass Condensate (CGC) approach.
As a novelty, we provide the contribution accounting for the quantum correction in which the two gluons come from a single projectile source, thus giving renewed insights about a breaking of the accidental symmetry of the CGC which straightforwardly...
We calculate [1] the contribution from the $q\bar{q}g$ state to the small-$x$ diffractive cross section in deep inelastic scattering in the saturation regime. The obtained cross section is finite by itself and a part of the full next-to-leading order result for the diffractive structure function. We perform the calculation in exact kinematics in the eikonal limit, and show that the previously...
Exclusive vector meson production is a powerful process to probe the small Bjorken-$x$ structure of protons and nuclei, as such processes are especially sensitive to gluonic structure and also provide access to the spatial distribution of small-$x$ gluons in nuclei. A powerful theoretical framework to study such high-energy processes is the Color Glass Condensate (CGC) effective field theory....
Using the color dipole picture for DIS, we study the production of a pair of jets initiated by a quark and an antiquark, through coherent diffraction. The transverse momenta of the two jets are taken to be larger than the target saturation momentum. Then the typical final-state configurations are such that the hard dijets are accompanied by a semi-hard gluon jet, with transverse momentum of...
We construct a framework that may be used to compute NLO kT-dependent impact factors from NLO on-shell parton scattering amplitudes. The key point of the method is an extension to the NLO accuracy of the auxillary parton method commonly used in the LO calculations. With the high energy (Regge) factorization at the NLO, the collinear scattering amplitudes are decomposed into the NLO impact...
High energy evolution of scattering amplitudes is governed by the JIMWLK Hamiltonian. At NLO it involves quark contributions. The NLO JIMWLK Hamiltonian with massless quarks has been known for some time.
Yet, the quest for precision requires inclusion of effects due to quark masses. This gap has been filled.
By describing the initial stage of heavy ion collisions in terms of freely-evolving classical fields, we perform a first-principles calculation of the energy density one- and two-point correlation functions at finite proper time. Our approach allows us to systematically resum the contributions of high momentum modes that would make a power series expansion in proper time divergent. In order to...
We study inclusive dijet production in deep inelastic scattering at NLO within the Color Glass Condensate Effective Field Theory. We begin by studying this process in general small-x kinematics where we: (i) show that the differential cross-section is infrared and collinear safe, (ii) demonstrate the factorization of large energy/rapidity logarithms which can then be resummed via JIMWLK...
Using the CGC effective theory together with the hybrid factorisation, we study forward photon+jet production in proton-nucleus collisions beyond leading order. We first compute the "real" next-to-leading order (NLO) corrections, i.e. the radiative corrections associated with a three-parton final state, out of which only two are being measured. Then we move to the "virtual" NLO corrections to...
