Related papers: Recent progress on intrinsic charm
Using the experimental data on pentaquarks with a hidden charm, new upper limits on the intrinsic charm in the proton are obtained, possible shapes of heavy quark distributions inside the proton are discussed.
We present the results of a recent analysis to study the nucleon's charm sigma term, $\sigma_{c\overline{c}}$. We construct a minimal model in terms of light-front variables and constrain the range of possibilities using extant knowledge…
The long-distance structure of the interacting nucleon receives important contributions from its couplings to light hadronic degrees of freedom -- a light meson cloud -- while an analogous nonperturbative mechanism is expected to generate…
Recent results indicate that charm quarks are intrinsic components of the proton wave function, and that the charm and anticharm distributions for a given value of the Bjorken - $x$ variable can be different. In this paper, we will…
We consider an observable very sensitive to the non-zero intrinsic charm (IC) contribution to the proton density. It is the ratio between the differential cross sections of the photon or $Z$-boson and $c$-jet production in the $pp$…
A new interpretation of intrinsic charm phenomenon based on the assumption of pentaquark $\left| u u d c\bar{c} \right>$ mixing with a proton is offered. The structure function of the $c$-quark in the pentaquark is constructed. Mixing…
According to general understanding, the proton as one of the main ingredients of the nucleus is composed of one down and two up quarks bound together by gluons, described by Quantum Chromodynamics (QCD). In this view, heavy quarks do not…
In this work we investigate the impact of intrinsic charm on the prompt atmospheric neutrino flux. The color dipole approach to heavy quark production is generalized to include the contribution of processes initiated by charm quarks. The…
We argue that a large fraction of the proton spin comes from a contribution due to a nonperturbative intrinsic charm component of the proton. An account of this contribution removes an apparent contradiction between the data and exact…
We review the current understanding of heavy quark parton distributions in nucleons and their impact on deep inelastic scattering, collider physics, and other processes at high energies. The determination of the heavy-quark parton…
We provide a first quantitative indication that the wave function of the proton contains unequal distributions of charm quarks and antiquarks, i.e. a nonvanishing intrinsic valence charm distribution. A significant nonvanishing valence…
We demonstrate that to a very good approximation the scale-evolution of the intrinsic heavy quark content of the nucleon is governed by non-singlet evolution equations. This allows us to analyze the intrinsic heavy quark distributions…
Measurement of $Z$ bosons produced in association with charm jets $(Zc)$ in proton-proton collisions in the forward region provides a direct probe of a potential non-perturbative (intrinsic) charm component in the proton wave function. We…
A pedagogically oriented review is given of progress made over the past year in our understanding of physics related to the charm quark. Included are discussions of the R_c deficit, the \psi' anomaly, charm spectroscopy, D nonleptonic…
For a long time the significance of charm has been overlooked as an important component of the heavy flavour programme. In recent years the balance has been redressed, and charm studies are quite rightly receiving much more attention. This…
Using the statistical approach additional light partons have been introduced in the Intrinsic Charm model. Explicit expressions are obtained for charmed and light quark distributions. A comparison is made with standard IC model predictions.…
The physics of charm has become one of the best laboratories exposing the limitations of the naive constituent quark model and also giving hints into a more mature description of hadron spectroscopy. Recent discoveries are a challenge that…
50 years after the discovery of the first charmed particle, charm physics continues to be an extremely lively field of research and a cornerstone in particle physics. The study of charm, with its unique properties, is characterised by many…
Up to now, the existence of intrinsic (or valence-like) heavy quark component of the proton distribution functions has not yet been confirmed or rejected. The LHC with pp-collisions at $\sqrt{s}$ = 7-13 TeV can supply us with extra unique…
We calculate differential energy spectra ($x_F$-distributions) of charmed particles produced in proton-nucleus collisions, assuming the existence of intrinsic heavy quark components in the proton wave function. For the calculation, the…