Related papers: Charm in the Nucleon
We investigate the charm sector of the nucleon structure phenomenologically, using the most up-to-date global QCD analysis. Going beyond the common assumption of purely radiatively generated charm, we explore possible degrees of freedom in…
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…
The theory of the strong force, quantum chromodynamics, describes the proton in terms of quarks and gluons. The proton is a state of two up quarks and one down quark bound by gluons, but quantum theory predicts that in addition there is an…
At low Q^2, charm production in deep-inelastic scattering is adequately described by assuming generation in electroweak boson-light parton scattering (dominantly boson-gluon fusion) which naturally incorporates the correct threshold…
The prospects to test the hypothesis of intrinsic charm quarks in the proton are investigated. We consider how this component can be directly or indirectly probed in deep inelastic scattering at HERA and in fixed target experiments and find…
Precise measurements of charm production in deep inelastic scattering are presented and compared with next-to-leading-order QCD. The data show sensitivity to the choice of parametrisation of the gluon density in the proton and could be used…
We estimate the intrinsic charm contributions to the quark flavor and spin observables of the nucleon in the SU(4) quark meson fluctuation model. In this model, the charm or anticharm reside in the charmed mesons created by the…
We present a fully differential next-to-next-to-leading order calculation of charm quark production in charged-current deep-inelastic scattering, with full charm-quark mass dependence. The next-to-next-to-leading order corrections in…
Charm quarks are expected to be produced mainly by the photon-gluon fusion mechanism in photon-Nucleon interactions. However, a small part of the total charm cross section originates in similar processes to those appearing in charm…
In this paper, we have investigated the importance of quark charm in nuclear structure functions in the color dipole model at small $x$. The charm structure function per nucleon $F_{2}^{cA}/A$ for light and heavy nuclei in a wide range of…
We discuss the role of intrinsic charm (IC) in the nucleon for forward production of $c$-quark (or $\bar c$-antiquark) in proton-proton collisions for low and high energies. The calculations are performed in collinear-factorization approach…
Over the past $\sim\!\! 10$ years, the topic of the nucleon's nonperturbative or $\textit{intrinsic}$ charm (IC) content has enjoyed something of a renaissance, largely motivated by theoretical developments involving quark modelers and PDF…
The quark spin and flavor structure of the nucleon is discussed in the SU(4) symmetry breaking chiral quark model. The spin and flavor contents for charm quarks and anti-charm quarks are predicted and compared with the results given by…
A calculation of the next-to-leading order exclusive extrinsic charm quark differential distributions in deeply inelastic electroproduction has recently been completed. Using these results we compare the NLO extrinsic contributions to the…
We reply to the Comment of Brodsky and Gardner on our paper "New limits on intrinsic charm in the nucleon from global analysis of parton distributions" [Phys. Rev. Lett. 114, 082002 (2015)]. We address a number of incorrect claims made…
We perform a comprehensive analysis of the role of nonperturbative (or intrinsic) charm in the nucleon, generated through Fock state expansions of the nucleon wave function involving five-quark virtual states represented by charmed mesons…
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…
A review is given of the QCD corrections to charm quark production in deep inelastic electron-proton scattering. An outline of the computation of the virtual photon-parton subprocesses, from which one obtains the heavy quark coefficient…
Recent experiments at Fermilab and CERN have observed a strong asymmetry between the hadroproduction cross sections of leading $D$ mesons, containing projectile valence quarks, and nonleading charmed mesons, without projectile valence…
We present the first lattice QCD calculation of the charm quark contribution to the nucleon electromagnetic form factors $G^c_{E,M}(Q^2)$ in the momentum transfer range $0\leq Q^2 \leq 1.4$ $\rm GeV^2$. The quark mass dependence, finite…