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A new code for the scale evolution of modified-minimal-subtraction-scheme parton densities is described. Through next-to-leading order the program uses exact splitting functions. In next-to-next-to-leading order approximate splitting functions are used. For efficiency the program includes analytical results for the evaluation of the weights required for the integrations over the longitudinal momentum fractions of the partons. It also incorporates the operator matrix elements required for the matching conditions across heavy flavor thresholds in higher order perturbation theory. The more efficient handling of the weights implies that the code is faster than similar evolution codes in all modes of operation. The program is written in the C programming language.
In this paper we introduce an alternative renormalization program for systems with non-perturbative conditions. The non-perturbative conditions that we concentrate on in this paper are confined to be either the presence of non-trivial boundary condit
Double parton distribution functions (DPDFs) are used in the QCD description of double parton scattering. The DPDFs evolve with hard scales through relatively new QCD evolution equations which obey nontrivial momentum and valence quark number sum rul
The systematic treatment of heavy quark mass effects in DIS in current CTEQ global analysis is summarized. Applications of this treatment to the comparison between theory and experimental data on DIS charm production are described. The possibility of
In this work, we carry out the study of heavy flavor pentatuarks with four heavy quarks, which have typical $QQQQbar q$ configuration. Within the Chromomagnetic Interaction model, the mass spectrum of these discussed $QQQQbar q$ pentaquarks is given.
Parton shower Monte Carlo event generators in which the shower evolves from hard splittings to soft splittings generally use the leading color approximation, which is the leading term in an expansion in powers of $1/N_c^2$, where $N_c = 3$ is the num