Related papers: String fragmentation of a quark pair with entangle…
Quark spin effects in $e^+e^-$ annihilation to pseudoscalar and vector mesons are implemented for the first time in the PYTHIA Monte Carlo event generator. The spin-dependent fragmentation of the string stretched between the produced…
The string+${}^3P_0$ model of spin-dependent hadronization is applied to the fragmentation of a string stretched between a quark and an antiquark with entangled spin states, assumed to be produced in the $e^+e^-$ annihilation process. The…
We present a model for Monte Carlo simulation of the fragmentation of a polarized quark. The model is based on string dynamics and the ${}^3P_0$ mechanism of quark pair creation at string breaking. The fragmentation is treated as a…
The quark spin effects are introduced for the first time in the string fragmentation routine of the Pythia 8 Monte Carlo event generator for the simulation of $e^+e^-$ annihilation to hadrons. To describe the spin effects the…
The quark spin effects have been introduced in the Pythia 8 Monte Carlo event generator for the simulation of $e^+e^-$ annihilation by interfacing the generator with the StringSpinner package. The package allows to simulate quark spin…
We present the main theoretical aspects of the quantum mechanical string+${}^3P_0$ model of polarized quark fragmentation for pseudoscalar and vector meson production. The model is an extension of the Lund string fragmentation model that…
We propose a Monte Carlo code for the simulation of the fragmentation process of polarized quarks into pseudoscalar mesons. Such process is generated recursively once the flavour, the energy and the spin density matrix of the initial quark…
We revisit our recursive model for the fragmentation of polarized quarks based on the string+${}^3P_0$ mechanism of $q\bar{q}$ pair creation. We make a different choice for one input function of the model that simplifies the implementation…
The recently developed quantum mechanical string+${}^3P_0$ model of polarized quark fragmentation with pseudoscalar and vector meson production has been implemented in a stand alone Monte Carlo program. The simulation enables the detailed…
The fragmentation of an unpolarized quark into a transversely polarized spin-1/2 particle is studied in the framework of a simple model. Special attention is payed to the gluon exchange which is incorporated in the gauge link of the…
An elementary recursive model accounting for the quark spin in the fragmentation of a quark into mesons is presented. The quark spin degree of freedom is represented by a two-components spinor. Spin one meson can be included. The model…
The thesis is devoted to the study of the fragmentation process of polarized quarks, and in particular of the Collins effect used for the extraction of the quark transversity distribution. The aim is to include the spin degree of freedom in…
The production of vector mesons in the fragmentation process of polarized quarks is studied within the recursive String+${}^3P_0$ model, improving a previous version of the model in which the production of pseudoscalar mesons only was…
We calculate the spin density matrix of the vector meson produced in e+e- annihilation at Z^0 pole. We show that the data imply a significant polarization for the antiquark which is created in the fragmentation process of the polarized…
The formalism of matrix product states is used to perform a numerical study of 1+1 dimensional QED -- also known as the (massive) Schwinger model -- in the presence of an external static `quark' and `antiquark'. We obtain a detailed picture…
We introduce spin-1/2 baryons in the string+${}^3P_0$ model of hadronization, previously restricted to the production of pseudoscalar and vector mesons. Baryons are modeled as quark-diquark bound states and baryon production is described by…
String breaking, the process by which flux tubes fragment into hadronic states, is a hallmark of confinement in strongly-interacting quantum field theories. A suite of quantum complexity measures is examined using Matrix Product States to…
Recent e+e- annihilation experiments show a striking spin alignment of vector mesons produced in the fragmentation of a polarized quark.We show that these data imply a simple relation between the polarization of the anti-quark, which is…
Quark spin effects in hadronization were recently included in the PYTHIA 8 Monte Carlo event generator for the simulation of the deep inelastic scattering (DIS) process off a polarized proton or neutron target. The spin effects were…
Quark spin effects in hadronization have been recently included in the PYTHIA 8 event generator for the simulation of the deep inelastic scattering (DIS) process off a polarized nucleon target via the external StringSpinner package. The…