First NNLO fragmentation functions of K 0 S and Λ/Λ and their uncertainties in the presence of hadron mass corrections (original) (raw)
Related papers
2020
The current paper presents a determination of K0SK^0_SK0S and Lambda/barLambda\Lambda/\bar{\Lambda}Lambda/barLambda fragmentation functions (FFs) from QCD analysis of single-inclusive electron-positron annihilation process (SIA). Our FFs determinations are performed at next-to-leading order (NLO), and for the first time, at next-to-next-to-leading order (NNLO) accuracy in perturbative Quantum Chromodynamics (pQCD) which is designated as {\tt SAK20} FFs. Each of these FFs is accompanied by their uncertainties which are determined using the `Hessian' method. Considering the hadron mass corrections, we clearly investigate the reliability of our results upon the inclusion of higher-order QCD correction. We provide comparisons of {\tt SAK20} FFs set with the available analysis from another group, finding in general a reasonable agreement, and also considerable differences. In order to judge the fit quality, our theoretical predictions are compared with the analyzed SIA datasets. {\tt SAK20} FFs at NLO and NNLO accura...
Physical Review D, 2019
In this paper, we present SGK18 FFs, a first global QCD analysis of parton-to-unidentified charged hadrons fragmentation functions (FFs) at next-to-next-to-leading order (NNLO) accuracy in per-turbative QCD. This analysis is based on single-inclusive charged hadron production in electron-positron (e − e +) annihilation. The uncertainties in the extraction of SGK18 FFs as well as the corresponding observables are estimated using the " Hessian " technique. We study the quality of the SGK18 FFs determined in this analysis by comparing with the recent results in literature. We also show how SGK18 FFs results describe the available data for single-inclusive unidentified charged hadron production in e − e + annihilation. We demonstrate that the theoretical uncertainties due to the variation of the renormalization and factorization scales improve when NNLO QCD corrections are considered. We find that the resulting SGK18 FFs are in good agreement with all data analyzed and the inclusion of NNLO corrections tends to improve the data description with somewhat smaller uncertainty.
Simultaneous extraction of fragmentation functions of light charged hadrons with mass corrections
2020
Achieving the highest possible precision for theoretical predictions at the present and future high-energy lepton and hadron colliders requires a precise determination of fragmentation functions (FFs) of light and heavy charged hadrons from a global QCD analysis with great accuracy. We describe a simultaneous determination of unpolarized FFs of charged pions, charged kaons and protons/antiprotons from single-inclusive hadron production in electron-positron annihilation (SIA) data at next-to-leading order and next-to-next-to-leading order accuracy in perturbative QCD. A new set of FFs, called SGKS20, is presented. We include data for identified light charged hadrons (π ± , K ± and p/p) as well as for unidentified light charged hadrons, h ±. We examine the inclusion of higher-order perturbative QCD corrections and finite-mass effects. We compare the new SGKS20 FFs with other recent FFs available in the literature and find in general reasonable agreement, but also important differences for some parton species. We show that theoretical predictions obtained from our new FFs are in very good agreement with the analyzed SIA data, especially at small values of z. The SGKS20 FF sets presented in this work are available via the LHAPDF interface.
2019
The main aim of this paper is to present new sets of non-perturbative fragmentation functions (FFs) for D 0 and D + mesons at next-to-leading (NLO) and, for the first time, at next-to-next-to-leading order (NNLO) accuracy in perturbative QCD. This new determination of FFs is based on the QCD fit to the OPAL experimental data for hadroproduction in the electron-positron single-inclusive annihilation (SIA). We discuss in details the novel aspects of the methodology used in our analysis and the validity of obtained FFs by comparing with previous works in literature which have been done up to NLO accuracy. We will also incorporate the effects of charmed meson mass corrections into our QCD analysis and discuss the improvements upon inclusion of these effects. The uncertainties of extracted FFs as well as SIA cross sections are estimated employing the "Hessian approach". For a typical application, we use the extracted FFs to make theoretical predictions for the scaled-energy distributions of charmed mesons inclusively produced in top quark decays.
2018
In this article, we present an extraction of the contribution from the " residual " light charged hadrons to the inclusive unidentified light charged hadron fragmentation functions (FFs) at next-to-leading (NLO) and, for the first time, at next-to-next-to-leading order (NNLO) accuracy in perturbative QCD. Considering the contributions from charged pion, kaon and (anti)proton FFs from recent NNFF1.0 charged hadron FFs, we determine the small but efficient residual charged hadron FFs from QCD analysis of all available single inclusive unidentified charged hadron data sets in electron-positron annihilations. The zero mass variable flavor number scheme (ZM-VFNS) has been used to account the heavy flavor contributions. The obtained optimum set of residual charged hadron FFs is accompanied by the Hessian technique to assess the uncertainties in the extraction of these new sets of FFs. It is shown that the residual contributions of charged hadron FFs have very important impact on the inclusive charged hadron FFs as well as on the quality and the reliability of the QCD fit. Contents
Physical Review D, 2019
We present nonperturbative fragmentation functions (FFs) for bottom-flavored (B) hadrons both at next-to-leading (NLO) and, for the first time, at next-to-next-to-leading order in the MS factorization scheme with five massless quark flavors. They are determined by fitting all available experimental data of inclusive single B-hadron production in e þ e − annihilation, from the ALEPH, DELPHI, and OPAL collaborations at CERN LEP1 and the SLD collaboration at SLAC SLC. The uncertainties in these FFs as well as in the corresponding observables are estimated using the Hessian approach. We perform comparisons with available NLO sets of B-hadron FFs. We apply our new FFs to generate theoretical predictions for the energy distribution of B hadrons produced through the decay of unpolarized or polarized top quarks, to be measured at the CERN LHC.
Physical Review D, 2018
We present, for the first time, a set of next-to-next-to-leading order (NNLO) fragmentation functions (FFs) describing the production of charmed-meson D * + from partons. Exploiting the univer-sality and scaling violations of FFs, we extract the NLO and NNLO FFs through a global fit to all relevant data sets from single-inclusive e + e − annihilation. The uncertainties for the resulting FFs as well as the corresponding observables are estimated using the Hessian approach. We evaluate the quality of the SKM18 FFs determined in this analysis by comparing with the recent results in literature and show how they describe the available data for single-inclusive D * +-meson production in electron-positron annihilation. As a practical application, we apply the extracted FFs to make our theoretical predictions for the scaled-energy distributions of D * +-mesons inclusively produced in top quark decays. We explore the implications of SKM18 for LHC phenomenology and show that our findings of this study can be introduced as a channel to indirect search for top-quark properties.
Perturbative quantum chromodynamic prediction for the heavy quark fragmentation function
Physics Letters B, 1987
Within the framework of a parhcular model for meson production, a perturbatlve QCD analysis is presented for the reclusive production of pseudoscalar and vector mesons to derive the fragmentatmn function of heavy quarks produced in e+e-anmhllatmn. The results are compared with experimental data for bottom and charm quark fragmentatmn functmns. The new generation of high energy e+e-colliders such as TRISTAN, SLC, and LEP, is expected to provide a wealth of information about production and hadronization of heavy quarks (c, b, t). The production of heavy particles in these accelerators will be an important testing ground for the perturbative quantum chromodynamics (QCD) [ 1-3 ]. One of the interesting properties of heavy quarks which can be studied in the framework of perturbative QCD is the evolution of quarks into hadrons. The mechanism responsible for hadronization, in general, is specified by the fragmentation function D~ (z, s) which represents the fragmentation of the quark Q into the final state hadron H with the momentum fraction z= 2E/~s, where E is the energy of the hadron and s is the square of the total e+e-CM energy. Various phenomenological models, like the Lund model [ 4 ], the Cascade model [ 5 ], and the Peterson et al. model [ 6 ], motivated by QCD, have been developed to describe the fragmentation function D~. Since these models [ 4-6 ] involve parameters to fit the experimental data, it is not clear how to check the consistency of their results with a general theorem for the extreme case of heavy quark fragmentation given Work supported by the Department of Energy, contract DE-AC03-76SF00515.
2019
The main aim of this paper is a new determination of transverse momentum dependence of unpo-larized fragmentation function (TMD FFs) in single inclusive hadron production in electron-positron annihilation (SIA) processes. Motivated by the need for a reliable and consistent determination of TMD FFs, we use the most recent TMD production cross sections of charged pions (π ±), kaons (K ±) and protons/antiprotons (p/¯ p) measured in inclusive e + e − collisions by Belle Collaboration. These datasets are the first identified light charged hadron measurements which depend on the transverse momentum in SIA process. In this analysis, referred to as SK19 TMD FFs, the common Gaussian distribution is used for the P hT dependent of the cross section. The uncertainties in the extraction of SK19 TMD FFs are estimated using the standard "Hessian" technique. We study the quality of the TMD FFs determined in this analysis by comparing with the available recent Belle cross sections measurement. For all hadron species, we found a very good agreement between this particular set of experimental data and the corresponding theory calculations over a relatively wide range of transverse momentum P hT. As a result of this study, suggestions were identified for possible future research considering the theory improvements and other available experimental observables.
The Role of Hadronization Processes in Determination of Fragmentation Functions
Acta Physica Polonica B Proceedings Supplement, 2014
We present the results of a global fit to data from different hadronization processes such as single-inclusive electron-positron annihilation and semi-inclusive deep inelastic scattering to calculate pion and kaon fragmentation functions. We perform an improvement to the pion and kaon fragmentation functions at next-to-leading order (NLO), by including recent single-inclusive electron-positron annihilation data from BaBar and Belle at Q = 10.54 GeV and Q = 10.52 GeV, respectively. Our main purpose is to show how much imposing of these new data in our analysis improves the fragmentation functions of pion and kaon at NLO.