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Related papers: The Polarised $\Lambda$ production in QCD

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Polarization of the \Lambda hyperon produced with a large transverse momentum in the unpolarized nucleon-nucleon collision is analyzed in the framework of QCD factorization. We focus on the mechanism in which the soft-gluon component of the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Y. Kanazawa , Yuji Koike

We present new sets of fragmentation functions for protons and inclusive charged hadrons obtained in combined NLO QCD analyses of single-inclusive hadron production in electron-positron annihilation, proton-proton collisions, and…

High Energy Physics - Phenomenology · Physics 2008-11-26 Daniel de Florian , Rodolfo Sassot , Marco Stratmann

We investigate the transverse polarization of the $\Lambda$ hyperon in the processes $e^+e^-\to\Lambda^\uparrow \pi^\pm X$ and $e^+e^-\to\Lambda^\uparrow K^\pm X$ within the framework of the transverse momentum dependent~(TMD)…

High Energy Physics - Phenomenology · Physics 2021-04-26 Hui Li , Xiaoyu Wang , Yongliang Yang , Zhun Lu

In this short review paper, we discuss some of the recent advances in the field of parton fragmentation processes into hadrons as well as their possible modifications in QCD media. Hadron production data in e+e-, deep inelastic scattering…

High Energy Physics - Phenomenology · Physics 2009-07-22 Francois Arleo

Spin dependent fragmentation functions for heavy flavor quarks to fragment into heavy baryons are calculated in a quark-diquark model. The production of intermediate spin 1/2 and 3/2 excited states is explicity included. $\Lambda_b$ ,…

High Energy Physics - Phenomenology · Physics 2009-10-31 Gary R. Goldstein

Experimental data from Belle Collaboration for the transverse polarization of $\Lambda$'s measured in $e^+ e^-$ annihilation processes are used to extract the polarizing fragmentation function (FF) within a TMD approach. We consider both…

High Energy Physics - Phenomenology · Physics 2021-08-03 Umberto D'Alesio , Francesco Murgia , Marco Zaccheddu

We argue that the collinear factorization of the fragmentation functions in high energy hadron and nuclei collisions breaks down at transverse momenta kT < Qs/g due to high parton densities in the colliding hadrons and/or nuclei. We…

High Energy Physics - Phenomenology · Physics 2008-11-26 Yang Li , Kirill Tuchin

We study the production of polarized $\Lambda$ hyperon in semi-inclusive deep inelastic scattering off an unpolarized target. We include the cases in which the $\Lambda$ hyperon is longitudinally polarized or transversely polarized, and in…

High Energy Physics - Phenomenology · Physics 2017-04-26 Yongliang Yang , Zhun Lu

Transversely polarized Lambda production in hard scattering processes is discussed in terms of a leading twist T-odd fragmentation function which describes the fragmentation of an unpolarized quark into a transversely polarized Lambda. We…

High Energy Physics - Phenomenology · Physics 2009-10-31 Daniel Boer

Calculations of the polarization of $\Lambda$ and $\bar{\Lambda}$ particles after fragmentation of a polarized quark produced in processes like $Z$-decay and deep inelastic polarized lepton scattering must include $\Lambda$ and…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Ashery , H. J. Lipkin

In this paper we calculate first order radiative QCD corrections to the decay process $b\to cW^-(\to\ell^-\bar\nu_\ell)$ of a polarized bottom quark. Taking into account both the bottom and charm quark masses, the analytical expressions…

High Energy Physics - Phenomenology · Physics 2022-07-07 Martin Fischer , Stefan Groote

We present the complete structure of the azimuthal dependences and polarization observables for two-hadron production in $e^+e^-$ annihilation processes within a transverse momentum dependent (TMD) approach adopting the helicity formalism.…

High Energy Physics - Phenomenology · Physics 2023-01-18 Umberto D'Alesio , Francesco Murgia , Marco Zaccheddu

We present an analytical solution for the evolution of parton distributions incorporating mixed-order QCD $\otimes$ QED corrections, addressing both polarized and unpolarized cases. Using the Altarelli-Parisi kernels extended to mixed…

High Energy Physics - Phenomenology · Physics 2026-02-16 Daniel de Florian , Lucas Palma Conte

The longitudinal polarization of hyperons in $e^+e^-$ annihilation at high energies depends on the longitudinal polarization of the quark produced at the $e^+e^-$ annihilation vertex whereas the spin alignment of vector mesons is…

High Energy Physics - Phenomenology · Physics 2017-02-22 Kai-bao Chen , Wei-hua Yang , Ya-jin Zhou , Zuo-tang Liang

We present analytic formulae for the heavy flavour coefficient functions for polarized deep inelastic lepton-hadron scattering. The expressions are valid in the kinematical regime $Q^2\gg m^2$ where $Q^2$ and $m^2$ stand for the masses…

High Energy Physics - Phenomenology · Physics 2009-10-28 M. Buza , Y. Matiounine , J. Smith , W. L. van Neerven

Based on a simple quark-diquark model, we propose a set of unpolarized, longitudinally polarized and transversely polarized fragmentation functions for the $\Lambda$ by fitting the unpolarized $\Lambda$ production data in $e^+ e ^- $…

High Energy Physics - Phenomenology · Physics 2009-11-07 Jian-Jun Yang

Polarization studies for heavy quarks can lead to important tests of the Standard Model. Top quark pair production in $e^+e^-$ annihilation is considered near energy threshold. It is shown that for longitudinally polarized electrons the…

High Energy Physics - Phenomenology · Physics 2011-03-02 M. Jezabek

The description of the polarized quark hadronization process is one of the most challenging problems in the physics of strong interactions. The various single hadron and dihadron fragmentation functions, that quantify this process, are…

High Energy Physics - Phenomenology · Physics 2019-07-22 Aram Kotzinian , Hrayr H. Matevosyan , Anthony W. Thomas

Produced partons have large local relative orbital angular momentum along the direction opposite to the reaction plane in the early stage of non-central heavy-ion collisions. Parton scattering is shown to polarize quarks along the same…

Nuclear Theory · Physics 2009-09-02 Zuo-Tang Liang , Xin-Nian Wang

We present MAPFF1.0_Lambda, the first global analysis at next-to-next-to-leading order in perturbative QCD of the collinear unpolarised fragmentation functions of Lambda hyperons. The fit is based on data from single-inclusive…

High Energy Physics - Phenomenology · Physics 2026-05-08 Valerio Bertone , Alessia Bongallino , Amedeo Chiefa , Miguel G. Echevarria , Gunar Schnell