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

200 papers

We check the $u$ and $d$ quark contributions to the spin content of the $\Lambda$ by means of the $q\to\Lambda$ fragmentation and find that the $u$ and $d$ quarks of the $\Lambda$ are likely positively polarized. The parton distributions in…

High Energy Physics - Phenomenology · Physics 2011-02-01 Jian-Jun Yang

We calculate the polarisation of $\psi$'s and $\Upsilon$'s produced by the fragmentation of heavy quarks. We find that fragmentation to transversely aligned quarkonium is slightly enhanced relative to longitudinally polarised. This net…

High Energy Physics - Phenomenology · Physics 2009-10-22 Adam F. Falk , Michael Luke , Martin J. Savage , Mark B. Wise

We discuss a few examples of structure functions for polarized, semi-inclusive scattering processes to show the richness of structure. Then we indicate how polarization and particle production can be used to study the quark and gluon…

Nuclear Theory · Physics 2007-05-23 P. J. Mulders

Analytic formulae are given for QCD corrections to the lepton spectra in decays of polarised up and down type heavy quarks. These formulae are much simpler than the published ones for the corrections to the spectra of charged leptons…

High Energy Physics - Phenomenology · Physics 2010-11-01 A. Czarnecki , M. Jeżabek

The first order correction to the parton fragmentation functions in a thermal medium is derived in the leading logarithmic approximation in the framework of thermal field theory. The medium-modified evolution equations of the parton…

High Energy Physics - Phenomenology · Physics 2014-11-17 Jonathan A. Osborne , Enke Wang , Xin-Nian Wang

Semi-inclusive hadron-production processes are becoming important in high-energy hadron reactions. They are used for investigating properties of quark-hadron matters in heavy-ion collisions, for finding the origin of nucleon spin in…

High Energy Physics - Phenomenology · Physics 2015-05-28 M. Hirai , S. Kumano

We study the prospects for HERA with polarized electron and/or proton beams to determine the functions describing the fragmentation of a longitudinally polarized parton into a polarized Lambda baryon. We examine both semi-inclusive…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. de Florian , M. Stratmann , W. Vogelsang

We consider for the first time the QED corrections to the evolution of (un)polarized quark and gluon transverse-momentum-dependent distribution and fragmentation functions (TMDs in general). By extending their operator definition to…

High Energy Physics - Phenomenology · Physics 2018-11-21 Alessandro Bacchetta , Miguel G. Echevarria

Within the context of flux tube models, heavy quark fragmentation takes place through the breaking of flux tubes with the production of a (di)quark-anti(di)quark pair. It is found that the (di)quark produced are more likely to be found in…

High Energy Physics - Phenomenology · Physics 2007-05-23 Chi-Keung Chow

A simple quark-diquark model for nucleon and $\Lambda$ structure is used to calculate leading twist light-cone fragmentation functions for a quark to inclusively decay into P or $\Lambda$. The parameters of the model are determined by…

High Energy Physics - Phenomenology · Physics 2016-09-01 Muhammad Nzar , Pervez Hoodbhoy

We calculate next to leading order QCD corrections to semi-inclusive polarized deep inelastic scattering and $e^+e^-$ annihilation cross sections for processes where the polarization of the identified final-state hadron can also be…

High Energy Physics - Phenomenology · Physics 2009-10-28 D. de Florian , R. Sassot

Compact analytic expressions have been obtained for the first order perturbative QCD corrections to the inclusive spectra of the leptons in the semileptonic decays of polarised heavy quarks. Charmed and beautiful $\Lambda$ baryons from…

High Energy Physics - Phenomenology · Physics 2007-05-23 Marek Jezabek

We study the production of longitudinally polarized Lambda-baryons in single-spin pp collisions at RHIC and HERA-N as a means of determining the spin-dependent Lambda fragmentation functions. It is shown that a measurement of the rapidity…

High Energy Physics - Phenomenology · Physics 2009-10-31 D. de Florian , M. Stratmann , W. Vogelsang

Making use of the collinear expansion technique developed by Ellis, Furmanski and Petrozio, and the special propagator concept invented by Qiu, we present a factorization approach to the photon fragmentation tensor for the inclusive Lambda…

High Energy Physics - Phenomenology · Physics 2019-08-15 Wei Lu , Xue-Qian Li , Hai-Ming Hu

The field of fragmentation functions of light quarks and gluons is reviewed. In addition to integrated fragmentation functions, attention is paid to the dependence of fragmentation functions on transverse momenta and on polarization degrees…

High Energy Physics - Experiment · Physics 2016-10-17 Andreas Metz , Anselm Vossen

Data from the Belle Collaboration for associated production (with a light unpolarized hadron) and single-inclusive production of transversely polarized $\Lambda$-hyperons in $e^+e^-$ annihilation processes allowed to extract within a TMD…

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

Fracture functions are parton distributions of an initial hadron in the presence of an almost collinear particle observed in the final state. They are important ingredients in QCD factorization for processes where a particle is produced…

High Energy Physics - Phenomenology · Physics 2020-01-08 X. P. Chai , K. B. Chen , J. P. Ma , X. B. Tong

The long-standing problem of transverse Lambda polarization in high-energy collisions of unpolarized hadrons can be tackled by considering new, spin and k_T-dependent quark fragmentation functions for an unpolarized quark into a polarized,…

High Energy Physics - Phenomenology · Physics 2015-06-25 M. Anselmino , D. Boer , U. D'Alesio , F. Murgia

We study the production of two almost back-to-back hadrons from the annihilation of an electron and a positron, allowing for the polarization of all particles involved. In particular, we conduct a general (model-independent) structure…

High Energy Physics - Phenomenology · Physics 2015-06-17 D. Pitonyak , M. Schlegel , A. Metz

Power-suppressed corrections to parton evolution may affect the theoretical accuracy of current determinations of parton distributions. We study the role of multigluon-exchange terms in the extraction of the gluon distribution for the Large…

High Energy Physics - Phenomenology · Physics 2008-11-26 F. Hautmann