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Distinctions between quark to $\Lambda$ and $\bar\Lambda$ longitudinal spin transfers in the semi-inclusive deep inelastic scattering process were observed by the E665 and COMPASS Collaborations. There are suggestions that the difference…

High Energy Physics - Phenomenology · Physics 2017-03-13 Xiaozhen Du , Bo-Qiang Ma

Although the distributions of sea quarks and antiquarks generated by leading-twist QCD evolution through gluon splitting $g \rightarrow \bar q q$ are necessarily CP symmetric, the distributions of nonvalence quarks and antiquarks which are…

High Energy Physics - Phenomenology · Physics 2009-09-11 S. J. Brodsky , B. -Q. Ma

The difference between the $\Lambda$ and $\bar \Lambda$ longitudinal spin transfers in the semi-inclusive deep inelastic scattering process is intensively studied. The study is performed in the current fragmentation region, by considering…

High Energy Physics - Phenomenology · Physics 2014-12-18 Yujie Chi , Xiaozhen Du , Bo-Qiang Ma

The flavor and helicity distributions of the $\Lambda$ and $\bar{\Lambda}$ hyperons for both valence and sea quarks are calculated in a perturbative QCD (pQCD) based model. We relate these quark distributions to the fragmentation functions…

High Energy Physics - Phenomenology · Physics 2011-09-13 Bo-Qiang Ma , Ivan Schmidt , Jacques Soffer , Jian-Jun Yang

It is shown that neutrino and antineutrino deep inelastic scattering of unpolarized and polarized $\Lambda$ and $\bar{\Lambda}$ productions, can provide a clean separation of unpolarized and polarized fragmentation functions of a quark into…

High Energy Physics - Phenomenology · Physics 2009-10-31 Bo-Qiang Ma , Jacques Soffer

We investigate an asymmetry in the angular distribution of hard elastic proton-neutron scattering with respect to 90deg center of mass scattering angle. We demonstrate that the magnitude of the angular asymmetry is related to the…

High Energy Physics - Phenomenology · Physics 2009-12-08 Carlos G. Granados , Misak M. Sargsian

Data on the nucleon spin structure suggests that the $u$ (and $d$) quark distributions in the $\Lambda$ hyperon may be polarized. If this correlation carries over into fragmentation, then the study of polarized $\Lambda$'s in the current…

High Energy Physics - Phenomenology · Physics 2010-01-06 R. L. Jaffe

The strange sea quarks distributions of nucleons obtained by two global analyses based on available structure function data of muon and neutrino deep inelastic scatterings are different from the strange sea quark distribution measured by…

High Energy Physics - Phenomenology · Physics 2015-06-25 Bo-Qiang Ma

The rapidity distribution of $\Lambda$ and $\bar{\Lambda}$ produced in nucleus-nucleus collisions at CERN energies is studied in the framework of an independent string model - with quark-antiquark as well as diquark-antidiquark pairs in the…

High Energy Physics - Phenomenology · Physics 2008-02-03 A. Capella , A. Kaidalov , A. Kouider Akil , C. Merino , J. Tran Thanh Van

Sea quark distributions in the nucleon have naively been expected to be generated perturbatively by gluon splitting. In this case, there is no reason for the light quark and anti-quark sea distributions to be different. No asymmetries in…

High Energy Physics - Phenomenology · Physics 2015-06-25 R. Vogt

We study the helicity distributions of light flavor quark-antiquark ($q \bar{q}$) pairs in the nucleon sea. The valence quarks are handled by adopting the light-cone SU(6) quark-spectator-diquark model and the sea $q \bar{q}$ pairs are…

High Energy Physics - Phenomenology · Physics 2018-09-12 Mengyun Liu , Bo-Qiang Ma

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

The isospin asymmetry of the sea quark distribution as well as the unexpectedly small quark spin fraction of the nucleon are two outstanding discoveries recently made in the physics of deep-inelastic structure functions. We evaluate here…

High Energy Physics - Phenomenology · Physics 2009-10-30 Masashi Wakamatsu , Takanori Kubota

It is shown that $\Lambda$-hyperon fragmentation in charged lepton deep inelastic scattering (DIS) on a polarized nucleon target can provide sensitive information concerning the quark helicity and transversity distributions for both nucleon…

High Energy Physics - Phenomenology · Physics 2014-11-17 Bo-Qiang Ma , Ivan Schmidt , Jacques Soffer , Jian-Jun Yang

The asymmetries of both light-flavor antiquark $\bar{d}(x)-\bar{u}(x)$ and strange-antistrange $s(x)-\bar{s}(x)$ distributions of the nucleon sea are considered with more details in the effective chiral quark model. We find that the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Yong Ding , Rong-Guang Xu , Bo-Qiang Ma

The particle-antiparticle asymmetries of $\Lambda$ production in 250 GeV/c $\pi^{\pm}$, $K^{\pm}$, and $p$ --nucleon collisions are studied with two model parametrizations of quark to $\Lambda$ fragmentation functions. It is shown that the…

High Energy Physics - Phenomenology · Physics 2009-11-10 Bo-Qiang Ma , Ivan Schmidt , Jian-Jun Yang

The intrinsic quark-antiquark pairs generated by the minimal energy nonperturbative meson-baryon fluctuations in the nucleon sea provide a consistent framework for understanding a number of empirical anomalies observed in the deep inelastic…

High Energy Physics - Phenomenology · Physics 2008-02-03 B. -Q. Ma , S. J. Brodsky

A physical model is presented for the non-perturbative parton distributions in the nucleon. This is based on quantum fluctuations of the nucleon into baryon-meson pairs convoluted with Gaussian momentum distributions of partons in hadrons.…

High Energy Physics - Phenomenology · Physics 2019-08-14 Andreas Ekstedt , Hazhar Ghaderi , Gunnar Ingelman , Stefan Leupold

We derive the nucleon non-perturbative sea-quark distributions coming from a composite model involving quarks and hadronic degrees of freedom. The model predicts a definite structured quark-antiquark asymmetry in the nucleon sea.

High Energy Physics - Phenomenology · Physics 2007-05-23 H. R. Christiansen , J. Magnin

The theoretical predictions of the chiral quark soliton model for the unpolarized and longitudinally polarized structure functions of the nucleon are compared with recent high energy data. The theory is shown to explain all the…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Wakamatsu
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