Measurement of the polarization in charged current interactions in the NOMAD experiment

We study the polarization of the anti-Lambda particle in polarized high energy pp collisions at large transverse momenta. The anti-Lambda polarization is found to be sensitive to the polarization of the anti-strange sea of the nucleon. We make predictions using different parameterizations of the polarized quark distribution functions. The results show that the measurement of longitudinal antiLambda polarization can distinguish different parameterizations, and that similar measurements in the transversely polarized case can give some insights into the transversity distribution of the anti-strange sea of nucleon.

mentioning

confidence: 99%

Anti-Lambda polarization in high energyppcollisions with polarized beams

Liang

Sichtermann

2006

“…The spin structure of the quark-diquark fragmentation functions for the Λ has been studied before [9,10], and it is supported by the available experimental data on Λ production in various processes [11,12,13,14,15,16]. In this work, we retain the flavor and spin structure of the fragmentation functions suggested by the diquark model.…”

Section: Quark Fragmentation Functions For the Octet Baryonsmentioning

confidence: 81%

Mass suppression in octet baryon production

Yang

Schmidt

2003

There is a striking suppression of the cross section for production of octet baryons in e + e − annihilation, as the mass of the produced hadron increases. We present a simple parametrization for the fragmentation functions into octet baryons guided by two input models: the SU(3) flavor symmetry part is given by a quark-diquark model, and the baryon mass suppression part is inspired by the string model. We need only eight free parameters to describe the fragmentation functions for all octet baryons. These free parameters are determined by a fit to the experimental data of octet baryon production in e + e − annihilation. Then we apply the obtained fragmentation functions to predict the cross section of the octet baryon production in charged lepton DIS and find consistency with the available experimental data. Furthermore, baryon production in pp collisions is suggested to be an ideal domain to check the predicted mass suppression.

“…Hence, they can be used to study the spin effects in high-energy fragmentation processes, in particular the spin transfer from the polarized fragmenting quark to the produced hadrons. We will limit ourselves to such kinematic regions in this paper and will not discuss the cases at lower energies 18,17 where no distinct separation between the fragmentation results of the struck quark and that of the rest of the target nucleon is possible 19 . We will discuss both the case where the virtual photon exchange dominates and the case where charged weak current interaction takes place.…”

Section: Andmentioning

confidence: 99%

“…Hence, till now, most of the studies [1][2][3][4][5][6][7][8][9][10][11][12][13][14][17][18][19][20] are concentrated on Λ polarization. However, as can be seen already in e + e − annihilation 11 , the origins of Λ are also most complicated.…”

mentioning

confidence: 99%

Hyperon polarization in semi-inclusive deeply inelastic lepton-nucleon scattering at high energy

Liu

Liang

2001

We calculate the polarizations for different octet hyperons produced in the current fragmentation regions of the deeply inelastic lepton-nucleon scatterings µ − N → µ − HX and ν µ N → µ − HX at high energy using different models for spin transfer in fragmentation processes. The results show that measurements of those hyperon polarizations should provide useful information to distinguish between different models in particular the SU(6) and the DIS pictures used frequently in the literature. We found, in particular, that measuring the polarization of Σ + produced in these processes can give a better test to the validity of the different spin transfer models.0