Scaled momentum distributions for $ K_S^0 $KS and $ \Lambda /\bar{\Lambda } $ in DIS at HERA

• Published in: The journal of high energy physics Vol. 2012; no. 3
• Main Authors: Abramowicz, H., Abt, I., Adamczyk, L., Adamus, M., Aggarwal, R., Antonelli, S., Antonioli, P., Antonov, A., Arneodo, M., Aushev, V., Aushev, Y., Bachynska, O., Bamberger, A., Barakbaev, A. N., Barbagli, G., Bari, G., Barreiro, F., Bartosik, N., Bartsch, D., Basile, M., Behnke, O., Behr, J., Behrens, U., Bellagamba, L., Bertolin, A., Bhadra, S., Bindi, M., Blohm, C., Bokhonov, V., Bold, T., Bondarenko, K., Boos, E. G., Borras, K., Boscherini, D., Bot, D., Brock, I., Brownson, E., Brugnera, R., Brümmer, N., Bruni, A., Bruni, G., Brzozowska, B., Bussey, P. J., Bylsma, B., Caldwell, A., Capua, M., Carlin, R., Catterall, C. D., Chekanov, S., Chwastowski, J., Ciborowski, J., Ciesielski, R., Cifarelli, L., Cindolo, F., Contin, A., Cooper-Sarkar, A. M., Coppola, N., Corradi, M., Corriveau, F., Costa, M., D’Agostini, G., Corso, F. Dal, del Peso, J., Dementiev, R. K., De Pasquale, S., Derrick, M., Devenish, R. C. E., Dobur, D., Dolgoshein, B. A., Dolinska, G., Doyle, A. T., Drugakov, V., Durkin, L. S., Dusini, S., Eisenberg, Y., Ermolov, P. F., Eskreys, A., Fang, S., Fazio, S., Ferrando, J., Ferrero, M. I., Figiel, J., Forrest, M., Foster, B., Gach, G., Galas, A., Gallo, E., Garfagnini, A., Geiser, A., Gialas, I., Gladilin, L. K., Gladkov, D., Glasman, C., Gogota, O., Golubkov, Yu. A., Göttlicher, P., Grabowska-Bold, I., Grebenyuk, J., Gregor, I., Grigorescu, G.
• Format: Journal Article
• Language: English
• Published: 01.03.2012
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP03(2012)020

A bstract Scaled momentum distributions for the strange hadrons $ K_{\text{S}}^0 $ and $ \Lambda /\bar{\Lambda } $ were measured in deep inelastic ep scattering with the ZEUS detector at HERA using an integrated luminosity of 330 pb −1 . The evolution of these distributions with the photon virtuality, Q 2 , was studied in the kinematic region 10  < Q 2   <  40000 GeV 2 and 0 . 001  < x <  0 . 75, where x is the Bjorken scaling variable. Clear scaling violations are observed. Predictions based on different approaches to fragmentation were compared to the measurements. Leading-logarithm parton-shower Monte Carlo calculations interfaced to the Lund string fragmentation model describe the data reasonably well in the whole range measured. Next-to-leading-order QCD calculations based on fragmentation functions, FFs, extracted from e + e − data alone, fail to describe the measurements. The calculations based on FFs extracted from a global analysis including e + e − , ep and pp data give an improved description. The measurements presented in this paper have the potential to further constrain the FFs of quarks, anti-quarks and gluons yielding $ K_{\text{S}}^0 $ and $ \Lambda /\bar{\Lambda } $ strange hadrons.