Measurement of the strange sea distribution using neutrino charm production

Abstract

A high-statistics study by the Columbia-Chicago-Fermilab-Rochester Collaboration of opposite-sign dimuon events induced by neutrino-nucleon scattering at the Fermilab Tevatron is presented. A sample of 5044 v M and 1062 vv induced /i^/i 1 events with P^ > 9 GeV/c, P^2> 5 GeV/c, 30 < E v < 600 GeV, and <g 2 )= s 22.2 GeW 2 /c 2 is observed. The data support the slow-rescaling model of charm production with a value of m c = 1.31 ±0.24 GeV/c 2 . The first measurement of the Q 2 dependence of the nucleon strange quark distribution xs(x) is presented. The data yield the Cabibbo-Kobayashi-Maskawa matrix element | V c d\ =0.209 ±0.012 and the nucleon fractional strangeness content r\ s =0.064-aoo?-

A new global analysis of deep inelastic scattering data

“…In particular, one may question two points of the CDHSW analysis (see [3] for more details): i) a rejection cut against the dimuon events was used but no correction for it was applied; ii) the background coming from muon production in hadronic showers was not taken into account. Using the recent CCFR results on σ ν,ν 2µ /σ ν,ν 1µ [45] and on the production rate of muons in hadronic showers [46], we estimated the effect of these two sources of errors on the measurements and found it to be at the level of 1% at most.…”

Next-to-Leading order QCD corrections to charged current charm production and the unpolarized and polarized strange sea at HERA

“…In recent sets of unpolarized parton distributions it is either assumed thats (= s) has the same x shape asū+d [1,2], ors is solely generated by QCD dynamics from a vanishing input distribution at some low scale [3], in both cases leading to an overall suppression of the x integrated second moment dx xs in the light sea of about 50% at Q 2 ≃ 5−10 GeV 2 [4][5][6][7], presumably due to the larger mass of strange quarks. The entire x dependence of the flavor decomposed unpolarized light sea is, however, still rather uncertain.…”

Flavor structure of the nucleon sea

“…2.2. The measurements of charm production with dimuon events in the final state have been performed by several experiments: CDHS [62], CCFR [63,64], CHARMII [65], NOMAD [66,67], NuTeV [68,69,70,71] and CHO-RUS [72,73]. The integrated strange over non-strange nucleon sea κ s , defined as…”