Nuclear dependence of dimuon production at 800 GeV

Abstract

A precise measurement of the atomic-mass dependence of dimuon production induced by 800-GeV protons is reported. Over 450000 muon pairs with dimuon mass A/> 4 GeV were recorded from targets of 2 H, C, Ca, Fe, and W. The ratio of dimuon yield per nucleon for nuclei versus 2 H, R ~YA/YI H , is sensitive to modifications of the antiquark sea in nuclei. No nuclear dependence of this ratio is observed over the range of target-quark momentum fraction 0.1 <x t <0.3. For x t <0.1 the ratio is slightly less than unity for the heavy nuclei. These results are compared with predictions of models of the European Muon Collaboration effect. PACS numbers: 13.85.Qk, 25.40.Ve

Measurement of the EMC effect in the deuteron

“…Over the following three decades, subsequent dedicated measurements [4][5][6][7][8] confirmed the EMC effect with everincreasing precision for a wide range of nuclei. DrellYan data from Fermilab [9], however, which were largely sensitive to sea quarks, showed no modifications of the anti-quark sea for 0.1 < x < 0.3, contrary to models predicting anti-quark enhancement. Despite many theoretical papers on the EMC effect, no universally accepted explanation has emerged.…”

Global analysis of nuclear parton distribution functions and their uncertainties at next-to-next-to-leading order

“…Statistically, most significant data that people use in their nuclear PDFs analysis are the deep inelastic scattering (DIS) experiment which have been taken by experimental groups in fixed-target experiments. These data incorporates: The SLAC (Stanford Linear Accelerator Center)-E49, E87, E139 and E140 Collaborations, the NMC (New Muon Collaboration), the EMC (European Muon Collaboration), the BCDMS (Bologna-CERN-Dubna-Munich-Saclay), HERMES, JLAB groups (Jefferson Lab), the Fermilab (Fermi National Accelerator Laboratory)-E665 Collaboration, the Drell-Yan data from the Fermilab-E772 and E866/NuSea Collaborations [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76]. The mentioned data confirm a specific feature of the nuclear reactions called EMC effect at certain region of x-Bjorken.…”

xF 3 ( x,Q 2 ) Structure Function and Gross-Llewellyn Smith Sum Rule with Nuclear Effect and Higher Twist Correction

“…In addition, data from the DrellYan reaction of protons off nuclear targets are also available [21]. The experiments usually measures the ratio R 2 (x, Q 2 ) of the structure function F 2 (x, Q 2 ) of a complex nucleus to deuterium.…”