Measurement of the EMC effect in the deuteron

This article reviews our current understanding of how the internal quark structure of a nucleon bound in nuclei differs from that of a free nucleon. We focus on the interpretation of measurements of the EMC effect for valence quarks, a reduction in the Deep Inelastic Scattering (DIS) cross-section ratios for nuclei relative to deuterium, and its possible connection to nucleon-nucleon Short-Range Correlations (SRC) in nuclei. Our review and new analysis (involving the amplitudes of non-nucleonic configurations in the nucleus) of the available experimental and theoretical evidence shows that there is a phenomenological relation between the EMC effect and the effects of SRC that is not an accident. The influence of strongly correlated neutron-proton pairs involving highly virtual nucleons is responsible for both effects. These correlated pairs are temporary high-density fluctuations in the nucleus in which the internal structure of the nucleons is briefly modified. This conclusion needs to be solidified by the future experiments and improved theoretical analyses that are discussed herein.

show abstract

“…The solid line (black) is the fit to the black points for 0.35 < x B < 0.7. From (Griffioen et al, 2015).…”

Section: The Deuteron Imc Effectmentioning

confidence: 99%

Nucleon-nucleon correlations, short-lived excitations, and the quarks within

et al. 2017

View full text Add to dashboard Cite

show abstract

“…In spite of the broad range of predictions, such studies indicate that nuclear effects in the deuteron are non-negligible and rise rapidly in the region of large Bjorken x. A recent direct measurement of nuclear effects in the deuteron [30] indicates a few-percent negative correction at x ∼ 0.5-0.6, with a steep rise at large x. Therefore, if neglected or treated incorrectly, these nuclear effects can potentially introduce significant uncertainties and/or biases in the extraction of the neutron structure functions and of the d quark distribution from the DIS data [31].…”

Section: Introductionmentioning

confidence: 99%

Nuclear effects in the deuteron and constraints on the d/u ratio

2017

View full text Add to dashboard Cite

We present a detailed study of nuclear corrections in the deuteron (D) by performing an analysis of data from deep inelastic scattering off proton and D, dilepton pair production in pp and pD interactions, and W ± and Z boson production in pp and pp collisions. In particular, we discuss the determination of the off-shell function describing the modification of the parton distribution functions in bound nucleons in the context of global QCD fits. Our results are consistent with the ones obtained independently from the study of data on deep inelastic scattering off heavy nuclei with mass number A ≥ 4, further confirming the universality of the off-shell function of the bound nucleon. We also study the sensitivity to the modeling of the deuteron wave function. As an important application we discuss the impact of nuclear corrections to the deuteron on the determination of the d quark distribution.

show abstract

“…Actually, the nuclear corrections in the deuteron structure function are small and usually are neglected in calculations. This fact is checked in the recent studies of the EMC effect in the deuteron by Griffioen et al [80] through analyzing the recently published CLAS data at Jefferson Lab [73]. However, we recalculated thed(x) −ū(x) considering the nuclear corrections in the deuteron but only for the last data point that its related R d EMC (= 1.07) is comparatively large, see Ref.…”

Section: Introductionmentioning

confidence: 85%

“…However, we recalculated thed(x) −ū(x) considering the nuclear corrections in the deuteron but only for the last data point that its related R d EMC (= 1.07) is comparatively large, see Ref. [80]. We found that it changes the result by 10% so that the negativity of data at large-x is still remaining.…”

Section: Introductionmentioning

confidence: 97%

Improved determination ofd¯(x)−u¯(x)flavor asymmetry in the proton by data from the BONuS experiment at JLAB and using an approach by Brodsky, Hoye

2017

View full text Add to dashboard Cite

The experimental data taken from both Drell-Yan and deep-inelastic scattering (DIS) experiments suggest a sign-change ind(x) −ū(x) flavor asymmetry in the proton at large values of momentum fraction x. In this work, we present a phenomenological study ofd(x)−ū(x) flavor asymmetry. First, we extract thed(x) −ū(x) distribution using the more recent data from the BONuS experiment at Jefferson Lab on the ratio of neutron to proton structure functions, F n 2 /F p 2 , and show that it undergoes a sing-change and becomes negative at large values of momentum fraction x, as expected. The stability and reliability of our obtained results have been examined by including target mass corrections (TMCs) as well as higher twist (HT) terms which are particularly important at the large-x region at low Q 2 . Then, we calculate thed(x) −ū(x) distribution using the Brodsky, Hoyer, Peterson, and Sakai (BHPS) model and show that if one chooses a mass for the down quark smaller than the one for the up quark it leads to a better description for the Fermilab E866 data. In order to prove this claim, we determine the masses of down and up sea quarks by fitting to the available and up-to-date experimental data for thed(x) −ū(x) distribution. In this respect, unlike the previous performed theoretical studies, we have shown that this distribution has a sign-change at x > 0.3 after evolution to the scale of available experimental data.

show abstract

Measurement of the EMC effect in the deuteron

Cited by 39 publications

References 54 publications

Nucleon-nucleon correlations, short-lived excitations, and the quarks within

Nucleon-nucleon correlations, short-lived excitations, and the quarks within

Nuclear effects in the deuteron and constraints on the d/u ratio

Improved determination ofd¯(x)−u¯(x)flavor asymmetry in the proton by data from the BONuS experiment at JLAB and using an approach by Brodsky, Hoye

Contact Info

Product

Resources

About