$$\bar d - \bar u$$ asymmetry in the proton in chiral effective theory

Journal Article · Wed Mar 25 00:00:00 EDT 2015 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.114.122001· OSTI ID:1176726

Salamu, Yusupujiang ^[1]; Ji, Chueng -Ryong ^[2]; Melnitchouk, W. ^[3]; Wang, P. ^[4]

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1. Institute of High Energy Physics, CAS, Beijing (China)
2. North Carolina State Univ., Raleigh, NC (United States)
3. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
4. Institute of High Energy Physics, Beijing (China); Theoretical Physics Center for Science Facilities, CAS, Beijing (China)

We compute the $$\bar d - \bar u$$ asymmetry in the proton in chiral effective theory, including both nucleon and Δ degrees of freedom, within both relativistic and heavy baryon frameworks. In addition to the distribution at $x>0$, we estimate the correction to the integrated asymmetry arising from zero momentum contributions from pion rainbow and bubble diagrams at $x=0$, which have not been accounted for in previous analyses. In conclusion, we find that the empirical $$x$$ dependence of $$\bar d - \bar u$$ as well as the integrated asymmetry can be well reproduced in terms of a transverse momentum cutoff parameter.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1176726
• Report Number(s): JLAB-THY-14-1954; DOE/OR/23177-3180; arXiv:1409.5885; PRLTAO; ArticleNumber: 122001
• Journal Information: Physical Review Letters, Vol. 114, Issue 12; ISSN 0031-9007
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

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