Beam spin asymmetries in deeply virtual Compton scattering (DVCS) with CLAS at 4.8 GeV

• Main Authors: Prok, Yelena (Contributor), Rowntree, D. (Contributor), Skabelin, Alexander V. (Contributor), Suleiman, R. (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2011-08-05T17:32:55Z.
• Subjects: Article
• Online Access: Get fulltext

 We report measurements of the beam spin asymmetry in deeply virtual Compton scattering (DVCS) at an electron beam energy of 4.8 GeV using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The DVCS beam spin asymmetry has been measured in a wide range of kinematics, 1.0<Q2<2.8 (GeV/c)2 [1.0 < Q superscript 2 < 2.8 (GeV/c) superscript 2], 0.12<xB<0.48 [0.12 < X subscript beta < 0.48], and 0.1<-t<0.8 (GeV/c)2 [0.1 < -t < 0.8 (GeV/c) superscript 2], using the reaction e⃗p→e'pX [e superscript right arrow e prime pX]. The number of H(e,e'γp) [H (e,e prime yp)] and H(e,e'π0p) [H(e,e prime pi superscript 0 p] events are separated in each (Q2,xB,t) [(Q superscript 2, x subscript beta, t)] bin by a fit to the line shape of the H(e,e'p)X Mx2 [H (e, e prime p) X M subscript x superscript 2] distribution. The validity of the method was studied in detail using experimental and simulated data. It was shown that with the achieved missing mass squared resolution and the available statistics, the separation of DVCS-Bethe-Heitler and π0 [pi superscript 0] events can reliably be done with less than 5% uncertainty. Also, the Q2 [Q superscript 2] and t dependences of the sinϕ [sin phi] moments of the asymmetry are extracted and compared with theoretical calculations.