Measurement of the p(e,e 'pi( ))n reaction close to threshold and at low Q(2)

作者：Friscic I^*; Achenbach P; Gayoso C Ayerbe; Baumann D; Boehm R; Bosnar D; Debenjak L; Denig A; Ding M; Distler M O; Esser A; Merkel H; Middleton D G; Mihovilovic M; Mueller U; Pochodzalla J; Schlimme B S; Schoth M; Schulz F; Sfienti C; Sirca S; Thiel M; Walcher Th

来源：Physics Letters B, 2017, 766: 301-305.

DOI：10.1016/j.physletb.2017.01.033

• Short-orbit spectrometer
• Low-energy pions
• Electroproduction experiments

The cross section of the p(e, e' pi( )) nreaction has been measured for five kinematic settings at an invariant mass of W= 1094 MeVand for a four-momentum transfer of Q (2)= 0.078(GeV/c)(2). The measurement has been performed at MAMI using a new short-orbit spectrometer (SOS) of the A1 collaboration, intended for detection of low-energy pions. The transverse and longitudinal cross section terms were separated using the Rosenbluth method and the transverse-longitudinal interference term has been determined from the left-right asymmetry. The experimental cross section terms are compared with the calculations of three models: DMT2001, MAID2007 and.MAID. The results show that we do not yet understand the dynamics of the fundamental pion.

• 出版日期2017-3-10
• 单位MIT