Περίληψη:
We report new precise H(e,e(’)p)pi(0) measurements at the Delta(1232)
resonance at Q(2)=0.127 (GeV/c)(2) obtained at the MIT-Bates
out-of-plane scattering facility which are particularly sensitive to the
transverse electric amplitude (E2) of the gamma(*)N–>Delta
transition. The new data have been analyzed together with those of
earlier measurements to yield precise quadrupole to dipole amplitude
ratios: Re(E-1+(3/2)/M-1+(3/2))=(-2.3+/-0.3(stat+syst)+/-0.6(model))%
and Re(S-1+(3/2)/M-1+(3/2))=(-6.1+/-0.2(stat+syst)+/-0.5(model))% for
M-1+(3/2)=(41.4+/-0.3(stat+syst)+/-0.4(model))(10(-3)/m(pi)(+)). The
derived amplitudes give credence to the conjecture of deformation in
hadrons favoring, at low Q(2), the dominance of mesonic effects.
Συγγραφείς:
Sparveris, NF
Alarcon, R
Bernstein, AM
Bertozzi, W and
Botto, T
Bourgeois, P
Calarco, J
Casagrande, F
Distler,
MO
Dow, K
Farkondeh, M
Georgakopoulos, S
Gilad, S and
Hicks, R
Holtrop, M
Hotta, A
Jiang, X
Karabarbounis, A
and Kirkpatrick, J
Kowalski, S
Milner, R
Miskimen, R and
Nakagawa, I
Papanicolas, CN
Sarty, AJ
Sato, Y
Sirca, S
and Shaw, J
Six, E
Stave, S
Stiliaris, E
Tamae, T and
Tsentalovich, G
Tschalaer, C
Turchinetz, W
Zhou, ZL and
Zwart, T
