First measurement of the helicity dependence of 3He photoreactions in the Δ(1232)Δ(1232) resonance region
A. Bartolomé P.
(1)
,
A. Mushkarenkov
(2)
,
J. Ahrens
(1)
,
J.R.M. Annand
(3)
,
H.-J. Arends
(1)
,
R. Beck
(4)
,
V. Bekrenev
(5)
,
H. Berghäuser
(6)
,
A. Braghieri
(2)
,
W. J. Briscoe
(7)
,
N. Cherepnya S.
(8)
,
S. Costanza
(2)
,
P. Drexler
(6)
,
V. Filʼkov L.
(8)
,
A. Fix
(9)
,
G. Giardina
(2, 10)
,
D. I. Glazier
(3)
,
D. Hamilton
(3)
,
E. Heid
(1)
,
W. Heil
(11)
,
D. Hornidge
(12)
,
D. Howdle
(3)
,
I. Jaegle
(13)
,
O. Jahn
(1)
,
T. Jude
(3)
,
L. Kashevarov V.
(1, 8)
,
I. Keshelashvili
(13)
,
R. Kondratiev
(14)
,
M. Korolija
(15)
,
J. Krimmer
(16)
,
B. Krusche
(13)
,
S. Kruglov
(5)
,
A. Kulbardis
(5)
,
M. Lisin
(14)
,
K. Livingston
(3)
,
J. Mancell
(3)
,
G. Middleton D.
(1, 12)
,
I. J. D. Macgregor
(3)
,
D.M. Manley
(17)
,
J.C. Mcgeorge
(3)
,
V. Metag
(6)
,
B.M.K. Nefkens
(18)
,
A. Nikolaev
(4)
,
M. Oberle
(13)
,
M. Ostrick
(1)
,
H. Ortega
(1)
,
P.B. Otte
(1)
,
B. Oussena
(1)
,
P. Pedroni
(2)
,
F. Pheron
(13)
1
Institut für Kernphysik
2 INFN - Istituto Nazionale di Fisica Nucleare, Sezione di Pavia
3 SUPA School of Physics and Astronomy [Glasgow]
4 HISKP - Helmholtz-Institut für Strahlen- und Kernphysik
5 Petersburg Nuclear Physics Institute
6 Physikalisches Institut [Gießen]
7 Department of Physics
8 LPI RAS - P. N. Lebedev Physical Institute of the Russian Academy of Sciences [Moscow]
9 Department of Higher Mathematics and Mathematical Physics
10 Dipartimento di Fisica e Scienze della Terra [Messina]
11 Institut für Physik [Mainz]
12 Department of Physics
13 Institut für Physik
14 Institute for Nuclear Research
15 Rudjer Boskovic Institute [Zagreb]
16 IPNL - Institut de Physique Nucléaire de Lyon
17 Department of Physics
18 UCLA - University of California [Los Angeles]
2 INFN - Istituto Nazionale di Fisica Nucleare, Sezione di Pavia
3 SUPA School of Physics and Astronomy [Glasgow]
4 HISKP - Helmholtz-Institut für Strahlen- und Kernphysik
5 Petersburg Nuclear Physics Institute
6 Physikalisches Institut [Gießen]
7 Department of Physics
8 LPI RAS - P. N. Lebedev Physical Institute of the Russian Academy of Sciences [Moscow]
9 Department of Higher Mathematics and Mathematical Physics
10 Dipartimento di Fisica e Scienze della Terra [Messina]
11 Institut für Physik [Mainz]
12 Department of Physics
13 Institut für Physik
14 Institute for Nuclear Research
15 Rudjer Boskovic Institute [Zagreb]
16 IPNL - Institut de Physique Nucléaire de Lyon
17 Department of Physics
18 UCLA - University of California [Los Angeles]
Résumé
The first measurement of the helicity dependence of the total inclusive 3He photo-absorption cross section and of the partial cross sections for several reaction channels was carried out at MAMI (Mainz) in the photon energy range between 150 and 500 MeV. The experiment used the large acceptance Crystal Ball spectrometer, complemented by charged particle and vertex detectors, a circularly polarised tagged photon beam and a longitudinally polarised high-pressure 3He gas target. The results obtained give information on the GDH integral on 3He and on the neutron and allow an investigation of the modifications of nucleon properties inside 3He.