40Ca(alpha, gamma)44Ti reaction in the energy regime of supernova nucleosynthesis.
The 44Ti(t1/2=59 yr) nuclide, an important signature of supernova nucleosynthesis, has recently been observed as live radioactivity by gamma-ray astronomy from the Cas A remnant. We investigate in the laboratory the major 44Ti production reaction 40Ca(alpha, gamma)44Ti (Ec.m. approximately 0.6-1.2 MeV/u by direct off-line counting of 44Ti nuclei. The yield, significantly higher than inferred from previous experiments, is analyzed in terms of a statistical model using microscopic nuclear inputs. The associated stellar rate has important astrophysical consequences, increasing the calculated supernova 44Ti yield by a factor approximately 2 over previous estimates and bringing it closer to Cas A observations.
Nassar
H
H
Racah Institute of Physics, Hebrew University, 91904 Jerusalem, Israel.
Paul
M
M
Ahmad
I
I
Ben-Dov
Y
Y
Caggiano
J
J
Ghelberg
S
S
Goriely
S
S
Greene
J P
JP
Hass
M
M
Heger
A
A
Heinz
A
A
Henderson
D J
DJ
Janssens
R V F
RV
Jiang
C L
CL
Kashiv
Y
Y
Nara Singh
B S
BS
Ofan
A
A
Pardo
R C
RC
Pennington
T
T
Rehm
K E
KE
Savard
G
G
Scott
R
R
Vondrasek
R
R