({sup 3}He,t) reaction on the double {beta} decay nucleus {sup 48}Ca and the importance of nuclear matrix elements

Journal Article · Thu Nov 15 00:00:00 EST 2007 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.76.054307· OSTI ID:21067888

Grewe, E -W; Frekers, D; Rakers, S; Baeumer, C; Dohmann, H; Thies, J ^[1]; Adachi, T; Fujita, Y; Shimbara, Y ^[2]; Botha, N T ^[3]; Fujita, H ^[4]; Hatanaka, K; Nakanishi, K; Sakemi, Y; Shimizu, Y; Tameshige, Y; Tamii, A ^[5]; Negret, A; Popescu, L ^[6]; Neveling, R ^[7]

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1. Institut fuer Kernphysik, Westfaelische Wilhelms-Universitaet, D-48149 Muenster (Germany)
2. Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan)
3. Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa)
4. School of Physics, University of the Witwatersrand, Johannesburg 2050 (South Africa)
5. Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan)
6. Vakgroep Subatomaire en Stralingfysica, Universiteit Gent, B-9000 Gent (Belgium)
7. iThemba LABS, POB 722, Somerset West 7129 (South Africa)

High-resolution ({sup 3}He,t) measurements on the double {beta}-decay ({beta}{beta}) nucleus {sup 48}Ca have been performed at RCNP (Osaka, Japan) to determine Gamow-Teller (GT{sup -}) transitions to the nucleus {sup 48}Sc, which represents the intermediate nucleus in the second-order perturbative description of the {beta}{beta} decay. At a bombarding energy of E{sub {sup 3}He}=420 MeV an excitation energy resolution of 40 keV was achieved. The measurements were performed at two angle positions of the Grand Raiden Spectrometer (GRS): 0 deg. and 2.5 deg. The results of both settings were combined to achieve angular distributions, by which the character of single transitions could be determined. To characterize the different multipoles, theoretical angular distributions for states with J{sup {pi}}=1{sup +},2{sup +},2{sup -}, and 3{sup +} were calculated using the distorted-wave Born approximation (DWBA) Code DW81. The GT{sup -} strength was extracted up to E{sub x}=7 MeV and combined with corresponding GT{sup +} strength deduced from the {sup 48}Ti(d,{sup 2}He){sup 48}Sc data to calculate the low-energy part of the {beta}{beta}-decay matrix element for the {sup 48}Ca 2{nu}{beta}{beta} decay. We show that after applying trivial momentum corrections to the ({sup 3}He,t) spectrum, the two reaction probes (p,n) and ({sup 3}He,t) reveal a spectral response to an impressively high degree of similarity in the region of low momentum transfer.

• OSTI ID: 21067888
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 76, Issue 5; Other Information: DOI: 10.1103/PhysRevC.76.054307; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
CALCIUM 48
CORRECTIONS
DOUBLE BETA DECAY
DWBA
ENERGY RESOLUTION
EXCITATION
GAMOW-TELLER RULES
HELIUM 2
HELIUM 3 REACTIONS
KEV RANGE
MATRIX ELEMENTS
MEV RANGE
MOMENTUM TRANSFER
MULTIPOLE TRANSITIONS
NUCLEAR MATRIX
SCANDIUM 48
SPECTRAL RESPONSE
TITANIUM 48