1 resultado para Project 2002-043-B : Smart Building For Healthy and Sustainable Workplaces – Scoping Study

em CaltechTHESIS


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<p>The lowest T = 2 states have been identified and studied in the nuclei <sup>12</sup>C, <sup>12</sup>B, <sup>20</sup>F and and <sup>28</sup>Al. The first two of these were produced in the reactions <sup>14</sup>C(p,t)<sup>12</sup>C and <sup>14</sup>C (p,<sup>3</sup>He)<sup>12</sup>B, at 50.5 and 63.4 MeV incident proton energy respectively, at the Oak Ridge National Laboratory. The T = 2 states in <sup>20</sup>F and <sup>28</sup>Al were observed in (<sup>3</sup>He,p) reactions at 12-MeV incident energy, with the Caltech Tandem accelerator.</p> <p>The results for the four nuclei studied are summarized below:</p> <p>(1) <sup>12</sup>C: the lowest T = 2 state was located at an excitation energy of 27595 ± 20 keV, and has a width less than 35 keV.</p> <p>(2) <sup>12</sup>B: the lowest T = 2 state was found at an excitation energy of 12710 ± 20 keV. The width was determined to be less than 54 keV and the spin and parity were confirmed to be 0<sup>+</sup>. A second <sup>12</sup>B state (or doublet) was observed at an excitation energy of 14860 ± 30 keV with a width (if the group corresponds to a single state) of 226 ± 30 keV.</p> <p>(3) <sup>20</sup>F: the lowest T = 2 state was observed at an excitation of 6513 ± 5 keV; the spin and parity were confirmed to be 0<sup>+</sup>. A second state, tentatively identified as T = 2 from the level spacing, was located at 8210 ± 6 keV.</p> <p>(4) <sup>28</sup>Al: the lowest T = 2 state was identified at an excitation of 5997 ± 6 keV; the spin and parity were confirmed to be 0<sup>+</sup>. A second state at an excitation energy of 7491 ± 11 keV is tentatively identified as T = 2, with a corresponding (tentative) spin and parity assignment J<sup>Ï</sup> = 2<sup>+</sup>.</p> <p>The results of the present work and the other known masses of T = 2 states and nuclei for 8 &#8804; A &#8804; 28 are summarized, and massequation coefficients have been extracted for these multiplets. These coefficients were compared with those from T = 1 multiplets, and then used to predict the mass and stability of each of the unobserved members of the T = 2 multiplets.</p>