(Li6,d) on

Abstract

the observed average final energies. On the basis of these initial conditions we further calculated by the method of Boneh, Fraenkel, and Nebenzahl 5 the average energy of the 5 He at the time of its decay taking into consideration its exponential decay with a half-life of 8 xlO" 22 sec. This curve is also shown in Fig. 3. The measured average energy of the 5 He at the time of breakup (6.3 ±0.8 MeV) yields a unique graphical solution to the initial conditions, i.e., E F (0) = 40 ±11 MeV and £ 5 (0) = 3.9±0.9 MeV. This solution applies only to neutrons which are coincident with a particles above 9 MeV. An approximate correction for the missing events gives E F (0) = 31 ± 11 MeV and £ 5 (0) = 3.2 ±0.9 MeV.The average initial conditions obtained here for the emission of 5 He are similar to those obtained in Ref. 5 from trajectory calculations which were used to reproduce the properties of the longrange a particles in spontaneous fission of 252 Cf and in particular their angular distribution relative to the fragments. Our results are also in good agreement with a similar trajectory calculation performed by Musgrove 6 who fitted his calculation to the experimental angular distribution of Raisbeck and Thomas 7 which is narrower than the experimental angular distribution 8 used by Boneh, Fraenkel, and Nabenzahl. Rajagopalan and Thomas 9 recently remeasured this angular distribution and found it to be in substantial agreement with the results of Raisbeck and Thomas. 10 We have also performed trajectory calculations in which E F (0) is a Gaussian distribution with cr = 12 MeV and a mean E F (0) = 28 MeV,The investigation of four-particle configurations in nuclei has recently been extended from nuclei of the sd shell into the Ni region 1 " 3 via the ( le O, 12 C) reaction. However, extraction of reliable spectroscopic information is difficult because of the strong Q -value dependence of the cross section 4 and the uncertainties in knowing E 5 (0) has a Maxwellian distribution with E s (0) = 3.0 MeV, and the initial emission of the 5 He is isotropic between 30° and 150° with respect to the fragment direction. The calculated a spectrum (which takes into account the lifetime of 5 He and the backward recoil of the a in the 5 He decay) is shown in Fig. 2 to be in good agreement with the experimental results. 9) also made trajectory calculations to fit their experimental results. They state (Ref. 9) that their results are in substantial agreement with the results of Musgrove (Ref. 6) despite the fact that they obtain a much lower fragment kinetic energy at scission (7.5 MeV versus 25 MeV of Ref. 6).the various configurations of the transferred fournucleon cluster. 5 A more attractive approach is the ( 6 Li,d) reaction which extensive studies 6 " 7 on light nuclei have shown to be a good a -transfer reaction. Furthermore, distorted-wave Bornapproximation (DWBA) calculations 7 indicate that the Q-value dependence of the cross section is ( 6 Li, tf)on 58 Niand 64 NiThe ( 6 Li,d) reaction has been performed on 58 Ni and 64 Ni at 38 ...

String Tension in Gauge Theories

“…In particular we refer to studies of Creutz ratios up to (4; 4) 154 : an improvement of previous string tension estimates 14;16 is allowed and it is also shown that Creutz ratios (I; J) are not stable under increasing (I; J) from (3; 3) to (4; 4). It is this a clear tendency of the estimated string tension to decrease as already noted in that period by a potential analysis 157 and a Polyakov loop measurement 155;156 .…”

Combined nonrelativistic constituent quark model and heavy quark effective theory study of semileptonic decays ofΛbandΞbbaryons

“…Their free parameters had been adjusted in the meson sector [46,47,48]. The potentials considered differ in the form factors used for the hyperfine terms, the power of the confining term 10 (p = 1, as suggested by lattice QCD calculations [50], or p = 2/3 which for mesons gives the correct asymptotic Regge trajectories [51]), or 8 They are known up to order α 2 s (zlnz) n , where z = mc/m b is the ratio of the heavy-quark masses and n = 0, 1, 2 9 Note the values for those correction factors are somewhat different from the ones quoted in Ref. [45] 10 The force which confines the quarks is still not well understood, although it is assumed to come from long-range non-perturbative features of QCD [49].…”

In beam gamma spectroscopy of62Zn

“…This state maybe identified with the 2.75 +0.01 MeV level observed in (p, t) reactions [2][3][4][5] and in (6Li, d) reaction [8] as a jr = 3-or 4 + state. Unfortunately in our experiment the 557 keV ?…”

“…The neutron deficient 62Zn nucleus has previously been studied by various transfert reactions: (160, 12C) [1], (p, t) [2][3][4][5], (3He, n) [6,7] and (6Li, d) [8] reactions, and J~ assignments up to 4 + have been deduced principally from the DWBA analysis of the (p, t) angular distributions. A few decay 7-rays were also known from the 63Cu(p, 2n7) reaction [4] (assigned from the relative pattern of the excitation function).…”