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981.
The production of ?0 and f mesons in πN→π+π?N reactions in the momentum range 4 to 17 GeV/c is investigated in a model-independent way by imposing in full the positivity of the density matrix. The results so obtained are used in order to determine the effective Regge trajectories for unnatural and natural parity exchanges and are compared to results obtained in different analyses. 相似文献
982.
983.
H. Lemke 《Annalen der Physik》1974,486(3):287-292
It is assumed that in an inelastic collision of two particles at high energy fireballs are created, the decay of which produces the observed particles. The fireball distribution results from the decay of the primary hadron system into a leading fireball and a rest system, which can decay further. The decay is assumed to behave according to a bootstrap condition, making the fireball distribution, that results from the rest system in its rest frame, equal to the fireball distribution in the total collision in the c.m. frame. This bootstrap condition leads to an integral equation. Approximate solutions of this integral equation in the scaling limit are discussed. 相似文献
984.
H. Alexander 《Mathematische Annalen》1974,209(3):249-256
985.
S. Alexander 《Solid State Communications》1974,14(11):1069-1071
It is demonstrated that phase transitions predicted to be first order by the Landau symmetry arguments can be continuous for a finite range of the physical parameters. For transitions with a rank-two tensor order parameter it is shown that fluctuations in a phase associated with the anisotropy of the tensor result in a renormalization of the cubic term. This leads to continuous transitions when the coefficient of the bare cubic term is small compared to the coefficient of the quartic term. It is shown that the argument can be extended to more general cases when the order parameter belongs to a multidimensional representation of the broken symmetry group. 相似文献
986.
Pionic atom data are refitted in terms of conventional π? nuclear optical potentials, modified to allow for finite range in the underlying p-wave πN interaction. We find that level shifts and widths in light and medium-weight nuclei cannot distinguish between the various ranges tested. In heavy nuclei, and for reasonable choices of neutron radii, the data tend to exclude ranges of order 0.5 fm and larger. 相似文献
987.
G. Alexander L. Criegee H.C. Dehne K. Derikum R. Devenish G. Flügge G. Franke Ch. Gerke E. Hackmack P. Harms G. Horlitz Th. Kahl G. Knies E. Lehmann R. Schmitz U. Timm P. Waloschek K. Wacker 《Physics letters. [Part B]》1978,78(1):162-166
The decay of the heavy lepton τ into πv has been established using the magnetic detector PLUTO. The branching ratio is determined to be BR(τ→πv)=(9.0 ± 2.9)% with an additional systematic uncertainty of 2.5%. This value is in good agreement with the theoretical prediction. 相似文献
988.
Alexander McKillop Alan Henderson Partha S. Ray Carmen Avendano Encarnacion G. Molinero 《Tetrahedron letters》1982,23(33):3357-3360
Ethyl carboethoxyformimidate is shown to be a versatile reagent for the synthesis of a variety of mono- and bicyclic heterocyclic systems. 相似文献
989.
990.
Bicyclo[3.1.0]hexane-2.3.4-trione and its 1.5-dimethyl derivative have been synthesized and investigated by means of photoelectron spectroscopy. 相似文献