In a hydrogen bubble chamber experiment with a KL beam we have measured the K" /K" ~3 e3 branching ratio to be R = .741 * .044 and the slope of the f+ form factor to be A+ = .019 f. .013. The data have been analyzed with a new variable, (p;)*, which isolates a sample of unique K e3 decays and is independent of the KL beam momentum. These results are compatible with the predictions of K* dominan...

The structure of the title compound, C(19)H(9)O, has been redetermined at 150 K. The redetermination is of significantly higher precision than a previous room-temperature structure [Ribar et al. (1974 ▶). Cryst. Struct. Commun.3, 323-325]. The C-N bond lengths for this redetermination are much closer to those observed in comparable structures, and the orientation of the methyl group with respec...

The subject of present note are relationships between certain class of noncommutative C∗-algebras and geometry of 3-dimensional manifolds which fiber over the circle. We suggest a new classification of such manifolds which is based on the K-theory of a C∗-algebra coming from measured foliations and geodesic laminations studied by Thurston et al. In the first part of the paper a bijection betwee...

In the crystal of the title compound, C(6)H(7)N(2)O(+)·C(2)HF(2)O(2) (-), the cation adopts a catemeric N-H⋯O hydrogen-bonded chain motif involving the carboxamide group, with two further N-H⋯O hydrogen bonds connecting the cations to adjacent difluoro-acetate anions via the carboxamide and pyridinium N atoms. The carboxamide group of the nicotinamidium ion is twisted by 32.3 (6)° from the pyri...

We consider an equivariant analogue of a conjecture of Borcherds. Let (Y,σ) be a real K3 surface without real points. We shall prove that the equivariant determinant of the Laplacian of (Y,σ) with respect to a σ-invariant Ricci-flat Kähler metric is expressed as the norm of the Borcherds Φ-function at the “period point”. Here the period of (Y,σ) is not the one in algebraic geometry.

We present a complete calculation of the Kl3 decays K + → πlνl and K → πlνl to O(p4, (md −mu)p, ep) in chiral perturbation theory with virtual photons and leptons. We introduce the concept of generalized form factors and kinematical densities in the presence of electromagnetism, and propose a possible treatment of the real photon emission in K l3 decays. We illustrate our results by applying th...

In [59], we introduced an invariant of K3 surfaces with involution, which we obtained using equivariant analytic torsion. This invariant gives rise to a function on the moduli space of K3 surfaces with involution and is expressed as the Petersson norm of an automorphic form characterizing the discriminant locus. In this paper, we study the structure of this automorphic form. Under certain assum...

In this article, we study the discriminant of those K3 surfaces with invo-lution which were introduced and investigated by Matsumoto, Sasaki, and Yoshida. We extend several classical results on the discriminant of elliptic curves to the dis-criminant of Matsumoto-Sasaki-Yoshida's K3 surfaces.