Showing papers in "Physics Letters B in 1999"

TL;DR: In this article, the authors extend the theory of cosmological perturbations to the case when the "matter" Lagrangian is an arbitrary function of the scalar field and its first derivatives.

TL;DR: In this article, the authors present new results based on the entire CHOOZ (The CHooZ experiment is named after the new nuclear power station operated by Electricite de France (EdF) near the village of Chooz in the Ardennes region of France) data sample.

TL;DR: In this paper, the Generalized Uncertainty Principle (GUP) was derived from a measure gedanken experiment involving micro-black holes at the Planck scale of spacetime.

TL;DR: In this paper, a transverse mass variable was introduced for measuring masses of particles which are pair produced at hadron colliders, where each particle decays to one particle that is directly observable and another particle whose existence can only be inferred from missing transverse momentum.

TL;DR: In this article, first-order Bogomol'nyi equations are found for dilaton domain walls of D-dimensional gravity with the general dilaton potential admitting a stable anti-de Sitter vacuum.

TL;DR: Using a nonlinear electrodynamics coupled to General Relativity, a new regular exact black hole solution was found in this paper, where the nonlinear theory reduces to the Maxwell one in the weak limit, and the solution corresponds to a charged black hole for |q|≤2s c m≈1.05 m, with metric, curvature invariants, and electric field regular everywhere.

TL;DR: In this article, the entropy of extremal black holes arising from terms quadratic in the Riemann tensor in N = 2, D = 4 supergravity theories was determined.

TL;DR: In this article, the cosmology of the two recently proposed scenarios for a five dimensional universe with localized gravity was examined, and it was shown that the scenario with a non-compact fifth dimension is potentially viable, while the scenario which might solve the hierarchy problem predicts a contracting universe, leading to a variety of cosmological problems.

TL;DR: In this paper, the dimensionally regularized double box Feynman diagram with powers of propagators equal to one was analytically evaluated for general values of the Mandelstam variables s and t.

TL;DR: In this article, an improved statistical model with excluded volume corrections and resonance decays is introduced and applied to the complete presently available set of particle ratios as measured by the various experiments at the SPS in Pb+Pb collisions.

TL;DR: In this paper, the scalar potential of the supergravity model has been shown to have the form V(Q)= Λ 4+α Q α e κ 2 Q 2.

TL;DR: In this article, the non-commutative supersymmetric Yang-Mills theory at strong coupling using the AdS/CFT correspondence was studied and it was shown that the supergravity solution dual to the nonsymmetric N = 4 SYM in four dimensions has no boundary and defines a minimal scale.

TL;DR: The non-planar Feynman diagram with seven massless, scalar propagators and four on-shell legs (the crossed double box) is calculated analytically in dimensional regularization as mentioned in this paper.

TL;DR: In this article, dual Type I' string descriptions to five dimensional supersymmetric fixed points with E N f + 1 global symmetry were constructed for the D4-D8 brane system in massive Type IIA supergravity.

TL;DR: In this article, a chiral tachyon-free perturbative orientifold model with supersymmetry breaking at the string scale on a collection of branes was constructed.

TL;DR: The large n limit of the n-particle SU(1,1|2) superconformal Calogero model provides a microscopic description of the extreme Reissner-Nordstrom black hole in the near-horizon limit.

TL;DR: In this paper, the static QCD potential to two-loop order was evaluated, and a sizable reduction of the twoloop coefficient was found compared to a previous calculation, which showed that the potential of QCD can be reduced by a factor of 2.

TL;DR: The results of the Troitsk ν -mass experiment on the search for the neutrino rest mass in the tritium beta-decay are presented in this article.

TL;DR: The existence of a black hole horizon is considered as a boundary condition to be imposed on the fluctuating metrics as discussed by the authors, and coordinate invariant form of the condition for class of spherically symmetric metrics is formulated The diffeomorphisms preserving this condition act in (arbitrary small) vicinity of the horizon and form the group of conformal transformations of two-dimensional space.

TL;DR: In this article, the particle states are decomposed into orthonormal basis vectors in a light-cone Fock representation and a detailed comparison with other mixing schemes is also presented.

TL;DR: The NA48 experiment at CERN has performed a new measurement of direct CP violation, based on data taken in 1997 by simultaneously collecting KL and KS decays into π0π0 and π+π− as discussed by the authors.

TL;DR: In this article, the authors reported a measurement of the atmospheric neutrino flavor ratio, R, using a sample of quasi-elastic neutrinos interactions occurring in an iron medium.

TL;DR: In this article, two-loop W-box and Z-penguin diagrams were used to evaluate the effect of perturbative QCD corrections on IR divergences.

TL;DR: In this paper, it was shown that in SUSY theories with large tan β, contributions to the amplitude arising out of exchange of neutral Higgs Bosons considerably enhances the decay of B s into l + l −.

TL;DR: In this paper, it was shown that there exists a consistent truncation of 11-dimensional supergravity to the massless fields of maximal (n = 4) 7-dimensional gauged supergravity.

TL;DR: In this paper, a leptogenesis via decays of heavy Majorana neutrinos produced non-thermally in inflaton decays was studied and it was shown that this scenario is fully consistent with existing supersymmetric inflation models such as for topological or for hybrid inflation and the Froggatt-Nielsen mechanism generating hierarchies in quark and lepton mass matrices.

TL;DR: In this article, the endpoint region of the tritium β decay spectrum was investigated to determine the mass of the electron antineutrino and an upper bound of m ν 2 =−3.7±5.3 stat ±2.1 sys eV 2 /c 4 was derived.

TL;DR: In this article, the authors consider the possibility that the masses of the three light neutrinos of the Standard Model might be almost degenerate and close to the present upper limits from Tritium β decay and cosmology and show that the renormalized neutrino masses and mixing angles are not compatible with all the experimental constraints, even for tan β as low as unity.

TL;DR: In this paper, the authors investigated the WIMP annual modulation signature with 14962 kg. day collected with the large mass highly radiopure DAMA NaI (TI) set-up.