Search results for "Strange"

Search for the exotic Θ+ resonance in the NOMAD experiment

2006

12 pages, 16 figures.-- PACS nrs.: 13.15.+g; 13.60.Le; 13.87.Fh; 14.40.Ev.-- ISI Article Identifier: 000243973100007.-- ArXiv pre-print available at: http://arxiv.org/abs/hep-ex/0612063.-- et al.

Two-photon and one-photon–one-vector meson decay widths of thef0(1370),f2(1270),f0(1710),f2′(1525), andK2*(1430)

2010

We calculate the radiative decay widths, two-photon ($\ensuremath{\gamma}\ensuremath{\gamma}$) and one-photon--one-vector meson ($V\ensuremath{\gamma}$), of the dynamically generated resonances from vector-meson--vector-meson interaction in a unitary approach based on the hidden-gauge Lagrangians. In the present paper we consider the following dynamically generated resonances: ${f}_{0}(1370)$, ${f}_{0}(1710)$, ${f}_{2}(1270)$, ${f}_{2}^{\ensuremath{'}}(1525)$, ${K}_{2}^{*}(1430)$, two $\mathrm{\text{strangeness}}=0$ and $\mathrm{\text{isospin}}=1$ states, and two $\mathrm{\text{strangeness}}=1$ and $\mathrm{\text{isospin}}=1/2$ states. For the ${f}_{0}(1370)$ and ${f}_{2}(1270)$ we reproduc…

Dense Quark Matter in a Magnetic Field

2006

We explore the effects of an applied strong external magnetic field in the structure and magnitude of the color superconducting diquark condensate of a three massless flavor theory. The long-range component of the B field that penetrates the superconductor enhances the condensates formed by quarks charged with respect to this electromagnetic field.

España ante el mundo

1937

Core-collapse supernova simulations in one and two dimensions: comparison of codes and approximations

2018

We present spherically symmetric (1D) and axisymmetric (2D) supernova simulations for a convection-dominated 9 Msun and a 20 Msun progenitor that develops violent activity by the standing-accretion-shock instability (SASI). We compare in detail the Aenus-Alcar code, which uses fully multidimensional two-moment neutrino transport with an M1 closure, with a ray-by-ray-plus (RbR+) version of this code and with the Prometheus-Vertex code that employs RbR+ two-moment transport with a Boltzmann closure. Besides testing consequences of ignored non-radial neutrino-flux components in the RbR+ approximation, we also discuss the influence of various transport ingredients applied or not applied in rece…

Génétique des textes et système chaotique

2016

Textual genetics and chaotic system Although we share Louis Hay's idea that it is impossible to homologate and systematize the operations which can be observed in manuscripts, it is however possible to interpret whatever creation process in terms of the passage from entropy to order. The possibility of an analogy between text and chaotic system had been advanced by Noëlle Batt according to whom each work actually satisfies the principles of the chaotic system. It is starting from such principles that we will try to show the analogy between chaotic system and textual genetics: 1. The fact that we are dealing with an evolving system (with variables and permanent features) endowed with a tempo…

Λb→J/ψK0Λreaction and a hidden-charm pentaquark state with strangeness

2016

We study the Lambda(b) -> J/psi K-0 Lambda reaction considering both the K-0 Lambda interaction with its coupled channels and the J/psi Lambda interaction. The latter is described by taking into account the fact that there are predictions for a hidden-charm state with strangeness that couples to J/psi Lambda By using the coupling of the resonance to J/psi Lambda from these predictions, we show that a neat peak can be observed in the J/psi Lambda invariant mass distribution, rather stable under changes of unknown magnitudes. In some cases, one finds a dip structure associated to that state, but a signal of the state shows up in the J/psi Lambda spectrum.

Antineutrino induced Λ(1405) production off the proton

2015

We have studied the strangeness-changing antineutrino-induced reactions ${\overline{\ensuremath{\nu}}}_{l}p\ensuremath{\rightarrow}{l}^{+}\ensuremath{\phi}B$, with $\ensuremath{\phi}B={K}^{\ensuremath{-}}p$, ${\overline{K}}^{0}n$, ${\ensuremath{\pi}}^{0}\ensuremath{\Lambda}$, ${\ensuremath{\pi}}^{0}{\ensuremath{\Sigma}}^{0}$, $\ensuremath{\eta}\ensuremath{\Lambda}$, $\ensuremath{\eta}{\ensuremath{\Sigma}}^{0}$, ${\ensuremath{\pi}}^{+}{\ensuremath{\Sigma}}^{\ensuremath{-}}$, ${\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\Sigma}}^{+}$, ${K}^{+}{\ensuremath{\Xi}}^{\ensuremath{-}}$, and ${K}^{0}{\ensuremath{\Xi}}^{0}$, using a chiral unitary approach. These ten coupled channels are allowed t…

DYNAMICALLY GENERATED RESONANCES IN THE CHIRAL UNITARY APPROACH TO MESON BARYON INTERACTION

2004

In this talk we report on the use of a chiral unitary approach for the interaction of the octets of meson and baryon and the octet of mesons with the decuplet of baryons. Two octets of $J^{\pi}=1/2^-$ baryon states and a singlet are generated dynamically in the first case, resulting in the case of strangeness $S=-1$ in two poles of the scattering matrix close to the nominal $\Lambda(1405)$ resonance. In the second case many resonances are also generated, among them an exotic baryon with S=1 corresponding to a $\Delta K$ resonance. We make suggestions of experiments which could show evidence for the existence of these states.

S=−1meson-baryon unitarized coupled channel chiral perturbation theory and theS01resonances Λ(1405) and -Λ(1670)

2003

The $s-$wave meson-baryon scattering is analyzed for the strangeness $S=-1$ and isospin I=0 sector in a Bethe-Salpeter coupled channel formalism incorporating Chiral Symmetry. Four channels have been considered: $\pi \Sigma$, $\bar K N$, $\eta \Lambda$ and $K \Xi$. The required input to solve the Bethe-Salpeter equation is taken from lowest order Chiral Perturbation Theory in a relativistic formalism. There appear undetermined low energy constants, as a consequence of the renormalization of the amplitudes, which are obtained from fits to the $\pi\Sigma\to\pi\Sigma$ mass-spectrum, to the elastic $\bar K N \to \bar K N$ and $ \bar K N\to \pi \Sigma$ $t$--matrices and to the $ K^- p \to \eta \…