papers

Publications (22)

gr-qc1998

Free Fields for Chiral 2D Dilaton Gravity

J. Cruz, J. Navarro-Salas, M. Navarro

We give an explicit canonical transformation which transforms a generic chiral 2D dilaton gravity model into a free field theory.

hep-th1997

Free fields via canonical transformations of matter-coupled 2D dilaton gravity models

J. Cruz, J. M. Izquierdo, D. J. Navarro +1

It is shown that the 1+1-dimensional matter-coupled Jackiw-Teitelboim model and the model with an exponential potential can be converted by means of appropriate canonical transform…

gr-qc1997

Symmetries and solvable models for evaporating 2D black holes

J. Cruz, J. Navarro-Salas, M. Navarro +1

We study the evaporation process of a 2D black hole in thermal equilibrium when the ingoing radiation is switched off suddenly. We also introduce global symmetries of generic 2D di…

nucl-ex2016

Cross Sections for proton induced high energy -ray emission (PIGE) in reaction F(p,)O at incident proton energies between 1.5 and 4 MeV

P. Cabanelas, J. Cruz, M. Fonseca +11

We have studied the high energy gamma-rays produced in the reaction F(p,)O for incident proton energies from 1.5 to 4.0 MeV over NaF/Ag and CaF/Ag thin targ…

nucl-ex2005

Feasibility of low energy radiative capture experiments at the LUNA underground accelerator facility

D. Bemmerer, F. Confortola, A. Lemut +29

The LUNA (Laboratory Underground for Nuclear Astrophysics) facility has been designed to study nuclear reactions of astrophysical interest. It is located deep underground in the Gr…

hep-th1999

Can conformal Transformations change the fate of 2D black holes?

J. Cruz, A. Fabbri, J. Navarro-Salas

By using a classical Liouville-type model of two dimensional dilaton gravity we show that the one-loop theory implies that the fate of a black hole depends on the conformal frame.…

hep-th1996

Black Hole Evaporation by Thermal Bath Removal

J. Cruz, J. Navarro-Salas

We study the evaporation process of 2D black holes in thermal equilibrium when the incoming radiation is turned off. Our analysis is based on two different classes of 2D dilaton gr…

hep-th1995

Solvable Models for radiating Black Holes and Area-preserving Diffeomorphisms

J. Cruz, J. Navarro-Salas

Solvable theories of 2D dilaton gravity can be obtained from a Liouville theory by suitable field redefinitions. In this paper we propose a new framework to generate 2D dilaton gra…

hep-th1997

Canonical Equivalence of a Generic 2D Dilaton Gravity Model and a Bosonic String Theory

J. Cruz, J. Navarro-Salas

We show that a canonical tranformation converts, up to a boundary term, a generic 2d dilaton gravity model into a bosonic string theory with a Minkowskian target space.

hep-th1997

General Covariance and Free Fields in Two Dimensions

J. Cruz, D. J. Navarro, J. Navarro-Salas

We investigate the canonical equivalence of a matter-coupled 2D dilaton gravity theory defined by the action functional $S = \int d^2x \sqrt{-g} (Rϕ+ V(ϕ) - 1/2 H(ϕ) (\nablaf)^2…

astro-ph2004

The bottleneck of the CNO burning and the age of the Globular Clusters

G. Imbriani, H. Costantini, A. Formicola +27

The transition between the Main Sequence and the Red Giant Branch in low mass stars is powered by the onset of the CNO burning, whose bottleneck is the N(p,O. The…

hep-th1997

Conformal and Nonconformal Symmetries in 2d Dilaton gravity

J. Cruz, J. Navarro-Salas, M. Navarro +1

We study finite-dimensional extra symmetries of generic 2D dilaton gravity models. Using a non-linear sigma model formulation we show that the unique theories admitting an extra (c…

nucl-ex2006

First measurement of the 14N(p,gamma)15O cross section down to 70 keV

A. Lemut, D. Bemmerer, F. Confortola +28

In stars with temperatures above 20*10^6 K, hydrogen burning is dominated by the CNO cycle. Its rate is determined by the slowest process, the 14N(p,gamma)15O reaction. Deep underg…

gr-qc1998

Free Field Realization of Cylindrically Symmetric Einstein Gravity

J. Cruz, A. Mikovic, J. Navarro-Salas

Cylindrically reduced Einstein gravity can be regarded as an sigma model coupled to 2D dilaton gravity. By using the corresponding 2D diffeomorphism algebra of cons…

gr-qc1999

Integrable models, degenerate horizons and AdS_2 black holes

J. Cruz, A. Fabbri, D. J. Navarro +2

The near extremal Reissner-Nordstrom black holes in arbitrary dimensions ca be modeled by the Jackiw-Teitelboim (JT) theory. The asymptotic Virasoro symmetry of the corresponding J…

gr-qc1996

New Symmetries in Two-Dimensional Dilaton Gravity

J. Cruz, J. Navarro-Salas, M. Navarro +1

We present three types of non-conformal symmetries for a wide class of 2D dilaton-gravity models. For the particular CGHS, or string-inspired model, a linear combination of these s…

hep-th1998

Hidden conformal symmetry of a massive scalar field in 2-dimensional Anti-De Sitter space

J. Cruz

We show that a massive scalar field on a 2-dimensional Anti-De Sitter space can be mapped by means of a time-dependent canonical transformation into a massless free field theory wh…

physics.ins-det2025

Towards a comprehensive study of the 14N(p,g)15O astrophysical key reaction: Description of the experimental technique including novel target preparation

A. Compagnucci, A. Formicola, M. Campostrini +46

While the 14N(p,g)15O reaction plays a key role in the hydrogen-burning processes in various stellar conditions, its reaction rate is not known with sufficient precision. Therefore…

gr-qc1999

On the normalization of Killing vectors and energy conservation in two-dimensional gravity

J. Cruz, A. Fabbri, J. Navarro-Salas

We explicitly show that, in the context of a recently proposed 2D dilaton gravity theory, energy conservation requires the ``natural'' Killing vector to have, asymptotically, an un…

nucl-ex2005

S-factor of 14N(p,gamma)15O at astrophysical energies

G. Imbriani, H. Costantini, A. Formicola +31

The astrophysical S-factor of 14N(p,gamma)15O has been measured for effective center-of-mass energies between E_eff = 119 and 367 keV at the LUNA facility using TiN solid targets a…

hep-th1996

A Quantum Model of Schwarzschild Black Hole Evaporation

J. Cruz, A. Mikovic, J. Navarro-Salas

We construct a one-loop effective metric describing the evaporation phase of a Schwarzschild black hole in a spherically symmetric null-dust model. This is achieved by quantising t…

hep-th1999

Integrable models and degenerate horizons in two-dimensional gravity

J. Cruz, A. Fabbri, D. J. Navarro +1

We analyse an integrable model of two-dimensional gravity which can be reduced to a pair of Liouville fields in conformal gauge. Its general solution represents a pair of ``mirror'…