Resumen: In this work we present a search for (solar) chameleons with the CERN Axion Solar Telescope (CAST). This novel experimental technique, in the field of dark energy research, exploits both the chameleon coupling to matter (ßm) and to photons (ß¿) via the Primakoff effect. By reducing the X-ray detection energy threshold used for axions from 1keV to 400eV CAST became sensitive to the converted solar chameleon spectrum which peaks around 600eV. Even though we have not observed any excess above background, we can provide a 95% C.L. limit for the coupling strength of chameleons to photons of ß¿¿1011 for 1<ßm<106. Idioma: Inglés DOI: 10.1016/j.physletb.2015.07.049 Año: 2015 Publicado en: Physics Letters B 749 (2015), 172-180 ISSN: 0370-2693 Factor impacto JCR: 4.787 (2015) Categ. JCR: ASTRONOMY & ASTROPHYSICS rank: 14 / 62 = 0.226 (2015) - Q1 - T1 Categ. JCR: PHYSICS, NUCLEAR rank: 4 / 21 = 0.19 (2015) - Q1 - T1 Categ. JCR: PHYSICS, PARTICLES & FIELDS rank: 7 / 28 = 0.25 (2015) - Q1 - T1 Factor impacto SCIMAGO: 3.32 - Nuclear and High Energy Physics (Q1)