Publication
First measurement of proton-induced low-momentum dielectron radiation off cold nuclear matter
| dc.contributor.author | HADES collaboration (97 authors) | |
| dc.contributor.author | Blanco, A. | |
| dc.contributor.author | Fonte, P. | |
| dc.contributor.author | Lopes, L. | |
| dc.contributor.author | Mangiarotti, A. | |
| dc.date.accessioned | 2019-02-03T19:54:01Z | |
| dc.date.available | 2019-02-03T19:54:01Z | |
| dc.date.issued | 2012-09-10 | |
| dc.date.updated | 2019-02-03T19:54:01Z | |
| dc.description.abstract | We present data on dielectron emission in proton induced reactions on a Nb target at 3.5 GeV kinetic beam energy measured with HADES installed at GSI. The data represent the first high statistics measurement of proton-induced dielectron radiation from cold nuclear matter in a kinematic regime, where strong medium effects are expected. Combined with the good mass resolution of 2%, it is the first measurement sensitive to changes of the spectral functions of vector mesons, as predicted by models for hadrons at rest or small relative momenta. Comparing the e+e invariant mass spectra to elementary p+p data, we observe for e+e momenta Pee < 0.8 GeV/c a strong modification of the shape of the spectrum, which we attribute to an additional rho-like contribution and a decrease of omega yield. These opposite trends are tentatively interpreted as a strong coupling of the rho meson to baryonic resonances and an absorption of the omega meson, which are two aspects of in-medium modification of vector mesons. | |
| dc.description.version | Peer Reviewed | |
| dc.identifier | Phys.Lett. B715 (2012) 304-309; DOI 10.1016/j.physletb.2012.08.004 | |
| dc.identifier.uri | http://dx.doi.org/10.1016/j.physletb.2012.08.004 | |
| dc.identifier.uri | http://hdl.handle.net/10400.26/26173 | |
| dc.language.iso | eng | |
| dc.title | First measurement of proton-induced low-momentum dielectron radiation off cold nuclear matter | |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| rcaap.rights | openAccess | pt |
| rcaap.type | article |