1. Nuclear dependence of light neutral meson production in p–A collisions at 400 GeV with NA60
- Author
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R. Arnaldi, K. Banicz, K. Borer, J. Castor, B. Chaurand, W. Chen, C. Cicalò, A. Colla, P. Cortese, S. Damjanovic, A. David, A. De Falco, A. Devaux, L. Ducroux, H. En’yo, J. Fargeix, A. Ferretti, M. Floris, A. Förster, P. Force, N. Guettet, A. Guichard, H. Gulkanian, J. M. Heuser, P. Jarron, M. Keil, L. Kluberg, Z. Li, C. Lourenço, J. Lozano, F. Manso, P. Martins, A. Masoni, A. Neves, H. Ohnishi, C. Oppedisano, P. Parracho, P. Pillot, T. Poghosyan, G. Puddu, E. Radermacher, P. Ramalhete, P. Rosinsky, E. Scomparin, J. Seixas, S. Serci, R. Shahoyan, P. Sonderegger, H. J. Specht, R. Tieulent, A. Uras, G. Usai, R. Veenhof, H. K. Wöhri, and NA60 Collaboration
- Subjects
Astrophysics ,QB460-466 ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract The NA60 experiment has studied low-mass muon pair production in proton–nucleus collisions with a system of Be, Cu, In, W, Pb and U targets, using a 400 GeV proton beam at the CERN SPS. The transverse momentum spectra of the $$\rho /\omega $$ ρ/ω and $$\phi $$ ϕ mesons are measured in the full $$p_{\mathrm {T}}$$ pT range accessible, from $$p_{\mathrm {T}}= 0$$ pT=0 up to $$2 \, {\hbox {GeV/c}}$$ 2GeV/c . The nuclear dependence of the production cross sections of the $$\eta $$ η , $$\omega $$ ω and $$\phi $$ ϕ mesons has been found to be consistent with the power law $$\sigma _{\mathrm {pA}} \propto {\mathrm {A}}^\alpha $$ σpA∝Aα , with the $$\alpha $$ α parameter increasing as a function of $$p_{\mathrm {T}}$$ pT for all the particles, and an approximate hierarchy $$\alpha _\eta \approx \alpha _\phi > \alpha _\omega $$ αη≈αϕ>αω . The cross section ratios $$\sigma _\eta /\sigma _\omega $$ ση/σω , $$\sigma _\rho /\sigma _\omega $$ σρ/σω and $$\sigma _\phi /\sigma _\omega $$ σϕ/σω have been studied as a function of the size A of the production target, and an increase of the $$\eta $$ η and $$\phi $$ ϕ yields relative to the $$\omega $$ ω is observed from p–Be to p–U collisions.
- Published
- 2019
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