A strong signal for double parton scattering (DP) is observed in a 16 pb(-1) sample of (p) over bar p(-1) sample of (p) over bar p --> gamma + 3 jets + X data from the CDF experiment at the Fermilab Tevatron. The process-independent DP parameter, sigma(eff), is obtained without reference to theoretical calculations by comparing observed DP events to events with hard scatterings at separate (p) over bar p collisions. The result, sigma(eff) = (14.5 +/- 1.7(-2.3)(+1.7)) mb. represents a significant improvement over previous measurements. For the first time, the Feynman x dependence of the sigma(eff) parameter is investigated, and no dependence is seen. RI Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Chiarelli, Giorgio/E-8953-2012; Azzi, Patrizia/H-5404-2012
Digital Object Identifier (DOI): | http://dx.doi.org/10.1103/PhysRevLett.79.584 |
Codice identificativo ISI: | WOS:A1997XM97500013 |
Codice identificativo Scopus: | 2-s2.0-0031185729 |
Handle: | http://hdl.handle.net/11695/3959 |
Abstract: | A strong signal for double parton scattering (DP) is observed in a 16 pb(-1) sample of (p) over bar p(-1) sample of (p) over bar p --> gamma + 3 jets + X data from the CDF experiment at the Fermilab Tevatron. The process-independent DP parameter, sigma(eff), is obtained without reference to theoretical calculations by comparing observed DP events to events with hard scatterings at separate (p) over bar p collisions. The result, sigma(eff) = (14.5 +/- 1.7(-2.3)(+1.7)) mb. represents a significant improvement over previous measurements. For the first time, the Feynman x dependence of the sigma(eff) parameter is investigated, and no dependence is seen. RI Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Chiarelli, Giorgio/E-8953-2012; Azzi, Patrizia/H-5404-2012 |
Titolo: | Measurement of double parton scattering in (p)over-bar-p collisions at root s=1.8 TeV |
Autori: | |
Appare nelle tipologie: | 1.1 Articolo in rivista |