Comparison of the isolated direct photon cross sections inpp¯collisions ats=1.8 TeVands=0.63 TeV
Citations Over TimeTop 10% of 2002 papers
Abstract
We have measured the cross sections ${d}^{2}\ensuremath{\sigma}{/dP}_{T}d\ensuremath{\eta}$ for production of isolated direct photons in $p\overline{p}$ collisions at two different center-of-mass energies, 1.8 TeV and 0.63 TeV, using the Collider Detector at Fermilab. The normalization of both data sets agrees with the predictions of quantum chromodynamics for a photon transverse momentum ${(P}_{T})$ of 25 GeV/c, but the shapes versus photon ${P}_{T}$ do not. These shape differences lead to a significant disagreement in the ratio of cross sections in the scaling variable ${x}_{T}(\ensuremath{\equiv}{2P}_{T}/\sqrt{s}).$ This disagreement in the ${x}_{T}$ ratio is difficult to explain with conventional theoretical uncertainties such as scale dependence and parton distribution parametrizations.
Related Papers
- → Unintegrated double parton distributions(2017)11 cited
- → Parton Model Without Wee Partons(1973)
- Susquehanna Chorale Spring Concert "Roots and Wings"(2017)
- → Double parton distributions out of bounds in colour space(2021)