Heavy-flavour hadro-production from fixed-target to collider energies

Abstract

We review the hadro-production data presently available on open charm and beauty absolute production cross-sections, collected by experiments at CERN, DESY and Fermilab. The published charm production cross-section values are updated, in particular for the "time evolution" of the branching ratios. These measurements are compared to LO pQCD calculations, as a function of the collision energy, using recent parameterisations of the parton distribution functions. We then estimate, including nuclear effects on the parton densities, the charm and beauty production cross-sections relevant for measurements at SPS and RHIC energies, in proton-proton, proton-nucleus and nucleus-nucleus collisions. The calculations are also compared with measurements of single D and B kinematical distributions, and DD pair correlations. We finish with two brief comments, concerning the importance of beauty production as a feed-down source of J/ψ production, and open charm measurements performed using leptonic decays.

Phenomenology of a very light scalar (100 MeV < m h < 10 GeV) mixing with the SM Higgs

“…However, we note that it does not appear that any of these experiments has probed the area above the eta meson threshold for h, because of insufficient direct or indirect production at given √ s (see figure 30 of ref. [92] for B meson production rates) and/or the distance to the detector being too great. Ideally, high luminosity (and acceptance) fixed target experiments with energy √ s 20 GeV and a detector placed at a distance O(1-10 m) would be needed to probe parameter space below the B decay bound for m h 360 MeV.…”

“…The BB cross section in 7 TeV (8/13 TeV) pp collisions has been calculated as ≈ 2.5 × 10 11 fb (≈ 3/10 × 10 11 fb) [92]. Then, for example, using eq.…”

THE SHIP experiment and its detector for neutrino physics

“…The choice of a proton beam with an energy of 400 GeV/c ( √ s = 27GeV /c) is the optimal solution because at this energy the production cross sections of cc tend to saturate ( fig.2b) [6], [7], [8].…”

“…(b) Total cc production cross sections at fixed target energies [6], [7], [8]. A hybrid target made of blocks of molybdenum and tungsten, materials with a short interaction length, is adopted to maximize neutrinos from charmed hadrons while minimizing those coming from pions and kaons decays.…”

pQCD calculations of heavy quark andJ/ψ production

“…Non-photonic electron cross sections from PHENIX and STAR, compared to the FONLL theoretical prediction of [28] an uncertainty band more like an almost flat probability distribution for the 'correct' prediction, with the probability of it falling within the band depending on the way it has been obtained, but possibly (again from experience) around 80-90% for a typical NLO calculation. Figure 1 shows some recent comparisons between experimental results and theoretical predictions (in the form of uncertainty bands) for production of charm and bottom quarks at various colliders (see [25] for a recent review of fixed target data). One can see a generally good agreement within both experimental and theoretical errors.…”