Global QCD fit from Q2=0 to Q2=30000 GeV2 with Regge-compatible initial condition -: art. no. 076001

In this paper I show that it is possible to use Regge theory to constrain the initial parton distribution functions of a global Dokshitzer, Gribov, Lipatov, Altarelli, and Parisi (DGLAP) fit. In this approach, both quarks and gluons have the same high-energy behavior which may also be used to describe soft interactions. More precisely, I show that, if we parametrize the parton distributions with a triple-pole pomeron, i.e. like log(2)(1/x) at small x, at Q(2)=Q(0)(2) and evolve these distributions with the DGLAP equation, we can reproduce F-2(p), F-2(d), F-2(n)/F-2(p), F-2(nu N), and xF(3)(nu N) for W-2>= 12.5 GeV2. In this case, we obtain a new leading-order global QCD fit with a Regge-compatible initial condition. I shall also show that it is possible to use Regge theory to extend the parton distribution functions to small Q(2). This leads to a description of the structure functions over the whole Q(2) range based on Regge theory at low Q(2) and on QCD at large Q(2). Finally, I shall argue that, at large Q(2), the parton distribution functions obtained from DGLAP evolution and containing an essential singularity at j=1 can be approximated by a triple-pole pomeron behavior.