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WGA Theory. Low x BFKL and DGLAP BK Structure functions Diffraction. BFKL and DGLAP. L.N. Lipatov presented the talk “ DGLAP and BFKL equations in supersymmetric gauge theories ”.
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WGA Theory • Low x BFKL and DGLAP BK • Structure functions • Diffraction V. Fadin Institute of Nuclear Physics, Novosibirsk
BFKL and DGLAP L.N. Lipatov presented the talk “DGLAP and BFKL equations in supersymmetricgauge theories”. Next-to-leading corrections to the BFKL kernel and to anomalous dimension matrix in N=4 SUSY are calculated. The DGLAP equation The BFKL equation for the gluon distributions at small x V. Fadin Institute of Nuclear Physics, Novosibirsk
The eigenvalues of the kernel V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
Dmitry Colfefrai Gluon Evolution at small-x:Extending the PT Domain of QCD ’ ’ ’ ’ ’ ’
h’ hG’ Gh’ h Scale change: ; V. Fadin Institute of Nuclear Physics, Novosibirsk
Resummed splitting function Gluon density Evolution eqn. is independent of : important check of RG factorization High-energy exponent wc(as) V. Fadin Institute of Nuclear Physics, Novosibirsk
Conclusions • 2 main problems of high-energy perturbative QCD: • occurrence of large leading log s contributions and of subleading ones of comparable size and opposite sign • increasing importance of wee partons, whence a strong coupling non-perturbative Pomeron regime • RGI approach tames both problems: • through an understanding and consequent resummation of the most important subleading contributions • Subleading corrections and running coupling effects lower high-energy exponents and diffusion/tunneling into NP region • We expect a large domain of applicability of PT QCD • We have the tools to make reliable physical predictions: g *-g *, forward jets, Mueller-Navelet jets, … V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
The talk Improved Small-x Evolution with Running Coupling Effects was presented by Guido Altarelli . The talk was devoted to construction of a relatively simple, closed form, improved anomalous dimensions gI(a,N) V. Fadin Institute of Nuclear Physics, Novosibirsk
It was shown that BFKL with running coupling is fully compatible with RGE , factorisation and duality. In the Airy approximation the splitting functions are completely free of unphysical oscillations. An improved anomalous dimension that reduces to the perturbative result at large x and incorporates BFKL with running coupling effects at small x was constructed. The running coupling effects in the LO softens the asymptotic small x behaviour as indicated by the data. V. Fadin Institute of Nuclear Physics, Novosibirsk
Mellin transf. (MT) Inverse MT (x>0) V. Fadin Institute of Nuclear Physics, Novosibirsk
The minimum value of ac0 at M=1/2 is the Lipatov intercept: l0=ac0(1/2)=ac0= a4nc/plog2~2.65a~0.5 It corresponds to (for x->0): Too hard not supported by data xP(x)~x-l0 c as=0.2 ac0 ac0+a2c1 M V. Fadin Institute of Nuclear Physics, Novosibirsk
The effect of running on c in the Airy model Is a softer small-x behaviour xP ~ x-N0 xP ~ x-l V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk
V. Fadin Institute of Nuclear Physics, Novosibirsk