1 / 14

ROLE OF GLUONS in SOFT and SEMI-HARD P-P COLLISIONS AT HIGH ENERGIES

V.A. Bednyakov*, A.Grinyuk* , G.I. Lykasov*, A.F.Pikelner*, M.G. Poghosyan** *JINR ,Dubna ** CERN, Geneva. ROLE OF GLUONS in SOFT and SEMI-HARD P-P COLLISIONS AT HIGH ENERGIES. 1. Gluon distribution in proton 2. Quark –Gluon-String Model ( QGSM ) and gluons

thalia
Download Presentation

ROLE OF GLUONS in SOFT and SEMI-HARD P-P COLLISIONS AT HIGH ENERGIES

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. V.A. Bednyakov*, A.Grinyuk* , G.I. Lykasov*, A.F.Pikelner*, M.G. Poghosyan** *JINR ,Dubna ** CERN, Geneva ROLE OF GLUONS in SOFT and SEMI-HARD P-P COLLISIONS AT HIGH ENERGIES

  2. 1. Gluon distribution in proton 2. Quark –Gluon-String Model (QGSM) and gluons in proton. 3. Inclusive spectra of pions in p-p within QGSM including gluons 4. Elastic parton-parton scatetring and semi-hard p-p collisions 5. Summary OUTLOOK

  3. DIAGRAMS in ppcollisions within QGSM Fig. 1. The one-cylinder graph (at the left) and the multi-cylinder graph (at the right) for the inclusive pp hX process. QGSM A.B.Kaidalov, Phys.Lett., B116, 459 (1982) A.B.Kaidalov, K.A.Ter-Martirosyan, Phys.Lett., B117, 247 (1982) DPM • A.Capella, J.Tran Thanh Van, Phys.Lett., B114, 450 (1982)

  4. INCLUSIVE INVARIANT SPECTRUM of HADRONS PRODUCTION in PP- COLLISIONS The general form for the invariant inclusive hadron spectrum within QGSM is Eq(*) E– is an energy of the produced hadron in l.s.,p– is three-momentum in l.s. x– is Feynman variable,pt– is the transverse momentum of hadron, n– is the cross-section for production of n-pomeron chain. (*) The cross-section is calculated in “eiconal approximation”. (**) * [G.L., V.V.Lyubushkin, V.A.Bednyakov, Nucl.Phys. B198(2010)165]

  5. where, according to the CKMT And we assume that or GLUON DISTRIBUTION IN PROTON

  6. aπ = 0.4 γF = 2.8 γQ = 4.5

  7. aK = 0.04 γF = 2.3

  8. Inclusive hadron production in central region and the AGK cancellation According to the AGK, the n-Pomeron contributions to the inclusive hadron spectrum at y=0 are cancelled and only the one-Pomeron contributes. This was proved asymptotically, i.e., at very high energies. Using this AGK we estimate the inclusive spectrum of the charged hadrons produced in p-p at y=0 as a function of the transverse momentum including the quark and gluon components in the proton. So, the inclusive spectrum is presented in the following form: Aq = 11.91 ± 0.39, bq = 7.29 ± 0.11 Ag = 3.76 ± 0.13 bg = 3.51 ± 0.02 February 2009, CERN 10

  9. pt GeV

  10. Gluons in proton S QCD P QCD pt GeV

  11. SUMMARY • The soft QCD or the QGSM describes the experimental data on inclusive spectra of charge hadrons produced in p-p at low pt (< 1 GeV) rather satisfactorily. • The inclusion of the gluon distributions in proton allows us to apply the QGSM to analyze the hadron production in p-p at higher transverse momenta (~ 2 GeV). • Starting from ~ 2 GeV hard processes dominate: model of Field, Feynman and Fox. • The contribution of gluons in proton to the multiplicity distribution at LHC energies is studied in detail.

  12. THANK YOU VERY MUCH FOR YOUR ATTENTION !

More Related