Abstract
We study effects of imposing various forms of the kinematical constraint on the full form of the CCFM equation and its non-linear extension. We find, that imposing the constraint in its complete form modifies significantly the shape of gluon density as compared to forms of the constraint used in numerical calculations and phenomenological applications. In particular the resulting gluon density is suppressed for large values of the hard scale related parameter and k T of gluon. This result might be important in description of jet correlations at Large Hadron Collider within the CCFM approach.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
L.V. Gribov, E.M. Levin and M.G. Ryskin, Semihard Processes in QCD, Phys. Rept. 100 (1983) 1 [INSPIRE].
S. Catani, M. Ciafaloni and F. Hautmann, High-energy factorization and small-x heavy flavor production, Nucl. Phys. B 366 (1991) 135 [INSPIRE].
M. Ciafaloni, Coherence Effects in Initial Jets at Small Q 2 /s, Nucl. Phys. B 296 (1988) 49 [INSPIRE].
S. Catani, F. Fiorani and G. Marchesini, Small-x Behavior of Initial State Radiation in Perturbative QCD, Nucl. Phys. B 336 (1990) 18 [INSPIRE].
S. Catani, F. Fiorani and G. Marchesini, QCD Coherence in Initial State Radiation, Phys. Lett. B 234 (1990) 339 [INSPIRE].
H. Jung et al., The CCFM Monte Carlo generator CASCADE version 2.2.03, Eur. Phys. J. C 70 (2010) 1237 [arXiv:1008.0152] [INSPIRE].
F. Hautmann and H. Jung, Transverse momentum dependent gluon density from DIS precision data, Nucl. Phys. B 883 (2014) 1 [arXiv:1312.7875] [INSPIRE].
F. Hautmann, H. Jung and S.T. Monfared, The CCFM uPDF evolution uPDFevolv Version 1.0.00, Eur. Phys. J. C 74 (2014) 3082 [arXiv:1407.5935] [INSPIRE].
J. Kwiecinski, A.D. Martin and P.J. Sutton, Constraints on gluon evolution at small x, Z. Phys. C 71 (1996) 585 [hep-ph/9602320] [INSPIRE].
K. Kutak, K. Golec-Biernat, S. Jadach and M. Skrzypek, Nonlinear equation for coherent gluon emission, JHEP 02 (2012) 117 [arXiv:1111.6928] [INSPIRE].
K. Kutak, Nonlinear extension of the CCFM equation, arXiv:1206.1223 [INSPIRE].
K. Kutak, Resummation in nonlinear equation for high energy factorisable gluon density and its extension to include coherence, JHEP 12 (2012) 033 [arXiv:1206.5757] [INSPIRE].
M. Deak, F. Hautmann, H. Jung and K. Kutak, Forward Jet Production at the Large Hadron Collider, JHEP 09 (2009) 121 [arXiv:0908.0538] [INSPIRE].
M. Deak, F. Hautmann, H. Jung and K. Kutak, Jets in the forward region at the LHC, arXiv:0908.1870 [INSPIRE].
M. Deak, F. Hautmann, H. Jung and K. Kutak, Forward-Central Jet Correlations at the Large Hadron Collider, arXiv:1012.6037 [INSPIRE].
K. Kutak and S. Sapeta, Gluon saturation in dijet production in p-Pb collisions at Large Hadron Collider, Phys. Rev. D 86 (2012) 094043 [arXiv:1205.5035] [INSPIRE].
CMS collaboration, Measurement of the inclusive production cross sections for forward jets and for dijet events with one forward and one central jet in pp collisions at \( \sqrt{s} \) = 7 TeV, JHEP 06 (2012) 036 [arXiv:1202.0704] [INSPIRE].
A. van Hameren, P. Kotko, K. Kutak and S. Sapeta, Small-x dynamics in forward-central dijet decorrelations at the LHC, Phys. Lett. B 737 (2014) 335 [arXiv:1404.6204] [INSPIRE].
A. van Hameren, P. Kotko, K. Kutak, C. Marquet and S. Sapeta, Saturation effects in forward-forward dijet production in p + P b collisions, Phys. Rev. D 89 (2014) 094014 [arXiv:1402.5065] [INSPIRE].
K. Kutak, Hard scale dependent gluon density, saturation and forward-forward dijet production at the LHC, Phys. Rev. D 91 (2015) 034021 [arXiv:1409.3822] [INSPIRE].
M. Deak, Estimation of saturation and coherence effects in the KGBJS equation — a non-linear CCFM equation, JHEP 07 (2013) 087 [arXiv:1209.6092] [INSPIRE].
K. Kutak and D. Toton, Gluon saturation scale from the KGBJS equation, JHEP 11 (2013) 082 [arXiv:1306.3369] [INSPIRE].
G.P. Salam, Associated quantities from the CCFM approach, in Brussels 1998, Deep inelastic scattering and QCD, pg. 543-547 hep-ph/9805322 [INSPIRE].
G. Bottazzi, G. Marchesini, G.P. Salam and M. Scorletti, Small-x one particle inclusive quantities in the CCFM approach, JHEP 12 (1998) 011 [hep-ph/9810546] [INSPIRE].
G.P. Salam, Soft emissions and the equivalence of BFKL and CCFM final states, JHEP 03 (1999) 009 [hep-ph/9902324] [INSPIRE].
E. Avsar and A.M. Stasto, Non-linear evolution in CCFM: The interplay between coherence and saturation, JHEP 06 (2010) 112 [arXiv:1005.5153] [INSPIRE].
A. Bacchetta, H. Jung, A. Knutsson, K. Kutak and F. Samson-Himmelstjerna, A method for tuning parameters of Monte Carlo generators and a its application to the determination of the unintegrated gluon density, Eur. Phys. J. C 70 (2010) 503 [arXiv:1001.4675] [INSPIRE].
G. Chachamis, M. Deak, A.S. Vera and P. Stephens, A comparative study of small x Monte Carlos with and without QCD coherence effects, Nucl. Phys. B 849 (2011) 28 [arXiv:1102.1890] [INSPIRE].
CMS collaboration, Measurement of azimuthal correlations between forward and central jets in proton proton collisions at \( \sqrt{s} \) = 7 TeV, CMS-PAS-FSQ-12-008.
Open Access
This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.
Author information
Authors and Affiliations
Corresponding author
Additional information
ArXiv ePrint: 1503.00536v2
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0), which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
About this article
Cite this article
Deak, M., Kutak, K. Kinematical constraint effects in the evolution equations based on angular ordering. J. High Energ. Phys. 2015, 68 (2015). https://doi.org/10.1007/JHEP05(2015)068
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/JHEP05(2015)068