Investigations into the BFKL mechanism with a running QCD coupling
(1998) In Physical Review D (Particles and Fields) 57(9). p.5543-5554- Abstract
- We present approximations of varying degree of sophistication to the integral equations for the (gluon) structure functions of a hadron ("the partonic flux factor") in a model valid in the leading log approximation with a running coupling constant. The results are all of the BFKL type, i.e., a power in the Bjorken variable x(B)(-lambda) with the parameter lambda determined from the size alpha(0) of the "effective" running coupling <(alpha)over bar>=3 alpha(s)/pi =alpha(0)/ln(k(perpendicular to)(2)) and varying depending upon the treatment of the transverse momentum pole, we also consider the implications for the transverse momentum (k(perpendicular to)) fluctuations along the emission chains and we obtain an exponential falloff in... (More)
- We present approximations of varying degree of sophistication to the integral equations for the (gluon) structure functions of a hadron ("the partonic flux factor") in a model valid in the leading log approximation with a running coupling constant. The results are all of the BFKL type, i.e., a power in the Bjorken variable x(B)(-lambda) with the parameter lambda determined from the size alpha(0) of the "effective" running coupling <(alpha)over bar>=3 alpha(s)/pi =alpha(0)/ln(k(perpendicular to)(2)) and varying depending upon the treatment of the transverse momentum pole, we also consider the implications for the transverse momentum (k(perpendicular to)) fluctuations along the emission chains and we obtain an exponential falloff in the relevant kappa=ln(k(perpendicular to)(2)) variable, i.e., an inverse power (k(perpendicular to)(2))(-(2+lambda)) with the same parameter lambda. This is different from the BFKL result for a fixed coupling, where the distributions are Gaussian in the kappa variable with a width as in a Brownian motion determined by "the length" of the emission chains, i.e., In(1/x(B)). The results are verified by a realistic Monte Carlo simulation and we provide a simple physics motivation for the change. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/33704
- author
- Andersson, Bo LU ; Gustafson, Gösta LU and Kharraziha, Hamid
- organization
- publishing date
- 1998
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physical Review D (Particles and Fields)
- volume
- 57
- issue
- 9
- pages
- 5543 - 5554
- publisher
- American Physical Society
- external identifiers
-
- scopus:0001663240
- ISSN
- 0556-2821
- DOI
- 10.1103/PhysRevD.57.5543
- language
- English
- LU publication?
- yes
- id
- 561f6048-9d73-45d9-bf43-2d36ca2c7ac1 (old id 33704)
- alternative location
- http://link.aps.org/abstract/PRD/v57/p5543
- date added to LUP
- 2016-04-01 15:44:47
- date last changed
- 2024-01-10 19:10:51
@article{561f6048-9d73-45d9-bf43-2d36ca2c7ac1, abstract = {{We present approximations of varying degree of sophistication to the integral equations for the (gluon) structure functions of a hadron ("the partonic flux factor") in a model valid in the leading log approximation with a running coupling constant. The results are all of the BFKL type, i.e., a power in the Bjorken variable x(B)(-lambda) with the parameter lambda determined from the size alpha(0) of the "effective" running coupling <(alpha)over bar>=3 alpha(s)/pi =alpha(0)/ln(k(perpendicular to)(2)) and varying depending upon the treatment of the transverse momentum pole, we also consider the implications for the transverse momentum (k(perpendicular to)) fluctuations along the emission chains and we obtain an exponential falloff in the relevant kappa=ln(k(perpendicular to)(2)) variable, i.e., an inverse power (k(perpendicular to)(2))(-(2+lambda)) with the same parameter lambda. This is different from the BFKL result for a fixed coupling, where the distributions are Gaussian in the kappa variable with a width as in a Brownian motion determined by "the length" of the emission chains, i.e., In(1/x(B)). The results are verified by a realistic Monte Carlo simulation and we provide a simple physics motivation for the change.}}, author = {{Andersson, Bo and Gustafson, Gösta and Kharraziha, Hamid}}, issn = {{0556-2821}}, language = {{eng}}, number = {{9}}, pages = {{5543--5554}}, publisher = {{American Physical Society}}, series = {{Physical Review D (Particles and Fields)}}, title = {{Investigations into the BFKL mechanism with a running QCD coupling}}, url = {{http://dx.doi.org/10.1103/PhysRevD.57.5543}}, doi = {{10.1103/PhysRevD.57.5543}}, volume = {{57}}, year = {{1998}}, }