Status and developments of event generators

Sjöstrand, Torbjörn

doi:10.22323/1.276.0007

Cited by 13 publications

(12 citation statements)

References 167 publications

(190 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Instead, we employ the approach developed in [27,67]. Following this approach, first a kernel A b a x , µ 2 is determined from the Monte Carlo solution of the evolution equation for any initial parton of flavor b evolving to a final parton of flavor a; 5 then, this is folded 5 In practice, since the initial state partons can be only light quarks or gluons, it is enough to determine the kernel A b a only for one initial state quark and a gluon. with the non-perturbative starting distribution A 0,b (x):…”

Section: Fit To Precision Dis Datamentioning

confidence: 99%

“…While great progress has been achieved in the last decade on matching and merging methods [5][6][7] to combine parton showers with perturbative calculations through next-to-leading order (NLO), important open questions still remain, both conceptual and technical, on the appropriate use of parton distribution functions in parton showers (see e.g. [8][9][10][11]) and on the treatment of the shower's transverse momentum kinematics (see e.g.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Collinear and TMD quark and gluon densities from parton branching solution of QCD evolution equations

Hautmann

Jung

Žlebčík

et al. 2018

J. High Energ. Phys.

114

115

View full text Add to dashboard Cite

We study parton-branching solutions of QCD evolution equations and present a method to construct both collinear and transverse momentum dependent (TMD) parton densities from this approach. We work with next-to-leading-order (NLO) accuracy in the strong coupling. Using the unitarity picture in terms of resolvable and non-resolvable branchings, we analyze the role of the soft-gluon resolution scale in the evolution equations. For longitudinal momentum distributions, we find agreement of our numerical calculations with existing evolution programs at the level of better than 1% over a range of five orders of magnitude both in evolution scale and in longitudinal momentum fraction. We make predictions for the evolution of transverse momentum distributions. We perform fits to the high-precision deep inelastic scattering (DIS) structure function measurements, and we present a set of NLO TMD distributions based on the parton branching approach.

show abstract

Section: Fit To Precision Dis Datamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Collinear and TMD quark and gluon densities from parton branching solution of QCD evolution equations

Hautmann

Jung

Žlebčík

et al. 2018

J. High Energ. Phys.

114

115

View full text Add to dashboard Cite

show abstract

“…Deductor starts with the Born matrix elements for two jet production. It would, of course, be best to put in the right NLO matrix elements and subtractions to make the shower cross section match the NLO jet cross section [57,[71][72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90]. In principle, this is straightforward in the Deductor framework [4].…”

Section: A One Jet Inclusive Cross Sectionmentioning

confidence: 99%

Jets and threshold summation in deductor

Nagy

Soper

2018

Phys. Rev. D

View full text Add to dashboard Cite

We explore jet physics in hadron collisions using the parton shower event generator DEDUCTOR. Of particular interest is the one jet inclusive cross section dσ=dP T for jets of very high P T . Compared to the Born level, the cross section decreases substantially because of P T loss from the jet during showering. We compare to the same effect in PYTHIA and DIRE. The cross section then increases substantially because of the summation of threshold logarithms included in DEDUCTOR. We also study the cross section to have a gap with no jets between two hard jets that are widely separated in rapidity. Here we compare Atlas data to DEDUCTOR with virtuality based ordering and to DEDUCTOR with k T ordering. We also compare with perturbation theory. In both cases, we check whether adding an underlying event and hadronization has a significant effect beyond that found with just a parton shower.

show abstract

“…The successor programs [1][2][3][17][18][19][20][21][22][23], are quite sophisticated. Useful reviews of the field can be found in [24,25]. One of the available successor programs is our own, Deductor [15,21,[26][27][28][29][30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

What is a parton shower?

Nagy¹,

Soper²

2018

Phys. Rev. D

106

View full text Add to dashboard Cite

We consider idealized parton shower event generators that treat parton spin and color exactly, leaving aside the choice of practical approximations for spin and color. We investigate how the structure of such a parton shower generator is related to the structure of QCD. We argue that a parton shower with splitting functions proportional to α s can be viewed not just as a model, but as the lowest order approximation to a shower that is defined at any perturbative order. To support this argument, we present a formulation for a parton shower at order α k s for any k. Since some of the input functions needed are specified by their properties but not calculated, this formulation does not provide a useful recipe for an order α k s parton shower algorithm. However, in this formulation we see how the operators that generate the shower are related to operators that specify the infrared singularities of QCD.

show abstract

Status and developments of event generators

Cited by 13 publications

References 167 publications

Collinear and TMD quark and gluon densities from parton branching solution of QCD evolution equations

Collinear and TMD quark and gluon densities from parton branching solution of QCD evolution equations

Jets and threshold summation in deductor

What is a parton shower?

Contact Info

Product

Resources

About