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Title: What is a parton shower?

Abstract

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 $${{\alpha}}_{\mathrm{s}}$$ 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 $${{\alpha}}_{\mathrm{s}}^{k}$$ 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 $${{\alpha}}_{\mathrm{s}}^{k}$$ 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.

Authors:
;
Publication Date:
Research Org.:
Univ. of Oregon, Eugene, OR (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25); National Science Foundation (NSF)
OSTI Identifier:
1461617
Alternate Identifier(s):
OSTI ID: 1498659
Grant/Contract Number:  
SC0011640; PHY11-25915
Resource Type:
Published Article
Journal Name:
Physical Review D
Additional Journal Information:
Journal Name: Physical Review D Journal Volume: 98 Journal Issue: 1; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; quantum chromodynamics; quark & gluon jets; resummation methods

Citation Formats

Nagy, Zoltán, and Soper, Davison E. What is a parton shower?. United States: N. p., 2018. Web. doi:10.1103/PhysRevD.98.014034.
Nagy, Zoltán, & Soper, Davison E. What is a parton shower?. United States. doi:10.1103/PhysRevD.98.014034.
Nagy, Zoltán, and Soper, Davison E. Wed . "What is a parton shower?". United States. doi:10.1103/PhysRevD.98.014034.
@article{osti_1461617,
title = {What is a parton shower?},
author = {Nagy, Zoltán and Soper, Davison E.},
abstractNote = {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 ${{\alpha}}_{\mathrm{s}}$ 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 ${{\alpha}}_{\mathrm{s}}^{k}$ 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 ${{\alpha}}_{\mathrm{s}}^{k}$ 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.},
doi = {10.1103/PhysRevD.98.014034},
journal = {Physical Review D},
number = 1,
volume = 98,
place = {United States},
year = {2018},
month = {7}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1103/PhysRevD.98.014034

Citation Metrics:
Cited by: 5 works
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    Works referencing / citing this record:

    What is a parton shower?
    text, January 2018


    High-energy-physics event generation with PYTHIA 5.7 and JETSET 7.4
    journal, August 1994


    A model for initial state parton showers
    journal, July 1985


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    journal, August 2017


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    journal, February 2001


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    journal, May 2002


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    • Journal of High Energy Physics, Vol. 2007, Issue 01
    • DOI: 10.1088/1126-6708/2007/01/013

    A subtraction scheme for computing QCD jet cross sections at NNLO: regularization of doubly-real emissions
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    • Somogyi, Gábor; Trócsányi, Zoltán; Duca, Vittorio Del
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