Small- x asymptotics of the quark helicity distribution: Analytic results

Kovchegov, Yuri V.; Pitonyak, Daniel; Sievert, Matthew D.

doi:10.1016/j.physletb.2017.06.032

Title: Small- x asymptotics of the quark helicity distribution: Analytic results

Abstract

In this Letter, we analytically solve the evolution equations for the small-x asymptotic behavior of the (flavor singlet) quark helicity distribution in the large- limit. These evolution equations form a set of coupled integro-differential equations, which previously could only be solved numerically. This approximate numerical solution, however, revealed simplifying properties of the small-x asymptotics, which we exploit here to obtain an analytic solution. We find that the small-x power-law tail of the quark helicity distribution scales as with , in excellent agreement with the numerical estimate obtained previously. We then verify this solution by cross-checking the predicted scaling behavior of the auxiliary “neighbor dipole amplitude” against the numerics, again finding excellent agreement.

Authors:

; Pitonyak, Daniel;

Publication Date:: Fri Sep 01 00:00:00 EDT 2017

Research Org.:: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); The Ohio State University, Columbus, OH

Sponsoring Org.:: USDOE Office of Science (SC). Nuclear Physics (NP) (SC-26); USDOE Office of Science (SC), Nuclear Physics (NP)

OSTI Identifier:: 1364064

Alternate Identifier(s):: OSTI ID: 1369207; OSTI ID: 1604437

Report Number(s):: LA-UR-17-22988
Journal ID: ISSN 0370-2693; S0370269317305087; PII: S0370269317305087

Grant/Contract Number:: AC52-06NA25396; 2012LANL7033; 20160183ER; SC0004286

Resource Type:: Published Article

Journal Name:: Physics Letters. B

Additional Journal Information:: Journal Name: Physics Letters. B Journal Volume: 772 Journal Issue: C; Journal ID: ISSN 0370-2693

Publisher:: Elsevier

Country of Publication:: Netherlands

Language:: English

Subject:: 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Atomic and Nuclear Physics

Citation Formats


                    Kovchegov, Yuri V., Pitonyak, Daniel, and Sievert, Matthew D. Small- x asymptotics of the quark helicity distribution: Analytic results.  Netherlands: N. p., 2017. 
Web.  doi:10.1016/j.physletb.2017.06.032.

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                    Kovchegov, Yuri V., Pitonyak, Daniel, & Sievert, Matthew D. Small- x asymptotics of the quark helicity distribution: Analytic results.  Netherlands.  https://doi.org/10.1016/j.physletb.2017.06.032

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                    Kovchegov, Yuri V., Pitonyak, Daniel, and Sievert, Matthew D. Fri .  
"Small- x asymptotics of the quark helicity distribution: Analytic results".  Netherlands.  https://doi.org/10.1016/j.physletb.2017.06.032.

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@article{osti_1364064,

  title        = {Small- x asymptotics of the quark helicity distribution: Analytic results},

  author       = {Kovchegov, Yuri V. and Pitonyak, Daniel and Sievert, Matthew D.},

  abstractNote = {In this Letter, we analytically solve the evolution equations for the small-x asymptotic behavior of the (flavor singlet) quark helicity distribution in the large- limit. These evolution equations form a set of coupled integro-differential equations, which previously could only be solved numerically. This approximate numerical solution, however, revealed simplifying properties of the small-x asymptotics, which we exploit here to obtain an analytic solution. We find that the small-x power-law tail of the quark helicity distribution scales as with , in excellent agreement with the numerical estimate obtained previously. We then verify this solution by cross-checking the predicted scaling behavior of the auxiliary “neighbor dipole amplitude” against the numerics, again finding excellent agreement.},

  doi          = {10.1016/j.physletb.2017.06.032},

  journal      = {Physics Letters. B},

  number       = C,

  volume       = 772,

  place        = {Netherlands},

  year         = {Fri Sep 01 00:00:00 EDT 2017},

  month        = {Fri Sep 01 00:00:00 EDT 2017}

}

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Works referenced in this record:

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Kovchegov, Yuri V.
Physical Review D, Vol. 61, Issue 7
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Baryon stopping and valence quark distribution at small x
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Small- $x$ Asymptotics of the Quark Helicity Distribution
journal, January 2017

Kovchegov, Yuri V.; Pitonyak, Daniel; Sievert, Matthew D.
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Helicity evolution at small $x$ : Flavor singlet and nonsinglet observables
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Kovchegov, Yuri V.; Pitonyak, Daniel; Sievert, Matthew D.
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Reggeon interactions in perturbative QCD
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Resumming double logarithms in the QCD evolution of color dipoles
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Title: Small- x asymptotics of the quark helicity distribution: Analytic results

Abstract

Citation Formats

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