We present the joint threshold and recoil resummed transverse momentum distributions for heavy quark hadroproduction, at next-to-leading logarithmic accuracy. We exhibit their dependence on the production channel and the color configurations, and compare t

2Ban ,Laenen

higherordercorrectionstothedi erential9crosssectionsforthesepartonicprocesseshavebeencomputedtoNLO8,,10,11.UptocorrectionsO(1/p2T),mayatanyorder12theobservable

bewritteninthefollowingfactorizedformdσAB→Q+X

dp(ξT

a,ξb,αs(µ),pT),

(1)

withdσ ab→Q+X/dpTthepartonicdi erentialcross-section,φa/Aandφb/Bparton

densities,andµthefactorization/renormalizationscale.

Thresholdenhancementsessentiallyinvolvetheenergyofsoftgluons.Inthecontextofthefactorization(1)wede nehadronicandpartonicthresholdbytheconditions

S=4m2Tand s=4m2T,respectively,withmTthetransversemassm2S

,

x 2T

=4T

2

.(3)

Thekinematicallyallowedrangefortheinvariantmasslimitedfrombelowby2mT=2

Qoftheheavyquarkpairin

thishardscatteringis′

Q2

=1.

(4)

Arefactorizationanalysis2leadstothefollowingexpressionfortheobservableinEq.(1)

dσAB→Q+X

dpTd2Q

,

(5)

T