scholarly journals Heavy quarkonium fragmentation functions from a heavy quark pair. II.Pwave

2014 ◽  
Vol 89 (9) ◽  
Author(s):  
Yan-Qing Ma ◽  
Jian-Wei Qiu ◽  
Hong Zhang
Keyword(s):  
Heavy Quark ◽  
Heavy Quarkonium ◽  
Fragmentation Functions ◽  
Heavy Quark Pair

scholarly journals Spin-dependent fragmentation functions of gluon splitting into heavy quarkonia considering three different scenarios

2015 ◽  
Vol 30 (32) ◽  
pp. 1550179 ◽  
Author(s):  
S. Mohammad Moosavi Nejad ◽  
Mahdi Delpasand
Keyword(s):  
Heavy Quark ◽  
Bound State ◽  
Heavy Quarkonia ◽  
Heavy Quarkonium ◽  
Heavy Quark Mass ◽  
Spin Singlet ◽  
Fragmentation Probability ◽  
Spin Triplet ◽  
Fragmentation Functions ◽  
Heavy Quark Pair

Heavy quarkonium production is a powerful implement to study the strong interaction dynamics and QCD theory. Fragmentation is the dominant production mechanism for heavy quarkonia with large transverse momentum. With the large heavy quark mass, the relative motion of the heavy quark pair inside a heavy quarkonium is effectively nonrelativistic and it is also well known that their fragmentation functions can be calculated in the perturbative QCD framework. Here, we analytically calculate the process-independent fragmentation functions for a gluon to split into the spin-singlet and spin-triplet [Formula: see text]-wave heavy quarkonia using three different scenarios. We will show that the fragmentation probability of the gluon into the spin-triplet bound-state is the biggest one.

scholarly journals Power expansion for heavy quarkonium production at next-to-leading order in e+e− annihilation

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Kyle Lee ◽  
George Sterman
Keyword(s):  
Heavy Quark ◽  
Dimensional Regularization ◽  
Heavy Quarkonium ◽  
Group Equation ◽  
Leading Order ◽  
Energy Fraction ◽  
Analytical Results ◽  
Quarkonium Production ◽  
Fragmentation Functions ◽  
Heavy Quark Pair

Abstract We study heavy quarkonium production associated with gluons in e+e− annihilation as an illustration of the perturbative QCD (pQCD) factorization approach, which incorporates the first nonleading power in the energy of the produced heavy quark pair. We show how the renormalization of the four-quark operators that define the heavy quark pair fragmentation functions using dimensional regularization induces “evanescent” operators that are absent in four dimensions. We derive closed forms for short-distance coefficients for quark pair production to next-to-leading order ($$ {\alpha}_s^2 $$ α s 2 ) in the relevant color singlet and octet channels. Using non-relativistic QCD (NRQCD) to calculate the heavy quark pair fragmentation functions up to v4 in the velocity expansion, we derive analytical results for the differential energy fraction distribution of the heavy quarkonium. Calculations for $$ {}^3{S}_1^{\left[1\right]} $$ 3 S 1 1 and $$ {}^1{S}_0^{\left[8\right]} $$ 1 S 0 8 channels agree with analogous NRQCD analytical results available in the literature, while several color-octet calculations of energy fraction distributions are new. We show that the remaining corrections due to the heavy quark mass fall off rapidly in the energy of the produced state. To explore the importance of evolution at energies much larger than the mass of the heavy quark, we solve the renormalization group equation perturbatively to two-loop order for the $$ {}^1{S}_0^{\left[8\right]} $$ 1 S 0 8 case.

scholarly journals High-energy resummation in heavy-quark pair hadroproduction

2019 ◽  
Vol 79 (11) ◽  
Author(s):  
A. D. Bolognino ◽  
Francesco Giovanni Celiberto ◽  
M. Fucilla ◽  
D. Yu. Ivanov ◽  
A. Papa
Keyword(s):  
Heavy Quark ◽  
Cross Section ◽  
Center Of Mass ◽  
High Energy ◽  
Heavy Quarks ◽  
Mass Energy ◽  
Center Of Mass Energy ◽  
Large Separation ◽  
Bfkl Approach ◽  
Heavy Quark Pair

AbstractThe inclusive hadroproduction of two heavy quarks, featuring a large separation in rapidity, is proposed as a novel probe channel of the Balitsky–Fadin–Kuraev–Lipatov (BFKL) approach. In a theoretical setup which includes full resummation of leading logarithms in the center-of-mass energy and partial resummation of the next-to-leading ones, predictions for the cross section and azimuthal coefficients are presented for kinematic configurations typical of current and possible future experimental analyses at the LHC.

scholarly journals How to measure the linear polarization of gluons in unpolarized proton using the heavy-quark pair production

2019 ◽  
Vol 204 ◽  
pp. 02006 ◽  
Author(s):  
N. Ya. Ivanov ◽  
A. V. Efremov ◽  
O. V. Teryaev
Keyword(s):  
Pair Production ◽  
Heavy Quark ◽  
Linear Polarization ◽  
Heavy Quark Production ◽  
Production Plane ◽  
Linearly Polarized ◽  
Quark Production ◽  
Mulders Function ◽  
Heavy Quark Pair ◽  
Azimuthal Asymmetries

In recent papers [1, 2], two new ways have been proposed to probe the linear polarization of gluons in unpolarized proton: using the azimuthal asymmetries and Callan-Gross ratio in heavy-quark pair leptoproduction, lN → l′QQ̅X. In this talk, we discuss in details the sensitivity of the QCD predictions for the azimuthal cos φ and cos 2φ asymmetries to the contribution of linearly polarized gluons inside unpolarized proton, where the azimuth φ is the angle between the lepton scattering plane (l, l′) and the heavy quark production plane (N, Q). Our analysis shows that the azimuthal distributions under consideration vary from 0 to 1 depending on the value of the gluonic counterpart of the Boer- Mulders function, $h_{1}^{ \bot g}$. We conclude that the cos φ and cos 2φ asymmetries in heavy-quark pair production in DIS processes are predicted to be large in wide kinematic ranges and sensitive to the contribution of linearly polarized gluons.

scholarly journals Exclusive heavy quark-pair production in ultraperipheral collisions

2019 ◽  
Vol 99 (3) ◽  
Author(s):  
Mateus Reinke Pelicer ◽  
Emmanuel Gräve de Oliveira ◽  
Roman Pasechnik
Keyword(s):  
Pair Production ◽  
Heavy Quark ◽  
Heavy Quark Pair
Sign in / Sign up

Export Citation Format

Share Document