scholarly journals Inclusive production of a heavy-light dijet system in hybrid high-energy and collinear factorization

2021 ◽  
Vol 103 (9) ◽  
Author(s):  
A. D. Bolognino ◽  
F. G. Celiberto ◽  
M. Fucilla ◽  
D. Yu. Ivanov ◽  
A. Papa
1985 ◽  
Vol 31 (4) ◽  
pp. 1241-1244
Author(s):  
J. Mahalanobis ◽  
P. Bandyopadhyay

2016 ◽  
Vol 31 (24) ◽  
pp. 1630039 ◽  
Author(s):  
Anna M. Staśto ◽  
David Zaslavsky

We review the recent progress on the calculations on the inclusive forward hadron production within the saturation formalism. After introducing the concept of perturbative parton saturation and nonlinear evolution we discuss the formalism for the forward hadron production at high energy in the leading and next-to-leading order. Numerical results are presented and compared with the experimental data on forward hadron production in [Formula: see text] and [Formula: see text]. We discuss the problem of the negativity of the NLO cross-section at high transverse momenta, study its origin in detail and present possible improvements which include the corrected kinematics and the suitable choice of the rapidity cutoff.


2021 ◽  
Vol 81 (8) ◽  
Author(s):  
Francesco G. Celiberto ◽  
Michael Fucilla ◽  
Dmitry Yu. Ivanov ◽  
Alessandro Papa

AbstractWe present a study on inclusive emissions of a double $$\Lambda _c$$ Λ c or of a $$\Lambda _c$$ Λ c plus a light-flavored jet system as probe channels in the semi-hard regime of QCD. Our formalism relies on the so-called hybrid high-energy/collinear factorization, where the standard collinear description is supplemented by the t-channel resummation à la BFKL of energy logarithms up to the next-to-leading accuracy. We make use of the modular interface, suited to the analysis of different semi-hard reactions, employing the novel parameterization for the description of parton fragmentation into $$\Lambda _c$$ Λ c baryons. We provide predictions for rapidity distributions and azimuthal correlations, that can be studied at current and forthcoming LHC configurations, hunting for possible stabilizing effects of the high-energy series.


2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Rafał Maciuła ◽  
Antoni Szczurek

Abstract We discuss the role of intrinsic charm (IC) in the nucleon for forward production of c-quark (or $$ \overline{c} $$ c ¯ -antiquark) in proton-proton collisions for low and high energies. The calculations are performed in collinear-factorization approach with on-shell partons, kT-factorization approach with off-shell partons as well as in a hybrid approach using collinear charm distributions and unintegrated (transverse momentum dependent) gluon distributions. For the collinear-factorization approach we use matrix elements for both massless and massive charm quarks/antiquarks. The distributions in rapidity and transverse momentum of charm quark/antiquark are shown for a few different models of IC. Forward charm production is dominated by gc-fusion processes. The IC contribution dominates over the standard pQCD (extrinsic) gg-fusion mechanism of $$ c\overline{c} $$ c c ¯ -pair production at large rapidities or Feynman-xF. We perform similar calculations within leading-order and next-to-leading order kT-factorization approach. The kT-factorization approach leads to much larger cross sections than the LO collinear approach. At high energies and large rapidities of c-quark or $$ \overline{c} $$ c ¯ -antiquark one tests gluon distributions at extremely small x. The IC contribution has important consequences for high-energy neutrino production in the Ice-Cube experiment and can be, to some extent, tested at the LHC by the SHIP and FASER experiments by studies of the ντ neutrino production.


2003 ◽  
Vol 18 (08) ◽  
pp. 1219-1228
Author(s):  
JACQUES SOFFER

Some aspects of hyperon polarization phenomena in inclusive production in several high energy collision processes are reviewed. We concentrate on ways to achieve an accurate determination of the unpolarized and polarized fragmentation functions of a quark into a [Formula: see text]. A possible extension to the production of the other hyperons (Σ±,0, Ξ-,0), will be also briefly discussed.


Universe ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. 64 ◽  
Author(s):  
Jamal Jalilian-Marian

Particle production in high energy hadronic/nuclear collisions in the Bjorken limit Q 2 , s → ∞ can be described in the collinear factorization framework of perturbative Quantum ChromoDynamics (QCD). On the other hand in the Regge limit, at fixed and not too high Q 2 with s → ∞ , a k ⊥ factorization approach (or a generalization of it) is the appropriate framework. A new effective action approach to QCD in the Regge limit, known as the Color Glass Condensate (CGC) formalism, has been developed which allows one to investigate particle production in high energy collisions in the kinematics where collinear factorization breaks down. Here we give a brief overview of particle production in CGC framework and the evolution equation which governs energy dependence of the observables in this formalism. We show that the new evolution equation reduces to previously known evolution equations in the appropriate limits.


2020 ◽  
Vol 80 (7) ◽  
Author(s):  
A. Bermudez Martinez ◽  
P. L. S. Connor ◽  
D. Dominguez Damiani ◽  
L. I. Estevez Banos ◽  
F. Hautmann ◽  
...  

Abstract It has been observed in the literature that measurements of low-mass Drell–Yan (DY) transverse momentum spectra at low center-of-mass energies $$\sqrt{s}$$s are not well described by perturbative QCD calculations in collinear factorization in the region where transverse momenta are comparable with the DY mass. We examine this issue from the standpoint of the Parton Branching (PB) method, combining next-to-leading-order (NLO) calculations of the hard process with the evolution of transverse momentum dependent (TMD) parton distributions. We compare our predictions with experimental measurements at low DY mass, and find very good agreement. In addition we use the low mass DY measurements at low $$\sqrt{s}$$s to determine the width $$q_s$$qs of the intrinsic Gauss distribution of the PB-TMDs at low evolution scales. We find values close to what has earlier been used in applications of PB-TMDs to high-energy processes at the Large Hadron Collider (LHC) and HERA. We find that at low DY mass and low $$\sqrt{s}$$s even in the region of $$p_\mathrm{T}/m_\mathrm{DY}\sim 1$$pT/mDY∼1 the contribution of multiple soft gluon emissions (included in the PB-TMDs) is essential to describe the measurements, while at larger masses ($$m_\mathrm{DY}\sim m_{{\mathrm{Z}}}$$mDY∼mZ) and LHC energies the contribution from soft gluons in the region of $$p_\mathrm{T}/m_\mathrm{DY}\sim 1$$pT/mDY∼1 is small.


2007 ◽  
Vol 22 (02n03) ◽  
pp. 587-590
Author(s):  
WOLFGANG SCHÄFER

The inclusive production of high-p⊥ particles (pions) in the beam fragmentation regions of high–energy hadronic collisions is driven by the breakup of valence constituents of the beam hadrons into their two–body Fock–state components,and their subsequent fragmentation. We briefly discuss an approach, that allows the consistent inclusion of intrinsic and radiatively generated transverse momenta of initial state partons, and describe an extension of our approach to nuclear targets.


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