scholarly journals Testing the running couplingkT-factorization formula for the inclusive gluon production

2016 ◽  
Vol 94 (5) ◽  
Author(s):  
F. O. Durães ◽  
A. V. Giannini ◽  
V. P. Gonçalves ◽  
F. S. Navarra
Keyword(s):  
Factorization Formula ◽  
Gluon Production

A Factorization of Least-Squares Projection Schemes for Ill-Posed Problems

2020 ◽  
Vol 20 (4) ◽  
pp. 783-798
Author(s):  
Shukai Du ◽  
Nailin Du
Keyword(s):  
Least Squares ◽  
Rate Of Convergence ◽  
Convergence Conditions ◽  
Principal Angles ◽  
Factorization Formula ◽  
Ill Posed

AbstractWe give a factorization formula to least-squares projection schemes, from which new convergence conditions together with formulas estimating the rate of convergence can be derived. We prove that the convergence of the method (including the rate of convergence) can be completely determined by the principal angles between {T^{\dagger}T(X_{n})} and {T^{*}T(X_{n})}, and the principal angles between {X_{n}\cap(\mathcal{N}(T)\cap X_{n})^{\perp}} and {(\mathcal{N}(T)+X_{n})\cap\mathcal{N}(T)^{\perp}}. At the end, we consider several specific cases and examples to further illustrate our theorems.

scholarly journals CHARMONIUM PRODUCTION AT THE LHC

1996 ◽  
Vol 11 (19) ◽  
pp. 1555-1562 ◽  
Author(s):  
K. SRIDHAR
Keyword(s):  
Cross Section ◽  
Event Rate ◽  
Charm Quark ◽  
Large Transverse Momentum ◽  
Fragmentation Mechanism ◽  
Charmonium Production ◽  
Quark Fragmentation ◽  
Gluon Production ◽  
Gluon Fragmentation ◽  
Important Test

The analyses of large transverse momentum charmonium production at the Tevatron have shown that fragmentation of gluons is an important production mechanism. We study large-pT charmonium production in pp collisions at the LHC, and find that due to the copious gluon production at this energy, the gluon fragmentation contribution completely overwhelms the fusion contribution and the charm quark fragmentation contribution. Our analysis shows that for J/ψ production at the LHC, there is a significant event rate even for pT ~ 100 GeV. The measurement of the cross-section at such large values of pT will provide a very important test of the fragmentation mechanism.

scholarly journals Gluon production, cooling, and entropy in nuclear collisions

1994 ◽  
Vol 50 (1) ◽  
pp. 406-409 ◽  
Author(s):  
J. Letessier ◽  
J. Rafelski ◽  
A. Tounsi
Keyword(s):  
Nuclear Collisions ◽  
Gluon Production

scholarly journals Factorization at subleading power and endpoint divergences in h → γγ decay. Part II. Renormalization and scale evolution

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Ze Long Liu ◽  
Bianka Mecaj ◽  
Matthias Neubert ◽  
Xing Wang
Keyword(s):  
Decay Amplitude ◽  
Factorization Theorem ◽  
Effective Theory ◽  
Operator Matrix ◽  
Quark Loop ◽  
Perfect Agreement ◽  
Soft Collinear Effective Theory ◽  
Convolution Integrals ◽  
Factorization Formula ◽  
Massless Quark

Abstract Building on the recent derivation of a bare factorization theorem for the b-quark induced contribution to the h → γγ decay amplitude based on soft-collinear effective theory, we derive the first renormalized factorization theorem for a process described at subleading power in scale ratios, where λ = mb/Mh « 1 in our case. We prove two refactorization conditions for a matching coefficient and an operator matrix element in the endpoint region, where they exhibit singularities giving rise to divergent convolution integrals. The refactorization conditions ensure that the dependence of the decay amplitude on the rapidity regulator, which regularizes the endpoint singularities, cancels out to all orders of perturbation theory. We establish the renormalized form of the factorization formula, proving that extra contributions arising from the fact that “endpoint regularization” does not commute with renormalization can be absorbed, to all orders, by a redefinition of one of the matching coefficients. We derive the renormalization-group evolution equation satisfied by all quantities in the factorization formula and use them to predict the large logarithms of order $$ {\alpha \alpha}_s^2{L}^k $$ αα s 2 L k in the three-loop decay amplitude, where $$ L=\ln \left(-{M}_h^2/{m}_b^2\right) $$ L = ln − M h 2 / m b 2 and k = 6, 5, 4, 3. We find perfect agreement with existing numerical results for the amplitude and analytical results for the three-loop contributions involving a massless quark loop. On the other hand, we disagree with the results of previous attempts to predict the series of subleading logarithms $$ \sim {\alpha \alpha}_s^n{L}^{2n+1} $$ ∼ αα s n L 2 n + 1 .

scholarly journals Inclusive gluon production in the QCD Reggeon field theory: Pomeron loops included

2009 ◽  
Vol 2009 (03) ◽  
pp. 110-110 ◽  
Author(s):  
Tolga Altinoluk ◽  
Alex Kovner ◽  
Michael Lublinsky
Keyword(s):  
Field Theory ◽  
Gluon Production ◽  
Reggeon Field Theory

scholarly journals TRANSVERSE MOMENTUM DISTRIBUTIONS FROM EFFECTIVE FIELD THEORY

2011 ◽  
Vol 04 ◽  
pp. 106-114
Author(s):  
SONNY MANTRY ◽  
FRANK PETRIELLO
Keyword(s):  
Transverse Momentum ◽  
Z Boson ◽  
Effective Field ◽  
Factorization Theorem ◽  
Effective Theory ◽  
Gauge Bosons ◽  
Soft Collinear Effective Theory ◽  
Factorization Formula ◽  
Momentum Distributions ◽  
Momentum Function

We present a factorization theorem for the low transverse momentum (pT) and rapidity (Y) distribution of the Higgs and electroweak gauge bosons using the Soft-Collinear Effective Theory. In the region M ≫ pT ≫ ΛQCD, where M denotes the mass of the electroweak object, the factorization formula is given in terms of perturbatively calculable functions and the standard PDFs. For pT ~ ΛQCD, the factorization theorem is given in terms of non-perturbative Impact-parameter Beam Functions (iBFs) and an Inverse Soft Function (iSF). The iBFs correspond to completely unintegrated PDFs and can be interesting probes of momentum distributions in the nucleon. The iBFs and the iSF are grouped together and written as a product of a gauge invariant and non-perturbative Transverse Momentum Function (TMF) with the standard PDFs. We present results of NLL resummation for the Higgs and Z-boson distributions and give a comparison with Tevatron data.

scholarly journals Gluon production from non-Abelian Weizsäcker-Williams fields in nucleus-nucleus collisions

1995 ◽  
Vol 52 (11) ◽  
pp. 6231-6237 ◽  
Author(s):  
Alex Kovner ◽  
Larry McLerran ◽  
Heribert Weigert
Keyword(s):  
Gluon Production
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