scholarly journals Supersymmetry across the Hadronic Spectrum

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Hans Günter Dosch
Keyword(s):  
Heavy Quark ◽  
Dimensional Space ◽  
Conformal Symmetry ◽  
Bound State ◽  
Light Front ◽  
De Sitter ◽  
State Equations ◽  
Classical Action ◽  
Heavy Quark Mass ◽  
Dimensional Minkowski Space

Semiclassical light-front bound-state equations for hadrons are presented and compared with experiment. The essential dynamical feature is the holographic approach; that is, the hadronic equations in four-dimensional Minkowski space are derived as holograms of classical equations in a 5-dimensional anti-de Sitter space. The form of the equations is constrained by the imposed superconformal algebra, which fixes the form of the light-front potential. If conformal symmetry is strongly broken by heavy quark masses, the combination of supersymmetry and the classical action in the 5-dimensional space still fixes the form of the potential. By heavy quark symmetry, the strength of the potential is related to the heavy quark mass. The contribution is based on several recent papers in collaboration with Stan Brodsky and Guy de Téramond.

Variational mass perturbation theory for light-front bound-state equations

1998 ◽  
Vol 57 (4) ◽  
pp. 2460-2474 ◽  
Author(s):  
Koji Harada ◽  
Thomas Heinzl ◽  
Christian Stern
Keyword(s):  
Perturbation Theory ◽  
Bound State ◽  
Light Front ◽  
State Equations

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 INTERPRETATION OF D(2637) FROM HEAVY QUARK SYMMETRY

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 480-482
Author(s):  
PHILIP R. PAGE
Keyword(s):  
Heavy Quark ◽  
Excited States ◽  
Quark Mass ◽  
Charm Quark ◽  
Bound State ◽  
Mass Region ◽  
Delphi Collaboration ◽  
Heavy Quark Mass ◽  
Heavy Quark Symmetry ◽  
D Wave

We demonstrate from heavy quark symmetry that the width of D(2637) claimed by the DELPHI Collaboration is inconsistent with any bound state with one charm quark predicted in the D(2637) mass region, except possibly the D-wave orbitally excited states [Formula: see text] and [Formula: see text] or the radially excited state D′. The former two possibilities are favoured by heavy quark mass relations.

scholarly journals Heavy-flavor hadro-production with heavy-quark masses renormalized in the $$ \overline{\mathrm{MS}} $$, MSR and on-shell schemes

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
M. V. Garzelli ◽  
L. Kemmler ◽  
S. Moch ◽  
O. Zenaiev
Keyword(s):  
Heavy Quark ◽  
Cross Sections ◽  
Top Quark ◽  
Quark Mass ◽  
Production Cross ◽  
Hadron Collider ◽  
Distribution Functions ◽  
Heavy Flavor ◽  
Parton Distribution Functions ◽  
Heavy Quark Mass

Abstract We present predictions for heavy-quark production at the Large Hadron Collider making use of the $$ \overline{\mathrm{MS}} $$ MS ¯ and MSR renormalization schemes for the heavy-quark mass as alternatives to the widely used on-shell renormalization scheme. We compute single and double differential distributions including QCD corrections at next-to-leading order and investigate the renormalization and factorization scale dependence as well as the perturbative convergence in these mass renormalization schemes. The implementation is based on publicly available programs, MCFM and xFitter, extending their capabilities. Our results are applied to extract the top-quark mass using measurements of the total and differential $$ t\overline{t} $$ t t ¯ production cross-sections and to investigate constraints on parton distribution functions, especially on the gluon distribution at low x values, from available LHC data on heavy-flavor hadro-production.

scholarly journals Consistent treatment of rapidity divergence in soft-collinear effective theory

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Junegone Chay ◽  
Chul Kim
Keyword(s):  
Heavy Quark ◽  
Soft Mode ◽  
Form Factors ◽  
Effective Theory ◽  
Large Rapidity ◽  
Soft Modes ◽  
Heavy Quark Mass ◽  
Soft Collinear Effective Theory ◽  
Matching Procedure ◽  
Consistent Treatment

Abstract In soft-collinear effective theory, we analyze the structure of rapidity divergence due to the collinear and soft modes residing in disparate phase spaces. The idea of an effective theory is applied to a system of collinear modes with large rapidity and soft modes with small rapidity. The large-rapidity (collinear) modes are integrated out to obtain the effective theory for the small-rapidity (soft) modes. The full SCET with the collinear and soft modes should be matched onto the soft theory at the rapidity boundary, and the matching procedure becomes exactly the zero-bin subtraction. The large-rapidity region is out of reach for the soft mode, which results in the rapidity divergence. The rapidity divergence in the collinear sector comes from the zero-bin subtraction, which ensures the cancellation of the rapidity divergences from the soft and collinear sectors. In order to treat the rapidity divergence, we construct the rapidity regulators consistently for all the modes. They are generalized by assigning independent rapidity scales for different collinear directions. The soft regulator incorporates the correct directional dependence when the innate collinear directions are not back-to-back, which is discussed in the N-jet operator. As an application, we consider the Sudakov form factor for the back-to-back collinear current and the soft-collinear current, where the soft rapidity regulator for a soft quark is developed. We extend the analysis to the boosted heavy quark sector and exploit the delicacy with the presence of the heavy quark mass. We present the resummed results of large logarithms in the form factors for various currents with the light and the heavy quarks, employing the renormalization group evolution on the renormalization and the rapidity scales.

Electromagnetic Casimir effect of concentric cylinders in (D + 1)-dimensional space–time

2019 ◽  
Vol 34 (08) ◽  
pp. 1950035
Author(s):  
Chun Yong Chew ◽  
Yong Kheng Goh
Keyword(s):  
Boundary Condition ◽  
Interaction Energy ◽  
Casimir Effect ◽  
Dimensional Space ◽  
Order Term ◽  
Perturbation Technique ◽  
Space Time ◽  
Concentric Cylinders ◽  
Dimensional Minkowski Space ◽  
Dimensional Space Time

We study the electromagnetic Casimir interaction energy between two parallel concentric cylinders in [Formula: see text]-dimensional Minkowski space–time for different combinations of perfectly conducting boundary condition and infinitely permeable boundary condition. We consider two cases where one cylinder is outside each other and where one is inside the other. By solving the equation of motion and computing the TGTG formulas, explicit formulas for the Casimir interaction energy can be derived and asymptotic behavior of the Casimir interaction energy in the nanoregime is calculated by using perturbation technique. We computed the interaction energy analytically up to next-to-leading order term.

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