scholarly journals Bottomonia production and polarization in the NRQCD with $$k_T$$-factorization. I: $$\Upsilon (3S)$$ and $$\chi _b(3P)$$ mesons

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
N. A. Abdulov ◽  
A. V. Lipatov
Keyword(s):  
Bound States ◽  
Spin Density Matrix ◽  
Unintegrated Gluon ◽  
Factorization Approach ◽  
Transverse Momentum Dependent ◽  
High Energies ◽  
Radiation Theory ◽  
Multipole Radiation ◽  
Shell Production ◽  
Good Agreement

Abstract The $$\Upsilon (3S)$$Υ(3S) production and polarization at high energies is studied in the framework of $$k_T$$kT-factorization approach. Our consideration is based on the non-relativistic QCD formalism for bound states formation and off-shell production amplitudes for hard partonic subprocesses. The transverse momentum dependent (TMD, or unintegrated) gluon densities in a proton were derived from the Ciafaloni-Catani-Fiorani-Marchesini (CCFM) evolution equation as well as from the Kimber–Martin–Ryskin (KMR) prescription. Treating the non-perturbative color octet transitions in terms of the multipole radiation theory and taking into account feed-down contributions from radiative $$\chi _b(3P)$$χb(3P) decays, we extract the corresponding non-perturbative matrix elements for $$\Upsilon (3S)$$Υ(3S) and $$\chi _b(3P)$$χb(3P) mesons from a combined fit to $$\Upsilon (3S)$$Υ(3S) transverse momenta distributions measured by the CMS and ATLAS Collaborations at the LHC energies $$\sqrt{s} = 7$$s=7 and 13 TeV and central rapidities. Then we apply the extracted values to describe the CDF and LHCb data on $$\Upsilon (3S)$$Υ(3S) production and to investigate the polarization parameters $$\lambda _\theta $$λθ, $$\lambda _\phi $$λϕ and $$\lambda _{\theta \phi }$$λθϕ, which determine the $$\Upsilon (3S)$$Υ(3S) spin density matrix. Our predictions have a good agreement with the currently available data within the theoretical and experimental uncertainties.

scholarly journals ϒ(3S) and χb(3P) production and polarization in the NRQCD with kT–factorization

2019 ◽  
Vol 222 ◽  
pp. 03013
Author(s):  
Nizami Abdulov ◽  
Artem Lipatov
Keyword(s):  
Transverse Momentum ◽  
Bound States ◽  
Matrix Elements ◽  
Unintegrated Gluon ◽  
Factorization Approach ◽  
Transverse Momentum Dependent ◽  
High Energies ◽  
Radiation Theory ◽  
Shell Production ◽  
Good Agreement

The ϒ(3S) production and polarization at high energies is studied in the framework of kT–factorization approach. Our consideration is based on the non-relativistic QCD formalism for bound states formation and off-shell production amplitudes for hard partonic subprocesses. The transverse momentum dependent (TMD, or unintegrated) gluon densities in a proton were derived from the CiafaloniCatani-Fiorani-Marchesini (CCFM) evolution equation as well as from the Kimber–Martin–Ryskin (KMR) prescription. Treating the nonperturbative color octet transitions in terms of the mulitpole radiation theory and taking into account feed-down contributions from radiative χb(3P) decays, we extract the corresponding non-perturbative matrix elements for ϒ(3S) and χb(3P) mesons from a combined fit to ϒ(3S) transverse momenta distributions measured by the CMS and ATLAS Collaborations at the LHC energies √s = 7 and 13 TeV and central rapidities. Then we apply the extracted values to investigate the polarization parameters λθ, λφ and λθφ, which determine the ϒ(3S) spindensity matrix. Our predictions have a good agreement with the currently available data within the theoretical and experimental uncertainties.

scholarly journals Bottomonium production and polarization in the NRQCD with $$k_T$$-factorization. III: $$\Upsilon (1S)$$ and $$\chi _b(1P)$$ mesons

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
N. A. Abdulov ◽  
A. V. Lipatov
Keyword(s):  
Bound States ◽  
Meson Production ◽  
Spin Density Matrix ◽  
Factorization Approach ◽  
Direct Production ◽  
Transverse Momentum Dependent ◽  
Radiation Theory ◽  
Multipole Radiation ◽  
Shell Production ◽  
Upsilon 1S

AbstractThe $$\Upsilon (1S)$$ Υ ( 1 S ) meson production and polarization at high energies is studied in the framework of the $$k_T$$ k T -factorization approach. Our consideration is based on the non-relativistic QCD formalism for a bound states formation and off-shell production amplitudes for hard partonic subprocesses. The direct production mechanism, feed-down contributions from radiative $$\chi _b(mP)$$ χ b ( m P ) decays and contributions from $$\Upsilon (3S)$$ Υ ( 3 S ) and $$\Upsilon (2S)$$ Υ ( 2 S ) decays are taken into account. The transverse momentum dependent (TMD) gluon densities in a proton were derived from the Ciafaloni–Catani–Fiorani–Marchesini evolution equation and the Kimber-Martin–Ryskin prescription. Treating the non-perturbative color octet transitions in terms of multipole radiation theory, we extract the corresponding non-perturbative matrix elements for $$\Upsilon (1S)$$ Υ ( 1 S ) and $$\chi _b(1P)$$ χ b ( 1 P ) mesons from a combined fit to transverse momenta distributions measured at various LHC experiments. Then we apply the extracted values to investigate the polarization parameters $$\lambda _\theta $$ λ θ , $$\lambda _\phi $$ λ ϕ and $$\lambda _{\theta \phi }$$ λ θ ϕ , which determine the $$\Upsilon (1S)$$ Υ ( 1 S ) spin density matrix. Our predictions have a reasonably good agreement with the currently available Tevatron and LHC data within the theoretical and experimental uncertainties.

scholarly journals Central and peripheral hadron–nucleus collisions in the Additive Quark Model

2019 ◽  
Vol 34 (06) ◽  
pp. 1950048
Author(s):  
G. H. Arakelyan ◽  
Yu. M. Shabelski ◽  
A. G. Shuvaev
Keyword(s):  
Experimental Data ◽  
Quark Model ◽  
Constituent Quark ◽  
High Energies ◽  
Central Collisions ◽  
Energy Formula ◽  
Incident Nucleon ◽  
Good Agreement

Peripheral nucleon–nucleus collisions occur at high energies mainly through the interaction with one constituent quark from the incident nucleon. The central collisions should involve all three constituent quarks and each of them can interact several times. We calculate the average number of quark–nucleus interactions for both the cases in good agreement with the experimental data on [Formula: see text]-meson, [Formula: see text] and all charged secondaries productions in [Formula: see text] collisions at LHC energy [Formula: see text] TeV.

scholarly journals BOUND STATES IN DIMERIZED AND FRUSTRATED HEISENBERG CHAINS

2001 ◽  
Vol 15 (19n20) ◽  
pp. 2821-2831 ◽  
Author(s):  
G. BOUZERAR ◽  
S. SIL
Keyword(s):  
Bound States ◽  
Quantitative Agreement ◽  
Elementary Excitation ◽  
Operator Technique ◽  
Heisenberg Chain ◽  
Parameter Region ◽  
Energy Excitation ◽  
Heisenberg Chains ◽  
Good Agreement ◽  
The Continuum

Using the Bond-Operator Technique (BOT), we have studied the low energy excitation spectrum of a frustrated dimerized antiferromagnetic Heisenberg chain. In particular, we have compared our analytical results with previous Exact Diagonalization (ED) data. Qualitatively, the BOT results are in good agreement with the ED data. And even a very good quantitative agreement is obtained in some parameter region. It is clearly shown that there is only one elementary excitation branch (lowest triplet branch) and that the two other well defined excitations which appear below the continuum, one singlet and one triplet, are bound states of two elementary triplets.

PSEUDORAPIDITY DISTRIBUTION OF CHARGED PARTICLES IN $p\bar p$ AND AA COLLISIONS AT HIGH ENERGIES

2005 ◽  
Vol 14 (04) ◽  
pp. 579-586
Author(s):  
FU SONG ◽  
FU-HU LIU
Keyword(s):  
Center Of Mass ◽  
Charged Particles ◽  
Pseudorapidity Distribution ◽  
Mass Energy ◽  
Center Of Mass Energy ◽  
High Energies ◽  
Cylinder Model ◽  
Energy Formula ◽  
Good Agreement ◽  
Aa Collisions

The pseudorapidity distributions of charged particles produced in [Formula: see text] annihilations and AA collisions at high energies are investigated by using a revised thermalized cylinder model. The Monte Carlo calculated results are compared and found to be in good agreement with the experimental data of [Formula: see text] annihilations at center-of-mass energy [Formula: see text], 546, 200, and 53 GeV, Au–Au collisions at [Formula: see text] and 130 A GeV, and Pb–Pb collisions at [Formula: see text].

a0(980) AND f0(980) MESONS AS HADRONIC MOLECULES

2009 ◽  
Vol 24 (02n03) ◽  
pp. 568-571 ◽  
Author(s):  
T. BRANZ ◽  
T. GUTSCHE ◽  
V. E. LYUBOVUTSKIJ
Keyword(s):  
Size Effects ◽  
Bound States ◽  
Finite Size ◽  
Finite Size Effects ◽  
Gauge Invariant ◽  
Electromagnetic Decay ◽  
Invariant Model ◽  
Scalar Mesons ◽  
Decay Properties ◽  
Good Agreement

We discuss a possible interpretation of the scalar mesons f0(980) and a0(980) as hadronic molecules - bound states of K and [Formula: see text] mesons. Using a phenomenological Lagrangian approach we calculate strong as well as the electromagnetic decay properties of both scalars. The covariant and gauge invariant model, which also allows for finite size effects of the hadronic molecule, delivers results in good agreement with experimental data.

scholarly journals Spin Splitting Spectroscopy of Heavy Quark and Antiquarks Systems

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hesham Mansour ◽  
Ahmed Gamal ◽  
M. Abolmahassen
Keyword(s):  
Mass Spectra ◽  
Bound States ◽  
Good Accuracy ◽  
Theoretical Calculations ◽  
Spin Splitting ◽  
Energy Eigenvalues ◽  
Central Case ◽  
Nu Method ◽  
Better Than ◽  
Good Agreement

Phenomenological potentials describe the quarkonium systems like c c ¯ , b b , ¯   and   b ¯ c where they give a good accuracy for the mass spectra. In the present work, we extend one of our previous works in the central case by adding spin-dependent terms to allow for relativistic corrections. By using such terms, we get better accuracy than previous theoretical calculations. In the present work, the mass spectra of the bound states of heavy quarks   c c ¯ , b b ¯ , and 𝐵𝑐 mesons are studied within the framework of the nonrelativistic Schrödinger equation. First, we solve Schrödinger’s equation by Nikiforov-Uvarov (NU) method. The energy eigenvalues are presented using our new potential. The results obtained are in good agreement with the experimental data and are better than the previous theoretical estimates.

scholarly journals Strangeness Enhancement at LHC Energies Using the Thermal Model and EPOSLHC Event Generator

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mahmoud Hanafy ◽  
Omnia S. A. Qandil ◽  
Asmaa G. Shalaby
Keyword(s):  
Cosmic Ray ◽  
Heavy Ion ◽  
Event Generator ◽  
Relativistic Heavy Ion Collider ◽  
Model Calculations ◽  
High Energies ◽  
Particle Ratios ◽  
Strangeness Enhancement ◽  
The Mean ◽  
Good Agreement

The strangeness enhancement signature of QGP formation at LHC energies is carefully tackled in the present study. Based on HRG, the particle ratios of mainly strange and multistrange particles are studied at energies from lower s ~ 0.001 up to 13 TeV. The strangeness enhancement clearly appeared at more high energies, and the ratios are confronted to the available experimental data. The particle ratios are also studied using the Cosmic Ray Monte Carlo (CRMC) interface model with its two different event generators, namely, EPOS 1.99 and EPOSlhc, which show a good agreement with the model calculations at the whole range of the energy. We utilize them to produce some particles ratios. EPOS 1.99 is used to estimate particle ratios at lower energies from AGS up to the Relativistic Heavy Ion Collider (RHIC) while EPOSlhc is used at LHC energies. The production of kaons and lambda particles is studied in terms of the mean multiplicity in p-p collisions at energies ranging from 4 to 26 GeV. We find that both HRG model and the used event generators, EPOS 1.99 and EPOSlhc, can describe the particle ratios very well. Additionally, the freeze-out parameters are estimated for different collision systems, such as p-p and Pb-Pb, at LHC energies using both models.

scholarly journals Gamma-Ray Attenuation and Exposure Buildup Factor of Novel Polymers in Shielding Using Geant4 Simulation

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5051
Author(s):  
Mahmoud T. Alabsy ◽  
Jamila S. Alzahrani ◽  
M. I. Sayyed ◽  
Mahmoud I. Abbas ◽  
Daria I. Tishkevich ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Effective Atomic Number ◽  
Buildup Factor ◽  
Geant4 Simulation ◽  
Polybutylene Terephthalate ◽  
Attenuation Coefficients ◽  
High Energies ◽  
Gamma Ray Attenuation ◽  
Mass Attenuation Coefficients ◽  
Good Agreement

Polymers are often used in medical applications, therefore, some novel polymers and their interactions with photons have been studied. The gamma-ray shielding parameters for Polymethylpentene (PMP), Polybutylene terephthalate (PBT), Polyoxymethylene (POM), Polyvinylidenefluoride (PVDF), and Polychlorotrifluoroethylene (PCTFE) polymers were determined using the Geant4 simulation and discussed in the current work. The mass attenuation coefficients (μ/ρ) were simulated at low and high energies between 0.059 and 1.408 MeV using different radionuclides. The accuracy of the Geant4 simulated results were checked with the XCOM software. The two different methods had good agreement with each other. Exposure buildup factor (EBF) was calculated and discussed in terms of polymers under study and photon energy. Effective atomic number (Zeff) and electron density (Neff) were calculated and analyzed at different energies. Additionally, the half-value layer (HVL) of the polymers was evaluated, and the results of this parameter showed that PCTFE had the highest probability of interaction with gamma photons compared to those of the other tested polymers.

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