scholarly journals SEARCHING FOR THE QUARK–DIQUARK SYSTEMATICS OF BARYONS COMPOSED BY LIGHT QUARKS q = u, d

2010 ◽  
Vol 25 (15) ◽  
pp. 2965-2995 ◽  
Author(s):  
A. V. ANISOVICH ◽  
V. V. ANISOVICH ◽  
M. A. MATVEEV ◽  
V. A. NIKONOV ◽  
A. V. SARANTSEV ◽  
...  
Keyword(s):  
Axial Vector ◽  
Mass Region ◽  
High Mass ◽  
Vector State ◽  
Double Pole ◽  
High Mass Region ◽  
Pole Structure ◽  
State Formula ◽  
Baryon Resonances

Supposing quark–diquark structure of baryons, we look for systematics of baryons composed of light quarks (q = u, d). We systematize baryons using the notion of two diquarks: (i) axial–vector state, [Formula: see text], with the spin SD = 1 and isospin ID = 1 and (ii) scalar one, [Formula: see text], with the spin SD = 0 and isospin ID = 0. We consider several schemes for the composed baryons: (1) with different diquark masses, [Formula: see text], (2) with [Formula: see text] and overlapping [Formula: see text] and [Formula: see text] states (resonances), (3) with/without SU(6) constraints for low-lying states (with quark–diquark orbital momenta L = 0). In the high-mass region, the model predicts several baryon resonances at M ~ 2.0–2.9 GeV . Moreover, the model gives us the double pole structure (i.e. two poles with the same Re M but different Im M) in many amplitudes at masses M ≳ 2.0 GeV . We see also that for description of low-lying baryons (with L = 0), the SU(6) constraint is needed.

scholarly journals Large scalar multiplet dark matter in the high-mass region

2017 ◽  
Vol 96 (1) ◽  
Author(s):  
Heather E. Logan ◽  
Terry Pilkington
Keyword(s):  
Dark Matter ◽  
Mass Region ◽  
High Mass ◽  
High Mass Region

scholarly journals Studies of the resonance components in the $$B_s$$ decays into charmonia plus kaon pair

2019 ◽  
Vol 79 (9) ◽  
Author(s):  
Zhou Rui ◽  
Ya Li ◽  
Hong Li
Keyword(s):  
Mass Spectra ◽  
Branching Ratios ◽  
Mass Region ◽  
Lhcb Collaboration ◽  
High Mass ◽  
Mass Window ◽  
Resonant Structures ◽  
Three Body ◽  
Near Future ◽  
Existing Data

Abstract In this work, the decays of $$B_s$$Bs meson to a charmonium state and a $$K^+K^-$$K+K- pair are carefully investigated in the perturbative QCD approach. Following the latest fit from the LHCb experiment, we restrict ourselves to the case where the produced $$K^+K^-$$K+K- pair interact in isospin zero S, P, and D wave resonances in the kinematically allowed mass window. Besides the dominant contributions of the $$\phi (1020)$$ϕ(1020) resonance in the P-wave and $$f_2'(1525)$$f2′(1525) in the D-wave, other resonant structures in the high mass region as well as the S-wave components are also included. The invariant mass spectra for most of the resonances in the $$B_s\rightarrow J/\psi K^+K^-$$Bs→J/ψK+K- decay are well reproduced. The obtained three-body decay branching ratios can reach the order of $$10^{-4}$$10-4, which seem to be accessible in the near future experiments. The associated polarization fractions of those vector-vector and vector-tensor modes are also predicted, which are compared with the existing data from the LHCb Collaboration.

scholarly journals A SEARCH FOR NEUTRAL BARYON RESONANCES BELOW PION THRESHOLD

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1947-1950
Author(s):  
XIAODONG JIANG
Keyword(s):  
High Resolution ◽  
Mass Region ◽  
Mass Resolution ◽  
Yield Ratio ◽  
Missing Mass ◽  
Pion Threshold ◽  
Baryon Resonances

The reaction p(e,e′π+)X0 was studied with two high resolution magnetic spectrometers to search for narrow baryon resonances. A missing mass resolution of 2.0 MeV was achieved. A search for structures in the mass region of 0.97<MX0<1.06 GeV yielded no significant signal. The yield ratio of p(e,e′π+)X0/p(e,e′π+)n was determined to be (-0.35±0.35)×10-3 at 1.004 GeV and (0.34±0.42)×10-3 at 1.044 GeV. This measurement clearly demonstrated the potential of high resolution missing mass searches in coincidence experiments.

CLUSTER PHYSICS WITH DARK ENERGY

2011 ◽  
Vol 20 (08) ◽  
pp. 1327-1337
Author(s):  
SEOKCHEON LEE
Keyword(s):  
Dark Energy ◽  
Critical Density ◽  
Mass Region ◽  
High Mass ◽  
Cluster Number ◽  
The Press ◽  
Energy Dependent ◽  
The Universe ◽  
Matter Energy ◽  
Mass Fluctuation

Dark energy affects the abundance and evolution of clusters owing to their dependence on the geometry of the Universe and the power spectrum. Usually, there exits the degeneracy between σ8 and the matter energy density contrast [Formula: see text]. We avoid this by using the explicit dark energy dependent rms linear mass fluctuation σ8 which is consistent with the CMB normalization for general constant dark energy equation of state, ω Q . When we use the correct value of the critical density threshold δc = 1.58 into the cluster number density n calculation in the Press–Schechter (PS) formalism, PS formalism predicts the cluster number consistent with both simulation and observed data at the high mass region. The improved coefficients of Sheth–Tormen (ST) formalism by using the correct δc is also obtained. We found that changing ω Q by Δω Q = -0.1 from ω Q = -1.0 causes the changing of the comoving numbers of high mass clusters of M = 1016h-1M⊙ by about 20 and 40% at z = 0 and 1, respectively.

Effect of Stereoregularity on TOF-SIMS Spectra of Polymers

1994 ◽  
Vol 48 (5) ◽  
pp. 620-622 ◽  
Author(s):  
Paul A. Zimmerman ◽  
David M. Hercules
Keyword(s):  
Mass Spectrometry ◽  
Methyl Methacrylate ◽  
Secondary Ion Mass Spectrometry ◽  
Time Of Flight ◽  
Mass Region ◽  
High Mass ◽  
Polypropylene Oxide ◽  
Tof Sims ◽  
Stereoregular Polymers ◽  
Secondary Ion

This study shows the utility of time-of-flight secondary ion mass spectrometry (TOF-SIMS) for the analysis of stereoregular polymers. It is possible to obtain distinctive spectra for polymers of different stereoregularity. The high mass region of the spectrum from 600 to 3000 Da is related to differences in polymer stereoregularity. Differences occur in the relative intensities and/or locations of clusters for polymers of different stereoregularities. Polymers studied include poly(methyl methacrylate), polypropylene, and polypropylene oxide. The extent of stereoregularity influences the degree of difference observed in the TOF-SIMS spectra.

J/ψ DECAYS AND η-η′-ι MIXING

1994 ◽  
Vol 09 (31) ◽  
pp. 5489-5506 ◽  
Author(s):  
ICHIJIRO KITAMURA ◽  
NORIKAZU MORISITA ◽  
TADAYUKI TESHIMA
Keyword(s):  
Experimental Data ◽  
Perturbation Theory ◽  
Mass Region ◽  
High Mass ◽  
Radial Excitation ◽  
Recent Experimental Data ◽  
Chiral Perturbation ◽  
Pseudoscalar Mesons ◽  
Low Mass ◽  
Excitation State

The mass region near η(1440) has more than one resonance, and two resonances with M≈1420 MeV and M≈1490 MeV are shown to give a better description of the recent experimental data. We investigate whether η(1420) or η(1490) is the glueball, if it exists, and which of them is the isospin 0 partner of the radially excited state η(1295) expected to exist near the 1500–1600 MeV region. We study the J/ψ→VP and Pγ decays, using the new data of 1992, to estimate the mixing among (η, η′, ι), where ι refers to the glueball, and obtain the result that the N component in ι is larger than the S component. Comparing the N and S components in ι with the N and S components in η(1420) and η(1490) obtained from their decaying pattern, we conjecture that the low mass state η(1420) is the glueball and the high mass state η(1490) is the radial excitation state. We discuss the relation between the mass formulae for the pseudoscalar mesons and the mixing among (η, η′, ι) obtained considering the chiral perturbation theory and the chiral U(3) × U(3) symmetry formulation.

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