ON THE EXISTENCE OF THE SUPERSTRING AXION MINI-STAR

2002 ◽  
Vol 17 (03) ◽  
pp. 171-174 ◽  
Author(s):  
M. D. POLLOCK
Keyword(s):  
Strong Interaction ◽  
Decay Constant ◽  
Critical Value ◽  
Decay Constants ◽  
Laser Amplification ◽  
Model Independent ◽  
Theory Formula ◽  
Lasing Mechanism

It is shown that the lasing mechanism of axion solitonic stars found by Tkachev is suppressed above a critical value of the QCD decay constant fa ≈ 1015 GeV . This means, in particular, that the heterotic superstring axion mini-star — for which theory [Formula: see text], where λ ≡ fB/fA is the ratio of the decay constants of the second and model-independent axions, respectively, and [Formula: see text] is the strong-interaction coupling — is allowed to form, the laser amplification being exp A, where [Formula: see text]. Relaxation may occur either by the "gravitational cooling" proposed by Seidel and Suen, and by Khlebnikov, and/or by the four-axion self-interaction studied by Tkachev.

ON THE RELAXATION OF SUPERSTRING AXION MINI-CLUSTERS

2003 ◽  
Vol 18 (14) ◽  
pp. 947-953 ◽  
Author(s):  
M. D. POLLOCK
Keyword(s):  
Decay Constant ◽  
Galactic Center ◽  
Coupling Parameter ◽  
Relaxation Mechanism ◽  
Superstring Theory ◽  
Decay Constants ◽  
Model Independent ◽  
Age Of The Universe ◽  
Axion Decay ◽  
The Universe

The cosmological axion theory leads to the prediction of axionic mini-clusters of mass M ~ 10-9M⊙, which form at the time t e of equipartition of matter and radiation. By applying the two-body relaxation formula of Spitzer and Hart, we show, for the heterotic superstring theory of Gross et al., that these mini-clusters, considered as point masses, themselves cluster into axion mini-stars of mass [Formula: see text] within the age of the Universe t0 only if they are located within a distance R ~ 0.1 pc of the Galactic Center. Here, λ ≡ fB/fA is the ratio of the second to model-independent axion decay constants, assuming the QCD decay constant to be in the range [Formula: see text], and [Formula: see text] is the strong-interaction coupling parameter. Thus, if axion mini-stars are to explain the microlensing observations by the EROS and MACHO groups towards the Galactic Bulge and the Large and Small Magellanic Clouds, then a collisionless relaxation mechanism is required, as proposed by Seidel and Suen (essentially the violent relaxation of Lynden–Bell), or the four-axion self-interaction effect considered by Tkachev.

scholarly journals The Charm and Beauty of Strong Interactions

2018 ◽  
Vol 172 ◽  
pp. 02005 ◽  
Author(s):  
Bruno El-Bennich
Keyword(s):  
Mass Spectrum ◽  
Strong Interaction ◽  
Bound States ◽  
Flavor Physics ◽  
Weak Decay ◽  
Strong Interactions ◽  
Interaction Models ◽  
Common Features ◽  
Decay Constants

We briefly review common features and overlapping issues in hadron and flavor physics focussing on continuum QCD approaches to heavy bound states, their mass spectrum and weak decay constants in different strong interaction models.

Substituent positional effect on radiative lifetimes of anthracene sulphonates

1980 ◽  
Vol 58 (10) ◽  
pp. 1046-1050 ◽  
Author(s):  
A. K. Gupta ◽  
Sekhar Basu ◽  
K. K. Rohatgi-Mukherjee
Keyword(s):  
Sharp Increase ◽  
Decay Constant ◽  
Radiative Decay ◽  
Steric Effect ◽  
Single Photon ◽  
Photon Counting ◽  
Molecular Geometry ◽  
Single Photon Counting ◽  
Decay Constants ◽  
Exciplex Formation

Excited state lifetimes of anthracene-1-sulphonate, anthracene-2-sulphonate, anthracene-1,5-disulphonate, and anthracene-1,8-disulphonate have been studied by photoselection and single photon counting methods. Experimental lifetimes are compared with theoretical values. For anthracene- monosulphonates, exciplex formation with water is proposed. In the case of anthracene-1,8-disulphonate, distortion in molecular geometry is found responsible for the higher non-radiative decay constant. Summation of nonradiative decay constants, Σki, increase in the series [Formula: see text]. The sharp increase for 1,8-AS is perhaps due to distortion of the molecular geometry due to steric effect of two bulky and charged —SO3− groups on the same side of the anthracene skeleton.

scholarly journals Mass Transfer Along an Ice Surface Observed by a Groove Relaxation Technique

1973 ◽  
Vol 12 (64) ◽  
pp. 121-127 ◽  
Author(s):  
K. Itagaki ◽  
T. M. Tobin
Keyword(s):  
Mass Transfer ◽  
Viscous Flow ◽  
Decay Constant ◽  
Relaxation Technique ◽  
Decay Constants ◽  
Ice Surface

AbstractThe mass transfer on an ice surface was measured using a groove decay technique on (0001) plane and <1010> direction at −10° C. The evaporation–condensation and viscous flow terms in Mullins’ theory were deduced from the change of decay constant as a function of groove wavelength between 16 and 80μm. A viscous flow term contributes the most to groove decay while an evaporation–condensation term contributes up to 31.5% of the mass transfer for the shortest wavelength measured and other terms were found to be negligible. Large discrepancies between the decay constants obtained from the measurements and constants calculated from theory indicate that other mechanisms not considered in Mullins’ theory may be responsible for the groove decay.

On the Chemically Induced Decay Constant Variation of Tc-99 m

1978 ◽  
Vol 33 (9) ◽  
pp. 1050-1055
Author(s):  
M. Nagel ◽  
G. Brunner ◽  
K.-P. Dostal ◽  
E. Hartmann ◽  
D. Hinneburg ◽  
...  
Keyword(s):  
Atomic Structure ◽  
Decay Constant ◽  
Complex Compounds ◽  
Decay Constants ◽  
Chemically Induced ◽  
Atomic Structure Calculations ◽  
Structure Calculations ◽  
Spectrochemical Series

The chemical induced decay constant variations for some complex compounds of Tc-99 m were measured by means of a semidifferential approach, using the scintillation technique. The results are λ(TcO4-) - λ(TcCl62-) = (2.52±0.30) · 10-3 λ,λ(TcCl62-) - λ(TcBr62-) = (-0.02±0.20) · 10-3 λ,λ(TcCl62-) - λ (TcI62-) = (0.78 ± 0.41) · 10-3 λ, λ(TcO4-) - λ(TcI62-) = (3.30 ± 0.30) · 10-3 λ, λ(TcO4-) - λ(TcBr62-) = (2.50 ± 0.41) · 10-3 λ.Theoretical estimations by means of atomic structure calculations show that TcO4- should have the greatest decay constant among the compounds investigated, in accordance with the measured values, and that the decay constants of the octahedral complexes should follow the spectrochemical series, partly confirmed by the experiments.

B′ MIXING AND THE PSEUDOSCALAR DECAY CONSTANT

1990 ◽  
Vol 05 (17) ◽  
pp. 3335-3346
Author(s):  
WEI-SHU HOU
Keyword(s):  
Decay Constant ◽  
B Meson ◽  
Meson Decay ◽  
Vector Mesons ◽  
Decay Constants ◽  
Light System ◽  
Meson Mixing ◽  
Pseudoscalar Decay Constant ◽  
Present Understanding ◽  
B Mixing

The possibilities of B′ meson mixing is discussed. It is found that if fB′ is not much smaller than fπ, B's (or B'd) mixing is possible if |Vt′s Vt′b′/Vcb′| is large, but only for not too heavy b′ masses, e.g. below LEP I energies. The B'b meson will have large mixing for a broad range of parameters; however, it is hard to produce. The vector mesons (B′*) may exhibit mixing phenomena as well. A discussion of our present understanding of meson decay constants of a heavy-light system [Formula: see text] is given. Further efforts on this problem is needed, which will have an impact on our understanding of B mixing as well.

B-MESON DECAY CONSTANT REVISITED AND EXTRACTION OF $|\frac{v_{td}}{v_{ts}}|$ FROM $B^0\hbox{--}{\bar B}^0$ MIXING

2004 ◽  
Vol 19 (12) ◽  
pp. 921-925 ◽  
Author(s):  
A. BHATTACHARYA ◽  
S. N. BANERJEE ◽  
B. CHAKRABARTI ◽  
S. BANERJEE
Keyword(s):  
Variational Method ◽  
Decay Constant ◽  
B Meson ◽  
Heavy Meson ◽  
Meson Decay ◽  
Matrix Elements ◽  
Ckm Matrix ◽  
B Meson Decay ◽  
Decay Constants ◽  
Good Agreement

The ratios of Bd and Bs meson decay constant have been estimated using the variational method in conjunction with the relativistic Hamiltonian of the heavy meson in the framework of the statistical model. The ratio of CKM matrix elements [Formula: see text] has been extracted from [Formula: see text] mixing using the estimated decay constants and ratio of Bd and Bs mass differences. The results are found to be in good agreement with the existing theoretical and experimental predictions.

scholarly journals ON THE COMPLEXION OF PSEUDOSCALAR MESONS

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1778-1784 ◽  
Author(s):  
A. HÖLL ◽  
A. KRASSNIGG ◽  
C. D. ROBERTS ◽  
S. V. WRIGHT
Keyword(s):  
Quark Mass ◽  
Decay Constant ◽  
Chiral Limit ◽  
Mass Function ◽  
Mass Scale ◽  
Radial Excitation ◽  
Decay Constants ◽  
Pseudoscalar Mesons ◽  
Constituent Quark Mass ◽  
Goldstone Modes

A strongly momentum-dependent dressed-quark mass function is basic to QCD. It is central to the appearance of a constituent-quark mass-scale and an existential prerequisite for Goldstone modes. Dyson-Schwinger equation (DSEs) studies have long emphasised this importance, and have proved that QCD's Goldstone modes are the only pseudoscalar mesons to possess a nonzero leptonic decay constant in the chiral limit when chiral symmetry is dynamically broken, while the decay constants of their radial excitations vanish. Such features are readily illustrated using a rainbow-ladder truncation of the DSEs. In this connection we find (in GeV): fηc(1S)=0.233, mηc(2S)=3.42; and support for interpreting η(1295), η(1470) as the first radial excitations of η(548), η′(958), respectively, and K(1460) as the first radial excitation of the kaon. Moreover, such radial excitations have electromagnetic diameters greater than 2 fm. This exceeds the spatial length of lattices used typically in contemporary lattice-QCD.

scholarly journals Some Aspects of the U(1) Problem and the Pseudoscalar Mass Spectrum

1984 ◽  
Vol 37 (3) ◽  
pp. 241 ◽  
Author(s):  
GA Christos
Keyword(s):  
Mass Spectrum ◽  
Quark Mass ◽  
Decay Constant ◽  
Point Of View ◽  
The Other ◽  
Decay Constants ◽  
Large N ◽  
Complete Discussion ◽  
Usual Scheme ◽  
Mixing Problem

A complete discussion of the nonet pseudoscalar mass spectrum and related topics is given. The U(l) problern is briefly reviewed and the large-N point of view is considered. The necessity for a vector ghost gluonic particle, in order to resolve the U(l) problem, is stressed. Scalar ghosts and the Kogut-Susskind mechanism are shown to be insufficient. An analysis of the 1]-1]' mixing problem, with and without PCAC corrections, is made and it is suggested that the singlet decay constant may be nearly twice as large as the other octet decay constants. A general discussion of PCAC corrections is given and the remaining pseudoscalars are considered. As byproducts quark mass values are given and the rnq dependence of <ijq) is elucidated. In the usual scheme, it is found that (8S) ~ 1�48(uu). The 1] ~ tttttt decays are also discussed.

scholarly journals Axial-tensor Meson family at $$T\ne 0$$

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
J. Y. Süngü ◽  
A. Türkan ◽  
E. Sertbakan ◽  
E. Veli Veliev
Keyword(s):  
Excited States ◽  
Decay Constant ◽  
Sum Rules ◽  
Heavy Ion ◽  
Heavy Ion Collision ◽  
Model Data ◽  
Decay Constants ◽  
Increasing Temperature ◽  
Ion Collision ◽  
Threshold Point

AbstractThe mass and decay constants of $$\rho _2,~\omega _2$$ ρ 2 , ω 2 and a missing member in the $$ 2^{--} $$ 2 - - nonet along with their first excited states are analyzed by the Thermal QCD sum rules approach, including QCD condensates up to dimension five. Mass and decay constant values of these mesons are stable from $$T=0$$ T = 0 up to  $$T \cong 120 ~\mathrm {MeV}$$ T ≅ 120 MeV . However, after this threshold point, our numerical analyses indicates that they begin to diminish with increasing temperature. When we compare the hadronic parameters with their vacuum values, masses of these mesons and their first excited states decrease between (1–13%) from the PDG data and (10–26%) for the decay constants. However they diminish in the interval of (9–26%) and (2–34%) respectively with regards to Regge Trajectory Model data. We expect our numerical results will be confirmed by future heavy-ion collision experiments.

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