Medium Strong Interaction Research Articles

Imprisoning Yoga: Yoga Practice May Increase the Character Maturity of Male Prison Inmates

Background: A specific personality profile, characterized by low character maturity (low scores on the self-directedness and cooperativeness character dimensions) and high scores on the novelty seeking temperament dimension of the temperament and character inventory (TCI), has been associated with aggressive antisocial behavior in male prison inmates. It has also been shown that yoga practiced in Swedish correctional facilities has positive effects on the inmates’ well-being and on risk factors associated with criminal recidivism (e.g., antisocial behavior). In this study, we aimed to investigate whether the positive effect of yoga practice on inmates’ behaviors could be extended to include eventual changes in their personality profile. Methods: Male prison inmates (N = 111) in Sweden participated in a randomized controlled 10-week long yoga intervention trial. Participants were randomly assigned to either a yoga group (one class a week; n = 57) or a control group (free of choice weekly physical activity; n = 54). All the inmates completed the TCI questionnaire before and after the intervention period as part of an assessment battery. Results: After the 10-week-long intervention period male inmates scored significantly lower on the novelty seeking and the harm avoidance and significantly higher on the self-directedness dimensions of the TCI. There was a significant medium strong interaction effect between time and group belonging for the self-directedness dimension of character favoring the yoga group. Conclusion: A 10-week-long yoga practice intervention among male inmates in Swedish correctional facilities increased the inmates’ character maturity, improving such abilities as their capability to take responsibility, feel more purposeful, and being more self-acceptant—features that previously were found to be associated with decreased aggressive antisocial behavior.

Impacts of nickel loading on properties, catalytic behaviors of Ni/γ–Al2O3 catalysts and the reaction intermediates formed in methanation of CO2

In this study, methanation of CO2 over Ni/Al2O3 with varied nickel loading (from 0 to 50 wt%) was evaluated, striving to explore the effects of nickel loading on catalytic behaviors and the reaction intermediates formed. The results showed that agglomeration of nickel particles were closely related to interaction between nickel and alumina. Increasing nickel loading resulted in the increased proportion of nickel having medium strong interaction with alumina, the reduced reduction degree of NiO, the increase of medium to strong basic sites, the enhanced activity for methanation and the competition between reverse water gas shift (RWGS) reaction and methanation. Lower nickel loading promoted RWGS reaction while methanation of CO2 dominated at higher nickel loading. The catalyst with a nickel loading around 25% achieved the best activity for methanation. The in–situ DRIFTS studies of methanation of CO2 showed that CO2 could be absorbed on surface of metallic Ni, NiO or alumina. More metallic nickel species on alumina suppressed formation of carbonate species while promoted further conversion of HCOO∗ species and ∗CH3 species, achieving a higher catalytic efficiency. Moreover, more metallic nickel species was crucial for gasifying the carbonaceous intermediates, prevented aggregation of the intermediates to coke and achieving a higher catalytic stability.

The eightfold way model, the SU(3)-flavor model and the medium–strong interaction

Lack of any baryon number in the eightfold way model, and its intrinsic presence in the SU(3)-flavor model, has been a puzzle since the genesis of these models in 1961–1964. First we show that the conventional popular understanding of this puzzle is actually fundamentally wrong, and hence the problem being so old, begs urgently for resolution. In this paper we show that the issue is linked to the way that the adjoint representation is defined mathematically for a Lie algebra, and how it manifests itself as a physical representation. This forces us to distinguish between the global and the local charges and between the microscopic and the macroscopic models. As a bonus, a consistent understanding of the hitherto mysterious medium–strong interaction is achieved. We also gain a new perspective on how confinement arises in quantum chromodynamics.

Phenomenological analysis of the properties of narrow resonances and possible evidence for a new quantum number

A phenomenological analysis is carried out to show that the narrow resonances at 3095 and 3685 MeV probably carry a new quantum number which forbids them to decay into ordinary hadrons by strong and medium-strong interactions. It is also shown that the radiative decay modes of these particles are considerably suppressed relative to that of ordinary hadrons. Production in hadronic collisions and photoproduction of these particles are analyzed in this framework. It is suggested that no resonance carrying the same new quantum number can exist with a mass below 2.5 GeV and that the 4.1-GeV resonance can only decay into 3095-MeV and 3685-MeV particles with a width of less than 1 MeV. It is shown, moreover, that the assignment of the ordinary SU(3) quantum numbers of $\ensuremath{\omega}(783)$ to these states, besides the new quantum number, is favored by experiments.

Irreducible representations of a parafield and the connection of the parafield with usual fields

All irreducible separable representations of the non-relativistic para-Fermi field of order 3 in the configuration space are considered. The existence of many different irreducible representations of the parafield permits us to interpret the excited states of this field as the states of particles with internal degrees of freedom. These states can be labelled by the Young patterns and the eigenvalues of internal quantum number like baryonic and hypercharges. The parafield theory is shown to be equivalent to the theory of three kinds of ordinary ferminons, like quarks, and one of them, ‘strange’, can be distinguished from the other two by means of its interaction, not only statistically but also dynamically. Thus the parafield theory is shown to be equivalent to some model of the physicalSU (3) symmetry of hadrons when the strong and medium-strong interactions could be switched on but the electromagnetic and weak interactions should be switched off.

Improved Simulation of Extensive Air Showers with a Medium-Strong Interaction

An improved version of a previous simulation of extensive air showers above ${10}^{13}$ eV is discussed. In the simulation, the central assumption of a medium-strong contact interaction between protons is retained, but a model is used in which secondary pions are produced during $\mathrm{pp}$ collisions rather than through isobar decay. The influence of several different expressions for the multiplicity of pions and for the magnetic form factor of the proton is examined. While these expressions have noticeable quantitative effects on the behavior of the showers, the previous qualitative observation that the medium-strong interaction leads to a gradual increase in a measure of transverse momentum above a primary energy of ${10}^{14}$ eV is unchanged.

Radiative Corrections to Pion-Nucleon Coupling Constants

We formulate a renormalization procedure for avoiding the problem of electromagnetic divergences in second-order electromagnetic amplitudes. We apply it to evaluate radiative corrections to pion-nucleon coupling constants. Such corrections are essentially divided into two categories: "low momentum" to ordinary minimal-coupling expressions and "tadpole" corrections originating from the high-momentum part of the photon integral. The first part is calculated using a Cottingham procedure, weak partial conservation of axial-vector current (PCAC), and saturation by low-lying intermediate states. The tadpole contribution is related to the analogous one in the case of electromagnetic mass shifts and is parametrized in terms of the ratio $\frac{{C}_{3}}{{C}_{8}}$ between tadpole-electromagnetic and medium-strong interactions and of the deviations from S${\mathrm{U}}_{3}$ symmetry for meson-baryon coupling constants. The corrections to the pion-nucleon coupling constants due to electromagnetic mass shifts are estimated separately.

Effect of Rapidly Rising Proton?Proton Total Cross Sections on Idealized Extensive Air Showers

A simulation of extensive air showers above 1013 eV in which proton?proton scattering takes place partly through a medium-strong interaction is reported. In previous papers the simulation has been shown to be in fair agreement with observational data. The present version includes for the first time the assumption that the total cross section for proton-proton scattering increases with energy, as concluded in a recent paper by Yodh, Pal, and Trefil. The effect of the assumption is to make a noticeably better agreement between the simulation and the data.

Simulated Extensive Air Showers with a Medium-Strong Interaction

It is proposed that anomalous measurements of cosmic-ray pions and muons above a characteristic energy of ${10}^{12}$ eV can be explained, at least in part, by the presence of the medium-strong contact interaction between protons. That has been suggested by Abarbanel, Drell, and Gilman. The results of a programmed simulation of extensive air showers in a simple model have the correct behavior to explain the pion measurements, and they show a slight tendency in the correct direction for an explanation of the measurements of muons. Some remarks are made on the difficulties associated with theories of direct production of muons.

The fifth interaction and baryon mass differences

The problem of theSU3-breaking mass splittings and their connection with the electromagnetic ones has been re-examined by using the «fifth interaction» Lagrangian proposed by Ne’eman to interpret the high-energy large-angle proton-proton scattering data, in the framework of the approach suggested by Harari and Segre. Satisfactory results are found for the mass differences andF/D ratio which support the Ne’eman model and provide a justification for the use of a secondorder perturbation formula even for the medium-strong interaction.

BrokenSU(3)Symmetry, Sum Rules, and the Magnetic Moments of the Baryons

Motivated by the increasing accuracy with which the magnetic moments of strange baryons are being measured, we present a calculation of these moments in broken $\mathrm{SU}(3)$ symmetry without appeal to a highly detailed theory of symmetry breaking. As primary ingredients in the calculation, we assume only the $\mathrm{SU}(2)$ transformation properties of the electromagnetic current, the octet transformation property of the symmetry-breaking medium-strong interaction, and the validity of the Drell-Hearn-Gerasimov sum rule for the anomalous moments. Saturating this sum rule with the dominant states, the decuplet and a singlet, but making no $\mathrm{SU}(3)$ assumptions on the couplings of these states or their masses, we find that all eight baryon anomalous magnetic moments and the ${\ensuremath{\Sigma}}^{0}\ensuremath{\Lambda}$ transition moment can be expressed in terms of ${\ensuremath{\kappa}}_{n}$, ${\ensuremath{\kappa}}_{\ensuremath{\Lambda}}$, and ${{\ensuremath{\kappa}}_{\ensuremath{\Sigma}}}^{+}$ through relations that are valid in broken symmetry with an expected accuracy of about 10%. Further assuming the absence of the 27, in the current, we have, in addition, ${{\ensuremath{\kappa}}_{\ensuremath{\Sigma}}}^{+}={\ensuremath{\kappa}}_{n}\ensuremath{-}4{\ensuremath{\kappa}}_{\ensuremath{\Lambda}}$. We also find that our saturation assumption implies the absence of a unitary singlet piece in the electromagnetic current in the symmetry limit, so that the existing particle spectrum supports the hypothesis of a pure octet transformation property for the electromagnetic current. We also examine the Drell-Hearn-Gerasimov sum rule for high-spin systems, and this forward-direction sum rule would appear to require towers of states require towers of states for its saturation. Forward-direction sum rules for the nonflip Compton amplitude, based on the absence of fixed or moving poles in the $J$ plane with $I=2$, are also considered and found to be consistent with the results obtained from the magnetic-moment sum rules.

Subtractions in a Dispersive Approach to Internal Symmetry Breaking

It is shown how the subtractions, in a dispersive approach to SU(3) and SU(2) breaking, reproduce the results of the tadpole model, under the assumption of certain widely used forms for the medium-strong interaction.

The breaking ofSU 3 symmetry in a strong-coupling theory

With the help ofSU3 symmetry and strong coupling of an octet of baryons and an octet of scalar mesons the mass breakings of the physical baryon octet and decuplet are computed. The bare baryon masses are assumed not to be broken, but the symmetry breaking is assumed to appear due to a breaking of the masses within the meson octet. In this way the mass breaking due to the medium strongSU3-breaking interactions and due to the electromagnetic interaction are calculated. If we require that the mass breakings in the octet due to the medium strong interactions agree with reality, then the ratioα=F/(F+D) is fixed and turns out to be about 0.3.

The dashen-frautschi method and parity-conserving baryon-meson couplings

The Dashen-Frautschi method (1), which was successfully applied in particular to the mass differences among the baryon octet and decuplet (2), is here used to treat parity-conservingSU3-noninvariant baryon-meson couplings (the method being « universal », the same arguments hold for medium-strongSU3 breaking and for parity-conserving weak interactions). The results are not very gratifying: 1) Both octet and 27-like coupling shifts are enhanced by comparable factors, which means in particular that the ΔI=1/2 rule forP-wave nonleptonic hyperon decays does not come out as a consequence of a dynamical enhancement, as it did in theS-wave (parity-violating) case. 2) Furthermore, if one nevertheless tries the hypothesis of octet dominance, the model investigated is incapable of fitting the experimental results concerning the relevant hyperon decays. As for medium-strong interactions, the situation is better: the calculated widths for the 3/2+ resonances are reasonable; however, the over-all magnitude of theSU3-breaking constants needed is so large as to make the use of first-order perturbation theory quite questionable.

Electromagnetic masses of baryons and unitary symmetry

Electromagnetic masses of the octet and the decuplet baryons are investigated in the (symmetry-breaking) unitary symmetry model of Gell-Mann and Ne'eman. The symmetry breaking arising from the medium strong interaction is introduced into the electromagnetic mass operator in the direct product form of the SU 3 group. The masses of the decuplet baryons are found to satisfy the relation 3M( N ∗+)−3M( N ∗0)=M( N ∗++)−M N ∗−) . A main purpose of this paper is to give a clear physical interpretation of the various theoretical relations between the electromagnetic masses of the octet baryons and to derive some useful information. First the isotensor contribution is found to be small (about 20%) compared to the isovector one. It is well known that in low-energy nuclear physics the former is negligibly small compared to the latter. Assuming then a similar effect for the decuplet baryons, we get two more approximate relations, M( N ∗+)−M( N ∗0) ≈ M( N ∗++)−M( N ∗+) and M( Y 1 ∗+)−M( Y 1 ∗0) ≈ M( Y 1 ∗0)−M( Y 1 ∗−) . Moreover the isoscalar and the isovector contributions are found to be small if they arise from the operators belonging to the highest irreducible representation of the problem in question. From the detailed analysis of the transient masses (one is purely electromagnetic and the other is mixed strong and electromagnetic) we determine the effect of non-electromagnetic origin due to the second-order symmetry breaking. The nature of the electromagnetic masses for the baryons and the nucleides need not necessarily be the same but that of the various contributions obtained from the octet baryons should remain the same for the decuplet baryons if they arise from the same physical origin of the symmetries.

Departures from the Eightfold Way: Theory of Strong Interaction Symmetry Breakdown

We consider the three kinds of departure from exact unitary symmetry: medium-strong interactions which leave only isospin and hypercharge as good symmetries, electromagnetism, and weak interactions. We postulate the existence of an octet of scalar mesons that give the possibility of symmetry-breaking tadpole diagrams. Our fundamental dynamical assumption---that symmetry-violating processes are dominated by symmetry-breaking tadpole diagrams---gives an immediate explanation of the success of two empirical laws: the Gell-Mann-Okubo mass formulas and the nonleptonic $\ensuremath{\Delta}I=\frac{1}{2}$ rules. Moreover, including tadpole diagrams and some other electromagnetic corrections, we calculate the six electromagnetic mass splittings of mesons and baryons in terms of a single unknown parameter correctly to within 0.5 MeV.

The effect of a scalar meson interaction between muons and baryons

The effect of a scalar meson interaction (as well as the usual photon interaction) in muon-nucleon scattering is evaluated in second order perturbation theory and is compared with the known properties of the muon. The existence of the new interactions is found to be compatible with the experimental results on the muon range and scattering and the nuclear photo-production of muon pairs if the meson mass is approximately three nucleon masses and the meson has medium strong interactions with baryons and muons.