Axial Transition Form Factors and Pion Decay of Baryon Resonances

The pion decay constants of the lowest orbitally excited states of the nucleon and the $\Delta(1232)$ along with the corresponding axial transition form factors are calculated with Poincar\'e covariant constituent-quark models with instant, point and front forms of relativistic kinematics. The model wave functions are chosen such that the calculated electromagnetic and axial form factors of the nucleon represent the empirical values in all three forms of kinematics, when calculated with single-constituent currents. The pion decay widths calculated with the three forms of kinematics are smaller than the empirical values. Front and instant form kinematics provide a similar description, with a slight preference for front form, while the point form values are significantly smaller in the case of the lowest positive parity resonances.Comment: 18 pages, 5 figures. Slightly revised, accepted in Phys. Rev.

Sea-quark effects in the pion charge form factor

It is shown that the data on the pion charge form factor admit the possibility for a substantial sea-quark components in the pion wave function. If the charge form factor is calculated with instant form kinematics in a constituent quark model that is extended to include explicit $(q\bar q)^2$ components in the pion wave function, that component will give the dominant contribution to the calculated $\pi^+$ charge form factor at large values of momentum transfer. The present experimental values $Q^2$ can be described well with $(q\bar q)^2$ component admixtures of up to 50%. The sensitivity of the calculated $\pi^+$ charge form factor to whether one of the quarks or one of the antiquarks is taken to be in the P-state is small.Comment: 14 page

The role of qqˉq\bar q components in the N(1440) resonance

The role of 5-quark components in the pion and electromagnetic decays and transition form factors of the N(1440) is explored. The $qqqq\bar q$ components, where the 4-quark subsystem has the flavor-spin symmetries $[4]_{FS}[22]_F[22]_S$ and $[4]_{FS}[31]_F[31]_S$, which are expected to have the lowest energy of all $qqqq\bar q$ configurations, are considered in detail with a nonrelativistic quark model. The matrix elements between the 5-quark components of the N(1440) and the nucleon, $qqqq\bar q\to qqqq\bar q$, play a minor role in these decays, while the transition matrix elements $qqqq\bar q\to qqq$ and $qqq\to qqqq\bar q$ that involve quark antiquark annihilation are very significant. Both for the electromagnetic and strong decay the change from the valence quark model value is dominated by the confinement triggered $q\bar q$ annihilation transitions. In the case of pion decay the calculated decay width is enhanced substantially both by the direct $q\bar q \to \pi$ and also by the confinement triggered $q\bar q\to \pi$ transitions. Agreement with the empirical value for the pion decay width may be reached with a $\sim$ 30% $qqqq\bar q$ component in the N(1440).Comment: 23 pages revte

The role of qqqqqˉqqqq\bar{q} components in the nucleon and the N(1440) resonance

The role of $q\bar q$ components in the nucleon and the N(1440) resonance is studied by explicit coupling of the lowest positive parity $qqqq\bar q$ state to the $qqq$ components in the harmonic oscillator quark model. The lowest energy $qqqq\bar q$ component, where the 4-quark subsystem has the flavor-spin symmetry $[4]_{FS}[22]_F[22]_S$, is close in energy to the lowest positive parity excitation of the nucleon in the $qqq$ quark model. The confining interaction leads to a strong mixing of the $qqqq\bar q$ system and the positive parity excited state of the $qqq$ system. This result is in line with the phenomenological indications for a two-component structure of the N(1440) resonance. The presence of substantial $q\bar q$ components in the N(1440) can bring about a reconciliation of the constituent quark model with the large empirical decay width of the N(1440).Comment: Accepted for publication in Nucl. Phys.

Five-quark components in Δ(1232)→Nπ\Delta(1232)\to N\pi decay

Five-quark $qqqq\bar q$ components in the $\Delta(1232)$ are shown to contribute significantly to $\Delta(1232)\to N\pi$ decay through quark-antiquark annihilation transitions. These involve the overlap between the $qqq$ and $qqqq\bar q$ components and may be triggered by the confining interaction between the quarks. With a $\sim$ 10% admixture of five-quark components in the $\Delta(1232)$ the decay width can be larger by factors 2 - 3 over that calculated in the quark model with 3 valence quarks, depending on the details of the confining interaction. The effect of transitions between the $qqqq\bar q$ components themselves on the calculated decay width is however small. The large contribution of the quark-antiquark annihilation transitions thus may compensate the underprediction of the width of the $\Delta(1232)$ by the valence quark model, once the $\Delta(1232)$ contains $qqqq\bar q$ components with $\sim$ 10% probability.Comment: accepted versio

Bound States of Heavy Flavor Hyperons

Several realistic phenomenological nucleon-nucleon interaction models are employed to investigate the possibility of bound deuteron-like states of such heavy flavor hyperons and nucleons, for which the interaction between the light flavor quark components is expected to be the most significant interaction. The results indicate that deuteron-like bound states are likely to form between nucleons and the $\Xi_c^{'}$ and $\Xi_{cc}$ charm hyperons as well as between $\Xi$ hyperons and double-charm hyperons. Bound states between two $\Sigma_c$ hyperons are also likely. In the case of beauty hyperons the corresponding states are likely to be deeply bound.Comment: 25 pages, 3 figures. Accepted Nucl. Phys.

Tingkat Perubahan Kesejahteraan Ekonomi Keluarga Buruh Migran

Gondanglegi sub district is occupying the first position as the largest supplier of migrant workers in the area of ​​South Malang in 2014. This research focuses on Panggungrejo Village as the object of research. A village with area of ​​203 km2, population of 1,877 people consisting of 866 men and 1,011 women. This village pervades 12 RTs, and this research took 2 RTs namely RT 5 and 6, with 5 respondents. These five respondents are representatives of various migrant workers. Some represent their wives as migrant workers, husbands and children. This study uses the theory of social mobility; a change, shift, increase or decrease of the status and role of its members. Welfare indicators used are economic, educational, social and health. The result of the research shows that there is a change of the respondents\u27 life level in terms of economic, social, educational and even health compared to prior becoming migrant worker, although the rate of change is not too significant