Scattering in Noncommutative Quantum Mechanics

We derive the correction due to noncommutativity of space on Born approximation, then the correction for the case of Yukawa potential is explicitly calculated. The correction depends on the angle of scattering. Using partial wave method it is shown that the conservation of the number of particles in elastic scattering is also valid in noncommutative spaces which means that the unitarity relation is held in noncommutative spaces. We also show that the noncommutativity of space has no effect on the optical theorem. Finally we study Gaussian function potential in noncommutative spaces which generates delta function potential as $\theta \to 0$.Comment: 7 Pages, no figure, accepted for publication in Modern Physics Letters

Berry's phase in noncommutative spaces

We introduce the perturbative aspects of noncommutative quantum mechanics. Then we study the Berry's phase in the framework of noncommutative quantum mechanics. The results show deviations from the usual quantum mechanics which depend on the parameter of space/space noncommtativity.Comment: 7 pages, no figur

Optimal Observer Synthesis for Microgrids With Adaptive Send-on-Delta Sampling Over IoT Communication Networks

State estimation is one of the main challenges in the microgrids, due to the complexity of the system dynamics and the limitations of the communication network. In this regard, a novel real-time event-based optimal state estimator is introduced in this paper, which uses the proposed adaptive send-on-delta (SoD) non-uniform sampling method over wireless sensors networks. The proposed estimator requires low communication bandwidth and incurs lower computational resource cost. The threshold for the SoD sampler is made adaptive based on the average communication link delay, which is computed in a distributed form using the event-based average consensus protocol. The SoD non-uniform signal sampling approach reduces the traffic over the wireless communication network due to the events transmitted only when there is a level crossing in the measurements. The state estimator structure is extended on top of the traditional Kalman filter with the additional stages for the fusion of the received events. The error correction stage is further improved by optimal reconstruction of the signals using projection onto convex sets (POCS) algorithm. Finally, an Internet of things (IoT) experimental platform based on LoRaWAN and IEEE 802.11 (WiFi) protocols is developed to analyse the performance of the state estimator for the IEEE 5 Bus case study microgrid

Psychometric assessment of beck scale for suicidal ideation (BSSI) in general population in Tehran

Background: Beck Scale for Suicidal Ideation (BSSI) is a widely used instrument to assess suicidality. However, there is only limited information about the psychometric characteristics of BSSI in the Persian language. In this study, we investigated the validity, reliability and factor structure of the BSSI in the general population of Tehran. Methods: Initially, 900 questionnaire packages were distributed to the general population of Tehran (response rate: 59 percent), using cluster random sampling method. The questionnaire package consisted of a demographic questionnaire, the Persian translation of the BSSI, Symptom checklist-90- Revised (SCL-90-R), Beck Hopelessness Inventory (BHI) and Philips Social Support Appraisal Scale. Internal consistency and correlations of the BSSI scores with other constructs were investigated. Factor analysis was done using principal component method. Results: The Cronbach's alpha coefficients of the screening part and the whole scale were satisfactory (>0.8). The scores of both the screening part and the total scale in individuals who experienced suicidal attempt were higher than others. Both the screening part and the total scale had a positive correlation with depression and Global Severity Index in SCL-90-R, and a negative correlation with social support. The scores of the screening part had a positive correlation with anxiety, psychoticism, hostility and hopelessness as well. The screening part consisted of a single factor which explains 60 of the total variance. Conclusion: The Persian translation of the BSSI has desirable psychometric properties in research setting. However, the clinical usage of the scale remains to be explored, and the factor structure of the whole questionnaire should be assessed in a clinical sample

NMR evidence for very slow carrier density fluctuations in the organic metal (TMTSF)2_2ClO4_4

We have investigated the origin of the large increase in spin-echo decay rates for the $^{77}$Se nuclear spins at temperatures near to $T=30K$ in the organic superconductor (TMTSF)$_2$ClO$_4$. The measured angular dependence of $T_2^{-1}$ demonstrates that the source of the spin-echo decays lies with carrier density fluctuations rather than fluctuations in TMTSF molecular orientation. The very long time scales are directly associated with the dynamics of the anion ordering occurring at $T=25K$, and the inhomogeneously broadened spectra at lower temperatures result from finite domain sizes. Our results are similar to observations of line-broadening effects associated with charge-ordering transitions in quasi-two dimensional organic conductors.Comment: 5 pages, 4 figure

Experimental search for the decay mode K_L -> pi^0 gamma e^+ e^-

We report on results of a search for the decay mode K_L -> pi^0 gamma e^+ e^- conducted by the E162 experiment at KEK. We observed no events and set a 90% confidence level upper limit of Br(K_L -> pi^0 gamma e^+ e^-)< 7.1x10^{-7} for its branching ratio. This is the first published experimental result on this decay mode.Comment: 10 pages, 4 figures, submitted to Physics Letters

Analytic nuclear forces and molecular properties from full configuration interaction quantum Monte Carlo

Unbiased stochastic sampling of the one- and two-body reduced density matrices is achieved in full configuration interaction quantum Monte Carlo with the introduction of a second, "replica" ensemble of walkers, whose population evolves in imaginary time independently from the first, and which entails only modest additional computational overheads. The matrices obtained from this approach are shown to be representative of full configuration-interaction quality, and hence provide a realistic opportunity to achieve high-quality results for a range of properties whose operators do not necessarily commute with the hamiltonian. A density-matrix formulated quasi-variational energy estimator having been already proposed and investigated, the present work extends the scope of the theory to take in studies of analytic nuclear forces, molecular dipole moments and polarisabilities, with extensive comparison to exact results where possible. These new results confirm the suitability of the sampling technique and, where sufficiently large basis sets are available, achieve close agreement with experimental values, expanding the scope of the method to new areas of investigation.Comment: 11 page

Heisenberg quantization for the systems of identical particles and the Pauli exclusion principle in noncommutative spaces

We study the Heisenberg quantization for the systems of identical particles in noncommtative spaces. We get fermions and bosons as a special cases of our argument, in the same way as commutative case and therefore we conclude that the Pauli exclusion principle is also valid in noncommutative spaces.Comment: 8 pages, 1 figur

Electron-lattice coupling and the broken symmetries of the molecular salt (TMTTF)2_2SbF6_6

(TMTTF)$_2$SbF$_6$ is known to undergo a charge ordering (CO) phase transition at $T_{CO}\approx156K$ and another transition to an antiferromagnetic (AF) state at $T_N\approx 8K$. Applied pressure $P$ causes a decrease in both $T_{CO}$ and $T_N$. When $P>0.5 GPa$, the CO is largely supressed, and there is no remaining signature of AF order. Instead, the ground state is a singlet. In addition to establishing an expanded, general phase diagram for the physics of TMTTF salts, we establish the role of electron-lattice coupling in determining how the system evolves with pressure.Comment: 4 pages, 5 figure

Light hadron spectrum and quark masses in QCD with two flavors of dynamical quarks

We present updated results of the CP-PACS calculation of the light hadron spectrum in $N_{\rm f}=2$ full QCD. Simulations are made with an RG-improved gauge action and a tadpole-improved clover quark action for sea quark masses corresponding to $m_{\rm PS}/m_{\rm V} \approx 0.8$--0.6 and the lattice spacing $a=0.22$--0.09 fm. A comparison of the full QCD spectrum with new quenched results, obtained with the same improved action, shows clearly the existence of sea quark effects in vector meson masses. Results for light quark masses in $N_{\rm f}=2$ QCD are also presented.Comment: Latex 3 pages, 6 PostScript figures, Talk presented at LATTICE99(QCD Spectrum and Quark Masses