Some Remarks on Exotic Resonances

Using large $N_c$ counting rule, it is argued that tetra-quark resonances do not exist. Also it is pointed out that there exists the violation of exchange degeneracy in the exotic $KN$ scattering channel. It implies either the failure of resonance saturation assumption or it suggests the existence of exotic baryon resonances in such a channel.Comment: Talk given at 10th International Symposium on Meson-Nucleon Physics and the Structure of the Nucleon (MENU 2004), Beijing, China, 29 Aug - 4 Sep 200

Light airplane crash tests at three pitch angles

Three similar twin-engine general aviation airplane specimens were crash tested at an impact dynamics research facility at 27 m/sec, a flight path angle of -15 deg, and pitch angles of -15 deg, 0 deg, and 15 deg. Other crash parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed

Light airplane crash tests at impact velocities of 13 and 27 m/sec

Two similar general aviation airplanes were crash tested at the Langley impact dynamics research facility at velocities of 13 and 27 m/sec. Other flight parameters were held constant. The facility, instrumentation, tests specimens, and test method are briefly described. Structural damage and accelerometer data are discussed

Impact dynamics research facility for full-scale aircraft crash testing

An impact dynamics research facility (IDRF) was developed to crash test full-scale general aviation aircraft under free-flight test conditions. The aircraft are crashed into the impact surface as free bodies; a pendulum swing method is used to obtain desired flight paths and velocities. Flight paths up to -60 deg and aircraft velocities along the flight paths up to about 27.0 m/s can be obtained with a combination of swing-cable lengths and release heights made available by a large gantry. Seven twin engine, 2721-kg aircraft were successfully crash tested at the facility, and all systems functioned properly. Acquisition of data from signals generated by accelerometers on board the aircraft and from external and onboard camera coverage was successful in spite of the amount of damage which occurred during each crash. Test parameters at the IDRF are controllable with flight path angles accurate within 8 percent, aircraft velocity accurate within 6 percent, pitch angles accurate to 4.25 deg, and roll and yaw angles acceptable under wind velocities up to 4.5 m/s

The dual parameterization of the proton generalized parton distribution functions H and E and description of the DVCS cross sections and asymmetries

We develop the minimal model of a new leading order parameterization of GPDs introduced by Shuvaev and Polyakov. The model for GPDs H and E is formulated in terms of the forward quark distributions, the Gegenbauer moments of the D-term and the forward limit of the GPD E. The model is designed primarely for small and medium-size values of x_B, x_B \leq 0.2. We examined two different models of the t-dependence of the GPDs: The factorized exponential model and the non-factorized Regge-motivated model. Using our model, we successfully described the DVCS cross section measured by H1 and ZEUS, the moments of the beam-spin A_{LU}^{\sin \phi}, beam-charge A_{C}^{\cos \phi} and transversely-polarized target A_{UT}^{\sin \phi \cos \phi} DVCS asymmetries measured by HERMES and A_{LU}^{\sin \phi} measured by CLAS. The data on A_{C}^{\cos \phi} prefers the Regge-motivated model of the t-dependence of the GPDs. The data on A_{UT}^{\sin \phi \cos \phi} indicates that the u and d quarks carry only a small fraction of the proton total angular momentum.Comment: 33 pages, 11 figure

Quantum Inverse Square Interaction

Hamiltonians with inverse square interaction potential occur in the study of a variety of physical systems and exhibit a rich mathematical structure. In this talk we briefly mention some of the applications of such Hamiltonians and then analyze the case of the N-body rational Calogero model as an example. This model has recently been shown to admit novel solutions, whose properties are discussed.Comment: Talk presented at the conference "Space-time and Fundamental Interactions: Quantum Aspects" in honour of Prof. A.P.Balachandran's 65th birthday, Vietri sul Mare, Italy, 26 - 31 May, 2003, Latex file, 9 pages. Some references added in the replaced versio

New insight into WDVV equation

We show that Witten-Dijkgraaf-Verlinde-Verlinde equation underlies the construction of N=4 superconformal multi--particle mechanics in one dimension, including a N=4 superconformal Calogero model.Comment: 16 pages, no figures, LaTeX file, PACS: 04.60.Ds; 11.30.P

Quantum Cosmology and Conformal Invariance

According to Belinsky, Khalatnikov and Lifshitz, gravity near a space-like singularity reduces to a set of decoupled one-dimensional mechanical models at each point in space. We point out that these models fall into a class of conformal mechanical models first introduced by de Alfaro, Fubini and Furlan (DFF). The deformation used by DFF to render the spectrum discrete corresponds to a negative cosmological constant. The wave function of the universe is the zero-energy eigenmode of the Hamiltonian, also known as the spherical vector of the representation of the conformal group SO(1,2). A new class of conformal quantum mechanical models is constructed, based on the quantization of nilpotent coadjoint orbits, where the conformal group is enhanced to an ADE non-compact group for which the spherical vector is known.Comment: 4 pages, latex2e, uses revtex