Experimental search for B = 2, T= 0 states in the d + d → d + X reaction

A search for isoscalar dibaryonic resonances by means of missing-mass spectra in the d + d → d + X reaction has been attempted using deuteron beams of T = 2.29,2.00 and 1.65 GeV. The results do not show any evidence for a narrow peak with a limit of $\text{30 nb}\text{GeV}{}^2$ for a 15 MeV width or a broad enhancement which could be unambiguously attributed to a dibaryonic resonance.     

Triple solutions for a nonlocal functional boundary value problem by leggett–williams theorem

The existence of triple solutions for a second-order nonlocal functional boundary value problem is proved by using a fixed-point theorem on cones in Banach spaces due to Leggett and Williams. The obtained results are new even in the ordinary case for three-point boundary value problems discussed quite recently in [Xiaoming He and Weigao Ge (2002). Triple solutions for second-order three-point boundary value problems. J. Math. Anal. Appl., 268, 256–265].     

Pricing vulnerable European options with stochastic default barriers

CF Lo and KC Ku Institute of Theoretical Physics and Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China Email: cho-hoi_hui{at}hkma.gov.hk Received on 31 July 2006. Accepted on 15 March 2007. This paper develops a valuation model of European options incorporatinga stochastic default barrier, which extends a constant defaultbarrier proposed in the Hull–White model. The defaultbarrier is considered as an option writer's liability. Closed-formsolutions of vulnerable European option values based on themodel are derived to study the impact of the stochastic defaultbarriers on option values. The numerical results show that negativecorrelation between the firm values and the stochastic defaultbarriers of option writers gives material reductions in optionvalues where the options are written by firms with leverageratios corresponding to BBB or BB ratings.     

Measurements on diproton emission from the break-up channels of 23Al and 22Mg

Two-proton relative momentum distributions from the break-up channels ²³Al→p+p+²¹Na and ²²Mg→p+p+²⁰Ne at an energy of 60–70 A MeV have been measured together with two-proton opening angles at the projectile fragment separator beamline (RIPS) in the RIKEN Ring Cyclotron Facility. The results demonstrate the existence of diproton emission component from single-step ²He for highly excited ²³Al and ²²Mg.     

High-resolution spectroscopy using interleaved 100 GHz optical frequency comb scanned by phase modulator

A high-resolution spectroscopy technique is proposed with an optical phase modulator combined with an interleaved optical frequency comb. The optical phase modulator and a frequency-locked laser light guarantee a spectral resolution less than 1 MHz on an absolute frequency axis. A wide measurement frequency range was realized using a 25 GHz optical frequency comb lying over a 4 THz frequency region. An extraction of single tooth intensity from the comb was realized by a heterodyne technique with a frequency-tunable laser used as a local oscillator. Also, the 25 GHz optical frequency comb was interleaved to generate four 100-GHz combs for removing the crosstalk from the 25 GHz neighboring sidebands in the teeth. This proposed spectroscopy technique was experimentally demonstrated with a resonator of less than 1 MHz linewidth and a H¹³C¹⁴N gas cell. Thus, a measurement frequency range higher than 4 THz (1530 nm-1560 nm) was confirmed with an effective spectral resolution 100 kHz order. In addition, the characteristics of the proposed system were compared with those of the previous system with a single-sideband (SSB) optical modulator.     

Ultrafast optical frequency comb synthesizer and analyzer

We propose an ultrafast optical arbitrary waveform synthesizing/analyzing technique demonstrated with 2 Tbit/s waveforms. An ultrafast waveform was generated by manipulating the amplitude and phase of a 400?GHz optical frequency comb using a newly developed colorless optical synthesizer. The 400?GHz optical frequency comb was generated from a 25?GHz optical frequency comb using a colorless arrayed waveguide grating. This waveform was then analyzed on the frequency axis using a custom heterodyne-detection technique based on the dual-heterodyne mixing method. The phase and amplitude spectra can be observed in parallel using another optical frequency comb as a reference combined with an arrayed waveguide grating. This optical system, named the ultrafast optical frequency comb synthesizer and analyzer, can synthesize and analyze an arbitrary waveform in the THz frequency region.     

ChemInform Abstract: Glass Formation in the System BaS-Ga2S3-GeS2 and the Structure of Ba2. 7Ga5.4Ge3.6S18.

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