Two photon couplings of the lightest isoscalars from BELLE data

Amplitude Analysis of two photon production of $\pi\pi$ and ${\overline K}K$, using S-matrix constraints and fitting all available data, including the latest precision results from Belle, yields a single partial wave solution up to 1.4 GeV. The two photon couplings of the $\sigma/f_0(500)$, $f_0(980)$ and $f_2(1270)$ are determined from the residues of the resonance poles.Comment: 11 pages, 3 figures, extended for detail

Supernova pencil beam survey

Type Ia supernovae (SNe Ia) can be calibrated to be good standard candles at cosmological distances. We propose a supernova pencil beam survey that could yield between dozens to hundreds of SNe Ia in redshift bins of 0.1 up to $z=1.5$, which would compliment space based SN searches, and enable the proper consideration of the systematic uncertainties of SNe Ia as standard candles, in particular, luminosity evolution and gravitational lensing. We simulate SNe Ia luminosities by adding weak lensing noise (using empirical fitting formulae) and scatter in SN Ia absolute magnitudes to standard candles placed at random redshifts. We show that flux-averaging is powerful in reducing the combined noise due to gravitational lensing and scatter in SN Ia absolute magnitudes. The SN number count is not sensitive to matter distribution in the universe; it can be used to test models of cosmology or to measure the SN rate. The SN pencil beam survey can yield a wealth of data which should enable accurate determination of the cosmological parameters and the SN rate, and provide valuable information on the formation and evolution of galaxies. The SN pencil beam survey can be accomplished on a dedicated 4 meter telescope with a square degree field of view. This telescope can be used to conduct other important observational projects compatible with the SN pencil beam survey, such as QSOs, Kuiper belt objects, and in particular, weak lensing measurements of field galaxies, and the search for gamma-ray burst afterglows.Comment: Final version, to appear in ApJ, 531, #2 (March 10, 2000). 22 pages including 5 figures. Improved presentatio

Can Universe Experience Many Cycles with Different Vacua ?

Recently, the notion that the number of vacua is enormous has received increased attentions, which may be regarded as a possible anthropical explanation to incredible small cosmological constant. Further, a dynamical mechanisms to implement this possibility is required. We show in an operable model of cyclic universe that the universe can experience many cycles with different vacua, which is a generic behavior independent of the details of the model. This might provide a distinct dynamical approach to an anthropically favorable vacuum.Comment: RevTex, 10 pages, 4 eps figures, accepted by PRD(R), new title and changes in the text to match publicatio

Demonstration of fine pitch FCOB (Flip Chip on Board) assembly based on solder bumps at Fermilab

Bump bonding is a superior assembly alternative compared to conventional wire bond techniques. It offers a highly reliable connection with greatly reduced parasitic properties. The Flip Chip on Board (FCOB) procedure is an especially attractive packaging method for applications requiring a large number of connections at moderate pitch. This paper reports on the successful demonstration of FCOB assembly based on solder bumps down to 250um pitch using a SUESS MA8 flip chip bonder at Fermilab. The assembly procedure will be described, microscopic cross sections of the connections are shown, and first measurements on the contact resistance are presented.Comment: 4 pages, 8 figure

Gamma-Ray Burst Environments and Progenitors

Likely progenitors for the GRBs (gamma-ray bursts) are the mergers of compact objects or the explosions of massive stars. These two cases have distinctive environments for the GRB afterglow: the compact object explosions occur in the ISM (interstellar medium) and those of massive stars occur in the preburst stellar wind. We calculate the expected afterglow for a burst in a Wolf-Rayet star wind and compare the results to those for constant, interstellar density. The optical afterglow for the wind case is generally expected to decline more steeply than in the constant density case, but this effect may be masked by variations in electron spectral index, and the two cases have the same evolution in the cooling regime. Observations of the concurrent radio and optical/X-ray evolution are especially useful for distinguishing between the two cases. The different rates of decline of the optical and X-ray afterglows of GRB 990123 suggest constant density interaction for this case. We have previously found strong evidence for wind interaction in SN 1998bw/GRB 980425 and here present a wind model for GRB 980519. We thus suggest that there are both wind type GRB afterglows with massive star progenitors and ISM type afterglows with compact binary star progenitors. The wind type bursts are likely to be accompanied by a supernova, but not the ISM type.Comment: 11 pages, 1 figure, revised version, ApJ Letters, in pres

Trauma-related psychological disorders among Palestinian children and adults in Gaza and West Bank, 2005-2008

BACKGROUND: Trauma from war and violence has led to psychological disorders in individuals living in the Gaza strip and West Bank. Few reports are available on the psychiatric disorders seen in children and adolescents or the treatment of affected populations. This study was conducted in order to describe the occurrence and treatment of psychiatric disorders in the Palestinian populations of the Gaza strip and Nablus district in the West Bank. METHODS: From 2005 to 2008, 1369 patients aged more than 1 year were identified through a local mental health and counseling health network. All were clinically assessed using a semi-structured interview based on the DSM-IV-TR criteria. RESULTS: Among 1254 patients, 23.2% reported post-traumatic stress disorder [PTSD], 17.3% anxiety disorder (other than PTSD or acute stress disorder), and 15.3% depression. PTSD was more frequently identified in children < or = 15 years old, while depression was the main symptom observed in adults. Among children < or = 15 years old, factors significantly associated with PTSD included being witness to murder or physical abuse, receiving threats, and property destruction or loss (p < 0.03). Psychological care, primarily in the form of individual, short-term psychotherapy, was provided to 65.1% of patients, with about 30.6% required psychotropic medication. Duration of therapy sessions was higher for children < or = 15 years old compared with adults (p = 0.05). Following psychotherapy, 79.0% had improved symptoms, and this improvement was significantly higher in children < or = 15 years old (82.8%) compared with adults (75.3%; p = 0.001). CONCLUSION: These observations suggest that short-term psychotherapy could be an effective treatment for specific psychiatric disorders occurring in vulnerable populations, including children, living in violent conflict zones, such as in Gaza strip and the West Bank

Superprotonic phase transition of CsHSO4: A molecular dynamics simulation study

The superprotonic phase transition (phase II --> phase I; 414 K) of cesium hydrogen sulfate, CsHSO4, was simulated using molecular dynamics with the "first principles" MSXX force field (FF). The structure, binding energy, and vibrational frequencies of the CsHSO4 monomer, the binding energy of the (H2SO4)2 dimer, and the torsion barrier of the HSO4- ion were determined from quantum mechanical calculations, and the parameters of the Dreiding FF for Cs, S, O, and H adjusted to reproduce these quantities. Each hydrogen atom was treated as bonded exclusively to a single oxygen atom (proton donor), but allowed to form hydrogen bonds to various second nearest oxygen atoms (proton acceptors). Fixed temperature-pressure (NPT) dynamics were employed to study the structure as a function of temperature from 298 to 723 K. In addition, the influence of several force field parameters, including the hydrogen torsional barrier height, hydrogen bond strength, and oxygen charge distribution, on the structural behavior of CsHSO4 was probed. Although the FF does not allow proton migration (i.e., proton jumps) between oxygen atoms, a clear phase transition occurred as demonstrated by a discrete change of unit cell symmetry (monoclinic to tetragonal), cell volume, and molar enthalpy. The dynamics of the HSO4- group reorientational motion also changed dramatically at the transition. The observation of a transition to the expected tetragonal phase using a FF in which protons cannot migrate indicates that proton diffusion does not drive the transition to the superprotonic phase. Rather, high conductivity is a consequence of the rapid reorientations that occur in the high temperature phase. Furthermore, because no input from the superprotonic phase was employed in these simulations, it may be possible to employ MD to hypothesize superprotonic materials

Counterrotating Nuclear Disks in Arp 220

The ultraluminous infrared galaxy Arp 220 has been observed at 0.5" resolution in CO(2-1) and 1 mm continuum using the newly expanded Owens Valley Millimeter Array. The CO and continuum peaks at the double nuclei and the surrounding molecular gas disk are clearly resolved. We find steep velocity gradients across each nucleus (dV ~ 500 km/s within r= 0.3") whose directions are not aligned with each other and with that of the outer gas disk. We conclude that the double nuclei have their own gas disks (r ~ 100 pc). They are counterrotating with respect to each other and embedded in the outer gas disk (r ~ 1 kpc) rotating around the dynamical center of the system. The masses of each nucleus are M_dyn > 2* 10^9 M_sun based on the CO kinematics. Although there is no evidence of an old stellar population in the optical or near infrared spectroscopy of the nuclei (probably due to the much brighter young population), it seems likely that these nuclei were 'seeded' from the pre-merger nuclei in view of their counterrotating gas kinematics. The gas disks probably constitute a significant fraction (~ 50 %) of the mass in each nucleus. The CO and continuum brightness temperatures imply that the nuclear gas disks have high area filling factors (~ 0.5-1) and have extremely high visual extinctions (Av ~ 1000 mag). The molecular gas must be hot (>= 40 K) and dense (>= 10^4-5 cm^-3), given the large mass and small scale-height of the nuclear disks. The continuum data suggest that the large luminosity (be it starburst or AGN) must originate within 100 pc of the two nuclear gas disks which were presumably formed through concentration of gas from the progenitor outer galaxy disks.Comment: 20 pages, 5 figures. Accepted for publication in The Astrophysical Journa