The pion-pion scattering amplitude

We obtain reliable $\pi\pi$ scattering amplitudes consistent with experimental data, both at low and high energies, and fulfilling appropriate analyticity properties. We do this by first fitting experimental low energy ($s^{1/2}\leq1.42 {\rm GeV}$) phase shifts and inelasticities with expressions that incorporate analyticity and unitarity. In particular, for the S wave with isospin~0, we discuss in detail several sets of experimental data. This provides low energy partial wave amplitudes that summarize the known experimental information. Then, we impose Regge behaviour as follows from factorization and experimental data for the imaginary parts of the scattering amplitudes at higher energy, and check fulfillment of dispersion relations up to 0.925 GeV. This allows us to improve our fits. The ensuing $\pi\pi$ scattering amplitudes are then shown to verify dispersion relations up to 1.42 GeV, as well as $s - t - u$ crossing sum rules and other consistency conditions. The improved parametrizations therefore provide a reliable representation of pion-pion amplitudes with which one can test chiral perturbation theory calculations, pionium decays, or use as input for CP-violating $K$ decays. In this respect, we find $[a_0^{(0)}-a_0^{(2)}]^2=(0.077\pm0.008) M^{-1}_\pi$ and $\delta_0^{(0)}(m^2_K)-\delta_0^{(2)}(m^2_K)=52.9\pm1.6^{\rm o}$.Comment: Version to be published in Phys. Rev. D. Plain TeX file. (minor changes). 16 figures (some multiple

Prediction of Early Childhood Negative Emotionality and Inhibition From Maternal Distress During Pregnancy

The association was investigated between psychological distress reported during each trimester of pregnancy and maternal ratings of temperament when the children were 6 months and 5 years of age. Mothers in the greater Helsinki area who were to give birth during a 1-year period completed a brief questionnaire describing their psychological adjustment and medical symptoms at each prenatal visit to government health clinics. Mothers rated their children\u27s temperament at ages 6 months and 5 years. Maternal psychological distress during pregnancy was only modestly associated with infant temperament. However, maternal distress during the first trimester was associated with ratings of negative emotionality at age 5 years, with a stronger correlation for males. Inhibition at age 5 was predicted by infant distress to novelty, particularly for males

Quarkonium Wave Functions at the Origin

We tabulate values of the radial Schr\"{o}dinger wave function or its first nonvanishing derivative at zero quark-antiquark separation, for $c\bar{c}$, $c\bar{b}$, and $b\bar{b}$ levels that lie below, or just above, flavor threshold. These quantities are essential inputs for evaluating production cross sections for quarkonium states.Comment: 9 pages, RevTeX, no figure

The Ursinus Weekly, February 9, 1948

Basketeers grab loop lead by thrashing Swarthmore, 49-38 • Color Day festivities here Thursday; Ursinus Women\u27s Club prexy to speak • Bertel, Widholm set pace as grizzlies register fifth win • Music of Clyde Walton sets tempo for dance at Sunnybrook Friday • Ursinus to debate G-burg next week • Thespians to attempt experimental theatre • Dr. Miller forum speaker • Harberger, M. Bell selected for leads in spring operetta • Enrollment augmented by 43 students; 14 seniors complete college careers • Rev. H. C. Baer vesper speaker • Y to hold services during Lent • Goal of 700 subscriptions set by \u2748 yearbook staff • Brotherhood of St. Paul plans Religious Emphasis Week events • Grapplers gain 16-16 tie with Mules; Duncan, Pond, Turner, Collins get wins • Bertel leads cagers to 59-44 victory over outclassed Drexel five • Snell\u27s belles whip East Stroudsburg in court opener • Matmen lose opener to Fords • Bears top Delaware 54-40; Jaffe leads scoring surge • Curtain Club announces promotion list • Frats begin week\u27s period of rushing • Sophs hold dance in gym; schedule hop for March 19 • Curtain Club to give pantomimehttps://digitalcommons.ursinus.edu/weekly/1630/thumbnail.jp

Like Sign Dilepton Signature for R-Parity Violating SUSY Search at the Tevatron Collider

The like sign dileptons provide the most promising signature for superparticle search in a large category of $R$-parity violating SUSY models. We estimate the like sign dilepton signals at the Tevatron collider, predicted by these models, over a wide region of the MSSM parameter space. One expects an unambiguous signal upto a gluino mass of $200 - 300$ GeV ($\geq 500$ GeV) with the present (proposed) accumulated luminosity of $\sim 0.1~(1)~{\rm fb}^{-1}$.Comment: 12 page LaTeX file; 5 figures available upon request from the autho

Constraints on the Charged Higgs Sector from the Tevatron Collider Data on Top Quark Decay

The top quark data in the lepton plus $\tau$ channel offers a viable probe for the charged Higgs boson signal. We analyse the recent Tevatron collider data in this channel to obtain a significant limit on the $H^\pm$ mass in the large $\tan\beta$ region.Comment: 8 pages, LaTeX file; 2 figures included (PS files

Direct Estimate of Cirrus Noise in Herschel Hi-GAL Images

In Herschel images of the Galactic plane and many star forming regions, a major factor limiting our ability to extract faint compact sources is cirrus confusion noise, operationally defined as the "statistical error to be expected in photometric measurements due to confusion in a background of fluctuating surface brightness". The histogram of the flux densities of extracted sources shows a distinctive faint-end cutoff below which the catalog suffers from incompleteness and the flux densities become unreliable. This empirical cutoff should be closely related to the estimated cirrus noise and we show that this is the case. We compute the cirrus noise directly, both on Herschel images from which the bright sources have been removed and on simulated images of cirrus with statistically similar fluctuations. We connect these direct estimates with those from power spectrum analysis, which has been used extensively to predict the cirrus noise and provides insight into how it depends on various statistical properties and photometric operational parameters. We report multi-wavelength power spectra of diffuse Galactic dust emission from Hi-GAL observations at 70 to 500 microns within Galactic plane fields at l= 30 degrees and l= 59 degrees. We find that the exponent of the power spectrum is about -3. At 250 microns, the amplitude of the power spectrum increases roughly as the square of the median brightness of the map and so the expected cirrus noise scales linearly with the median brightness. Generally, the confusion noise will be a worse problem at longer wavelengths, because of the combination of lower angular resolution and the rising power spectrum of cirrus toward lower spatial frequencies, but the photometric signal to noise will also depend on the relative spectral energy distribution of the source compared to the cirrus.Comment: 4 pages (in journal), 3 figures, Astronomy and Astrophysics, accepted for publication 13 May 201

Verbal Communication Skills Requirements for Information Systems Professionals

The role of information systems (IS) professionals in organizations has changed through the years, from one who works mostly with technically oriented peers, to one who spends a significant amount of time interacting with people who are involved in the functional areas of the organization. In many organizations, IS professionals are assigned permanently to the user area and they are expected to not only be technically competent, but also be competent in the user\u27s area. This move of IS professionals to the functional areas necessitates that they communicate more with the functional users whose IS needs they are fulfilling. The users, on the other hand, are also required to interact and communicate more with the IS people. With the move toward distributed IS, users are becoming more involved in the specification, design and sometimes even construction of their own systems. It is therefore imperative that analysts and users be able to communicate with each other unequivocally, so that the systems are specified and developed properly. This research investigated the verbal communication skills requirements for IS practicing professionals and new university graduates. A survey was used for data collection. It was sent to IS professionals in several large organizations, that represented the industry in general. A nearly perfect response rate was achieved. The findings are useful for both IS professionals and university programs. Organizations can use the findings to identify areas of weaknesses in the skills of their IS personnel and eliminate them with continuing education. Universities can use the findings to identify skills that they may not be currently emphasizing in their curricula and make necessary adjustments

Effective mobilities in pseudomorphic Si/SiGe/Si p-channel metal-oxide-semiconductor field-effect transistors with thin silicon capping layers

The room-temperature effective mobilities of pseudomorphic Si/Si0.64Ge0.36/Si p-metal-oxidesemiconductor field effect transistors are reported. The peak mobility in the buried SiGe channel increases with silicon cap thickness. It is argued that SiO2/Si interface roughness is a major source of scattering in these devices, which is attenuated for thicker silicon caps. It is also suggested that segregated Ge in the silicon cap interferes with the oxidation process, leading to increased SiO2/Si interface roughness in the case of thin silicon caps

Polarization tomography of metallic nanohole arrays

We report polarization tomography experiments on metallic nanohole arrays with square and hexagonal symmetry. As a main result, we find that a fully polarized input beam is partly depolarized after transmission through a nanohole array. This loss of polarization coherence is found to be anisotropic, i.e. it depends on the polarization state of the input beam. The depolarization is ascribed to a combination of two factors: i) the nonlocal response of the array due to surface plasmon propagation, ii) the non-plane wave nature of a practical input beam.Comment: 4 pages, 3 figures, 1 table, submitted to PR