Exclusive Vector Photoproduction: Confirmation of Regge Theory

Recent small-t ZEUS data for exclusive rho photoproduction are in excellent agreement with exchange of the classical soft pomeron with slope alpha'=0.25 GeV^{-2}. Adding in a flavour-blind hard-pomeron contribution, whose magnitude is calculated from the data for exclusive J/psi photoproduction, gives a good fit also to the ZEUS data for rho photoproduction at larger values of t, and to phi photoproduction.Comment: 6 pages, plain tex, with 5 figures embedded using eps

An Investigation of the Hard Contribution to phi Photoproduction

We investigate the possibility that the process of phi photoproduction may have a significant hard perturbative QCD component. This suggestion is based on a study of the energy dependence of the forward phi photoproduction cross section followed by a calculation where we show that a coherent sum of the pQCD and conventional soft Pomeron contributions provides an excellent reproduction of the experimental data. Our results suggest that the transition from the predominantly soft photoproduction of light rho and omega vector mesons to the predominantly hard photoproduction of heavy J/psi and upsilon is smooth and gradual, similar to the transition observed in deep inelastic scattering studies of the proton structure function in the small x limit. Our predictions for higher HERA energies are presented.Comment: 14 pages including 5 postscript figure

A C-13(alpha,n)O-16 calibration source for KamLAND

We report on the construction and performance of a calibration source for KamLAND using the reaction C-13(alpha,n)O-16 with Po-210 as the alpha progenitor. The source provides a direct measurement of this background reaction in our detector, high energy calibration points for the detector energy scale, and data on quenching of the neutron visible energy in KamLAND scintillator. We also discuss the possibility of using the reaction C-13(alpha,n)O-16 as a source of tagged slow neutrons.Comment: 6 pages, 4 figures. Revised to agree with the published tex

The Role of Screening Corrections in High Energy Photoproduction

The role of screening corrections, calculated using the eikonal model, is discussed in the context of soft photoproduction. We present a comprehensive calculation considering the total,elastic and diffractive cross sections jointly. We examine the differences between our results and those obtained from the supercritical Pomeron-Reggeon model with no unitarity corrections.Comment: 12 pages (Replacement due to PostScript file problem in previous posting

Experimental limits on the proton life-time from the neutrino experiments with heavy water

Experimental data on the number of neutrons born in the heavy water targets of the large neutrino detectors are used to set the limit on the proton life-time independently on decay mode through the reaction d -> n+?. The best up-to-date limit tau_p > 4 10^23 yr with 95% C.L. is derived from the measurements with D_2O target (mass 267 kg) installed near the Bugey reactor. This value can be improved by six orders of magnitude with future data accumulated with the SNO detector containing 1000 t of D_2O.Comment: LaTeX, 7 pages, 1 table; small typo is correcte

ANOMALOUS GAUGE BOSON INTERACTIONS

We discuss the direct measurement of the trilinear vector boson couplings in present and future collider experiments. The major goals of such experiments will be the confirmation of the Standard Model (SM) predictions and the search for signals of new physics. We review our current theoretical understanding of anomalous trilinear gauge boson self-interactions. If the energy scale of the new physics is $\sim 1$ TeV, these low energy anomalous couplings are expected to be no larger than ${\cal O}(10^{-2})$. Constraints from high precision measurements at LEP and low energy charged and neutral current processes are critically reviewed.Comment: 53 pages with 17 embedded figures, LaTeX, uses axodraw.sty, figures available on request. The complete paper, is available at ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-871.ps.Z or http://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-871.ps.Z Summary of the DPF Working Subgroup on Anomalous Gauge Boson Interactions of the DPF Long Range Planning Stud

Results from the Palo Verde neutrino oscillation experiment

The ν̅e flux and spectrum have been measured at a distance of about 800 m from the reactors of the Palo Verde Nuclear Generating Station using a segmented Gd-loaded liquid scintillator detector. Correlated positron-neutron events from the reaction ν̅ep→e+n were recorded for a period of 200 d including 55 d with one of the three reactors off for refueling. Backgrounds were accounted for by making use of the reactor-on and reactor-off cycles, and also with a novel technique based on the difference between signal and background under reversal of the e+ and n portions of the events. A detailed description of the detector calibration, background subtraction, and data analysis is presented here. Results from the experiment show no evidence for neutrino oscillations. ν̅e→ν̅x oscillations were excluded at 90% C.L. for Δm2>1.12×10-3 eV2 for full mixing and sin22θ>0.21 for large Δm2. These results support the conclusion that the observed atmospheric neutrino oscillations do not involve νe

Constraining Radon Backgrounds in LZ

The LZ dark matter detector, like many other rare-event searches, will suffer from backgrounds due to the radioactive decay of radon daughters. In order to achieve its science goals, the concentration of radon within the xenon should not exceed $2\mu$Bq/kg, or 20 mBq total within its 10 tonnes. The LZ collaboration is in the midst of a program to screen all significant components in contact with the xenon. The four institutions involved in this effort have begun sharing two cross-calibration sources to ensure consistent measurement results across multiple distinct devices. We present here five preliminary screening results, some mitigation strategies that will reduce the amount of radon produced by the most problematic components, and a summary of the current estimate of radon emanation throughout the detector. This best estimate totals $<17.3$ mBq, sufficiently low to meet the detector's science goals.Comment: Low Radioactivity Techniques (LRT) 2017 Workshop Proceedings. 6 pages; 3 figure

A review and road map of entrepreneurial equity financing research

Equity financing in entrepreneurship primarily includes venture capital, corporate venture capital, angel investment, crowdfunding, and accelerators. We take stock of venture financing research to date with two main objectives: (a) to integrate, organize, and assess the large and disparate literature on venture financing; and (b) to identify key considerations relevant for the domain of venture financing moving forward. The net effect is that organizing and assessing existing research in venture financing will assist in launching meaningful, theory-driven research as existing funding models evolve and emerging funding models forge new frontiers