Clarity on frequently asked questions about drought measurements in plant physiology

Drought, or environmental water deficit, is one of the major limiting factors affecting crop yield worldwide. Development of drought-resistant crop cultivars is a major research and development challenge. Drought-related experiments are performed usually to understand the physiological and molecular mechanisms of drought tolerance. Such experiments are also performed to develop transgenics or crop cultivars resistant to drought using physiological and molecular markers. Drought-related experiments are executed in growth chambers, growth rooms, greenhouses, wire net-houses or in research fields. However, a plethora of research publications investigating drought has experimental weaknesses and flaws with respect to the approaches used. It is, therefore, necessary for agronomists, plant breeders, plant physiologists, and molecular biologists to be aware of common pitfalls and have the minimum knowledge required for drought measurements. There are several questions that are often asked by students and professionals alike, and these questions often appear on academic social media platforms. This article summarises the questions we have been asked about drought measurements personally and those asked on academic social media platforms. It also addresses ambiguous questions arising from published literature. We aim to respond to them to the best of our knowledge in order to provide a reference point for a beginner interested in performing drought-related experiments. This article will only focus on drought in relation to plant physiology and will not cover the usage of the term or drought measurements in other contexts

Neutrino Detection with Inclined Air Showers

The possibilities of detecting high energy neutrinos through inclined showers produced in the atmosphere are addressed with an emphasis on the detection of air showers by arrays of particle detectors. Rates of inclined showers produced by both down-going neutrino interactions and by up-coming $\tau$ decays from earth-skimming neutrinos as a function of shower energy are calculated with analytical methods using two sample neutrino fluxes with different spectral indices. The relative contributions from different flavors and charged, neutral current and resonant interactions are compared for down-going neutrinos interacting in the atmosphere. No detailed description of detectors is attempted but rough energy thresholds are implemented to establish the ranges of energies which are more suitable for neutrino detection through inclined showers. Down-going and up-coming rates are compared.Comment: Submitted to New Journal of Physic

Measurement of the eta-Meson Mass using psi(2S) --> eta J/psi

We measure the mass of the eta meson using psi(2S) --> eta J/psi events acquired with the CLEO-c detector operating at the CESR e+e- collider. Using the four decay modes eta --> gamma gamma, 3pi0, pi+pi-pi0, and pi+pi-gamma, we find M(eta)=547.785 +- 0.017 +- 0.057 MeV, in which the first uncertainty is statistical and the second systematic. This result has an uncertainty comparable to the two most precise previous measurements and is consistent with that of NA48, but is inconsistent at the level of 6.5sigma with the much smaller mass obtained by GEM.Comment: 10 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2007/, Submitted to PR

Suppressed Decays of D_s^+ Mesons to Two Pseudoscalar Mesons

Using data collected near the Ds*+ Ds- peak production energy Ecm = 4170 MeV by the CLEO-c detector, we study the decays of Ds+ mesons to two pseudoscalar mesons. We report on searches for the singly-Cabibbo-suppressed Ds+ decay modes K+ eta, K+ eta', pi+ K0S, K+ pi0, and the isospin-forbidden decay mode Ds+ to pi+ pi0. We normalize with respect to the Cabibbo-favored Ds+ modes pi+ eta, pi+ eta', and K+ K0S, and obtain ratios of branching fractions: Ds+ to K+ eta / Ds+ to pi+ eta = (8.9 +- 1.5 +- 0.4)%, Ds+ to K+ eta' / Ds+ to pi+ eta' = (4.2 +- 1.3 +- 0.3)%, Ds+ to pi+ K0S / Ds+ to K+ K0S = (8.2 +- 0.9 +- 0.2)%, Ds+ to K+ pi0 / Ds+ to K+ K0S = (5.0 +- 1.2 +- 0.6)%, and Ds+ to pi+ pi0 / Ds+ to K+ K0S < 4.1% at 90% CL, where the uncertainties are statistical and systematic, respectively.Comment: 9 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2007/, Submitted to PR

Measurement of the Decay Constant fDS+f_D{_S^+} using $D_S^+ --> ell^+ nu

We measure the decay constant fDs using the Ds -> l+ nu channel, where the l+ designates either a mu+ or a tau+, when the tau+ -> pi+ nu. Using both measurements we find fDs = 274 +-13 +- 7 MeV. Combining with our previous determination of fD+, we compute the ratio fDs/fD+ = 1.23 +- 0.11 +- 0.04. We compare with theoretical estimates.Comment: 6 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2007

New Measurements of Upsilon(1S) Decays to Charmonium Final States

Using substantially larger data samples collected by the CLEO III detector, we report on new measurements of the decays of Upsilon(1S) to charmonium final states, including J/Psi, psi(2S), and chi_cJ. The latter two are first observations of these decays. We measure the branching fractions as follows: B(Y(1S)--> J/Psi+X)=(6.4+-0.4+-0.6)x10^-4, B(Y(1S)--> psi(2S)+X)/B(Y(1S)--> J/Psi+X)=0.41+-0.11+-0.08, B(Y(1S)--> chi_c1+X)/B(Y(1S)--> J/Psi+X)=0.35+-0.08+-0.06, B(Y(1S)--> chi_c2+X)/B(Y(1S)--> J/Psi+X)=0.52+-0.12+-0.09, and B(Y(1S)--> chi_c0+X)/B(Y(1S)--> J/Psi+X)<7.4% at 90% confidence level. We also report on the momentum and angular spectra of J/Psi's in Upsilon(1S) decay. The results are compared to predictions of the color octet and color singlet models.Comment: 27 pages postscript,also available through http://w4.lns.cornell.edu/public/CLNS/, submitted to PR

Search for Radiative Decays of Upsilon(1S) into eta and eta'

We report on a search for the radiative decay of Upsilon(1S) to the pseudoscalar mesons eta and etaprime in 21.2 +/- 0.2 times 10^6 Upsilon(1S) decays collected with the CLEO III detector at the Cornell Electron Storage Ring (CESR). The eta meson was reconstructed in the three modes eta to gamma-gamma, eta to pi+pi-pi0 and eta to 3pi0. The etaprime meson was reconstructed in the mode etaprime to pi+ pi- eta with eta decaying through any of the above three modes, and also etaprime to gamma rho, where rho decays to pi^+ pi^-. Five out of the seven sub-modes are found to be virtually background-free. In four of them we find no signal candidates and in one Upsilon(1S) to gamma-etaprime, etaprime to pi+ pi- eta, eta to pi+pi-pi0 there are two good signal candidates, which is insufficient evidence to claim a signal. The other two sub-modes eta to gamma-gamma and etaprime to gamma rho are background limited, and show no excess of events in their signal regions. We combine the results from different channels and obtain upper limits at the 90% C.L. which are B(Upsilon(1S) to gamma eta) < 1.0 times 10^-6 and B(Upsilon(1S) to gamma etaprime) < 1.9 times 10^-6. Our limits are an order of magnitude tighter than the previous ones and below the predictions made by some theoretical models.Comment: 14 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2007/, Submitted to PR

Di-electron Widths of the Upsilon(1S,2S,3S) Resonances

We determine the di-electron widths of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) resonances with better than 2% precision by integrating the cross-section of e+e- -> Upsilon over the e+e- center-of-mass energy. Using e+e- energy scans of the Upsilon resonances at the Cornell Electron Storage Ring and measuring Upsilon production with the CLEO detector, we find di-electron widths of 1.354 +- 0.004 (stat) +- 0.020 (syst) keV, 0.619 +- 0.004 +- 0.010 keV, and 0.446 +- 0.004 +- 0.007 keV for the Upsilon(1S), Upsilon(2S), and Upsilon(3S), respectively.Comment: 9 pages, 4 figures, also available through http://www.lns.cornell.edu/public/CLNS/2005/, published in PRL; corrected numerical values in abstrac

Measurement of Interfering K^*+K^- and K^*-K^+ Amplitudes in the Decay D^0 --> K^+K^-pi^0

We have studied the Cabibbo-suppressed decay mode D^0 into K^+ K^- pi^0 using a Dalitz plot technique and find the strong phase difference delta_D [defined as delta_(K*^- K^+) - delta_(K*^+ K^-)] = 332 degrees +- 8 degrees +- 11 degrees and relative amplitude r_D [defined as a_(K*^- K^+) / a_(K*^+ K^-)] = 0.52 +- 0.05 +- 0.04. This measurement indicates significant destructive interference between D^0 into K^+ (K^- pi^0)_K*^- and D^0 into K^- (K^+ pi^0)_K*^+ in the Dalitz plot region where these two modes overlap. This analysis uses 9.0 fb^(-1) of data collected at s^(1/2) of approximately 10.58 GeV with the CLEO III detector.Comment: 10 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2006/, Submitted to Phys. Rev. D (Rapid Communications

Confirmation of the Y(4260) Resonance Production in ISR

Using 13.3 fb^-1 of e+e- collision data taken in the Upsilon(1S-4S) region with the CLEO III detector at the CESR collider, a search has been made for the new resonance Y(4260) recently reported by the BaBar Collaboration. The production of Y(4260) in initial state radiation (ISR), and its decay into pi+pi-J/psi are confirmed. A good quality fit to our data is obtained with a single resonance. We determine M(Y(4260))=(4284+17-16(stat)+-4(syst)) MeV/c^2, Gamma(Y(4260))=(73+39-25(stat)+-5(syst)) MeV/c^2, and Gamma_ee(Y(4260))xBr(Y(4260)->pi+pi-J/psi)=(8.9+3.9-3.1(stat)+-1.9(syst)) eV/c^2.Comment: 8 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2006/, Submitted to PRD (Rapid Comm.