Study of the performance of a large scale water-Cherenkov detector (MEMPHYS)

MEMPHYS (MEgaton Mass PHYSics) is a proposed large-scale water Cherenkov experiment to be performed deep underground. It is dedicated to nucleon decay searches, neutrinos from supernovae, solar and atmospheric neutrinos, as well as neutrinos from a future Super-Beam or Beta-Beam to measure the CP violating phase in the leptonic sector and the mass hierarchy. A full simulation of the detector has been performed to evaluate its performance for beam physics. The results are given in terms of "Migration Matrices" of reconstructed versus true neutrino energy, taking into account all the experimental effects.Comment: Updated after JCAP's referee's comment

Future large-scale water-Cherenkov detector

MEMPHYS (MEgaton Mass PHYSics) is a proposed large-scale water-Cherenkov experiment to be performed deep underground. It is dedicated to nucleon decay searches and the detection of neutrinos from supernovae, solar, and atmospheric neutrinos, as well as neutrinos from a future beam to measure the CP violating phase in the leptonic sector and the mass hierarchy. This paper provides an overview of the latest studies on the expected performance of MEMPHYS in view of detailed estimates of its physics reach, mainly concerning neutrino beams

Phenological phases of flowering in hop (Humulus lupulus L.) and their correspondence with microsporogenesis and microgametogenesis

[EN] Hop (Humulus Lupulus L.) suffered, as many other crops, a shrinkage of its intraspecific agrobiodiversity. Biotechnological methods of breeding would offer new opportunities to produce improved varieties with interesting phytochemical profiles and adaptable to the challenging conditions of climate change. Doubled haploid (DH) technology could be a useful tool to increase hop agrobiodiversity but, unfortunately, there is a complete lack of information about hop flower biology. For this reason, the main aim of this work is the study of the different phenological phases of flowering in hop and the corresponding developmental stages of microspores/pollen grains contained therein. The results obtained allowed the identification of morphological markers (anther and flower bud length), easy and fast to measure, that would speed up the selection of flower buds containing the highest percentage of vacuolated microspores and young pollen, the stages considered in most species as the most responsive to androgenesis. A further result, derived from the flower bud and anther microscopical observation, evidenced the increase of lupulin glands on bud and anther surface as the bud proceeds in development from microsporogenesis to microgametogenesis.This work was supported by Spanish MINECO [grant number AGL2017-88135-R to JMSS] jointly funded by FEDER.Liberatore, C.; Calabuig-Serna, A.; Rodolfi, M.; Chiancone, B.; Seguí-Simarro, JM. (2019). Phenological phases of flowering in hop (Humulus lupulus L.) and their correspondence with microsporogenesis and microgametogenesis. Scientia Horticulturae. 256:1-6. https://doi.org/10.1016/j.scienta.2019.108639S16256Easterling, K. A., Pitra, N. J., Jones, R. J., Lopes, L. G., Aquino, J. R., Zhang, D., … Bass, H. W. (2018). 3D Molecular Cytology of Hop (Humulus lupulus) Meiotic Chromosomes Reveals Non-disomic Pairing and Segregation, Aneuploidy, and Genomic Structural Variation. Frontiers in Plant Science, 9. doi:10.3389/fpls.2018.01501Nagel, J., Culley, L. K., Lu, Y., Liu, E., Matthews, P. D., Stevens, J. F., & Page, J. E. (2008). EST Analysis of Hop Glandular Trichomes Identifies an O-Methyltransferase That Catalyzes the Biosynthesis of Xanthohumol. The Plant Cell, 20(1), 186-200. doi:10.1105/tpc.107.055178Parra-Vega, V., González-García, B., & Seguí-Simarro, J. M. (2012). Morphological markers to correlate bud and anther development with microsporogenesis and microgametogenesis in pepper (Capsicum annuum L.). Acta Physiologiae Plantarum, 35(2), 627-633. doi:10.1007/s11738-012-1104-xPatzak, J., Nesvadba, V., Henychová, A., & Krofta, K. (2010). Assessment of the genetic diversity of wild hops (Humulus lupulus L.) in Europe using chemical and molecular analyses. Biochemical Systematics and Ecology, 38(2), 136-145. doi:10.1016/j.bse.2009.12.023Patzak, J., Nesvadba, V., Krofta, K., Henychova, A., Marzoev, A. I., & Richards, K. (2010). Evaluation of genetic variability of wild hops (Humulus lupulus L.) in Canada and the Caucasus region by chemical and molecular methods. Genome, 53(7), 545-557. doi:10.1139/g10-024Salas, P., Rivas-Sendra, A., Prohens, J., & Seguí-Simarro, J. M. (2011). Influence of the stage for anther excision and heterostyly in embryogenesis induction from eggplant anther cultures. Euphytica, 184(2), 235-250. doi:10.1007/s10681-011-0569-9Seguí-Simarro, J. M. (2010). Androgenesis Revisited. The Botanical Review, 76(3), 377-404. doi:10.1007/s12229-010-9056-6Seguí-Simarro, J. M., & Nuez, F. (2005). Meiotic metaphase I to telophase II as the most responsive stage during microspore development for callus induction in tomato (Solanum lycopersicum) anther cultures. Acta Physiologiae Plantarum, 27(4), 675-685. doi:10.1007/s11738-005-0071-xSHEPHARD, H. L., PARKER, J. S., DARBY, P., & AINSWORTH, C. C. (2000). Sexual development and sex chromosomes in hop. New Phytologist, 148(3), 397-411. doi:10.1046/j.1469-8137.2000.00771.xXie, W., Xiong, W., Pan, J., Ali, T., Cui, Q., Guan, D., … Davis, S. J. (2018). Decreases in global beer supply due to extreme drought and heat. Nature Plants, 4(11), 964-973. doi:10.1038/s41477-018-0263-

MEMPHYS:A large scale water Cerenkov detector at Fr\'ejus

A water \v{C}erenkov detector project, of megaton scale, to be installed in the Fr\'ejus underground site and dedicated to nucleon decay, neutrinos from supernovae, solar and atmospheric neutrinos, as well as neutrinos from a super-beam and/or a beta-beam coming from CERN, is presented and compared with competitor projects in Japan and in the USA. The performances of the European project are discussed, including the possibility to measure the mixing angle $\theta_{13}$ and the CP-violating phase $\delta$.Comment: 1+33 pages, 14 figures, Expression of Interest of MEMPHYS projec

Establishing a nu_{mu,tau} Component in the Solar Neutrino Flux

We point out that the recoil electron kinetic energy spectra in the nu-e elastic scattering are different for incident nu_{e} or nu_{mu,tau}, and hence one can in principle establish the existence of the nu_{mu,tau} component in the solar neutrino flux by fitting the shape of the spectrum. This would be a new model-independent test of the solar neutrino oscillation in a single experiment, free from astrophysical and nuclear physics uncertainties. For the ^7Be neutrinos, it is possible to determine the nu_{mu,tau} component at BOREXINO or KamLAND, if the background is sufficiently low. Note that this effect is different from the distortion in the incident neutrino energy spectrum, which has been discussed in the literature.Comment: 12 pages, 3 figures, uses psfig. Figures reorganized, one corrected, conclusions unchange

Eigenvector Expansion and Petermann Factor for Ohmically Damped Oscillators

Correlation functions $C(t) \sim$ in ohmically damped systems such as coupled harmonic oscillators or optical resonators can be expressed as a single sum over modes $j$ (which are not power-orthogonal), with each term multiplied by the Petermann factor (PF) $C_j$, leading to "excess noise" when $|C_j| > 1$. It is shown that $|C_j| > 1$ is common rather than exceptional, that $|C_j|$ can be large even for weak damping, and that the PF appears in other processes as well: for example, a time-independent perturbation \sim\ep leads to a frequency shift \sim \ep C_j. The coalescence of $J$ ($>1$) eigenvectors gives rise to a critical point, which exhibits "giant excess noise" ($C_j \to \infty$). At critical points, the divergent parts of $J$ contributions to $C(t)$ cancel, while time-independent perturbations lead to non-analytic shifts \sim \ep^{1/J}.Comment: REVTeX4, 14 pages, 4 figures. v2: final, 20 single-col. pages, 2 figures. Streamlined with emphasis on physics over formalism; rewrote Section V E so that it refers to time-dependent (instead of non-equilibrium) effect

Muon-induced background to proton decay in the p→K+ν decay channel with large underground liquid argon TPC detectors

Large liquid argon TPC detector programs such as LBNE and LAGUNA-LBNO will be able to make measurements of the proton lifetime which will outperform Cherenkov detectors in the proton decay channel p→K+ν. At the large depths which are proposed for such experiments, a non-negligible source of isolated charged kaons may be produced in the showers of cosmogenic muons. We present an estimate of the cosmogenic muon background to proton decay in the p→K+ν channel. The simulation of muon transport to a depth of 4 km w.e. is performed in the MUSIC framework and the subsequent propagation of muons and secondary particles in the vicinity of a cylindrical 20 kt LAr target is performed using Geant4. An exposure time of 100 years is considered, with a rate of <0.0012 events/kt/year at 90% CL predicted from our simulations

Progress on a spherical TPC for low energy neutrino detection

The new concept of the spherical TPC aims at relatively large target masses with low threshold and background, keeping an extremely simple and robust operation. Such a device would open the way to detect the neutrino-nucleus interaction, which, although a standard process, remains undetected due to the low energy of the neutrino-induced nuclear recoils. The progress in the development of the fist 1 m$^3$ prototype at Saclay is presented. Other physics goals of such a device could include supernova detection, low energy neutrino oscillations and study of non-standard properties of the neutrino, among others.Comment: 3 pages, talk given at the 9th Workshop on Topics in Astroparticle and Underground Physics, Zaragoza, September 10-1

A New Upper Limit for the Tau-Neutrino Magnetic Moment

Using a prompt neutrino beam in which a nu_tau component was identified for the first time, the nu_tau magnetic moment was measured based on a search for an anomalous increase in the number of neutrino-electron interactions. One such event was observed when 2.3 were expected from background processes, giving an upper 90% confidence limit of 3.9x10^-7 Bohr magnetons.Comment: 9 pages; 1 figur

A first measurement of the interaction cross section of the tau neutrino

The DONuT experiment collected data in 1997 and published first results in 2000 based on four observed $\nu_\tau$ charged-current (CC) interactions. The final analysis of the data collected in the experiment is presented in this paper, based on $3.6 \times 10^{17}$ protons on target using the 800 GeV Tevatron beam at Fermilab. The number of observed $\nu_\tau$ CC interactions is 9, from a total of 578 observed neutrino interactions. We calculated the energy-independent part of the tau-neutrino CC cross section ($\nu + \bar \nu$), relative to the well-known $\nu_e$ and $\nu_\mu$ cross sections. The ratio $\sigma(\nu_\tau)$/$\sigma(\nu_{e,\mu})$ was found to be $1.37\pm0.35\pm0.77$. The $\nu_\tau$ CC cross section was found to be $0.72 \pm 0.24\pm0.36 \times 10^{-38}$ cm$^{2}\rm{GeV}^{-1}$. Both results are in agreement the Standard Model.Comment: 37 pages, 15 figure