Search

Your search keyword '"Coward, David"' showing total 638 results
Start Over Author "Coward, David"
638 results on '"Coward, David"'

3. A Flare-Type IV Burst Event from Proxima Centauri and Implications for Space Weather

Author

Zic, Andrew, Murphy, Tara, Lynch, Christene, Heald, George, Lenc, Emil, Kaplan, David L., Cairns, Iver H., Coward, David, Gendre, Bruce, Johnston, Helen, MacGregor, Meredith, Price, Danny C., and Wheatland, Michael S.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Studies of solar radio bursts play an important role in understanding the dynamics and acceleration processes behind solar space weather events, and the influence of solar magnetic activity on solar system planets. Similar low-frequency bursts detected from active M-dwarfs are expected to probe their space weather environments and therefore the habitability of their planetary companions. Active M-dwarfs produce frequent, powerful flares which, along with radio emission, reveal conditions within their atmospheres. However, to date, only one candidate solar-like coherent radio burst has been identified from these stars, preventing robust observational constraints on their space weather environment. During simultaneous optical and radio monitoring of the nearby dM5.5e star Proxima Centauri, we detected a bright, long-duration optical flare, accompanied by a series of intense, coherent radio bursts. These detections include the first example of an interferometrically detected coherent stellar radio burst temporally coincident with a flare, strongly indicating a causal relationship between these transient events. The polarization and temporal structure of the trailing long-duration burst enable us to identify it as a type IV burst. This represents the most compelling detection of a solar-like radio burst from another star to date. Solar type IV bursts are strongly associated with space weather events such as coronal mass ejections and solar energetic particle events, suggesting that stellar type IV bursts may be used as a tracer of stellar coronal mass ejections. We discuss the implications of this event for the occurrence of coronal mass ejections from Proxima Cen and other active M-dwarfs., Comment: 18 pages, 7 figures, 1 table. Published in the Astrophysical Journal

Published
2020
Full Text
View/download PDF

4. Ground-Based Gravitational-Wave Astronomy in Australia: 2019 White Paper

Author

Bailes, Matthew, McClelland, David, Thrane, Eric, Blair, David, Cooke, Jeffrey, Coward, David, Evans, Robin, Fenner, Yeshe, Galloway, Duncan, Hurley, Jarrod, Ju, Li, Lasky, Paul, Mandel, Ilya, McKenzie, Kirk, Melatos, Andrew, Ottaway, David, Scott, Susan, Slagmolen, Bram, Veitch, Peter, Wen, Linqing, and Zhao, Chunnong

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology
Abstract

The past four years have seen a scientific revolution through the birth of a new field: gravitational-wave astronomy. The first detection of gravitational waves---recognised by the 2017 Nobel Prize in Physics---provided unprecedented tests of general relativity while unveiling a previously unknown class of massive black holes, thirty times more massive than the Sun. The subsequent detection of gravitational waves from a merging binary neutron star confirmed the hypothesised connection between binary neutron stars and short gamma-ray bursts while providing an independent measurement of the expansion of the Universe. The discovery enabled precision measurement of the speed of gravity while shedding light on the origin of heavy elements. At the time of writing, the Laser Interferometer Gravitational-wave Observatory (LIGO) and its European partner, Virgo, have published the detection of eleven gravitational-wave events. New, not-yet-published detections are announced on a nearly weekly basis. This fast-growing catalogue of gravitational-wave transients is expected to yield insights into a number of topics, from the equation of state of matter at supra-nuclear densities to the fate of massive stars. The science potential of 3G observatories is enormous, enabling measurements of gravitational waves from the edge of the Universe and precise determination of the neutron star equation of state. Australia is well-positioned to help develop the required technology. The Mid-term Review for the Decadal plan for Australian astronomy 2016-2025 should consider investment in a scoping study for an Australian Gravitational-Wave Pathfinder that develops and validates core technologies required for the global 3G detector network., Comment: 8 pages, 7 figures

Published
2019

6. Gamma-ray burst radio afterglows from Population III stars: Simulation methods and detection prospects with SKA precursors

Author

Macpherson, Damien and Coward, David

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We investigate the prospects of detecting radio afterglows from long Gamma-Ray Bursts (GRBs) from Population III (Pop III) progenitors using the SKA precursor instruments WMA (Murchison Widefield Array) and ASKAP (Australian SKA Pathfinder). We derive a realistic model of GRB afterglows that encompasses the widest range of plausible physical parameters and observation angles. We define the best case scenario of Pop III GRB energy and redshift distributions. Using probability distribution functions fitted to the observed microphysical parameters of long GRBs, we simulate a large number of Pop III GRB afterglows to find the global probability of detection. We find that ASKAP may be able to detect 35% of Pop III GRB afterglows in the optimistic case, and 27% in the pessimistic case. A negligible number will be detectable by MWA in either case. Detections per image for ASKAP, found by incorporating intrinsic rates with detectable timescales, are as high as $\sim$ 6000 and as low as $\sim$ 11, which shows the optimistic case is unrealistic. We track how the afterglow flux density changes over various time intervals and find that, because of their very slow variability, the cadence for blind searches of these afterglows should be as long as possible. We also find Pop III GRBs at high redshift have radio afterglow lightcurves that are indistinguishable from those of regular long GRBs in the more local universe., Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Society

Published
2015
Full Text
View/download PDF

7. Selection biases in the gamma ray burst E$_{\rm iso}$ -- L$_{\rm opt,X}$ correlation

Author

Coward, David, Howell, Eric, Wan, Linfeng, and Macpherson, Damien

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Gamma ray burst (GRB) optical and X-ray afterglow luminosity is expected to correlate with the GRB isotropic equivalent kinetic energy of the outflow in the standard synchrotron model for GRB afterglows. Previous studies, using prompt GRB isotropic equivalent energy ($E_{\rm iso}$) as a proxy for isotropic equivalent kinetic energy, have generally confirmed a correlation between X-ray and optical afterglow luminosities. Assuming that GRB afterglow luminosity does not evolve strongly with redshift, we identify a strong Malmquist bias in GRB optical and X-ray afterglow luminosity data. We show that selection effects dominate the observed E$_{\rm iso}$ -- L$_{\rm opt,X}$ correlations, and have likely been underestimated in other studies. The bias is strongest for a subset of optically faint bursts $m>24$ at 24 hr with $z>2$. After removing this optical selection bias, the E$_{\rm iso}$ -- L$_{\rm opt,X}$ correlation for long GRBs is not statistically significant, but combining both long and short GRB luminosity data the correlation is significant. Using the median of the $E_{\rm iso}$ and $L_{\rm opt,X}$ distributions, we apply the synchrotron model assuming the same power law index for short and long GRBs, but different microphysical parameter distributions. Comparing the ratio of optical and X-ray luminosities, we find tentative evidence that the fraction of post-shock energy in magnetic fields, $\epsilon_B$, could be systematically higher in SGRBs compared to LGRBs., Comment: 6 pages, 3 figures, MNRAS Letter accepted, supplementary data to appear online

Published
2014
Full Text
View/download PDF

8. The detection efficiency of on-axis short gamma ray burst optical afterglows triggered by aLIGO/Virgo

Author

Coward, David, Branchesi, Marica, Howell, Eric, Lasky, Paul, and Boer, Michel

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Assuming neutron star (NS) or neutron star/stellar-mass black hole (BH) mergers as progenitors of the short gamma ray bursts, we derive and demonstrate a simple analysis tool for modelling the efficiency of recovering on-axis optical afterglows triggered by a candidate gravitational wave event detected by the Advanced LIGO and Virgo network. The coincident detection efficiency has been evaluated for different classes of operating telescopes using observations of gamma ray bursts. We show how the efficiency depends on the luminosity distribution of the optical afterglows, the telescope features, and the sky localisation of gravitational wave triggers. We estimate a plausible optical afterglow and gravitational wave coincidence rate of 1 yr$^{-1}$ (0.1 yr$^{-1}$) for NS-NS (NS-BH), and how this rate is scaled down in detection efficiency by the time it takes to image the gravitational wave sky localization and the limiting magnitude of the telescopes. For NS-NS (NS-BH) we find maximum detection efficiencies of $>80%$ when the total imaging time is less than 200 min (80 min) and the limiting magnitude fainter than 20 (21). We show that relatively small telescopes $(m<18)$ can achieve similar detection efficiencies to meter class facilities $(m<20)$ with similar fields of view, only if the less sensitive instruments can respond to the trigger and image the field within 10-15 min. The inclusion of LIGO India into the gravitational wave observatory network will significantly reduce imaging time for telescopes with limiting magnitudes $\sim20$ but with modest fields of view. An optimal coincidence search requires a global network of sensitive and fast response wide field instruments that could effectively image relatively large gravitational-wave sky localisations and produce transient candidates for further photometric and spectroscopic follow-up., Comment: 6 pages, 2 figures, version 2, reference added typo correction, Accepted by MNRAS

Published
2014
Full Text
View/download PDF

9. Nuclear Equation of State from Observations of Short Gamma-Ray Burst Remnants

Author

Lasky, Paul D., Haskell, Brynmor, Ravi, Vikram, Howell, Eric J., and Coward, David M.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology
Abstract

The favoured progenitor model for short $\gamma$-ray bursts (SGRBs) is the merger of two neutron stars that triggers an explosion with a burst of collimated $\gamma$-rays. Following the initial prompt emission, some SGRBs exhibit a plateau phase in their $X$-ray light curves that indicates additional energy injection from a central engine, believed to be a rapidly rotating, highly magnetised neutron star. The collapse of this `protomagnetar' to a black hole is likely to be responsible for a steep decay in $X$-ray flux observed at the end of the plateau. In this letter, we show that these observations can be used to effectively constrain the equation of state of dense matter. In particular, we show that the known distribution of masses in binary neutron star systems, together with fits to the $X$-ray light curves, provide constraints that exclude the softest and stiffest plausible equations of state. We further illustrate how a future gravitational wave observation with Advanced LIGO/Virgo can place tight constraints on the equation of state, by adding into the picture a measurement of the chirp mass of the SGRB progenitor., Comment: accepted for publication in Phys. Rev. D

Published
2013
Full Text
View/download PDF

10. The Swift Gamma-Ray Burst redshift distribution: selection biases or rate evolution at high-z?

Author

Coward, David, Howell, Eric, Branchesi, Marica, Gendre, Bruce, and Stratta, Giulia

Subjects
Astrophysics - Cosmology and Extragalactic Astrophysics
Abstract

We employ realistic constraints on selection effects to model the Gamma-Ray Burst (GRB) redshift distribution using {\it Swift} triggered redshift samples acquired from optical afterglows and the TOUGH survey. Models for the Malmquist bias, redshift desert, and the fraction of afterglows missing because of host galaxy dust extinction, are used to show how the "true" GRB redshift distribution is distorted to its presently observed biased distribution. Our analysis, which accounts for the missing fraction of redshifts in the two data subsets, shows that a combination of selection effects (both instrumental and astrophysical) can describe the observed GRB redshift distribution. The observed distribution supports the case for dust extinction as the dominant astrophysical selection effect that shapes the redshift distribution., Comment: 4 pages, Rencontres de Moriond, "Very High Energy Phenomena in the Universe", March 2013

Published
2013

11. The Swift Gamma-Ray Burst redshift distribution: selection biases and optical brightness evolution at high-z?

Author

Coward, David, Howell, Eric, Branchesi, Marica, Strata, Giulia, Guetta, Dafne, Gendre, Bruce, and Macpherson, Damien

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We employ realistic constraints on astrophysical and instrumental selection effects to model the Gamma-Ray Burst (GRB) redshift distribution using {\it Swift} triggered redshift samples acquired from optical afterglows (OA) and the TOUGH survey. Models for the Malmquist bias, redshift desert, and the fraction of afterglows missing because of host galaxy dust extinction, are used to show how the "true" GRB redshift distribution is distorted to its presently observed biased distribution. We also investigate another selection effect arising from a correlation between $E_{{\rm iso}}$ and $L_{{\rm opt}}$. The analysis, which accounts for the missing fraction of redshifts in the two data subsets, shows that a combination of selection effects (both instrumental and astrophysical) can describe the observed GRB redshift distribution. Furthermore, the observed distribution is compatible with a GRB rate evolution that tracks the global SFR, although the rate at high-$z$ cannot be constrained with confidence. Taking selection effects into account, it is not necessary to invoke high-energy GRB luminosity evolution with redshift to explain the observed GRB rate at high-$z$., Comment: Version 2. Includes new data, figures and refined analysis

Published
2012
Full Text
View/download PDF

12. VAST: An ASKAP Survey for Variables and Slow Transients

Author

Murphy, Tara, Chatterjee, Shami, Kaplan, David L., Banyer, Jay, Bell, Martin E., Bignall, Hayley E., Bower, Geoffrey C., Cameron, Robert, Coward, David M., Cordes, James M., Croft, Steve, Curran, James R., Djorgovski, S. G., Farrell, Sean A., Frail, Dale A., Gaensler, B. M., Galloway, Duncan K., Gendre, Bruce, Green, Anne J., Hancock, Paul J., Johnston, Simon, Kamble, Atish, Law, Casey J., Lazio, T. Joseph W., Lo, Kitty K., Macquart, Jean-Pierre, Rea, Nanda, Rebbapragada, Umaa, Reynolds, Cormac, Ryder, Stuart D., Schmidt, Brian, Soria, Roberto, Stairs, Ingrid H., Tingay, Steven J., Torkelsson, Ulf, Wagstaff, Kiri, Walker, Mark, Wayth, Randall B., and Williams, Peter K. G.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

The Australian Square Kilometre Array Pathfinder (ASKAP) will give us an unprecedented opportunity to investigate the transient sky at radio wavelengths. In this paper we present VAST, an ASKAP survey for Variables and Slow Transients. VAST will exploit the wide-field survey capabilities of ASKAP to enable the discovery and investigation of variable and transient phenomena from the local to the cosmological, including flare stars, intermittent pulsars, X-ray binaries, magnetars, extreme scattering events, interstellar scintillation, radio supernovae and orphan afterglows of gamma ray bursts. In addition, it will allow us to probe unexplored regions of parameter space where new classes of transient sources may be detected. In this paper we review the known radio transient and variable populations and the current results from blind radio surveys. We outline a comprehensive program based on a multi-tiered survey strategy to characterise the radio transient sky through detection and monitoring of transient and variable sources on the ASKAP imaging timescales of five seconds and greater. We also present an analysis of the expected source populations that we will be able to detect with VAST., Comment: 29 pages, 8 figures. Submitted for publication in Pub. Astron. Soc. Australia

Published
2012
Full Text
View/download PDF

13. The mystery of the missing GRB redshifts

Author

Coward, David, Howell, Eric, Branchesi, Marica, Guetta, Dafne, and Kanaan, Chadia

Subjects
Astrophysics - Cosmology and Extragalactic Astrophysics
Abstract

It is clear that optical selection effects have distorted the "true" GRB redshift distribution to its presently observed biased distribution. We constrain a statistically optimal model that implies GRB host galaxy dust extinction could account for up to 40% of missing optical afterglows and redshifts in $z = 0-3$, but the bias is negligible at very high-$z$. The limiting sensitivity of the telescopes, and the time to acquire spectroscopic/photometric redshifts, are significant sources of bias for the very high-$z$ sample. We caution on constraining star formation rate and luminosity evolution using the GRB redshift distribution without accounting for these selection effects., Comment: 4 pages, 1 figure, Poster: to appear in: Proceedings of Science, Gamma-Ray Bursts 2012 Conference - GRB2012, May 07-11, 2012, Munich Germany

Published
2012

14. The Swift short gamma-ray burst rate density: prospects for detecting binary neutron star mergers by aLIGO

Author

Coward, David, Howell, Eric, Piran, Tsvi, Stratta, Giulia, Branchesi, Marica, Bromberg, Omer, Gendre, Bruce, Burman, Ronald, and Guetta, Dafne

Subjects
Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology
Abstract

Presently only 30% of short gamma ray bursts (SGRBs) have accurate redshifts, and this sample is highly biased by the limited sensitivity of {\it Swift} to detect SGRBs. We account for the dominant biases to calculate a realistic SGRB rate density out to $z = 0.5$ using the {\it Swift} sample of peak fluxes, redshifts, and those SGRBs with a beaming angle constraint from X-ray/optical observations. Assuming a significant fraction of binary neutron star mergers produce SGRBs, we calculate lower and upper detection rate limits of (1-180) per Yr by an advanced LIGO and Virgo coincidence search. Our detection rate is compatible with extrapolations using Galactic pulsar observations and population synthesis., Comment: 6 pages, 1 figure, to appear in: Proceedings of Science, Gamma-Ray Bursts 2012 Conference - GRB2012, May 07-11, 2012, Munich Germany

Published
2012

15. The Swift short gamma-ray burst rate density: implications for binary neutron star merger rates

Author

Coward, David, Howell, Eric, Piran, Tsvi, Stratta, Giulia, Branchesi, Marica, Bromberg, Omer, Gendre, Bruce, Burman, Ronald, and Guetta, Dafne

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology
Abstract

Short gamma-ray bursts (SGRBs) observed by {\it Swift} are potentially revealing the first insight into cataclysmic compact object mergers. To ultimately acquire a fundamental understanding of these events requires pan-spectral observations and knowledge of their spatial distribution to differentiate between proposed progenitor populations. Up to April 2012 there are only some 30% of SGRBs with reasonably firm redshifts, and this sample is highly biased by the limited sensitivity of {\it Swift} to detect SGRBs. We account for the dominant biases to calculate a realistic SGRB rate density out to $z\approx0.5$ using the {\it Swift} sample of peak fluxes, redshifts, and those SGRBs with a beaming angle constraint from X-ray/optical observations. We find an SGRB lower rate density of $8^{+5}_{-3}$ $\mathrm{Gpc}^{-3}\mathrm{yr}^{-1}$ (assuming isotropic emission), and a beaming corrected upper limit of $1100^{+700}_{-470} $ $\mathrm{Gpc}^{-3}\mathrm{yr}^{-1}$. Assuming a significant fraction of binary neutron star mergers produce SGRBs, we calculate lower and upper detection rate limits of $(1-180)$ yr$^{-1}$ by an aLIGO and Virgo coincidence search. Our detection rate is similar to the lower and realistic rates inferred from extrapolations using Galactic pulsar observations and population synthesis., Comment: version 2: 7 pages, 1 figure, updated table & references, submitted to MNRAS

Published
2012
Full Text
View/download PDF

16. Correlated optical and gamma emissions from GRB 081126

Author

Klotz, Alain, Gendre, B., Atteia, J. L., Boër, Michel, Coward, David M., and Imerito, Alan C.

Subjects
Astrophysics - Cosmology and Extragalactic Astrophysics
Abstract

We present an analysis of time-resolved optical emissions observed from the gamma-ray burst GRB 081126 during the prompt phase. The analysis employed time-resolved photometry using optical data obtained by the TAROT telescope, using BAT data from the Swift spacecraft, and time-resolved spectroscopy at high energies from the GBM instrument onboard the Fermi spacecraft. The optical emission of GRB 081126 is found to be compatible with the second gamma emission pulse shifted by a positive time lag of 8.4 $\pm$ 3.9 s. This is the first well-resolved observation of a time lag between optical and gamma emissions during a gamma-ray burst. Our observations could potentially provide new constraints on the fireball model for gamma-ray burst early emissions. Furthermore, observations of time lags between optical and gamma ray photons provides an exciting opportunity to constrain quantum gravity theories., Comment: 4 pages, to be published in ApJ

Published
2009
Full Text
View/download PDF

17. Open issues with the gamma-ray burst redshift distribution

Author

Coward, David

Subjects
Astrophysics
Abstract

Cosmological gamma ray bursts (GRBs) are the brightest explosions in the Universe. Satellite detectors, such as Beppo-SAX, HETE2 and more recently Swift, have provided a wealth of data, including the localization and redshifts of subsets of GRBs. The redshift distribution has been utilized in several studies in attempts to constrain the evolving star formation rate and to probe GRB rate evolution in the high-redshift Universe. These studies find that the GRB luminosity function and/or the rate density evolve with redshift. We present a short review of the problems of constraining GRB rate evolution in the context of the complex mix of biases inherent in the redshift measurements. To disentangle GRB rate evolution from the biases prevalent in the redshift distribution will require accounting for the incompleteness of the observed redshift sample. We highlight the importance of formulating a `complete GRB selection function' to account for the main sources of bias., Comment: 26 pages, 4 figures, submitted to New Astronomy Reviews, accepted subject to minor revision

Published
2007
Full Text
View/download PDF

18. Detection regimes of the cosmological gravitational wave background from astrophysical sources

Author

Coward, David and Regimbau, Tania

Subjects
Astrophysics, General Relativity and Quantum Cosmology
Abstract

Key targets for gravitational wave (GW) observatories, such as LIGO and the next generation interferometric detector, Advanced LIGO, include core-collapse of massive stars and the final stage of coalescence of compact stellar remnants. The combined GW signal from such events occurring throughout the Universe will produce an astrophysical GW background (AGB), one that is fundamentally different from the GW background by very early Universe processes. One can classify contributions to the AGB for different classes of sources based on the strength of the GW emissions from the individual sources, their peak emission frequency, emission duration and their event rate density distribution. This article provides an overview of the detectability regimes of the AGB in the context of current and planned gravitational wave observatories. We show that there are two important AGB signal detection regimes, which we define as `continuous' and `popcorn noise'. We describe how the `popcorn noise' AGB regime evolves with observation time and we discuss how this feature distinguishes it from the GW background produced from very early Universe processes., Comment: accepted for publication in New Astronomy Reviews; 23 pages and 2 figures

Published
2006
Full Text
View/download PDF

19. Search for $K^+$ decays into the $\pi^+e^+e^-e^+e^-$ final state

Author

Cortina Gil, Eduardo, Minucci, Elisa, Padolski, Sergey, Petrov, Plamen, Velghe, Bob, Bryman, Douglas, Fu, Ji, Numao, Toshio, Petrov, Yevgeniy, Wong, Vincent Wai Sum, Husek, Tomas, Kampf, Karol, Zamkovsky, Michal, Jerhot, Jan, Aliberti, Riccardo, Khoriauli, Gia, Kunze, Jonas, Lomidze, David, Marchevski, Radoslav, Peruzzo, Letizia, Vormstein, Mario, Wanke, Rainer, Cotta Ramusino, Angelo, Dalpiaz, Pietro, Fiorini, Massimiliano, Gamberini, Enrico, Gianoli, Alberto, Neri, Ilaria, Norton, Alan, Petrucci, Ferruccio, Wahl, Heinrich, Bizzeti, Andrea, Bucci, Francesca, Iacopini, Enrico, Latino, Giuseppe, Lenti, Massimo, Parenti, Andrea, Volpe, Roberta, Antonelli, Antonella, Gonnella, Francesco, Lamanna, Gianluca, Lanfranchi, Gaia, Tinti, Gemma, Martellotti, Silvia, Moulson, Matthew, Kozhuharov, Venelin, Litov, Leandar, Georgiev, Georgi, Raggi, Mauro, Spadaro, Tommaso, Ambrosino, Fabio, Fiorenza, Renato, Capussela, Tiziana, Corvino, Michele, Di Filippo, Domenico, Massarotti, Paolo, Mirra, Marco, Napolitano, Marco, Saracino, Giulio, Anzivino, Giuseppina, Imbergamo, Ermanno, Lollini, Riccardo, Santoni, Cristiano, Brizioli, Francesco, Barbanera, Mattia, Cenci, Patrizia, Checcucci, Bruno, Duk, Viacheslav, Lupi, Matteo, Pepe, Monica, Piccini, Mauro, Lubrano, Pasquale, Costantini, Flavio, Doble, Niels, Giorgi, Marcello, Giudici, Sergio, Lari, Enrico, Pinzino, Jacopo, Pontisso, Luca, Sozzi, Marco, Di Lella, Luigi, Mannelli, Italo, Cerri, Claudio, Fantechi, Riccardo, Pedreschi, Elena, Piandani, Roberto, Spinella, Franco, Biagioni, Andrea, d'Agostini, Giulio, Leonardi, Emanuele, Lonardo, Alessandro, Valente, Paolo, Vicini, Piero, Cretaro, Paolo, Turisini, Matteo, Frezza, Ottorino, Ammendola, Roberto, Bonaiuto, Vincenzo, de Simone, Nicola, Federici, Luca, Fucci, Adolfo, Salamon, Andrea, Sargeni, Fausto, Arcidiacono, Roberta, Biino, Cristina, Bloch-Devaux, Brigitte, Boretto, Marco, Filippi, Alessandra, Iacobuzio, Lorenza, Marchetto, Flavio, Menichetti, Ezio, Migliore, Ernesto, Soldi, Dario, Engelfried, Jürgen, Estrada-Tristan, Nora, Bragadireanu, Alexandru Mario, Ghinescu, Stefan Alexandru, Hutanu, Ovidiu Emanuel, Enik, Temur, Falaleev, Valeri, Kekelidze, Vladimir, Korotkova, Anna, Madigozhin, Dmitry, Misheva, Milena, Molokanova, Natalia, Movchan, Sergei, Polenkevich, Irina, Potrebenikov, Yuri, Shkarovskiy, Sergey, Zinchenko, Andrey, Baeva, Aigul, Baigarashev, Dosbol, Emelyanov, Dmitry, Fedotov, Sergei, Khotyantsev, Alexey, Gushchin, Evgeny, Kleimenova, Alina, Kudenko, Yury, Kurochka, Viktoriia, Medvedeva, Mariia, Mefodev, Aleksandr, Shaikhiev, Artur, Kholodenko, Sergey, Kurshetsov, Viktor, Obraztsov, Vladimir, Ostankov, Aleksandr, Semenov, Vitali, Sugonyaev, Valentin, Yushchenko, Oleg, Bician, Lubos, Blazek, Tomas, Cerny, Vladimir, Koval, Michal, Kucerova, Zuzana, Ceccucci, Augusto, Bernhard, Johannes, Danielsson, Hans, Döbrich, Babette, Duval, Francois, Gatignon, Lau, Guida, Roberto, Hahn, Ferdinand, Holzer, Eva Barbara, Jenninger, Berthold, Laycock, Paul, Lehmann Miotto, Giovanna, Lichard, Peter, Mapelli, Alessandro, Noy, Matthew, Palladino, Vito, Perrin-Terrin, Mathieu, Ruggiero, Giuseppe, Ryjov, Vladimir, Schuchmann, Simone, Venditti, Stefano, Brunetti, Maria Brigida, Bache, Thomas, Goudzovski, Evgueni, Henshaw, Jack, Tomczak, Adam, Lazzeroni, Cristina, Fascianelli, Valeria, Lurkin, Nicolas, Newson, Francis, Parkinson, Christopher, Romano, Angela, Sergi, Antonino, Sturgess, Andrew, Swallow, Joel, Heath, Helen, Page, Ryan, Trilov, Stoyan, Angelucci, Bruno, Britton, David, Protopopescu, Dan, Graham, Connor, Jones, Roger William Lewis, Dainton, John Bourke, Fry, John Richard, Fulton, Liam, Hutchcroft, David, Carmignani, Joseph, Massri, Karim, Maurice, Emilie, Wrona, Bozydar, Conovaloff, Adam, Cooper, Peter, Coward, David, Rubin, Philip David, Hives, Zdenko, Akmete, Atakan Tugberk, Soldani, Mattia, Bandiera, Laura, Mazzolari, Andrea, Romagnoni, Marco, Sytov, Alexei, Panichi, Ilaria, Lo Chiatto, Prisco, d'Errico, Mariaelena, Giordano, Raffaele, Briano Olvera, Alejandro, Reyes Santos, Marco Antonio, Boboc, Petre, Kereibay, Dias, Gorshanov, Konstantin, Okhotnikov, Artem, Sadovskiy, Alexander, Sanders, Jack, Kenworthy, Chandler, de Martino, Bianca, Rosa, Ilaria, Ceoletta, Marco, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and NA62

Subjects
pair production, CERN Lab, quantum chromodynamics, axion, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], anomaly, mediation, branching ratio, hidden sector, NA62, Particle Physics - Experiment, High Energy Physics - Experiment
Abstract

The first search for ultra-rare $K^+$ decays into the $\pi^+e^+e^-e^+e^-$ final state is reported, using a dataset collected by the NA62 experiment at CERN in 2017-2018. An upper limit of $1.4\times 10^{-8}$ at 90% CL is obtained for the branching ratio of the $K^+\to\pi^+e^+e^-e^+e^-$ decay, predicted in the Standard Model to be $(7.2\pm0.7)\times 10^{-11}$. Upper limits at 90% CL are obtained at the level of $10^{-9}$ for the branching ratios of two prompt decay chains involving pair-production of hidden-sector mediators: $K^+\to\pi^+aa$, $a\to e^+e^-$ and $K^+\to\pi^+S$, $S\to A^\prime A^\prime$, $A^\prime\to e^+e^-$. The QCD axion is excluded as a possible explanation of the "17 MeV anomaly"., Comment: Version to be submitted to Physics Letters B

Published
2023

20. Proposed gravitational wave background from black hole-torus systems

Author

Coward, David M., van Putten, Maurice H. P. M., and Burman, Ronald R.

Subjects
Astrophysics
Abstract

Cosmological gamma-ray bursts may be powered by rotating black holes with contemporaneous emission of gravitational radiation from a surrounding torus. We calculate the resulting stochastic background radiation assuming strong cosmological evolution and a uniform black hole mass distribution of M= (4--14)M_odot. The predicted spectral flux density corresponds to a peak spectral closure density of (1--2) times 10^{-7}, and has comparable contributions at 450 Hz times kappa and over 300--450 Hz times kappa from nearby and distant sources, respectively, where kappa refers to an uncertainty factor of order unity in the radius of the torus. For two optimized advanced LIGO-type detectors the proposed gravitational wave background could be detectable within a year of integration., Comment: To appear in ApJ

Published
2002
Full Text
View/download PDF

21. Not the premier league: Jules Verne's publisher censored his novel to sell more copies

Author

Coward, David

Subjects
Twenty Thousand Leagues Under the Sea (Novel) -- Butcher, William -- Verne, Jules -- Book reviews, Books -- Book reviews, Literature/writing
Abstract

VINGT MILLE LIEUES SOUS LES MERS Texte restaure JULES VERNE Edition etablie, annotee et presentee par William Butcher 636pp. Presses Universitaires Blaise-Pascal, Clermont-Ferrand. 28 [euro]. Twenty Thousand Leagues Under the [...]

Published
2023

22. Deep space debris—Detection of potentially hazardous asteroids and objects from the southern hemisphere

Author

Kruzins, Ed, primary, Benner, Lance, additional, Boyce, Russell, additional, Brown, Melrose, additional, Coward, David, additional, Darwell, Sam, additional, Edwards, Phil, additional, Elizabeth-Glina, Lauren, additional, Giorgini, Jon, additional, Horiuchi, Shinji, additional, Lambert, Andrew, additional, Lazio, Joseph, additional, Calves, Guifre Molera, additional, Moore, John, additional, Peters, Edwin, additional, Phillips, Chris, additional, Stevens, Jamie, additional, and Verveer, Arie, additional

Published
2023
Full Text
View/download PDF

23. A study of the $K^+ \to \pi^0 e^+ \nu \gamma$ decay

Author

Cortina Gil, Eduardo, Minucci, Elisa, Padolski, Sergey, Petrov, Plamen, Velghe, Bob, Bryman, Douglas, Fu, Ji, Numao, Toshio, Petrov, Yevgeniy, Wong, Vincent Wai Sum, Husek, Tomas, Kampf, Karol, Zamkovsky, Michal, Jerhot, Jan, Aliberti, Riccardo, Khoriauli, Gia, Kunze, Jonas, Lomidze, David, Marchevski, Radoslav, Peruzzo, Letizia, Vormstein, Mario, Wanke, Rainer, Cotta Ramusino, Angelo, Dalpiaz, Pietro, Fiorini, Massimiliano, Gamberini, Enrico, Gianoli, Alberto, Neri, Ilaria, Norton, Alan, Petrucci, Ferruccio, Wahl, Heinrich, Bizzeti, Andrea, Bucci, Francesca, Iacopini, Enrico, Latino, Giuseppe, Lenti, Massimo, Parenti, Andrea, Volpe, Roberta, Antonelli, Antonella, Gonnella, Francesco, Lamanna, Gianluca, Lanfranchi, Gaia, Tinti, Gemma, Martellotti, Silvia, Moulson, Matthew, Kozhuharov, Venelin, Litov, Leandar, Georgiev, Georgi, Raggi, Mauro, Spadaro, Tommaso, Ambrosino, Fabio, Fiorenza, Renato, Capussela, Tiziana, Corvino, Michele, Di Filippo, Domenico, Massarotti, Paolo, Mirra, Marco, Napolitano, Marco, Saracino, Giulio, Anzivino, Giuseppina, Imbergamo, Ermanno, Lollini, Riccardo, Santoni, Cristiano, Brizioli, Francesco, Barbanera, Mattia, Cenci, Patrizia, Checcucci, Bruno, Duk, Viacheslav, Lupi, Matteo, Pepe, Monica, Piccini, Mauro, Lubrano, Pasquale, Costantini, Flavio, Doble, Niels, Giorgi, Marcello, Giudici, Sergio, Lari, Enrico, Pinzino, Jacopo, Pontisso, Luca, Sozzi, Marco, Di Lella, Luigi, Mannelli, Italo, Cerri, Claudio, Fantechi, Riccardo, Pedreschi, Elena, Piandani, Roberto, Spinella, Franco, Biagioni, Andrea, D'Agostini, Giulio, Leonardi, Emanuele, Lonardo, Alessandro, Valente, Paolo, Vicini, Piero, Cretaro, Paolo, Turisini, Matteo, Frezza, Ottorino, Ammendola, Roberto, Bonaiuto, Vincenzo, De Simone, Nicola, Federici, Luca, Fucci, Adolfo, Salamon, Andrea, Sargeni, Fausto, Arcidiacono, Roberta, Biino, Cristina, Bloch-Devaux, Brigitte, Boretto, Marco, Filippi, Alessandra, Iacobuzio, Lorenza, Marchetto, Flavio, Menichetti, Ezio, Migliore, Ernesto, Soldi, Dario, Engelfried, Jürgen, Estrada-Tristan, Nora, Bragadireanu, Alexandru Mario, Ghinescu, Stefan Alexandru, Hutanu, Ovidiu Emanuel, Enik, Temur, Falaleev, Valeri, Kekelidze, Vladimir, Korotkova, Anna, Madigozhin, Dmitry, Misheva, Milena, Molokanova, Natalia, Movchan, Sergei, Polenkevich, Irina, Potrebenikov, Yuri, Shkarovskiy, Sergey, Zinchenko, Alexander, Baeva, Aigul, Baigarashev, Dosbol, Emelyanov, Dmitry, Fedotov, Sergei, Khotyantsev, Alexey, Gushchin, Evgeny, Kleimenova, Alina, Kudenko, Yury, Kurochka, Viktoriia, Medvedeva, Mariia, Mefodev, Aleksandr, Shaikhiev, Artur, Kholodenko, Sergey, Kurshetsov, Viktor, Obraztsov, Vladimir, Ostankov, Aleksandr, Semenov, Vitali, Sugonyaev, Valentin, Yushchenko, Oleg, Bician, Lubos, Blazek, Tomas, Cerny, Vladimir, Koval, Michal, Kucerova, Zuzana, Ceccucci, Augusto, Bernhard, Johannes, Danielsson, Hans, Döbrich, Babette, Duval, Francois, Gatignon, Lau, Guida, Roberto, Hahn, Ferdinand, Holzer, Eva Barbara, Jenninger, Berthold, Laycock, Paul, Lehmann Miotto, Giovanna, Lichard, Peter, Mapelli, Alessandro, Noy, Matthew, Palladino, Vito, Perrin-Terrin, Mathieu, Ruggiero, Giuseppe, Ryjov, Vladimir, Schuchmann, Simone, Venditti, Stefano, Brunetti, Maria Brigida, Bache, Thomas, Goudzovski, Evgueni, Henshaw, Jack, Tomczak, Adam, Lazzeroni, Cristina, Fascianelli, Valeria, Lurkin, Nicolas, Newson, Francis, Parkinson, Christopher, Romano, Angela, Sergi, Antonino, Sturgess, Andrew, Swallow, Joel, Heath, Helen, Page, Ryan, Trilov, Stoyan, Angelucci, Bruno, Britton, David, Protopopescu, Dan, Graham, Connor, Jones, Roger William Lewis, Dainton, John Bourke, Fry, John Richard, Fulton, Liam, Hutchcroft, David, Carmignani, Joseph, Massri, Karim, Maurice, Emilie, Wrona, Bozydar, Conovaloff, Adam, Cooper, Peter, Coward, David, Rubin, Philip David, Hives, Zdenko, Akmete, Atakan Tugberk, Soldani, Mattia, Bandiera, Laura, Mazzolari, Andrea, Romagnoni, Marco, Sytov, Alexei, Panichi, Ilaria, Lo Chiatto, Prisco, D'Errico, Mariaelena, Giordano, Raffaele, Briano Olvera, Alejandro, Reyes Santos, Marco Antonio, Boboc, Petre, Kereibay, Dias, Gorshanov, Konstantin, Okhotnikov, Artem, Sadovskiy, Alexander, and Sanders, Jack

Subjects
Particle Physics - Experiment, High Energy Physics - Experiment
Abstract

A sample of $1.3 \times 10^5 K^+ \to \pi^0 e^+ \nu \gamma$ candidates with less than 1% background was collected by the NA62 experiment at the CERN SPS in 2017-2018. Branching fraction measurements are obtained at percent relative precision in three restricted kinematic regions, improving on existing results by a factor larger than two. An asymmetry, possibly related to T-violation, is investigated with no evidence observed within the achieved precision. A sample of $1.3 \times 10^5$$K^+ \to \pi^0 e^+ \nu \gamma$ candidates with less than 1% background was collected by the NA62 experiment at the CERN SPS in 2017-2018. Branching fraction measurements are obtained at percent relative precision in three restricted kinematic regions, improving on existing results by a factor larger than two. An asymmetry, possibly related to T-violation, is investigated with no evidence observed within the achieved precision.

Published
2023

24. Cracking of laminated glass initiated by low velocity impacts

Author

Coward, David Paul

Subjects
620, TA Engineering (General). Civil engineering (General)
Abstract

The work presented in this thesis is concerned with the determination of the relationship between low velocity impacts and the failure by cracking of 420mm square, 6.4 mm thick, three ply, laminated glass. An hydraulic test rig has been constructed which allows tests involving impacts with pre-determined velocities, up to 7 m/s, and deflections, up to 4.6mm, to be conducted upon the glass samples. Weibull's approach to describing the failure of brittle materials has been adopted. A Weibull cumulative distribution, which relates the probability of failure to the applied stress, has been generated from the experimental data, and the Weibull modulus or flaw density parameter has been determined to be 3.5. The stress intensity factor, K or fracture toughness value, is an indication of the toughness of a material. Glass, as a brittle material would be expected to have a low fracture toughness. Values for K can be determined experimentally, and as a material characteristic should not vary widely, however the value of 0.46 MPa m^1/2 for the fracture toughness, obtained dynamically in this work, appears to differ from those figures determined by others, using quasi-static loading, of between 0.7 and 0.8 MPa m^1/2. If the value for K determined during quasi-static loading is applicable to this work, then the length of surface cracks in the glass is calculated to be between 55 and 72 x 10(^-6) m. The stresses generated during the dynamic loading of glass by an impact can be divided into two distinct elements, the stresses produced by the bending of the glass, and the stresses generated during the impact. However, although the resulting stresses can be described separately, they have a combined effect upon the glass. The stress combination factor / is used to describe how the bending stresses and the impact stresses combine to occasion a micro-crack (which may be found on all exposed glass surfaces) to propagate and cause a fracture in the glass. The value of/is considered to be between 0.7 and 0.8.

Published
2001

25. Improved calorimetric particle identification in NA62 using machine learning techniques

Author

Cortina Gil, Eduardo, Minucci, Elisa, Padolski, Sergey, Petrov, Plamen, Velghe, Bob, Bryman, Douglas, Fu, Ji, Numao, Toshio, Petrov, Yevgeniy, Wong, Vincent Wai Sum, Yu, Mengda, Fedorko, Wojciech, Husek, Tomas, Kampf, Karol, Zamkovsky, Michal, Jerhot, Jan, Aliberti, Riccardo, Khoriauli, Gia, Kunze, Jonas, Lomidze, David, Marchevski, Radoslav, Peruzzo, Letizia, Vormstein, Mario, Wanke, Rainer, Cotta Ramusino, Angelo, Dalpiaz, Pietro, Fiorini, Massimiliano, Gamberini, Enrico, Gianoli, Alberto, Neri, Ilaria, Norton, Alan, Petrucci, Ferruccio, Wahl, Heinrich, Bizzeti, Andrea, Bucci, Francesca, Iacopini, Enrico, Latino, Giuseppe, Lenti, Massimo, Parenti, Andrea, Volpe, Roberta, Antonelli, Antonella, Gonnella, Francesco, Lamanna, Gianluca, Lanfranchi, Gaia, Tinti, Gemma, Martellotti, Silvia, Moulson, Matthew, Kozhuharov, Venelin, Litov, Leandar, Georgiev, Georgi, Raggi, Mauro, Spadaro, Tommaso, Ambrosino, Fabio, Fiorenza, Renato, Capussela, Tiziana, Corvino, Michele, Di Filippo, Domenico, Massarotti, Paolo, Mirra, Marco, Napolitano, Marco, Saracino, Giulio, Anzivino, Giuseppina, Imbergamo, Ermanno, Lollini, Riccardo, Santoni, Cristiano, Brizioli, Francesco, Barbanera, Mattia, Cenci, Patrizia, Checcucci, Bruno, Duk, Viacheslav, Lupi, Matteo, Pepe, Monica, Piccini, Mauro, Lubrano, Pasquale, Costantini, Flavio, Doble, Niels, Giorgi, Marcello, Giudici, Sergio, Lari, Enrico, Pinzino, Jacopo, Pontisso, Luca, Sozzi, Marco, Di Lella, Luigi, Mannelli, Italo, Cerri, Claudio, Fantechi, Riccardo, Pedreschi, Elena, Piandani, Roberto, Spinella, Franco, Biagioni, Andrea, D'Agostini, Giulio, Leonardi, Emanuele, Lonardo, Alessandro, Valente, Paolo, Vicini, Piero, Cretaro, Paolo, Turisini, Matteo, Frezza, Ottorino, Ammendola, Roberto, Bonaiuto, Vincenzo, De Simone, Nicola, Federici, Luca, Fucci, Adolfo, Salamon, Andrea, Sargeni, Fausto, Arcidiacono, Roberta, Biino, Cristina, Bloch-Devaux, Brigitte, Boretto, Marco, Filippi, Alessandra, Iacobuzio, Lorenza, Marchetto, Flavio, Menichetti, Ezio, Migliore, Ernesto, Soldi, Dario, Engelfried, Jürgen, Estrada-Tristan, Nora, Bragadireanu, Alexandru Mario, Ghinescu, Stefan Alexandru, Hutanu, Ovidiu Emanuel, Enik, Temur, Falaleev, Valeri, Kekelidze, Vladimir, Korotkova, Anna, Madigozhin, Dmitry, Misheva, Milena, Molokanova, Natalia, Movchan, Sergei, Polenkevich, Irina, Potrebenikov, Yuri, Shkarovskiy, Sergey, Zinchenko, Alexander, Baeva, Aigul, Baigarashev, Dosbol, Emelyanov, Dmitry, Fedotov, Sergei, Khotyantsev, Alexey, Gushchin, Evgeny, Kleimenova, Alina, Kudenko, Yury, Kurochka, Viktoriia, Medvedeva, Mariia, Mefodev, Aleksandr, Shaikhiev, Artur, Kholodenko, Sergey, Kurshetsov, Viktor, Obraztsov, Vladimir, Ostankov, Aleksandr, Semenov, Vitali, Sugonyaev, Valentin, Yushchenko, Oleg, Bician, Lubos, Blazek, Tomas, Cerny, Vladimir, Koval, Michal, Kucerova, Zuzana, Ceccucci, Augusto, Bernhard, Johannes, Danielsson, Hans, Döbrich, Babette, Duval, Francois, Gatignon, Lau, Guida, Roberto, Hahn, Ferdinand, Holzer, Eva Barbara, Jenninger, Berthold, Laycock, Paul, Lehmann Miotto, Giovanna, Lichard, Peter, Mapelli, Alessandro, Noy, Matthew, Palladino, Vito, Perrin-Terrin, Mathieu, Ruggiero, Giuseppe, Ryjov, Vladimir, Schuchmann, Simone, Venditti, Stefano, Brunetti, Maria Brigida, Bache, Thomas, Goudzovski, Evgueni, Henshaw, Jack, Tomczak, Adam, Lazzeroni, Cristina, Fascianelli, Valeria, Lurkin, Nicolas, Newson, Francis, Parkinson, Christopher, Romano, Angela, Sergi, Antonino, Sturgess, Andrew, Swallow, Joel, Heath, Helen, Page, Ryan, Trilov, Stoyan, Angelucci, Bruno, Britton, David, Protopopescu, Dan, Graham, Connor, Jones, Roger William Lewis, Dainton, John Bourke, Fry, John Richard, Fulton, Liam, Hutchcroft, David, Carmignani, Joseph, Massri, Karim, Maurice, Emilie, Wrona, Bozydar, Conovaloff, Adam, Cooper, Peter, Coward, David, Rubin, Philip David, Hives, Zdenko, Akmete, Atakan Tugberk, Soldani, Mattia, Bandiera, Laura, Mazzolari, Andrea, Romagnoni, Marco, Sytov, Alexei, Panichi, Ilaria, Lo Chiatto, Prisco, D'Errico, Mariaelena, Giordano, Raffaele, Briano Olvera, Alejandro, Reyes Santos, Marco Antonio, Boboc, Petre, Kereibay, Dias, Gorshanov, Konstantin, Okhotnikov, Artem, Sadovskiy, Alexander, and Sanders, Jack

Subjects
High Energy Physics - Experiment (hep-ex), Physics - Instrumentation and Detectors, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Particle Physics - Experiment, High Energy Physics - Experiment
Abstract

Measurement of the ultra-rare $K^+\to\pi^+\nu\bar\nu$ decay at the NA62 experiment at CERN requires high-performance particle identification to distinguish muons from pions. Calorimetric identification currently in use, based on a boosted decision tree algorithm, achieves a muon misidentification probability of $1.2\times 10^{-5}$ for a pion identification efficiency of 75% in the momentum range of 15-40 GeV/$c$. In this work, calorimetric identification performance is improved by developing an algorithm based on a convolutional neural network classifier augmented by a filter. Muon misidentification probability is reduced by a factor of six with respect to the current value for a fixed pion-identification efficiency of 75%. Alternatively, pion identification efficiency is improved from 72% to 91% for a fixed muon misidentification probability of $10^{-5}$., Comment: Updated author list and Ref. 4

Published
2023
Full Text
View/download PDF

26. A search for the $K^+ \to \mu^- \nu e^+ e^+$ decay

Author

Cortina Gil, Eduardo, Minucci, Elisa, Padolski, Sergey, Petrov, Plamen, Velghe, Bob, Bryman, Douglas, Fu, Ji, Numao, Toshio, Petrov, Yevgeniy, Wong, Vincent Wai Sum, Husek, Tomas, Kampf, Karol, Zamkovsky, Michal, Jerhot, Jan, Aliberti, Riccardo, Khoriauli, Gia, Kunze, Jonas, Lomidze, David, Marchevski, Radoslav, Peruzzo, Letizia, Vormstein, Mario, Wanke, Rainer, Cotta Ramusino, Angelo, Dalpiaz, Pietro, Fiorini, Massimiliano, Gamberini, Enrico, Gianoli, Alberto, Neri, Ilaria, Norton, Alan, Petrucci, Ferruccio, Wahl, Heinrich, Bizzeti, Andrea, Bucci, Francesca, Iacopini, Enrico, Latino, Giuseppe, Lenti, Massimo, Parenti, Andrea, Volpe, Roberta, Antonelli, Antonella, Gonnella, Francesco, Lamanna, Gianluca, Lanfranchi, Gaia, Tinti, Gemma, Martellotti, Silvia, Moulson, Matthew, Kozhuharov, Venelin, Litov, Leandar, Georgiev, Georgi, Raggi, Mauro, Spadaro, Tommaso, Ambrosino, Fabio, Fiorenza, Renato, Capussela, Tiziana, Corvino, Michele, Di Filippo, Domenico, Massarotti, Paolo, Mirra, Marco, Napolitano, Marco, Saracino, Giulio, Anzivino, Giuseppina, Imbergamo, Ermanno, Lollini, Riccardo, Santoni, Cristiano, Brizioli, Francesco, Barbanera, Mattia, Cenci, Patrizia, Checcucci, Bruno, Duk, Viacheslav, Lupi, Matteo, Pepe, Monica, Piccini, Mauro, Lubrano, Pasquale, Costantini, Flavio, Doble, Niels, Giorgi, Marcello, Giudici, Sergio, Lari, Enrico, Pinzino, Jacopo, Pontisso, Luca, Sozzi, Marco, Di Lella, Luigi, Mannelli, Italo, Cerri, Claudio, Fantechi, Riccardo, Pedreschi, Elena, Piandani, Roberto, Spinella, Franco, Biagioni, Andrea, d'Agostini, Giulio, Leonardi, Emanuele, Lonardo, Alessandro, Valente, Paolo, Vicini, Piero, Cretaro, Paolo, Turisini, Matteo, Frezza, Ottorino, Ammendola, Roberto, Bonaiuto, Vincenzo, de Simone, Nicola, Federici, Luca, Fucci, Adolfo, Salamon, Andrea, Sargeni, Fausto, Arcidiacono, Roberta, Biino, Cristina, Bloch-Devaux, Brigitte, Boretto, Marco, Filippi, Alessandra, Iacobuzio, Lorenza, Marchetto, Flavio, Menichetti, Ezio, Migliore, Ernesto, Soldi, Dario, Engelfried, Jürgen, Estrada-Tristan, Nora, Bragadireanu, Alexandru Mario, Ghinescu, Stefan Alexandru, Hutanu, Ovidiu Emanuel, Enik, Temur, Falaleev, Valeri, Kekelidze, Vladimir, Korotkova, Anna, Madigozhin, Dmitry, Misheva, Milena, Molokanova, Natalia, Movchan, Sergei, Polenkevich, Irina, Potrebenikov, Yuri, Shkarovskiy, Sergey, Zinchenko, Alexander, Baeva, Aigul, Baigarashev, Dosbol, Emelyanov, Dmitry, Fedotov, Sergei, Khotyantsev, Alexey, Gushchin, Evgeny, Kleimenova, Alina, Kudenko, Yury, Kurochka, Viktoriia, Medvedeva, Mariia, Mefodev, Aleksandr, Shaikhiev, Artur, Kholodenko, Sergey, Kurshetsov, Viktor, Obraztsov, Vladimir, Ostankov, Aleksandr, Semenov, Vitali, Sugonyaev, Valentin, Yushchenko, Oleg, Bician, Lubos, Blazek, Tomas, Cerny, Vladimir, Koval, Michal, Kucerova, Zuzana, Ceccucci, Augusto, Bernhard, Johannes, Danielsson, Hans, Döbrich, Babette, Duval, Francois, Gatignon, Lau, Guida, Roberto, Hahn, Ferdinand, Holzer, Eva Barbara, Jenninger, Berthold, Laycock, Paul, Lehmann Miotto, Giovanna, Lichard, Peter, Mapelli, Alessandro, Noy, Matthew, Palladino, Vito, Perrin-Terrin, Mathieu, Ruggiero, Giuseppe, Ryjov, Vladimir, Schuchmann, Simone, Venditti, Stefano, Brunetti, Maria Brigida, Bache, Thomas, Goudzovski, Evgueni, Henshaw, Jack, Tomczak, Adam, Lazzeroni, Cristina, Fascianelli, Valeria, Lurkin, Nicolas, Newson, Francis, Parkinson, Christopher, Romano, Angela, Sergi, Antonino, Sturgess, Andrew, Swallow, Joel, Heath, Helen, Page, Ryan, Trilov, Stoyan, Angelucci, Bruno, Britton, David, Protopopescu, Dan, Graham, Connor, Jones, Roger William Lewis, Dainton, John Bourke, Fry, John Richard, Fulton, Liam, Hutchcroft, David, Carmignani, Joseph, Massri, Karim, Maurice, Emilie, Wrona, Bozydar, Conovaloff, Adam, Cooper, Peter, Coward, David, Rubin, Philip David, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), and NA62

Subjects
flavor, CERN Lab, lepton, conservation law, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], lepton number, branching ratio, NA62, Particle Physics - Experiment, High Energy Physics - Experiment
Abstract

A search for the $K^+\to\mu^-\nu e^+e^+$ decay, forbidden within the Standard Model by either lepton number or lepton flavour conservation depending on the flavour of the emitted neutrino, has been performed using the dataset collected by the NA62 experiment at CERN in 2016--2018. An upper limit of $8.1\times 10^{-11}$ is obtained for the decay branching fraction at 90% CL, improving by a factor of 250 over the previous search., Comment: Final version, accepted for publication in Physics Letters B

Published
2022

27. A measurement of the $K^+ \to \pi^+ \mu^+ \mu^-$ decay

Author

Cortina Gil, Eduardo, Minucci, Elisa, Padolski, Sergey, Petrov, Plamen, Velghe, Bob, Bryman, Douglas, Fu, J., Numao, Toshio, Petrov, Yevgeniy, Wong, Vincent Wai Sum, Husek, Tomas, Kampf, Karol, Zamkovsky, Michal, Jerhot, Jan, Aliberti, Riccardo, Khoriauli, Gia, Kunze, Jonas, Lomidze, David, Potrebenikov, Yu., Marchevski, Radoslav, Peruzzo, Letizia, Vormstein, Mario, Wanke, Rainer, Cotta Ramusino, Angelo, Dalpiaz, Pietro, Fiorini, Massimiliano, Gamberini, Enrico, Gianoli, Alberto, Neri, Ilaria, Norton, Alan, Petrucci, Ferruccio, Wahl, Heinrich, Bizzeti, Andrea, Bucci, Francesca, Iacopini, Enrico, Latino, Giuseppe, Lenti, Massimo, Parenti, Andrea, Volpe, Roberta, Antonelli, Antonella, Gonnella, Francesco, Lamanna, Gianluca, Lanfranchi, Gaia, Tinti, Gemma, Martellotti, Silvia, Moulson, Matthew, Kozhuharov, Venelin, Litov, Leandar, Georgiev, Georgi, Raggi, Mauro, Spadaro, Tommaso, Ambrosino, Fabio, Fiorenza, Renato, Capussela, Tiziana, Corvino, Michele, Di Filippo, Domenico, Massarotti, Paolo, Mirra, Marco, Napolitano, Marco, Saracino, Giulio, Anzivino, Giuseppina, Imbergamo, Ermanno, Lollini, Riccardo, Santoni, Cristiano, Brizioli, Francesco, Barbanera, Mattia, Cenci, Patrizia, Checcucci, Bruno, Duk, Viacheslav, Lupi, Matteo, Pepe, Monica, Piccini, Mauro, Lubrano, Pasquale, Costantini, Flavio, Doble, Niels, Giorgi, Marcello, Giudici, Sergio, Lari, Enrico, Pinzino, Jacopo, Pontisso, Luca, Sozzi, Marco, Di Lella, Luigi, Mannelli, Italo, Cerri, Claudio, Fantechi, Riccardo, Pedreschi, Elena, Piandani, Roberto, Spinella, Franco, Biagioni, Andrea, d'Agostini, Giulio, Leonardi, Emanuele, Lonardo, Alessandro, Valente, Paolo, Vicini, Piero, Cretaro, Paolo, Turisini, Matteo, Frezza, Ottorino, Ammendola, Roberto, Bonaiuto, Vincenzo, de Simone, Nicola, Federici, Luca, Fucci, Adolfo, Salamon, Andrea, Sargeni, Fausto, Arcidiacono, Roberta, Biino, Cristina, Bloch-Devaux, Brigitte, Boretto, Marco, Filippi, Alessandra, Iacobuzio, Lorenza, Marchetto, Flavio, Menichetti, Ezio, Migliore, Ernesto, Soldi, Dario, Engelfried, Jürgen, Estrada-Tristan, Nora, Bragadireanu, Alexandru Mario, Ghinescu, Stefan Alexandru, Hutanu, Ovidiu Emanuel, Enik, Temur, Falaleev, Valeri, Kekelidze, Vladimir, Korotkova, Anna, Madigozhin, Dmitry, Misheva, Milena, Molokanova, Natalia, Movchan, Sergei, Polenkevich, Irina, Potrebenikov, Yuri, Shkarovskiy, Sergey, Zinchenko, Alexander, Baeva, Aigul, Baigarashev, Dosbol, Emelyanov, Dmitry, Fedotov, Sergei, Khotyantsev, Alexey, Gushchin, Evgeny, Kleimenova, Alina, Kudenko, Yury, Kurochka, Viktoriia, Medvedeva, Mariia, Mefodev, Aleksandr, Shaikhiev, Artur, Kholodenko, Sergey, Kurshetsov, Viktor, Obraztsov, Vladimir, Ostankov, Aleksandr, Semenov, Vitali, Sugonyaev, Valentin, Yushchenko, Oleg, Bician, Lubos, Blazek, Tomas, Cerny, Vladimir, Koval, Michal, Kucerova, Zuzana, Ceccucci, Augusto, Bernhard, Johannes, Danielsson, Hans, Döbrich, Babette, Duval, Francois, Gatignon, Lau, Guida, Roberto, Hahn, Ferdinand, Holzer, Eva Barbara, Jenninger, Berthold, Laycock, Paul, Lehmann Miotto, Giovanna, Lichard, Peter, Mapelli, Alessandro, Noy, Matthew, Palladino, Vito, Perrin-Terrin, Mathieu, Ruggiero, Giuseppe, Ryjov, Vladimir, Schuchmann, Simone, Venditti, Stefano, Brunetti, Maria Brigida, Bache, Thomas, Goudzovski, Evgueni, Henshaw, Jack, Tomczak, Adam, Lazzeroni, Cristina, Fascianelli, Valeria, Lurkin, Nicolas, Newson, Francis, Parkinson, Christopher, Romano, Angela, Sergi, Antonino, Sturgess, Andrew, Swallow, Joel, Heath, Helen, Page, Ryan, Trilov, Stoyan, Angelucci, Bruno, Britton, David, Protopopescu, Dan, Graham, Connor, Jones, Roger William Lewis, Dainton, John Bourke, Fry, John Richard, Fulton, Liam, Hutchcroft, David, Carmignani, Joseph, Massri, Karim, Maurice, Emilie, Wrona, Bozydar, Conovaloff, Adam, Cooper, Peter, Coward, David, Rubin, Philip David, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), and NA62

Subjects
Fixed Target Experiments, data analysis method, background, Flavour Changing Neutral Currents, perturbation theory: chiral, dimuon: mass spectrum, CERN SPS, pi+, mass dependence, NA62, High Energy Physics - Experiment, muon: pair production, K+: semileptonic decay, +pi%2B+muon%2B+muon%22">K+ --> pi+ muon+ muon, branching ratio: measured, Rare Decay, K+: branching ratio, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], decay: form factor, Branching fraction, K+: secondary beam, Particle Physics - Experiment, K: form factor, experimental results
Abstract

A sample of $2.8 \times 10^4$ $K^{+} \to \pi^{+} \mu^{+} \mu^{-}$ candidates with negligible background was collected by the NA62 experiment at the CERN SPS in 2017--2018. The model-independent branching fraction is measured to be $(9.15 \pm 0.08)\times 10^{-8}$, a factor three more precise than previous measurements. The decay form factor is presented as a function of the squared dimuon mass. A measurement of the form factor parameters and their uncertainties is performed using a description based on Chiral Perturbation Theory at $\mathcal{O}(p^6)$., Comment: 17 pages, 5 figures. Updated version (6 October 2022) accepted for publication in JHEP

Published
2022

29. Research Informed Science Enrichment Programs at the Gravity Discovery Centre

Author

Venville, Grady, Blair, David, Coward, David, Deshon, Fr, Gargano, Mark, Gondwe, Mzamose, Heary, Auriol, Longnecker, Nancy, Pitts, Marina, and Zadnik, Marjan

Abstract

Excursions to museums and science centres generally are great fun for students and teachers. The potential educational benefits beyond enjoyment, however, are rarely realised or analysed for their efficacy. The purpose of this paper is to describe four educational enrichment programs delivered at the Gravity Discovery Centre (GDC), near Gingin, Western Australia, that are informed by research in different ways. These programs are designed to maximise the educational outcomes for students, assess what they have learnt, and, at the same time, maintain the excitement and enthusiasm generated by a visit to a world class science centre. (Contains 8 figures.)

Published
2012

31. Brought to book: How a literary wild man achieved 'consecration in the Pleiade'

Author

Coward, David

Subjects
Album Romain Gary: Collection album de la Pleiade (Collection) -- Decout, Maxime, Romans et recits, vol. 1-2: Romain Gary (Biography) -- Sacotte, Mireille, Literature/writing
Abstract

ALBUM ROMAIN GARY Collection album de la Pleiade MAXIME DECOUT 248pp. Gallimard. 22 [euro]. ROMANS ET RECITS, I & II ROMAIN GARY Edited by Mireille Sacotte et al 1,688pp and [...]

Published
2020

32. CINQ SEMAINES EN BALLON

Author

Coward, David

Subjects
Five Weeks in a Balloon (Novel) -- Verne, Jules -- Book reviews, Literature/writing
Abstract

Jules Verne Edited by William Butcher 513pp. Galllmard. Jules Verne's 'balloon story', published in 1863, was the first of his sixty novels of adventure and science fantasy. It tells how [...]

Published
2020

34. Search for lepton number and flavour violation in $K^+ $ and $\pi^0$ decays

Author

Cortina Gil, Eduardo, Minucci, Elisa, Padolski, Sergey, Petrov, Plamen, Potrebenikov, Yu., Velghe, Bob, Bryman, Douglas, Fu, Ji, Numao, Toshio, Petrov, Yevgeniy, Husek, Tomas, Kampf, Karol, Zamkovsky, Michal, Jerhot, Jan, Aliberti, Riccardo, Khoriauli, Gia, Kunze, Jonas, Lomidze, David, Marchevski, Radoslav, Peruzzo, Letizia, Vormstein, Mario, Wanke, Rainer, Cotta Ramusino, Angelo, Dalpiaz, Pietro, Fiorini, Massimiliano, Gamberini, Enrico, Gianoli, Alberto, Neri, Ilaria, Norton, Alan, Petrucci, Ferruccio, Wahl, Heinrich, Bizzeti, Andrea, Bucci, Francesca, Iacopini, Enrico, Latino, Giuseppe, Lenti, Massimo, Parenti, Andrea, Volpe, Roberta, Antonelli, Antonella, Gonnella, Francesco, Lamanna, Gianluca, Lanfranchi, Gaia, Martellotti, Silvia, Moulson, Matthew, Kozhuharov, Venelin, Litov, Leandar, Georgiev, Georgi, Raggi, Mauro, Spadaro, Tommaso, Ambrosino, Fabio, Capussela, Tiziana, Corvino, Michele, Di Filippo, Domenico, Massarotti, Paolo, Mirra, Marco, Napolitano, Marco, Saracino, Giulio, Anzivino, Giuseppina, Imbergamo, Ermanno, Lollini, Riccardo, Santoni, Cristiano, Brizioli, Francesco, Barbanera, Mattia, Cenci, Patrizia, Checcucci, Bruno, Duk, Viacheslav, Lupi, Matteo, Pepe, Monica, Piccini, Mauro, Lubrano, Pasquale, Costantini, Flavio, Doble, Niels, Giorgi, Marcello, Giudici, Sergio, Lari, Enrico, Pinzino, Jacopo, Pontisso, Luca, Sozzi, Marco, Di Lella, Luigi, Mannelli, Italo, Cerri, Claudio, Fantechi, Riccardo, Pedreschi, Elena, Piandani, Roberto, Spinella, Franco, Biagioni, Andrea, D'Agostini, Giulio, Leonardi, Emanuele, Lonardo, Alessandro, Valente, Paolo, Vicini, Piero, Ammendola, Roberto, Bonaiuto, Vincenzo, De Simone, Nicola, Federici, Luca, Fucci, Adolfo, Salamon, Andrea, Sargeni, Fausto, Arcidiacono, Roberta, Biino, Cristina, Bloch-Devaux, Brigitte, Boretto, Marco, Filippi, Alessandra, Iacobuzio, Lorenza, Marchetto, Flavio, Menichetti, Ezio, Migliore, Ernesto, Soldi, Dario, Engelfried, Jürgen, Estrada-Tristan, Nora, Bragadireanu, Alexandru Mario, Ghinescu, Stefan Alexandru, Hutanu, Ovidiu Emanuel, Enik, Temur, Falaleev, Valeri, Kekelidze, Vladimir, Korotkova, Anna, Madigozhin, Dmitry, Misheva, Milena, Molokanova, Natalia, Movchan, Sergei, Polenkevich, Irina, Potrebenikov, Yuri, Shkarovskiy, Sergey, Zinchenko, Alexander, Baeva, Aigul, Baigarashev, Dosbol, Emelyanov, Dmitry, Fedotov, Sergei, Khotyantsev, Alexey, Gushchin, Evgeny, Kleimenova, Alina, Kudenko, Yury, Kurochka, Viktoriia, Medvedeva, Mariia, Mefodev, Aleksandr, Shaikhiev, Artur, Kholodenko, Sergey, Kurshetsov, Viktor, Obraztsov, Vladimir, Ostankov, Aleksandr, Semenov, Vitali, Sugonyaev, Valentin, Yushchenko, Oleg, Bician, Lubos, Blazek, Tomas, Cerny, Vladimir, Koval, Michal, Kucerova, Zuzana, Ceccucci, Augusto, Bernhard, Johannes, Danielsson, Hans, Döbrich, Babette, Duval, Francois, Gatignon, Lau, Guida, Roberto, Hahn, Ferdinand, Holzer, Eva Barbara, Jenninger, Berthold, Laycock, Paul, Lehmann Miotto, Giovanna, Lichard, Peter, Mapelli, Alessandro, Noy, Matthew, Palladino, Vito, Perrin-Terrin, Mathieu, Ruggiero, Giuseppe, Ryjov, Vladimir, Schuchmann, Simone, Venditti, Stefano, Brunetti, Maria Brigida, Bache, Thomas, Goudzovski, Evgueni, Henshaw, Jack, Lazzeroni, Cristina, Fascianelli, Valeria, Lurkin, Nicolas, Newson, Francis, Parkinson, Christopher, Romano, Angela, Sergi, Antonino, Sturgess, Andrew, Swallow, Joel, Heath, Helen, Page, Ryan, Trilov, Stoyan, Angelucci, Bruno, Britton, David, Protopopescu, Dan, Graham, Connor, Jones, Roger William Lewis, Dainton, John Bourke, Fry, John Richard, Fulton, Liam, Hutchcroft, David, Carmignani, Joseph, Massri, Karim, Maurice, Emilie, Wrona, Bozydar, Conovaloff, Adam, Cooper, Peter, Coward, David, and Rubin, Philip David

Subjects
High Energy Physics::Phenomenology, High Energy Physics::Experiment, Particle Physics - Experiment, High Energy Physics - Experiment
Abstract

Searches for the lepton number violating $K^{+} \rightarrow \pi^{-} \mu^{+} e^{+}$ decay and the lepton flavour violating $K^{+} \rightarrow \pi^{+} \mu^{-} e^{+}$ and $\pi^{0} \rightarrow \mu^{-} e^{+}$ decays are reported using data collected by the NA62 experiment at CERN in $2017$-$2018$. No evidence for these decays is found and upper limits of the branching ratios are obtained at 90% confidence level: $\mathcal{B}(K^{+}\rightarrow\pi^{-}\mu^{+}e^{+}), Comment: 8 pages, 4 figures

Published
2021

35. The avid biter bit: How Sade was outraged by Italian debauchery

Author

Coward, David

Subjects
Journey to Italy (Nonfiction work) -- de Sade, Marquis -- Steintrager, James A., Books -- Book reviews, Literature/writing
Abstract

JOURNEY TO ITALY MARQUIS DE SADE Translated, introduced and annotated by James A. Steintrager 832pp. University of Toronto Press. $125. Travel books were Europe's introduction to relativism. 'Abroad' was a [...]

Published
2021

38. From salon to cellar: A 'quietly shocking' account of wartime collaboration in Paris

Author

Coward, David

Subjects
The King of Nazi Paris: Henri Lafont and the Gangsters of the French Gestapo (Nonfiction work) -- Othen, Christopher, Books -- Book reviews, Literature/writing
Abstract

THE KING OF NAZI PARIS Henri Lafont and the gangsters of the French Gestapo CHRISTOPHER OTHON 306pp. Biteback. 20 [pounds sterling]. In June 1940, Henri Chamberlin, thirty-nine, a petty thief [...]

Published
2021

39. Crash Tests: Was Camus's death an accident?

Author

Coward, David

Subjects
The Death of Camus (Biography) -- Catelli, Giovanni -- Tanzi, Andrew, Books -- Book reviews, Literature/writing
Abstract

THE DEATH OF CAMUS GIOVANNI CATELLI Translated by Andrew Tanzi 154pp. Hurst. Paperback, 12.99 [pounds sterling]. ALBERT CAMUS SPENT Christmas 1959 at his house in the Vaucluse with his family [...]

Published
2020

40. An investigation of the very rare $K^+\rightarrow\pi^+\nu\bar{\nu}$ decay

Author

Cortina Gil, Eduardo, Minucci, Elisa, Padolski, Sergey, Petrov, Plamen, Velghe, Bob, Bryman, Douglas, Fu, Ji, Numao, Toshio, Husek, Tomas, Kampf, Karol, Zamkovsky, Michal, Jerhot, Jan, Aliberti, Riccardo, Khoriauli, Gia, Kunze, Jonas, Lomidze, David, Marchevski, Radoslav, Peruzzo, Letizia, Vormstein, Mario, Wanke, Rainer, Cotta Ramusino, Angelo, Dalpiaz, Pietro, Fiorini, Massimiliano, Gamberini, Enrico, Gianoli, Alberto, Neri, Ilaria, Norton, Alan, Petrucci, Ferruccio, Wahl, Heinrich, Bizzeti, Andrea, Bucci, Francesca, Iacopini, Enrico, Latino, Giuseppe, Lenti, Massimo, Parenti, Andrea, Volpe, Roberta, Antonelli, Antonella, Gonnella, Francesco, Lamanna, Gianluca, Lanfranchi, Gaia, Martellotti, Silvia, Moulson, Matthew, Kozhuharov, Venelin, Litov, Leandar, Georgiev, Georgi, Raggi, Mauro, Spadaro, Tommaso, Ambrosino, Fabio, Capussela, Tiziana, Corvino, Michele, Di Filippo, Domenico, Massarotti, Paolo, Mirra, Marco, Napolitano, Marco, Saracino, Giulio, Anzivino, Giuseppina, Imbergamo, Ermanno, Lollini, Riccardo, Santoni, Cristiano, Brizioli, Francesco, Barbanera, Mattia, Cenci, Patrizia, Checcucci, Bruno, Duk, Viacheslav, Lupi, Matteo, Pepe, Monica, Piccini, Mauro, Lubrano, Pasquale, Costantini, Flavio, Doble, Niels, Giorgi, Marcello, Giudici, Sergio, Lari, Enrico, Pinzino, Jacopo, Pontisso, Luca, Sozzi, Marco, Di Lella, Luigi, Mannelli, Italo, Cerri, Claudio, Fantechi, Riccardo, Pedreschi, Elena, Piandani, Roberto, Spinella, Franco, Biagioni, Andrea, D'Agostini, Giulio, Leonardi, Emanuele, Lonardo, Alessandro, Valente, Paolo, Vicini, Piero, Ammendola, Roberto, Bonaiuto, Vincenzo, De Simone, Nicola, Federici, Luca, Fucci, Adolfo, Salamon, Andrea, Sargeni, Fausto, Arcidiacono, Roberta, Biino, Cristina, Bloch-Devaux, Brigitte, Boretto, Marco, Filippi, Alessandra, Iacobuzio, Lorenza, Marchetto, Flavio, Menichetti, Ezio, Migliore, Ernesto, Soldi, Dario, Engelfried, Jürgen, Estrada-Tristan, Nora, Bragadireanu, Alexandru Mario, Ghinescu, Stefan Alexandru, Hutanu, Ovidiu Emanuel, Enik, Temur, Falaleev, Valeri, Kekelidze, Vladimir, Korotkova, Anna, Madigozhin, Dmitry, Misheva, Milena, Molokanova, Natalia, Movchan, Sergei, Polenkevich, Irina, Potrebenikov, Yuri, Shkarovskiy, Sergey, Zinchenko, Alexander, Baeva, Aigul, Baigarashev, Dosbol, Emelyanov, Dmitry, Fedotov, Sergei, Khotyantsev, Alexey, Gushchin, Evgeny, Kleimenova, Alina, Kudenko, Yury, Kurochka, Viktoriia, Medvedeva, Mariia, Mefodev, Aleksandr, Shaikhiev, Artur, Kholodenko, Sergey, Kurshetsov, Viktor, Obraztsov, Vladimir, Ostankov, Aleksandr, Semenov, Vitali, Sugonyaev, Valentin, Yushchenko, Oleg, Bician, Lubos, Blazek, Tomas, Cerny, Vladimir, Koval, Michal, Kucerova, Zuzana, Ceccucci, Augusto, Bernhard, Johannes, Danielsson, Hans, Döbrich, Babette, Duval, Francois, Gatignon, Lau, Guida, Roberto, Hahn, Ferdinand, Holzer, Eva Barbara, Jenninger, Berthold, Laycock, Paul, Lehmann Miotto, Giovanna, Lichard, Peter, Mapelli, Alessandro, Noy, Matthew, Palladino, Vito, Perrin-Terrin, Mathieu, Ruggiero, Giuseppe, Ryjov, Vladimir, Schuchmann, Simone, Venditti, Stefano, Brunetti, Maria Brigida, Bache, Thomas, Goudzovski, Evgueni, Lazzeroni, Cristina, Fascianelli, Valeria, Lurkin, Nicolas, Newson, Francis, Parkinson, Christopher, Romano, Angela, Sergi, Antonino, Sturgess, Andrew, Swallow, Joel, Heath, Helen, Page, Ryan, Trilov, Stoyan, Angelucci, Bruno, Britton, David, Protopopescu, Dan, Graham, Connor, Jones, Roger William Lewis, Dainton, John Bourke, Fry, John Richard, Fulton, Liam, Hutchcroft, David, Carmignani, Joseph, Massri, Karim, Maurice, Emilie, Wrona, Bozydar, Conovaloff, Adam, Cooper, Peter, Coward, David, and Rubin, Philip David

Subjects
hep-ex, Particle Physics - Experiment, High Energy Physics - Experiment
Abstract

A search for heavy neutral lepton (N) production in $K^+\rightarrow\pi^+\nu\bar{\nu}$ decays using the data sample collected by the NA62 experiment at CERN in 2017–2018 is reported. Upper limits of the extended neutrino mixing matrix element $|U_{e4}|^2$ are established at the level of $10^{−9}$ over most of the accessible heavy neutral lepton mass range 144–462 MeV/$c^2$, with the assumption that the lifetime exceeds 50 ns. These limits improve significantly upon those of previous production and decay searches. The $|U_{e4}|^2$ range favoured by Big Bang Nucleosynthesis is excluded up to a mass of about 340 MeV/$c^2$. The NA62 experiment reports an investigation of the $ {K}^{+}\to {\pi}^{+}\nu \overline{\nu} $ mode from a sample of K$^{+}$ decays collected in 2017 at the CERN SPS. The experiment has achieved a single event sensitivity of (0.389 ± 0.024) × 10$^{−10}$, corresponding to 2.2 events assuming the Standard Model branching ratio of (8.4 ± 1.0) × 10$^{−11}$. Two signal candidates are observed with an expected background of 1.5 events. Combined with the result of a similar analysis conducted by NA62 on a smaller data set recorded in 2016, the collaboration now reports an upper limit of 1.78 × 10$^{−10}$ for the $ {K}^{+}\to {\pi}^{+}\nu \overline{\nu} $ branching ratio at 90% CL. This, together with the corresponding 68% CL measurement of ($ {0.48}_{-0.48}^{+0.72} $) × 10$^{−10}$, are currently the most precise results worldwide, and are able to constrain some New Physics models that predict large enhancements still allowed by previous measurements. The NA62 experiment reports an investigation of the $K^+\rightarrow\pi^+\nu\bar{\nu}$ mode from a sample of $K^+$ decays collected in 2017 at the CERN SPS. The experiment has achieved a single event sensitivity of $(0.389\pm 0.024)\times10^{-10}$, corresponding to 2.2 events assuming the Standard Model branching ratio of $(8.4\pm1.0)\times10^{-11}$. Two signal candidates are observed with an expected background of 1.5 events. Combined with the result of a similar analysis conducted by NA62 on a smaller data set recorded in 2016, the collaboration now reports an upper limit of $1.78\times10^{-10}$ for the $K^+\rightarrow\pi^+\nu\bar{\nu}$ branching ratio at 90\%\,CL. This, together with the corresponding 68\%\,CL measurement of $(0.48^{+0.72 }_{-0.48})\times10^{-10}$, are currently the most precise results worldwide, and are able to constrain some New Physics models that predict large enhancements still allowed by previous measurements.

Published
2020

41. Searches for lepton number violating $K^+$ decays

Author

Cortina Gil, Eduardo, Velghe, Bob, Bryman, Douglas, Husek, Tomas, Kampf, Karol, Marchevski, Radoslav, Wanke, Rainer, Cotta Ramusino, Angelo, Fiorini, Massimiliano, Gamberini, Enrico, Gianoli, Alberto, Neri, Igor, Petrucci, Ferruccio, Bizzeti, Andrea, Bucci, Francesca, Iacopini, Enrico, Latino, Giuseppe, Lenti, Massimo, Parenti, Andrea, Volpe, Roberta, Antonelli, Antonella, Gonnella, Francesco, Lamanna, Gianluca, Lanfranchi, Gaia, David Moulson, Matthew, Kozhuharov, Venelin, Raggi, Mauro, Spadaro, Tommaso, Ambrosino, Fabio, Corvino, Michele, Di Filippo, Domenico, Massarotti, Paolo, Mirra, Marco, Napolitano, Marco, Saracino, Giulio, Anzivino, Giuseppina, Lollini, Riccardo, Santoni, Cristiano, Barbanera, Mattia, Cenci, Patrizia, checcucci, bruno, Duk, Viacheslav, Lupi, Matteo, Pepe, Monica, Piccini, Mauro, lubrano, pasquale, Costantini, Flavio, GIORGI, MARCELLO., Giudici, Sergio, Pinzino, Jacopo, Pontisso, Luca, Sozzi, Marco, Di Lella, Luigi, mannelli, italo, Fantechi, Riccardo, Pedreschi, Elena, piandani, roberto, Spinella, Franco, Biagioni, Andrea, D'Agostini, Giulio, Leonardi, Emanuele, Lonardo, Alessandro, Valente, Paolo, Vicini, Piero, Ammendola, Roberto, Bonaiuto, Vincenzo, Federici, Luca, Salamon, Andrea, Sargeni, Fausto, Arcidiacono, Roberta, Biino, Cristina, Bloch-Devaux, Brigitte, Boretto, Marco, Filippi, Alessandra, Pietro Marchetto, Flavio, Menichetti, Ezio, Migliore, Ernesto, Soldi, Dario, Engelfried, Jurgen, Patricia Estrada Tristan, Nora, Zinchenko, Alexander, Gushchin, Evgeny, Shaikhiev, Artur, Bician, Lubos, Cerny, Vladimir, Koval, Michal, Kucerova, Zuzana, Ceccucci, Augusto, Bernhard, Johannes, Döbrich, Babette, Gatignon, Lau, Laycock, Paul, Mapelli, Alessandro, Perrin-Terrin, Mathieu, Ruggiero, Giuseppe, Goudzovski, Evgueni, Lurkin, Nicolas, Sergi, Antonino, Heath, Helen, Britton, David, Protopopescu, Dan, Graham, Connor, Jones, Roger, Fry, John, Massri, Karim, Coward, David, and Rubin, Philip

Abstract

The NA62 experiment at CERN reports a search for the lepton number violating decays K+→π−e+e+ and K+→π−μ+μ+ using a data sample collected in 2017. No signals are observed, and upper limits on the branching fractions of these decays of 2.2×10−10 and 4.2×10−11 are obtained, respectively, at 90% confidence level. These upper limits improve on previously reported measurements by factors of 3 and 2, respectively.

Published
2019

42. A Flare-type IV Burst Event from Proxima Centauri and Implications for Space Weather

Author

Zic, Andrew, primary, Murphy, Tara, additional, Lynch, Christene, additional, Heald, George, additional, Lenc, Emil, additional, Kaplan, David L., additional, Cairns, Iver H., additional, Coward, David, additional, Gendre, Bruce, additional, Johnston, Helen, additional, MacGregor, Meredith, additional, Price, Danny C., additional, and Wheatland, Michael S., additional

Published
2020
Full Text
View/download PDF

43. Spice and violence: An enchanter now seen as a period oddity

Author

Coward, David

Subjects
Pierre Loti (Biography) -- Berrong, Richard M., Literature/writing
Abstract

PIERRE LOTI RICHARD M. BERRONG 214pp. Reaktion. Paperback, 11.99 [pounds sterling]. In 1887 the self-mythologizing Frank Harris attended a ball where he met Pierre Loti dressed as a gaudy Osiris [...]

Published
2020

46. The French Dickens: The author and director who was too successful to be universally admired

Author

Coward, David

Subjects
Je te souhaite beaucoup d'ennemis comme moi: Correspondances intimes et litteraires (Autobiography) -- Pagnol, Nicolas -- Dehayes, Thierry -- Pagnol, Marcel, Marcel Pagnol, 1895-1974: L'album d'une vie (Biography) -- Pagnol, Nicolas, Literature/writing
Abstract

Nicolas Pagnol MARCEL PAGNOL 1895-1974 L' Album d'une vie 230pp. Llammarion. 24.90 [euro]. 978 2 0814 1326 9 Marcel Pagnol 'JE TE SOUHAITE BEAUCOUP D'ENNEMIS COMME MOI' Correspondances intimes et [...]

Published
2019

47. Call the midwife: Mechanisms of the illicit book trade

Author

Coward, David

Subjects
A Literary Tour de France: The World of Books on the Eve of the French Revolution (Nonfiction work) -- Darnton, Robert, Literature/writing
Abstract

Robert Darnton A LITERARY TOUR DE FRANCE The world of books on the eve of the French Revolution 336pp. Oxford University Press. 25.49 [pounds sterling] 978 0 19 514451 2 [...]

Published
2019

48. A nose by any other name: The 400th anniversary of the real Cyrano

Author

Coward, David

Subjects
Playwrights -- Criticism and interpretation, Literature/writing
Abstract

Cyrano de Bergerac has suffered multiple identity theft. It was stolen in 1897 by Edmond Rostand who used him, his name and his nose for an intoxicatingly successful verse play, [...]

Published
2019

50. Contributors

Author

Barnes, Thomas R.E., primary, Coward, David M., additional, Curry, Stephen H., additional, Davis, John M., additional, Edwards, J. Guy, additional, Gerlach, Jes, additional, Harrison, Paul, additional, Hirsch, Steven R., additional, Iversen, Susan D., additional, Janicak, Philip G., additional, Johnson, D.A.W., additional, Kane, John M., additional, Leonard, Brian E., additional, Liddle, Peter F., additional, McCreadie, Robin G., additional, Rupniak, Nadia M.J., additional, Sharma, Rajiv P., additional, Singla, Abhin, additional, and Waddington, John L., additional

Published
1993
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results