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1. PITFALLS AND POTENTIALS OF CROWD SCIENCE: A META-ANALYSIS OF CONTEXTUAL INFLUENCES

Author

A. Klippel, K. Sparks, and J. O. Wallgrün

Subjects
Technology, Engineering (General). Civil engineering (General), TA1-2040, Applied optics. Photonics, TA1501-1820
Abstract

Crowd science is becoming an integral part of research in many disciplines. The research discussed in this paper lies at the intersection of spatial and behavioral sciences, two of the greatest beneficiaries of crowd science. As a young methodological development, crowd science needs attention from the perspective of a rigorous evaluation of the data collected to explore potentials as well as limitations (pitfalls). Our research has addressed a variety of contextual effects on the validity of crowdsourced data such as cultural, linguistic, regional, as well as methodological differences that we will discuss here in light of semantics.

Published
2015
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2. The High-Altitude Water Cherenkov (HAWC) Observatory in M\'exico: The Primary Detector

Author

Abeysekara, A. U., Albert, A., Alfaro, R., Álvarez, C., Álvarez, J. D., Araya, M., Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Babu, R., Barber, A. S., Becerril, A., Belmont-Moreno, E., BenZvi, S. Y., Blanco, O., Braun, J., Brisbois, C., Caballero-Mora, K. S., Martínez, J. I. Cabrera, Capistrán, T., Carramiñana, A., Casanova, S., Castillo, M., Chaparro-Amaro, O., Cotti, U., Cotzomi, J., de León, S. Coutiño, de la Fuente, E., de León, C., De Young, T., Hernández, R. Díaz, Dingus, B. L., DuVernois, M. A., Durocher, M., Díaz-Vélez, J. C., Ellsworth, R. W., Engel, K., Espinoza, C., Fan, K. L., Fang, K., Fick, U. B., Fleischhack, H., Flores, J. L., Fraija, N., García-González, J. A., García-Torales, G., Garfias, F., Giacinti, G., Goksu, H., González, M. M., González-Muñoz, A., Goodman, J. A., Harding, J. P., Hernández, E., Hernández, S., Hinton, J., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hui, C. M., Humensky, T. B., Hüntemeyer, P., Iriarte, A., Imran, A., Jardin-Blicq, A., Joshi, V., Kaufmann, S., Kieda, D., Kunde, G. J., Lara, A., Lauer, R., Lee, W. H., Lennarz, D., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., Lundeen, J., Malone, K., Marandon, V., Marinelli, A., Martínez, O., Martínez-Castellanos, I., Martínez-Castro, J., Martínez-Huerta, H., Matthews, J. A., Miranda-Romagnoli, P., Montaruli, T., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Oceguera-Becerra, T., Olivera-Nieto, L., Omodei, N., Peisker, A., Araujo, Y. Pérez, Pérez-Pérez, E. G., Ponce, E., Pretz, J., Rho, C. D., Rosa-González, D., Ruiz-Velasco, E., Salazar, H., Salazar-Gallegos, D., Greus, F. Salesa, Sandoval, A., Schneider, M., Schoorlemmer, H., Serna-Franco, J., Sinnis, G., Smith, A. J., Son, Y., Woodle, K. Sparks, Springer, R. W., Taboada, I., Tepe, A., Tibolla, O., Tollefson, K., Torres, I., Torres-Escobedo, R., Turner, R., Ureña-Mena, F., Ukwatta, T. N., Varela, E., Vargas-Magaña, M., Villaseñor, L., Wang, X., Watson, I. J., Werner, F., Westerhoff, S., Willox, E., Wisher, I., Wood, J., Yodh, G. B., Zaborov, D., Zepeda, A., and Zhou, H.

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

The High-Altitude Water Cherenkov (HAWC) observatory is a second-generation continuously operated, wide field-of-view, TeV gamma-ray observatory. The HAWC observatory and its analysis techniques build on experience of the Milagro experiment in using ground-based water Cherenkov detectors for gamma-ray astronomy. HAWC is located on the Sierra Negra volcano in M\'exico at an elevation of 4100 meters above sea level. The completed HAWC observatory principal detector (HAWC) consists of 300 closely spaced water Cherenkov detectors, each equipped with four photomultiplier tubes to provide timing and charge information to reconstruct the extensive air shower energy and arrival direction. The HAWC observatory has been optimized to observe transient and steady emission from sources of gamma rays within an energy range from several hundred GeV to several hundred TeV. However, most of the air showers detected are initiated by cosmic rays, allowing studies of cosmic rays also to be performed. This paper describes the characteristics of the HAWC main array and its hardware., Comment: Accepted for publications in Nuclear Inst. and Methods in Physics Research, A (2023) 168253 ( https://www.sciencedirect.com/science/article/abs/pii/S0168900223002437 ); 39 pages, 14 Figures

Published
2023
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3. Data Acquisition Architecture and Online Processing System for the HAWC gamma-ray observatory

Author

HAWC collaboration, Abeysekara, A. U., Alfaro, R., Alvarez, C., Álvarez, J. D., Arceo, R., Arteaga-Velázquez, J. C., Solares, H. A. Ayala, Barber, A. S., Baughman, B. M., Bautista-Elivar, N., Gonzalez, J. Becerra, Belmont-Moreno, E., BenZvi, S. Y., Berley, D., Rosales, M. Bonilla, Braun, J., Caballero-Lopez, R. A., Caballero-Mora, K. S., Carramiñana, A., Castillo, M., Cotti, U., Cotzomi, J., de la Fuente, E., De León, C., DeYoung, T., Diaz-Cruz, J., Hernandez, R. Diaz, Díaz-Vélez, J. C., Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., Fiorino, D. W., Fraija, N., Galindo, A., Garfias, F., González, M. M., Goodman, J. A., Grabski, V., Gussert, M., Hampel-Arias, Z., Harding, J. P., Hui, C. M., Hüntemeyer, P., Imran, A., Iriarte, A., Karn, P., Kieda, D., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. León, Linares, E. C., Linnemann, J. T., Proper, M. Longo, Luna-García, R., Malone, K., Marinelli, A., Marinelli, S. S., Martinez, O., Martínez-Castro, J., Martínez-Huerta, H., Matthews, J. A. J., McEnery, J., Torres, E. Mendoza, Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nellen, L., Newbold, M., Noriega-Papaqui, R., Oceguera-Becerra, T., Patricelli, B., Pelayo, R., Pérez-Pérez, E. G., Pretz, J., Rivière, C., Rosa-González, D., Ruiz-Velasco, E., Ryan, J., Salazar, H., Greus, F. Salesa, Sanchez, F. E., Sandoval, A., Schneider, M., Silich, S., Sinni, G., Smith, A. J., Woodle, K. Sparks, Springer, R. W., Taboada, I., Toale, P. A., Tollefson, K., Torres, I., Ukwatta, T. N., Villaseñor, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yapici, T., Yodh, G. B., Younk, P. W., Zaborov, D., Zepeda, A., and Zhou, H.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The High Altitude Water Cherenkov observatory (HAWC) is an air shower array devised for TeV gamma-ray astronomy. HAWC is located at an altitude of 4100 m a.s.l. in Sierra Negra, Mexico. HAWC consists of 300 Water Cherenkov Detectors, each instrumented with 4 photomultiplier tubes (PMTs). HAWC re-uses the Front-End Boards from the Milagro experiment to receive the PMT signals. These boards are used in combination with Time to Digital Converters (TDCs) to record the time and the amount of light in each PMT hit (light flash). A set of VME TDC modules (128 channels each) is operated in a continuous (dead time free) mode. The TDCs are read out via the VME bus by Single-Board Computers (SBCs), which in turn are connected to a gigabit Ethernet network. The complete system produces ~ 500 MB/s of raw data. A high-throughput data processing system has been designed and built to enable real-time data analysis. The system relies on off-the-shelf hardware components, an open-source software technology for data transfers (ZeroMQ) and a custom software framework for data analysis (AERIE). Multiple trigger and reconstruction algorithms can be combined and run on blocks of data in a parallel fashion, producing a set of output data streams which can be analyzed in real time with minimal latency (< 5 s). This paper provides an overview of the hardware set-up and an in-depth description of the software design, covering both the TDC data acquisition system and the real-time data processing system. The performance of these systems is also discussed., Comment: 14 pages, 3 figures, submitted to Nucl. Instrum. Meth. A

Published
2017
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4. Search for TeV Gamma-Ray Emission from Point-like Sources in the Inner Galactic Plane with a Partial Configuration of the HAWC Observatory

Author

Abeysekara, A. U., Alfaro, R., Alvarez, C., Álvarez, J. D., Arceo, R., Arteaga-Velázquez, J. C., Solares, H. A. Ayala, Barber, A. S., Baughman, B. M., Bautista-Elivar, N., Reyes, A. D. Becerril, Belmont, E., BenZvi, S. Y., Bernal, A., Braun, J., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Castillo, M., Cotti, U., Cotzomi, J., de León, S. Coutiño, de la Fuente, E., De León, C., DeYoung, T., Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., Enriquez-Rivera, O., Fiorino, D. W., Fraija, N., Garfias, F., González, M. M., Goodman, J. A., Gussert, M., Hampel-Arias, Z., Harding, J. P., Hernandez, S., Hüntemeyer, P., Hui, C. M., Imran, A., Iriarte, A., Karn, P., Kieda, D., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. León, Linnemann, J. T., Longo, M., Raya, G. Luis, Malone, K., Marinelli, A., Marinelli, S. S., Martinez, H., Martinez, O., Martínez-Castro, J., Matthews, J. A. J., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nellen, L., Newbold, M., Noriega-Papaqui, R., Patricelli, B., Pelayo, R., Pérez-Pérez, E. G., Pretz, J., Ren, Z., Rivière, C., Rosa-González, D., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Sinnis, G., Smith, A. J., Woodle, K. Sparks, Springer, R. W., Taboada, I., Tibolla, O., Tollefson, K., Torres, I., Ukwatta, T. N., Villaseñor, L., Vrabel, K., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yapici, T., Yodh, G. B., Younk, P. W., Zaborov, D., Zepeda, A., and Zhou, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

A survey of the inner Galaxy region of Galactic longitude l in [+15, +50] degree and latitude b in [-4,+4] degree is performed using one-third of the High Altitude Water Cherenkov (HAWC) Observatory operated during its construction phase. To address the ambiguities arising from unresolved sources in the data, we use a maximum likelihood technique to identify point source candidates. Ten sources and candidate sources are identified in this analysis. Eight of these are associated with known TeV sources but not all have differential fluxes compatible with previous measurements. Three sources are detected with significances $>5\,\sigma$ after accounting for statistical trials, and are associated with known TeV sources., Comment: Submitted to ApJ, 34 pages, 6 figures. Contact authors: Hao Zhou and C. Michelle Hui

Published
2015
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5. HAWC Contributions to the 34th International Cosmic Ray Conference (ICRC2015)

Author

HAWC Collaboration, Abeysekara, A. U., Alfaro, R., Alvarez, C., Álvarez, J. D., Arceo, R., Arteaga-Velázquez, J. C., Solares, H. A. Ayala, Barber, A. S., Baughman, B. M., Bautista-Elivar, N., Gonzalez, J. Becerra, Becerril, A., Belmont, E., BenZvi, S. Y., Berley, D., Bernal, A., Braun, J., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Castillo, M., Cotti, U., Cotzomi, J., de León, S. Coutiño, de la Fuente, E., De León, C., DeYoung, T., Hernandez, R. Diaz, Diaz-Cruz, L., Díaz-Vélez, J. C., Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., Engel, K., Enriquez-Rivera, O., Fick, B., Fiorino, D. W., Flores, J. L., Fraija, N., Garcia-Torales, G., Garfias, F., González, M. M., Goodman, J. A., Gussert, M., Hampel-Arias, Z., Hansen, P., Harding, J. Patrick, Hernandez, S., Hui, C. M., Hüntemeyer, P., Imran, A., Iriarte, A., Karn, P., Kieda, D., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. León, Linnemann, J. T., Proper, M. Longo, Raya, G. Luis, Luna-García, R., Malone, K., Marinelli, A., Marinelli, S. S., Martinez, H., Martinez, O., Martínez-Castro, J., Matthews, J. A. J., McEnery, J., Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nellen, L., Newbold, M., Nisa, M. Un, Noriega-Papaqui, R., Oceguera-Becerra, T., Patricelli, B., Pelayo, R., Pérez-Pérez, E. G., Pretz, J., Ren, Z., Rho, C. D., Rivière, C., Rosa-González, D., Ryan, J., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Sinnis, G., Smith, A. J., Smith, A. W., Woodle, K. Sparks, Springer, R. W., Taboada, I., Tibolla, O., Toale, P. A., Tollefson, K., Torres, I., Ukwatta, T. N., Villaseñor, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yapici, T., Yodh, G. B., Younk, P. W., Zepeda, A., and Zhou, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract

List of proceedings from the HAWC Collaboration presented at the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands., Comment: List of proceedings from the HAWC Collaboration presented at ICRC2015. Follow the "HTML" link to access the list

Published
2015

6. SEARCH FOR TeV GAMMA-RAY EMISSION FROM POINT-LIKE SOURCES IN THE INNER GALACTIC PLANE WITH A PARTIAL CONFIGURATION OF THE HAWC OBSERVATORY

Author

Abeysekara, AU, Alfaro, R, Alvarez, C, Álvarez, JD, Arceo, R, Arteaga-Velázquez, JC, Solares, HA Ayala, Barber, AS, Baughman, BM, Bautista-Elivar, N, Reyes, AD Becerril, Belmont, E, BenZvi, SY, Bernal, A, Braun, J, Caballero-Mora, KS, Capistrán, T, Carramiñana, A, Casanova, S, Castillo, M, Cotti, U, Cotzomi, J, de León, S Coutińo, de la Fuente, E, De León, C, DeYoung, T, Hernandez, R Diaz, Dingus, BL, DuVernois, MA, Ellsworth, RW, Enriquez-Rivera, O, Fiorino, DW, Fraija, N, Garfias, F, González, MM, Goodman, JA, Gussert, M, Hampel-Arias, Z, Harding, JP, Hernandez, S, Hüntemeyer, P, Hui, CM, Imran, A, Iriarte, A, Karn, P, Kieda, D, Lara, A, Lauer, RJ, Lee, WH, Lennarz, D, Vargas, H León, Linnemann, JT, Longo, M, Raya, G Luis, Malone, K, Marinelli, A, Marinelli, SS, Martinez, H, Martinez, O, Martínez-Castro, J, Matthews, JA, Miranda-Romagnoli, P, Moreno, E, Mostafá, M, Nellen, L, Newbold, M, Noriega-Papaqui, R, Patricelli, B, Pelayo, R, Pérez-Pérez, EG, Pretz, J, Ren, Z, Rivière, C, Rosa-González, D, Salazar, H, Greus, F Salesa, Sandoval, A, Schneider, M, Sinnis, G, Smith, AJ, Woodle, K Sparks, Springer, RW, Taboada, I, Tibolla, O, Tollefson, K, Torres, I, Ukwatta, TN, Villaseñor, L, Vrabel, K, Weisgarber, T, Westerhoff, S, Wisher, IG, Wood, J, Yapici, T, Yodh, GB, Younk, PW, Zaborov, D, Zepeda, A, and Zhou, H

Subjects
astroparticle physics, gamma rays: diffuse background, gamma rays: general, astro-ph.HE, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

A survey of the inner Galaxy region of Galactic longitude l ∈[+15,+50] and latitude b ∈ [-4, +4] is performed using one-third of the High Altitude Water Cherenkov Observatory, operated during ts construction phase. To address the ambiguities arising from unresolved sources in the data, we use a maximum likelihood technique to identify point source candidates. Ten sources and candidate sources are identified in this analysis. Eight of these are associated with known TeV sources but not all have ifferential fluxes that are compatible with previous measurements. Three sources are detected with significances >5 sigma; after accounting for statistical trials, and are associated with known TeV sources.

Published
2016

7. Search for gamma-rays from the unusually bright GRB 130427A with the HAWC Gamma-ray Observatory

Author

The HAWC collaboration, Abeysekara, A. U., Alfaro, R., Alvarez, C., Álvarez, J. D., Arceo, R., Arteaga-Velázquez, J. C., Solares, H. A. Ayala, Barber, A. S., Baughman, B. M., Bautista-Elivar, N., BenZvi, S. Y., Rosales, M. Bonilla, Braun, J., Caballero-Mora, K. S., Carramiñana, A., Castillo, M., Cotti, U., Cotzomi, J., de la Fuente, E., De León, C., DeYoung, T., Hernandez, R. Diaz, Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., Fiorino, D. W., Fraija, N., Galindo, A., Garfias, F., González, M. M., Goodman, J. A., Gussert, M., Hampel-Arias, Z., Harding, J. P., Hüntemeyer, P., Hui, C. M., Imran, A., Iriarte, A., Karn, P., Kieda, D., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. León, Linnemann, J. T., Longo, M., Luna-García, R., Malone, K., Marinelli, A., Marinelli, S. S., Martinez, H., Martinez, O., Martínez-Castro, J., Matthews, J. A., Torres, E. Mendoza, Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nellen, L., Newbold, M., Noriega-Papaqui, R., Oceguera-Becerra, T. O., Patricelli, B., Pelayo, R., Pérez-Pérez, E. G., Pretz, J., Rivière, C., Rosa-González, D., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Sinnis, G., Smith, A. J., Woodle, K. Sparks, Springer, R. W., Taboada, I., Tollefson, K., Torres, I., Ukwatta, T. N., Villaseñor, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yodh, G. B., Younk, P. W., Zaborov, D., Zepeda, A., and Zhou, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The first limits on the prompt emission from the long gamma-ray burst (GRB) 130427A in the $>100\nobreakspace\rm{GeV}$ energy band are reported. GRB 130427A was the most powerful burst ever detected with a redshift $z\lesssim0.5$ and featured the longest lasting emission above $100\nobreakspace\rm{MeV}$. The energy spectrum extends at least up to $95\nobreakspace\rm{GeV}$, clearly in the range observable by the High Altitude Water Cherenkov (HAWC) Gamma-ray Observatory, a new extensive air shower detector currently under construction in central Mexico. The burst occurred under unfavourable observation conditions, low in the sky and when HAWC was running 10% of the final detector. Based on the observed light curve at MeV-GeV energies, eight different time periods have been searched for prompt and delayed emission from this GRB. In all cases, no statistically significant excess of counts has been found and upper limits have been placed. It is shown that a similar GRB close to zenith would be easily detected by the full HAWC detector, which will be completed soon. The detection rate of the full HAWC detector may be as high as one to two GRBs per year. A detection could provide important information regarding the high energy processes at work and the observation of a possible cut-off beyond the $\mathit{Fermi}$-LAT energy range could be the signature of gamma-ray absorption, either in the GRB or along the line of sight due to the extragalactic background light., Comment: 10 pages, 4 figures, published in ApJ

Published
2014
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8. Observation of Small-scale Anisotropy in the Arrival Direction Distribution of TeV Cosmic Rays with HAWC

Author

Abeysekara, A. U., Alfaro, R., Alvarez, C., Álvarez, J. D., Arceo, R., Arteaga-Velázquez, J. C., Solares, H. A. Ayala, Barber, A. S., Baughman, B. M., Bautista-Elivar, N., Belmont, E., BenZvi, S. Y., Berley, D., Rosales, M. Bonilla, Braun, J., Caballero-Mora, K. S., Carramiñana, A., Castillo, M., Cotti, U., Cotzomi, J., de la Fuente, E., De León, C., DeYoung, T., Hernandez, R. Diaz, Díaz-Vélez, J. C., Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., Fiorino, D. W., Fraija, N., Galindo, A., Garfias, F., González, M. M., Goodman, J. A., Gussert, M., Hampel-Arias, Z., Harding, J. P., Hüntemeyer, P., Hui, C. M., Imran, A., Iriarte, A., Karn, P., Kieda, D., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. León, Linnemann, J. T., Longo, M., Luna-García, R., Malone, K., Marinelli, A., Marinelli, S. S., Martinez, H., Martinez, O., Martínez-Castro, J., Matthews, J. A. J., McEnery, J., Torres, E. Mendoza, Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nellen, L., Newbold, M., Noriega-Papaqui, R., Oceguera-Becerra, T., Patricelli, B., Pelayo, R., Pérez-Pérez, E. G., Pretz, J., Rivière, C., Rosa-González, D., Ruiz-Velasco, E., Ryan, J., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Sinnis, G., Smith, A. J., Woodle, K. Sparks, Springer, R. W., Taboada, I., Toale, P. A., Tollefson, K., Torres, I., Ukwatta, T. N., Villaseñor, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yodh, G. B., Younk, P. W., Zaborov, D., Zepeda, A., and Zhou, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The High-Altitude Water Cherenkov (HAWC) Observatory is sensitive to gamma rays and charged cosmic rays at TeV energies. The detector is still under construction, but data acquisition with the partially deployed detector started in 2013. An analysis of the cosmic-ray arrival direction distribution based on $4.9\times 10^{10}$ events recorded between June 2013 and February 2014 shows anisotropy at the $10^{-4}$ level on angular scales of about $10^\circ$. The HAWC cosmic-ray sky map exhibits three regions of significantly enhanced cosmic-ray flux; two of these regions were first reported by the Milagro experiment. A third region coincides with an excess recently reported by the ARGO-YBJ experiment. An angular power spectrum analysis of the sky shows that all terms up to $\ell=15$ contribute significantly to the excesses., Comment: 12 pages, 11 figures. Accepted by The Astrophysical Journal

Published
2014
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9. VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory

Author

Abeysekara, A. U., Alfaro, R., Alvarez, C., Álvarez, J. D., Ángeles, F., Arceo, R., Arteaga-Velázquez, J. C., Avila-Aroche, A., Solares, H. A. Ayala, Badillo, C., Barber, A. S., Baughman, B. M., Bautista-Elivar, N., Gonzalez, J. Becerra, Belmont, E., Benítez, E., BenZvi, S. Y., Berley, D., Bernal, A., Rosales, M. Bonilla, Braun, J., Caballero-Lopez, R. A., Caballero-Mora, K. S., Cabrera, I., Carramiñana, A., Castañeda-Martínez, L., Castillo, M., Cotti, U., Cotzomi, J., de la Fuente, E., De León, C., DeYoung, T., Diaz-Azuara, A., Diaz-Cruz, L., Hernandez, R. Diaz, Díaz-Vélez, J. C., Dingus, B. L., Dultzin, D., DuVernois, M. A., Ellsworth, R. W., Fernandez, A., Fiorino, D. W., Fraija, N., Galindo, A., García-Torales, G., Garfias, F., González, A., González, L. X., González, M. M., Goodman, J. A., Grabski, V., Gussert, M., Guzmán-Cerón, C., Hampel-Arias, Z., Harding, J. P., Hernández-Cervantes, L., Hui, C. M., Hüntemeyer, P., Imran, A., Iriarte, A., Karn, P., Kieda, D., Kunde, G. J., Langarica, R., Lara, A., Lara, G., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. León, Linares, E. C., Linnemann, J. T., Longo, M., Luna-Garcia, R., Marinelli, A., Martínez, L. A., Martínez, H., Martínez, O., Martínez-Castro, J., Martos, M., Matthews, J. A. J., McEnery, J., Torres, E. Mendoza, Miranda-Romagnoli, P., Moreno, E., Mostafá, M., Nava, J., Nellen, L., Newbold, M., Noriega-Papaqui, R., Oceguera-Becerra, T., Page, D. P., Patricelli, B., Pelayo, R., Pérez-Pérez, E. G., Pretz, J., Ramírez, I., Renter, A., Rivière, C., Rosa-González, D., Ruiz-Sala, F., Ruiz-Velasco, E. L., Ryan, J., Sacahui, J. R., Salazar, H., Salesa, F., Sandoval, A., Santos, E., Schneider, M., Silich, S., Sinnis, G., Smith, A. J., Woodle, K. Sparks, Springer, R. W., Suarez, F., Taboada, I., Tepe, A., Toale, P. A., Tollefson, K., Torres, I., Tinoco, S., Ukwatta, T. N., Galicia, J. F. Valdés, Vanegas, P., Vázquez, A., Villaseñor, L., Wall, W., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yodh, G. B., Younk, P. W., Zaborov, D., Zepeda, A., and Zhou, H.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l. in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design, construction techniques and data acquisition system of the HAWC observatory. HAWC is an air-shower array currently under construction at the same site of VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water Cherenkov detectors and two different data acquisition systems. It was in operation between October 2011 and May 2012 with an average live time of 30%. Besides the scientific verification purposes, the eight months of data were used to obtain the results presented in this paper: the detector response to the Forbush decrease of March 2012, and the analysis of possible emission, at energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B., Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages, 10 figures). Corresponding authors: A.Marinelli and D.Zaborov

Published
2014
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10. Milagro Limits and HAWC Sensitivity for the Rate-Density of Evaporating Primordial Black Holes

Author

Abdo, A. A., Abeysekara, A. U., Alfaro, R., Allen, B. T., Alvarez, C., Álvarez, J. D., Arceo, R., Arteaga-Velázquez, J. C., Aune, T., Solares, H. A. Ayala, Barber, A. S., Baughman, B. M., Bautista-Elivar, N., Gonzalez, J. Becerra, Belmont, E., BenZvi, S. Y., Berley, D., Rosales, M. Bonilla, Braun, J., Caballero-Lopez, R. A., Caballero-Mora, K. S., Carramiñana, A., Castillo, M., Chen, C., Christopher, G. E., Cotti, U., Cotzomi, J., de la Fuente, E., De León, C., DeYoung, T., Hernandez, R. Diaz, Diaz-Cruz, L., Díaz-Vélez, J. C., Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., Fiorino, D. W., Fraija, N., Galindo, A., Garfias, F., González, M. M., Goodman, J. A., Grabski, V., Gussert, M., Hampel-Arias, Z., Harding, J. P., Hays, E., Hoffman, C. M., Hui, C. M., Hüntemeyer, P., Imran, A., Iriarte, A., Karn, P., Kieda, D., Kolterman, B. E., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. León, Linares, E. C., Linnemann, J. T., Longo, M., Luna-GarcIa, R., MacGibbon, J. H., Marinelli, A., Marinelli, S. S., Martinez, H., Martinez, O., Martínez-Castro, J., Matthews, J. A. J., McEnery, J., Torres, E. Mendoza, Mincer, A. I., Miranda-Romagnoli, P., Moreno, E., Morgan, T., Mostafá, M., Nellen, L., Nemethy, P., Newbold, M., Noriega-Papaqui, R., Oceguera-Becerra, T., Patricelli, B., Pelayo, R., Pérez-Pérez, E. G., Pretz, J., Rivière, C., Rosa-González, D., Ryan, J., Salazar, H., Salesa, F., Sandoval, A., Parkinson, P. M. Saz, Schneider, M., Shoup, A., Silich, S., Sinnis, G., Smith, A. J., Stump, D., Woodle, K. Sparks, Springer, R. W., Taboada, I., Toale, P. A., Tollefson, K., Torres, I., Ukwatta, T. N., Vasileiou, V., Villaseñor, L., Walker, G. P., Weisgarber, T., Westerhoff, S., Williams, D. A., Wisher, I. G., Wood, J., Yodh, G. B., Younk, P. W., Zaborov, D., Zepeda, A., and Zhou, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Primordial Black Holes (PBHs) are gravitationally collapsed objects that may have been created by density fluctuations in the early universe and could have arbitrarily small masses down to the Planck scale. Hawking showed that due to quantum effects, a black hole has a temperature inversely proportional to its mass and will emit all species of fundamental particles thermally. PBHs with initial masses of ~5.0 x 10^14 g should be expiring in the present epoch with bursts of high-energy particles, including gamma radiation in the GeV - TeV energy range. The Milagro high energy observatory, which operated from 2000 to 2008, is sensitive to the high end of the PBH evaporation gamma-ray spectrum. Due to its large field-of-view, more than 90% duty cycle and sensitivity up to 100 TeV gamma rays, the Milagro observatory is well suited to perform a search for PBH bursts. Based on a search on the Milagro data, we report new PBH burst rate density upper limits over a range of PBH observation times. In addition, we report the sensitivity of the Milagro successor, the High Altitude Water Cherenkov (HAWC) observatory, to PBH evaporation events., Comment: Accepted to Astroparticle Physics Journal (25 Pages, 3 figures and 7 tables). Corresponding author: T. N. Ukwatta

Published
2014
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11. The Sensitivity of HAWC to High-Mass Dark Matter Annihilations

Author

Abeysekara, A. U., Alfaro, R., Alvarez, C., Alvarez, J. D., Arceo, R., Arteaga-Velazquez, J. C., Solares, H. A. Ayala, Barber, A. S., Baughman, B. M., Bautista-Elivar, N., Gonzalez, J. Becerra, Belmont, E., BenZvi, S. Y., Berley, D., Rosales, M. Bonilla, Braun, J., Caballero-Lopez, R. A., Caballero-Mora, K. S., Carraminana, A., Castillo, M., Cotti, U., Cotzomi, J., de la Fuente, E., De Leon, C., DeYoung, T., Hernandez, R. Diaz, Diaz-Cruz, L., Diaz-Velez, J. C., Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., E., S. F., Fiorino, D. W., Fraija, N., Galindo, A., Garfias, F., Gonzalez, M. M., Goodman, J. A., Grabski, V., Gussert, M., Hampel-Arias, Z., Harding, J. P., Hui, C. M., Huentemeyer, P., Imran, A., Iriarte, A., Karn, P., Kieda, D., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. Leon, Linares, E. C., Linnemann, J. T., Longo, M., Luna-Garcia, R., Marinelli, A., Martinez, H., Martinez, O., Martinez-Castro, J., Matthews, J. A. J., McEnery, J., Torres, E. Mendoza, Miranda-Romagnoli, P., Moreno, E., Mostafa, M., Nellen, L., Newbold, M., Noriega-Papaqui, R., Oceguera-Becerra, T., Patricelli, B., Pelayo, R., Perez-Perez, E. G., Pretz, J., Riviere, C., Rosa-Gonzalez, D., Ryan, J., Salazar, H., Salesa, F., Sandoval, A., Schneider, M., Silich, S., Sinnis, G., Smith, A. J., Woodle, K. Sparks, Springer, R. W., Taboada, I., Toale, P. A., Tollefson, K., Torres, I., Ukwatta, T. N., Villasenor, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yodh, G. B., Younk, P. W., Zaborov, D., Zepeda, A., Zhou, H., and Abazajian, K. N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Phenomenology
Abstract

The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19 degrees North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Spring 2015. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi- TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from non-luminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dark matter annihilation channels. If no gamma-ray excess is observed, we show the limits HAWC can place on the dark matter cross-section from these sources. In particular, in the case of dark matter annihilation into gauge bosons, HAWC will be able to detect a narrow range of dark matter masses to cross-sections below thermal. HAWC should also be sensitive to non-thermal cross-sections for masses up to nearly 1000 TeV. The constraints placed by HAWC on the dark matter cross-section from known sources should be competitive with current limits in the mass range where HAWC has similar sensitivity. HAWC can additionally explore higher dark matter masses than are currently constrained., Comment: 15 pages, 4 figures, version to be published in PRD

Published
2014
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13. HAWC Contributions to the 34th International Cosmic Ray Conference (ICRC2015)

Author

Collaboration, HAWC, Abeysekara, AU, Alfaro, R, Alvarez, C, Álvarez, JD, Arceo, R, Arteaga-Velázquez, JC, Solares, HA Ayala, Barber, AS, Baughman, BM, Bautista-Elivar, N, Gonzalez, J Becerra, Becerril, A, Belmont, E, BenZvi, SY, Berley, D, Bernal, A, Braun, J, Caballero-Mora, KS, Capistrán, T, Carramiñana, A, Castillo, M, Cotti, U, Cotzomi, J, León, S Coutiño de, Fuente, E de la, León, C De, DeYoung, T, Hernandez, R Diaz, Diaz-Cruz, L, Díaz-Vélez, JC, Dingus, BL, DuVernois, MA, Ellsworth, RW, Engel, K, Enriquez-Rivera, O, Fick, B, Fiorino, DW, Flores, JL, Fraija, N, Garcia-Torales, G, Garfias, F, González, MM, Goodman, JA, Gussert, M, Hampel-Arias, Z, Hansen, P, Harding, J Patrick, Hernandez, S, Hui, CM, Hüntemeyer, P, Imran, A, Iriarte, A, Karn, P, Kieda, D, Kunde, GJ, Lara, A, Lauer, RJ, Lee, WH, Lennarz, D, Vargas, H León, Linnemann, JT, Proper, M Longo, Raya, G Luis, Luna-García, R, Malone, K, Marinelli, A, Marinelli, SS, Martinez, H, Martinez, O, Martínez-Castro, J, Matthews, JAJ, McEnery, J, Miranda-Romagnoli, P, Moreno, E, Mostafá, M, Nellen, L, Newbold, M, Nisa, M Un, Noriega-Papaqui, R, Oceguera-Becerra, T, Patricelli, B, Pelayo, R, Pérez-Pérez, EG, Pretz, J, Ren, Z, Rho, CD, Rivière, C, Rosa-González, D, Ryan, J, Salazar, H, Greus, F Salesa, Sandoval, A, Schneider, M, Sinnis, G, Smith, AJ, Smith, AW, Woodle, K Sparks, Springer, RW, and Taboada, I

Subjects
astro-ph.HE, hep-ex
Abstract

List of proceedings from the HAWC Collaboration presented at the 34thInternational Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, TheNetherlands.

Published
2015

14. SEARCH FOR GAMMA-RAYS FROM THE UNUSUALLY BRIGHT GRB 130427A WITH THE HAWC GAMMA-RAY OBSERVATORY

Author

Abeysekara, AU, Alfaro, R, Alvarez, C, Álvarez, JD, Arceo, R, Arteaga-Velázquez, JC, Solares, HA Ayala, Barber, AS, Baughman, BM, Bautista-Elivar, N, BenZvi, SY, Rosales, M Bonilla, Braun, J, Caballero-Mora, KS, Carramiñana, A, Castillo, M, Cotti, U, Cotzomi, J, de la Fuente, E, De León, C, DeYoung, T, Hernandez, R Diaz, Dingus, BL, DuVernois, MA, Ellsworth, RW, Fiorino, DW, Fraija, N, Galindo, A, Garfias, F, González, MM, Goodman, JA, Gussert, M, Hampel-Arias, Z, Harding, JP, Hüntemeyer, P, Hui, CM, Imran, A, Iriarte, A, Karn, P, Kieda, D, Kunde, GJ, Lara, A, Lauer, RJ, Lee, WH, Lennarz, D, Vargas, H León, Linnemann, JT, Longo, M, Luna-García, R, Malone, K, Marinelli, A, Marinelli, SS, Martinez, H, Martinez, O, Martínez-Castro, J, Matthews, JAJ, Torres, E Mendoza, Miranda-Romagnoli, P, Moreno, E, Mostafá, M, Nellen, L, Newbold, M, Noriega-Papaqui, R, Oceguera-Becerra, TO, Patricelli, B, Pelayo, R, Pérez-Pérez, EG, Pretz, J, Rivière, C, Rosa-González, D, Salazar, H, Greus, F Salesa, Sandoval, A, Schneider, M, Sinnis, G, Smith, AJ, Woodle, K Sparks, Springer, RW, Taboada, I, Tollefson, K, Torres, I, Ukwatta, TN, Villaseñor, L, Weisgarber, T, Westerhoff, S, Wisher, IG, Wood, J, Yodh, GB, Younk, PW, Zaborov, D, Zepeda, A, and Zhou, and H

Subjects
gamma-ray burst: individual, gamma rays: general, astro-ph.HE, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

The first limits on the prompt emission from the long gamma-ray burst (GRB) 130427A in the >100 GeV energy band are reported. GRB 130427A was the most powerful burst ever detected with a redshift z ≲ 0.5 and featured the longest lasting emission above 100 MeV. The energy spectrum extends at least up to 95 GeV, clearly in the range observable by the High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory, a new extensive air shower detector currently under construction in central Mexico. The burst occurred under unfavorable observation conditions, low in the sky and when HAWC was running 10% of the final detector. Based on the observed light curve at MeV-GeV energies, eight different time periods have been searched for prompt and delayed emission from this GRB. In all cases, no statistically significant excess of counts has been found and upper limits have been placed. It is shown that a similar GRB close to zenith would be easily detected by the full HAWC detector, which will be completed soon. The detection rate of the full HAWC detector may be as high as one to two GRBs per year. A detection could provide important information regarding the high energy processes at work and the observation of a possible cut-off beyond the Fermi Large Area Telescope energy range could be the signature of gamma-ray absorption, either in the GRB or along the line of sight due to the extragalactic background light.

Published
2015

15. Sensitivity of HAWC to high-mass dark matter annihilations

Author

Abeysekara, AU, Alfaro, R, Alvarez, C, Álvarez, JD, Arceo, R, Arteaga-Velázquez, JC, Solares, HA Ayala, Barber, AS, Baughman, BM, Bautista-Elivar, N, Gonzalez, J Becerra, Belmont, E, BenZvi, SY, Berley, D, Rosales, M Bonilla, Braun, J, Caballero-Lopez, RA, Caballero-Mora, KS, Carramiñana, A, Castillo, M, Cotti, U, Cotzomi, J, de la Fuente, E, De León, C, DeYoung, T, Hernandez, R Diaz, Diaz-Cruz, L, Díaz-Vélez, JC, Dingus, BL, DuVernois, MA, Ellsworth, RW, Fiorino, DW, Fraija, N, Galindo, A, Garfias, F, González, MM, Goodman, JA, Grabski, V, Gussert, M, Hampel-Arias, Z, Harding, JP, Hui, CM, Hüntemeyer, P, Imran, A, Iriarte, A, Karn, P, Kieda, D, Kunde, GJ, Lara, A, Lauer, RJ, Lee, WH, Lennarz, D, Vargas, H León, Linares, EC, Linnemann, JT, Longo, M, Luna-Garcia, R, Marinelli, A, Martinez, H, Martinez, O, Martínez-Castro, J, Matthews, JAJ, McEnery, J, Torres, E Mendoza, Miranda-Romagnoli, P, Moreno, E, Mostafá, M, Nellen, L, Newbold, M, Noriega-Papaqui, R, Oceguera-Becerra, T, Patricelli, B, Pelayo, R, Pérez-Pérez, EG, Pretz, J, Rivière, C, Rosa-González, D, Ryan, J, Salazar, H, Salesa, F, Sanchez, FE, Sandoval, A, Schneider, M, Silich, S, Sinnis, G, Smith, AJ, Woodle, K Sparks, Springer, RW, Taboada, I, Toale, PA, Tollefson, K, Torres, I, Ukwatta, TN, Villaseñor, L, Weisgarber, T, Westerhoff, S, Wisher, IG, Wood, J, Yodh, GB, and Younk, PW

Subjects
astro-ph.HE, astro-ph.CO, hep-ph, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract

The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19° North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Spring 2015. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi-TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from nonluminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dark matter annihilation channels. If no gamma-ray excess is observed, we show the limits HAWC can place on the dark matter cross section from these sources. In particular, in the case of dark matter annihilation into gauge bosons, HAWC will be able to detect a narrow range of dark matter masses to cross sections below thermal. HAWC should also be sensitive to nonthermal cross sections for masses up to nearly 1000 TeV. The constraints placed by HAWC on the dark matter cross section from known sources should be competitive with current limits in the mass range where HAWC has similar sensitivity. HAWC can additionally explore higher dark matter masses than are currently constrained.

Published
2014

16. OBSERVATION OF SMALL-SCALE ANISOTROPY IN THE ARRIVAL DIRECTION DISTRIBUTION OF TeV COSMIC RAYS WITH HAWC

Author

Abeysekara, AU, Alfaro, R, Alvarez, C, Álvarez, JD, Arceo, R, Arteaga-Velázquez, JC, Solares, HA Ayala, Barber, AS, Baughman, BM, Bautista-Elivar, N, Belmont, E, BenZvi, SY, Berley, D, Rosales, M Bonilla, Braun, J, Caballero-Mora, KS, Carramiñana, A, Castillo, M, Cotti, U, Cotzomi, J, de la Fuente, E, De León, C, DeYoung, T, Hernandez, R Diaz, Díaz-Vélez, JC, Dingus, BL, DuVernois, MA, Ellsworth, RW, Fiorino, DW, Fraija, N, Galindo, A, Garfias, F, González, MM, Goodman, JA, Gussert, M, Hampel-Arias, Z, Harding, JP, Hüntemeyer, P, Hui, CM, Imran, A, Iriarte, A, Karn, P, Kieda, D, Kunde, GJ, Lara, A, Lauer, RJ, Lee, WH, Lennarz, D, Vargas, H León, Linnemann, JT, Longo, M, Luna-García, R, Malone, K, Marinelli, A, Marinelli, SS, Martinez, H, Martinez, O, Martínez-Castro, J, Matthews, JAJ, McEnery, J, Torres, E Mendoza, Miranda-Romagnoli, P, Moreno, E, Mostafá, M, Nellen, L, Newbold, M, Noriega-Papaqui, R, Oceguera-Becerra, T, Patricelli, B, Pelayo, R, Pérez-Pérez, EG, Pretz, J, Rivière, C, Rosa-González, D, Ruiz-Velasco, E, Ryan, J, Salazar, H, Greus, F Salesa, Sandoval, A, Schneider, M, Sinnis, G, Smith, AJ, Woodle, K Sparks, Springer, RW, Taboada, I, Toale, PA, Tollefson, K, Torres, I, Ukwatta, TN, Villaseñor, L, Weisgarber, T, Westerhoff, S, Wisher, IG, Wood, J, Yodh, GB, Younk, PW, Zaborov, D, Zepeda, A, and Zhou, and H

Subjects
Astroparticle physics, Cosmic rays, astroparticle physics, cosmic rays, astro-ph.HE, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

The High-Altitude Water Cherenkov (HAWC) Observatory is sensitive to gamma rays and charged cosmic rays at TeV energies. The detector is still under construction, but data acquisition with the partially deployed detector started in 2013. An analysis of the cosmic-ray arrival direction distribution based on 4.9 × 1010 events recorded between 2013 June and 2014 February shows anisotropy at the 10-4 level on angular scales of about 10°. The HAWC cosmic-ray sky map exhibits three regions of significantly enhanced cosmic-ray flux; two of these regions were first reported by the Milagro experiment. A third region coincides with an excess recently reported by the ARGO-YBJ experiment. An angular power spectrum analysis of the sky shows that all terms up to l = 15 contribute significantly to the excesses.

Published
2014

18. The High-Altitude Water Cherenkov (HAWC) observatory in México: The primary detector

Author

Abeysekara, A.U., primary, Albert, A., additional, Alfaro, R., additional, Alvarez, C., additional, Álvarez, J.D., additional, Araya, M., additional, Arteaga-Velázquez, J.C., additional, Arunbabu, K.P., additional, Rojas, D. Avila, additional, Solares, H.A. Ayala, additional, Babu, R., additional, Barber, A.S., additional, Becerril, A., additional, Belmont-Moreno, E., additional, BenZvi, S.Y., additional, Blanco, O., additional, Braun, J., additional, Brisbois, C., additional, Caballero-Mora, K.S., additional, Martínez, J.I. Cabrera, additional, Capistrán, T., additional, Carramiñana, A., additional, Casanova, S., additional, Castillo, M., additional, Chaparro-Amaro, O., additional, Cotti, U., additional, Cotzomi, J., additional, de León, S. Coutiño, additional, de la Fuente, E., additional, de León, C., additional, De Young, T., additional, Hernandez, R. Diaz, additional, Dingus, B.L., additional, DuVernois, M.A., additional, Durocher, M., additional, Díaz-Vélez, J.C., additional, Ellsworth, R.W., additional, Engel, K., additional, Espinoza, C., additional, Fan, K.L., additional, Fang, K., additional, Fick, B., additional, Fleischhack, H., additional, Flores, J.L., additional, Fraija, N., additional, García-González, J.A., additional, Garcia-Torales, G., additional, Garfias, F., additional, Giacinti, G., additional, Goksu, H., additional, González, M.M., additional, González-Muñoz, A., additional, Goodman, J.A., additional, Harding, J.P., additional, Hernandez, E., additional, Hernandez, S., additional, Hinton, J., additional, Hona, B., additional, Huang, D., additional, Hueyotl-Zahuantitla, F., additional, Hui, C.M., additional, Humensky, T.B., additional, Hüntemeyer, P., additional, Iriarte, A., additional, Imran, A., additional, Jardin-Blicq, A., additional, Joshi, V., additional, Kaufmann, S., additional, Kieda, D., additional, Kunde, G.J., additional, Lara, A., additional, Lauer, R., additional, Lee, W.H., additional, Lennarz, D., additional, Vargas, H. León, additional, Linnemann, J.T., additional, Longinotti, A.L., additional, Luis-Raya, G., additional, Lundeen, J., additional, Malone, K., additional, Marandon, V., additional, Marinelli, A., additional, Martinez, O., additional, Martínez-Castellanos, I., additional, Martínez-Castro, J., additional, Martínez-Huerta, H., additional, Matthews, J.A., additional, Miranda-Romagnoli, P., additional, Montaruli, T., additional, Morales-Soto, J.A., additional, Moreno, E., additional, Mostafá, M., additional, Nayerhoda, A., additional, Nellen, L., additional, Newbold, M., additional, Nisa, M.U., additional, Noriega-Papaqui, R., additional, Oceguera-Becerra, T., additional, Olivera-Nieto, L., additional, Omodei, N., additional, Peisker, A., additional, Araujo, Y. Pérez, additional, Pérez-Pérez, E.G., additional, Ponce, E., additional, Pretz, J., additional, Rho, C.D., additional, Rosa-González, D., additional, Ruiz-Velasco, E., additional, Salazar, H., additional, Salazar-Gallegos, D., additional, Greus, F. Salesa, additional, Sandoval, A., additional, Schneider, M., additional, Schoorlemmer, H., additional, Serna-Franco, J., additional, Sinnis, G., additional, Smith, A.J., additional, Son, Y., additional, Woodle, K. Sparks, additional, Springer, R.W., additional, Taboada, I., additional, Tepe, A., additional, Tibolla, O., additional, Tollefson, K., additional, Torres, I., additional, Torres-Escobedo, R., additional, Turner, R., additional, Ureña-Mena, F., additional, Ukwatta, T.N., additional, Varela, E., additional, Vargas-Magaña, M., additional, Villaseñor, L., additional, Wang, X., additional, Watson, I.J., additional, Werner, F., additional, Westerhoff, S., additional, Willox, E., additional, Wisher, I., additional, Wood, J., additional, Yodh, G.B., additional, Zaborov, D., additional, Zepeda, A., additional, and Zhou, H., additional

Published
2023
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20. The High-Altitude Water Cherenkov (HAWC) Observatory in México: The Primary Detector

Author

A.U. Abeysekara, A. Albert, R. Alfaro, C. Alvarez, J.D. Álvarez, M. Araya, J.C. Arteaga-Velázquez, K.P. Arunbabu, D. Avila Rojas, H.A. Ayala Solares, R. Babu, A.S. Barber, A. Becerril, E. Belmont-Moreno, S.Y. BenZvi, O. Blanco, J. Braun, C. Brisbois, K.S. Caballero-Mora, J.I. Cabrera Martínez, T. Capistrán, A. Carramiñana, S. Casanova, M. Castillo, O. Chaparro-Amaro, U. Cotti, J. Cotzomi, S. Coutiño de León, E. de la Fuente, C. de León, T. De Young, R. Diaz Hernandez, B.L. Dingus, M.A. DuVernois, M. Durocher, J.C. Díaz-Vélez, R.W. Ellsworth, K. Engel, C. Espinoza, K.L. Fan, K. Fang, B. Fick, H. Fleischhack, J.L. Flores, N. Fraija, J.A. García-González, G. Garcia-Torales, F. Garfias, G. Giacinti, H. Goksu, M.M. González, A. González-Muñoz, J.A. Goodman, J.P. Harding, E. Hernandez, S. Hernandez, J. Hinton, B. Hona, D. Huang, F. Hueyotl-Zahuantitla, C.M. Hui, T.B. Humensky, P. Hüntemeyer, A. Iriarte, A. Imran, A. Jardin-Blicq, V. Joshi, S. Kaufmann, D. Kieda, G.J. Kunde, A. Lara, R. Lauer, W.H. Lee, D. Lennarz, H. León Vargas, J.T. Linnemann, A.L. Longinotti, G. Luis-Raya, J. Lundeen, K. Malone, V. Marandon, A. Marinelli, O. Martinez, I. Martínez-Castellanos, J. Martínez-Castro, H. Martínez-Huerta, J.A. Matthews, P. Miranda-Romagnoli, T. Montaruli, J.A. Morales-Soto, E. Moreno, M. Mostafá, A. Nayerhoda, L. Nellen, M. Newbold, M.U. Nisa, R. Noriega-Papaqui, T. Oceguera-Becerra, L. Olivera-Nieto, N. Omodei, A. Peisker, Y. Pérez Araujo, E.G. Pérez-Pérez, E. Ponce, J. Pretz, C.D. Rho, D. Rosa-González, E. Ruiz-Velasco, H. Salazar, D. Salazar-Gallegos, F. Salesa Greus, A. Sandoval, M. Schneider, H. Schoorlemmer, J. Serna-Franco, G. Sinnis, A.J. Smith, Y. Son, K. Sparks Woodle, R.W. Springer, I. Taboada, A. Tepe, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, F. Ureña-Mena, T.N. Ukwatta, E. Varela, M. Vargas-Magaña, L. Villaseñor, X. Wang, I.J. Watson, F. Werner, S. Westerhoff, E. Willox, I. Wisher, J. Wood, G.B. Yodh, D. Zaborov, A. Zepeda, and H. Zhou

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Nuclear and High Energy Physics, FOS: Physical sciences, High Energy Physics, Molecular Developmental Biology, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract

The High-Altitude Water Cherenkov (HAWC) observatory is a second-generation continuously operated, wide field-of-view, TeV gamma-ray observatory. The HAWC observatory and its analysis techniques build on experience of the Milagro experiment in using ground-based water Cherenkov detectors for gamma-ray astronomy. HAWC is located on the Sierra Negra volcano in M\'exico at an elevation of 4100 meters above sea level. The completed HAWC observatory principal detector (HAWC) consists of 300 closely spaced water Cherenkov detectors, each equipped with four photomultiplier tubes to provide timing and charge information to reconstruct the extensive air shower energy and arrival direction. The HAWC observatory has been optimized to observe transient and steady emission from sources of gamma rays within an energy range from several hundred GeV to several hundred TeV. However, most of the air showers detected are initiated by cosmic rays, allowing studies of cosmic rays also to be performed. This paper describes the characteristics of the HAWC main array and its hardware., Comment: Accepted for publications in Nuclear Inst. and Methods in Physics Research, A (2023) 168253 ( https://www.sciencedirect.com/science/article/abs/pii/S0168900223002437 ); 39 pages, 14 Figures

Published
2023
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23. Data acquisition architecture and online processing system for the HAWC gamma-ray observatory

Author

Jorge Cotzomi, P. Karn, Fernando Garfias, M. Longo Proper, Anushka Udara Abeysekara, Petra Hüntemeyer, Thomas Weisgarber, J. P. Harding, T. Yapici, F. Salesa Greus, Alberto Carramiñana, A. Imran, Ruben Alfaro, H. León Vargas, Daniel Rosa-Gonzalez, T. N. Ukwatta, Varlen Grabski, R. Arceo, Pedro Miranda-Romagnoli, M. Bonilla Rosales, Michael Newbold, A. J. Smith, O. Martinez, Michael DuVernois, Nissim Illich Fraija, James E. Braun, E. De la Fuente, R. Noriega-Papaqui, R. A. Caballero-Lopez, J. C. Arteaga-Velázquez, Gerd Joachim Kunde, D. Berley, N. Bautista-Elivar, James M. Ryan, A. Sandoval, G. Sinnis, J. Becerra González, L. Nellen, William H. Lee, J. Pretz, S. S. Marinelli, E. Mendoza Torres, James W. Wood, Kelly Malone, C. M. Hui, Hao Zhou, C. De León, Umberto Cotti, H. Martínez-Huerta, Julie McEnery, Michael Schneider, I. G. Wisher, Edna Ruiz-Velasco, R. W. Springer, E. G. Pérez-Pérez, Tyce DeYoung, P. A. Toale, I. Taboada, K. Sparks Woodle, C. Alvarez, Rodrigo Pelayo, E. C. Linares, J. A.J. Matthews, A. Marinelli, A. Zepeda, David Kieda, S. Westerhoff, F. E. Sanchez, M. Castillo, Humberto Ibarguen Salazar, Juan Carlos Diaz-Velez, P. W. Younk, D. W. Fiorino, Dirk Lennarz, E. Moreno, J. D. Álvarez, Maria Magdalena González, Arturo Iriarte, T. Oceguera-Becerra, R. J. Lauer, A. Galindo, Karen S. Caballero-Mora, Jesús Martínez-Castro, H. A. Ayala Solares, K. Tollefson, Alejandro Lara, Z. Hampel-Arias, R. Diaz Hernandez, Ibrahim Torres, D. Zaborov, J. T. Linnemann, G. B. Yodh, A. S. Barber, R. W. Ellsworth, S. Silich, B. M. Baughman, C. Rivière, L. Villaseñor, J. A. Goodman, Ernesto Belmont-Moreno, Miguel Mostafa, Segev BenZvi, J. Diaz-Cruz, M. Gussert, B. Patricelli, Brenda Dingus, and R. Luna-Garcia

Subjects
Physics, Nuclear and High Energy Physics, business.industry, Gigabit Ethernet, Electrical engineering, FOS: Physical sciences, Dead time, 01 natural sciences, Data processing system, Time-to-digital converter, Air shower, Data acquisition, Observatory, 0103 physical sciences, Custom software, Astrophysics - Instrumentation and Methods for Astrophysics, 010306 general physics, business, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Instrumentation, Computer hardware
Abstract

The High Altitude Water Cherenkov observatory (HAWC) is an air shower array devised for TeV gamma-ray astronomy. HAWC is located at an altitude of 4100 m a.s.l. in Sierra Negra, Mexico. HAWC consists of 300 Water Cherenkov Detectors, each instrumented with 4 photomultiplier tubes (PMTs). HAWC re-uses the Front-End Boards from the Milagro experiment to receive the PMT signals. These boards are used in combination with Time to Digital Converters (TDCs) to record the time and the amount of light in each PMT hit (light flash). A set of VME TDC modules (128 channels each) is operated in a continuous (dead time free) mode. The TDCs are read out via the VME bus by Single-Board Computers (SBCs), which in turn are connected to a gigabit Ethernet network. The complete system produces ~ 500 MB/s of raw data. A high-throughput data processing system has been designed and built to enable real-time data analysis. The system relies on off-the-shelf hardware components, an open-source software technology for data transfers (ZeroMQ) and a custom software framework for data analysis (AERIE). Multiple trigger and reconstruction algorithms can be combined and run on blocks of data in a parallel fashion, producing a set of output data streams which can be analyzed in real time with minimal latency (< 5 s). This paper provides an overview of the hardware set-up and an in-depth description of the software design, covering both the TDC data acquisition system and the real-time data processing system. The performance of these systems is also discussed., 14 pages, 3 figures, submitted to Nucl. Instrum. Meth. A

Published
2018

24. 0106 The Effects of Caffeine on Blood Pressure and Cognitive Performance in Hypoxic Conditions on the Slopes of Mt. Everest

Author

P H Hackett, R R Wehling, T Musliu, S Acharya, K Sparks, Y Ozuru, S Baniya, and C M Jung

Subjects
medicine.medical_specialty, chemistry.chemical_compound, Blood pressure, chemistry, business.industry, Physiology (medical), Internal medicine, Cardiology, medicine, Neurology (clinical), Effects of sleep deprivation on cognitive performance, business, Caffeine
Abstract

Introduction 140 million people live above 2,400m worldwide. High altitude (HA) exposure can lead to sleep disruption, impaired cognitive performance, acute mountain sickness (AMS), elevated blood pressure (BP) and an increase in cardiovascular events in healthy people. Because caffeine can also increase BP, caffeine might need to be avoided at HA. Caffeine is the most widely used drug in the world but has yet to be studied extensively in hypoxic conditions. Therefore, the aim of the current study was to examine the effects of caffeine on cardiovascular variables and cognitive function at HA. Methods We conducted a non-randomized, single-blind, mixed model design at 4,300m on Mt. Everest. Thirty-three trekkers (nine females), aged 29.5±10.4 (mean±SD), ingested the study drug (placebo or 200 mg of caffeine) 1.5 hours after awakening. To control for withdrawal effects of caffeine, participants that self-reported consuming less than 47 mg of caffeine per day received the placebo while those that consumed more than that received caffeine. Cognitive function was tested using the Stroop task before and after the pill administration. BP was measured by a trained clinician using auscultatory method prior to and 30, 60 and 90 min after the pill administration. Results Caffeine improved cognitive performance when compared to the pretreatment measurement but was worse in the caffeine group prior to the pill administration when compared to the pretreatment placebo group. Additionally, caffeine did not have any major effect on BP when compared to pretreatment measures or the placebo group. Conclusion Caffeine does not seem to have an additive effect on increasing BP with HA. Additionally, because cognitive performance was worse in the chronic caffeine users prior to the pill administration, caffeine users might be more dependent on caffeine to perform optimally at HA. Based off of these data, caffeine seems to be a safe and beneficial drug at HA. Support NIH BUILD EXITO, University of Alaska Faculty Development Grant

Published
2020

25. Milagro limits and HAWC sensitivity for the rate-density of evaporating Primordial Black Holes

Author

Humberto Ibarguen Salazar, H. Martinez, J. Braun, Miguel Mostafa, B. Patricelli, Arnulfo Zepeda, Ibrahim Torres, J. McEnery, Varlen Grabski, H. León Vargas, R. Arceo, A. Marinelli, N. Bautista-Elivar, W.H. Lee, E. Moreno, V. Vasileiou, D.A. Williams, J.C. Arteaga-Velázquez, R. Noriega-Papaqui, C. M. Hui, A. A. Abdo, K. Sparks Woodle, F. Salesa, J. P. Harding, Michael DuVernois, Hao Zhou, P. Karn, R. A. Caballero-Lopez, Peter Nemethy, A. Sandoval, D. Berley, James M. Ryan, E. De la Fuente, Michael Schneider, T. Weisgarber, Fernando Garfias, Dirk Lennarz, Tyce DeYoung, E. Mendoza Torres, P.A. Toale, O. Martinez, S. Westerhoff, Petra Hüntemeyer, R. Diaz Hernandez, J. Martínez-Castro, Joshua A. Wood, Rodrigo Pelayo, B. T. Allen, E. Belmont, E. Ruiz-Velasco, A. Galindo, Z. Hampel-Arias, T. N. Ukwatta, A. J. Smith, Alberto Carramiñana, M. Bonilla Rosales, Alejandro Lara, Michael Newbold, J.H. MacGibbon, L. Nellen, Juan Carlos Diaz-Velez, R. Luna-GarcIa, C. M. Hoffman, D. W. Fiorino, C. Rivière, T. Aune, A. Imran, P.W. Younk, Segev BenZvi, J.A.J. Matthews, L. Villaseñor, J. A. Goodman, Ruben Alfaro, Daniel Rosa-Gonzalez, M. Gussert, C. De León, G. Sinnis, J. Becerra González, Daniel R. Stump, E.C. Linares, S.S. Marinelli, Jennifer Pretz, Anushka Udara Abeysekara, T. Morgan, Pedro Miranda-Romagnoli, A. Iriarte, P. M. Saz Parkinson, Jorge Cotzomi, M. Longo, Umberto Cotti, G.J. Kunde, T. Oceguera-Becerra, K. Tollefson, Maria Magdalena González, R. J. Lauer, E. Hays, D. Zaborov, Karen S. Caballero-Mora, H. A. Ayala Solares, J. D. Álvarez, G. B. Yodh, J. T. Linnemann, L. Diaz-Cruz, Allen Mincer, B. M. Baughman, A. S. Barber, G. E. Christopher, R. W. Ellsworth, S. Silich, B.E. Kolterman, M. Castillo, Nissim Illich Fraija, Brenda Dingus, I. Taboada, I.G. Wisher, R. W. Springer, E. G. Pérez-Pérez, C. Alvarez, and David Kieda

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Astronomy, FOS: Physical sciences, Primordial black hole, Astronomy and Astrophysics, Gamma-ray astronomy, Astrophysics, Black hole, Observatory, Milagro, Gamma-ray burst, Astrophysics - High Energy Astrophysical Phenomena, Cherenkov radiation
Abstract

Primordial Black Holes (PBHs) are gravitationally collapsed objects that may have been created by density fluctuations in the early universe and could have arbitrarily small masses down to the Planck scale. Hawking showed that due to quantum effects, a black hole has a temperature inversely proportional to its mass and will emit all species of fundamental particles thermally. PBHs with initial masses of ~5.0 x 10^14 g should be expiring in the present epoch with bursts of high-energy particles, including gamma radiation in the GeV - TeV energy range. The Milagro high energy observatory, which operated from 2000 to 2008, is sensitive to the high end of the PBH evaporation gamma-ray spectrum. Due to its large field-of-view, more than 90% duty cycle and sensitivity up to 100 TeV gamma rays, the Milagro observatory is well suited to perform a search for PBH bursts. Based on a search on the Milagro data, we report new PBH burst rate density upper limits over a range of PBH observation times. In addition, we report the sensitivity of the Milagro successor, the High Altitude Water Cherenkov (HAWC) observatory, to PBH evaporation events., Comment: Accepted to Astroparticle Physics Journal (25 Pages, 3 figures and 7 tables). Corresponding author: T. N. Ukwatta

Published
2015
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26. HAWC Contributions to the 34th International Cosmic Ray Conference (ICRC2015)

Author

HAWC Collaboration, Abeysekara, A. U., Alfaro, R., Alvarez, C., ��lvarez, J. D., Arceo, R., Arteaga-Vel��zquez, J. C., Solares, H. A. Ayala, Barber, A. S., Baughman, B. M., Bautista-Elivar, N., Gonzalez, J. Becerra, Becerril, A., Belmont, E., BenZvi, S. Y., Berley, D., Bernal, A., Braun, J., Caballero-Mora, K. S., Capistr��n, T., Carrami��ana, A., Castillo, M., Cotti, U., Cotzomi, J., de Le��n, S. Couti��o, de la Fuente, E., De Le��n, C., DeYoung, T., Hernandez, R. Diaz, Diaz-Cruz, L., D��az-V��lez, J. C., Dingus, B. L., DuVernois, M. A., Ellsworth, R. W., Engel, K., Enriquez-Rivera, O., Fick, B., Fiorino, D. W., Flores, J. L., Fraija, N., Garcia-Torales, G., Garfias, F., Gonz��lez, M. M., Goodman, J. A., Gussert, M., Hampel-Arias, Z., Hansen, P., Harding, J. Patrick, Hernandez, S., Hui, C. M., H��ntemeyer, P., Imran, A., Iriarte, A., Karn, P., Kieda, D., Kunde, G. J., Lara, A., Lauer, R. J., Lee, W. H., Lennarz, D., Vargas, H. Le��n, Linnemann, J. T., Proper, M. Longo, Raya, G. Luis, Luna-Garc��a, R., Malone, K., Marinelli, A., Marinelli, S. S., Martinez, H., Martinez, O., Mart��nez-Castro, J., Matthews, J. A. J., McEnery, J., Miranda-Romagnoli, P., Moreno, E., Mostaf��, M., Nellen, L., Newbold, M., Nisa, M. Un, Noriega-Papaqui, R., Oceguera-Becerra, T., Patricelli, B., Pelayo, R., P��rez-P��rez, E. G., Pretz, J., Ren, Z., Rho, C. D., Rivi��re, C., Rosa-Gonz��lez, D., Ryan, J., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Sinnis, G., Smith, A. J., Smith, A. W., Woodle, K. Sparks, Springer, R. W., Taboada, I., Tibolla, O., Toale, P. A., Tollefson, K., Torres, I., Ukwatta, T. N., Villase��or, L., Weisgarber, T., Westerhoff, S., Wisher, I. G., Wood, J., Yapici, T., Yodh, G. B., Younk, P. W., Zepeda, A., and Zhou, H.

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, High Energy Physics - Experiment (hep-ex), hep-ex, FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract

List of proceedings from the HAWC Collaboration presented at the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands., List of proceedings from the HAWC Collaboration presented at ICRC2015. Follow the "HTML" link to access the list

Published
2017

27. Leverage : Using PLCs to Promote Lasting Improvement in Schools

Author

Thomas W. Many, Susan K. Sparks-Many, Thomas W. Many, and Susan K. Sparks-Many

Subjects
Educational leadership--United States, Professional learning communities--United States, Educational change--United States
Abstract

Discover high-impact leadership strategies for a thriving learning community! Faced with the growing demands of leadership in today's schools, how can principals and teacher leaders ensure their actions will impact teaching and learning in positive ways? This compelling new book by Thomas Many and Susan Sparks-Many provides straightforward solutions for the complex challenges school leaders face. Discover how implementing a few specific high-leverage strategies, grounded in the core beliefs of Professional Learning Communities (PLCs), can promote lasting improvement in schools. This book's concrete examples of high-leverage, evidence-based practices help you: Understand the essential role principals and teacher leaders play in leading PLCs Foster an understanding of how PLCs can support implementation of major instructional shifts such as the new Common Core State Standards Apply high-leverage strategies across your own school and district to improve instruction and better serve the needs of all students You'll find invaluable self-assessment forms, templates, case studies, planning examples, and more. Use Leverage as your essential leadership tool to transform your school into a thriving learning community!'In Leverage, the authors craft a coherent and compelling argument for doing less but going deeper in support of school reform. A thoughtful sense of the literature informs approaches that we all need help with—how to integrate and align our efforts in supporting student success and how to do that in sustainable ways.'—Peter Dillon, Superintendent Berkshire Hills Regional School District, Stockbridge, MA'If you are wondering which items should be at the top of your priority list, read this book, after which you will truly know what is important and how to implement sustainable change in your school that will result in better student achievement.'—Jim Anderson, Principal Andersen Jr. High School, Chandler, AZ'This book addresses PRECISELY the tension that so many of us feel. The whole concept of leverage crystallizes what we′ve been wrestling with in our building.'—Ryan Giegling, Second-Grade Teacher Ganiard Elementary, Mt. Pleasant, MI

Published
2015

28. Search for TeV Gamma-Ray Emission from Point-like Sources in the Inner Galactic Plane with a Partial Configuration of the HAWC Observatory

Author

Karen S. Caballero-Mora, N. Bautista-Elivar, R. W. Springer, H. A. Ayala Solares, E. G. Pérez-Pérez, I. Torres, C. M. Hui, Lukas Nellen, O. Tibolla, C. Alvarez, David Kieda, Hao Zhou, P. Hüntemeyer, Segev BenZvi, B. M. Baughman, E. Moreno, J. Pretz, R. Alfaro, Fernando Garfias, Abel Bernal, Anushka Udara Abeysekara, Thomas Weisgarber, M. Newbold, C. Rivière, H. Martinez, M. Gussert, J.C. Arteaga-Velázquez, G. Luis Raya, O. Enríquez-Rivera, T. Yapici, L. Villaseñor, H. León Vargas, J. T. Linnemann, J. P. Harding, A. Zepeda, P. W. Younk, J. A. Goodman, R. Pelayo, G. Sinnis, A. Carraminana, A. S. Barber, J. Martínez-Castro, S. Hernandez, D. W. Fiorino, Dirk Lennarz, R. W. Ellsworth, A. D. Becerril Reyes, A. Iriarte, Humberto Ibarguen Salazar, D. Zaborov, James W. Wood, S. S. Marinelli, J. Braun, Ignacio Taboada, Brenda Dingus, M. Longo, B. Patricelli, W. H. Lee, Michael Schneider, I. G. Wisher, J. A. Matthews, Sabrina Casanova, Tyce DeYoung, A. Imran, J. Cotzomi, M. Mostafá, S. Westerhoff, J. D. Álvarez, Daniel Rosa-Gonzalez, Kirsten Tollefson, M. Castillo, Pedro Miranda-Romagnoli, G. B. Yodh, Maria Magdalena González, R. J. Lauer, Z. Ren, O. Martinez, R. Noriega-Papaqui, S. Coutiño de León, Alejandro Lara, Michael DuVernois, P. Karn, A. Sandoval, E. De la Fuente, E. Belmont, K. Vrabel, Z. Hampel-Arias, T. N. Ukwatta, K. Malone, U. Cotti, A. J. Smith, T. Capistrán, R. Arceo, F. Salesa Greus, C. De León, K. Sparks Woodle, A. Marinelli, and N. Fraija

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), HAWC - Abteilung Hinton, 010308 nuclear & particles physics, Point source, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Galactic plane, 01 natural sciences, Galaxy, Latitude, Space and Planetary Science, Observatory, 0103 physical sciences, Astrophysics - High Energy Astrophysical Phenomena, Longitude, 010303 astronomy & astrophysics, Cherenkov radiation
Abstract

A survey of the inner Galaxy region of Galactic longitude l in [+15, +50] degree and latitude b in [-4,+4] degree is performed using one-third of the High Altitude Water Cherenkov (HAWC) Observatory operated during its construction phase. To address the ambiguities arising from unresolved sources in the data, we use a maximum likelihood technique to identify point source candidates. Ten sources and candidate sources are identified in this analysis. Eight of these are associated with known TeV sources but not all have differential fluxes compatible with previous measurements. Three sources are detected with significances $>5\,\sigma$ after accounting for statistical trials, and are associated with known TeV sources., Comment: Submitted to ApJ, 34 pages, 6 figures. Contact authors: Hao Zhou and C. Michelle Hui

Published
2016

29. Deprioritization of heavy users in wireless networks

Author

Francis Dominique, Pantelis Monogioudis, P. Busschbach, Hai Zhou, Nandu Gopalakrishnan, James Paul Seymour, and K. Sparks

Subjects
Mobile radio, Radio access network, Wi-Fi array, Computer Networks and Communications, business.industry, Wireless network, Computer science, Quality of service, Wireless WAN, Bandwidth throttling, Computer Science Applications, Public land mobile network, Wireless site survey, Key distribution in wireless sensor networks, Cognitive radio, Electrical and Electronic Engineering, Radio resource management, business, Telecommunications, Municipal wireless network, Computer network
Abstract

The explosive demand for wireless data services that followed the introduction of application phones continues to create significant challenges for mobile operators. Measurement campaigns indicate that the consumption of wireless network capacity follows a power law where 20 percent of the users consume more than 80 percent of capacity. This creates unfairness among users in terms of the data volume they are allowed to consume and, more important, during congested periods of time it degrades the quality of experience of all the users. As a response, many operators are attempting to control demand by gradually moving away from unlimited data plans with the introduction of volume caps and tiered charging. Many operators throttle the heavy users after they have exceeded their cap, and consider doing the same during times of congestion. This article evaluates the concept of deprioritization of heavy users in wireless networks for congestion management, the difference between deprioritization and throttling, and the enabling technologies to implement the feature in real-world networks.

Published
2011

30. HYBRIDIZING 'MCINTOSH WIJCIK' AND HEAT-TOLERANT APPLE CULTIVARS TO DEVELOP PRECOCIOUS SEEDLING TREES WITH IMPROVED TREE ARCHITECTURE

Author

J. Daberkow, G. R. Welsh, Julia M. Harshman, Christopher S. Walsh, K. Sparks, and Michael J. Newell

Subjects
Horticulture, biology, Seedling, Tree architecture, Pink lady, Growing season, Preharvest, Cultivar, biology.organism_classification, Rootstock, Dwarfing
Abstract

This project began in 1991 with a cross between ‘McIntosh Wijcik’ and ‘Gala’ apples in an effort to develop a new apple cultivar that was well-suited to the Mid-Atlantic’s hot and humid growing season. The goal was to create a grower friendly cultivar that was dwarfing which would not require labor intensive methods of budding, pruning, and branch angle manipulation. A second cross made in 1999 between the ‘CompactGalaMac’ (CGMx) progeny of the 1991 cross and four commercial cultivars yielded progeny which had compact phenotype; field tolerance to diseases and pests; precocity and productivity; heat tolerance, fruit firmness and lack of preharvest drop typical of ‘Gala’; fruit taste attributes from both ‘Pink Lady’ and ‘Fuji’. These trees could potentially be grown on their own roots, avoiding the problems that accompany size-controlling rootstocks.

Published
2011

31. Enhancing teacher moral judgment in difficult political times: Swimming upstream

Author

Richard K. Sparks, Jacques S. Benninga, and Susan Tracz

Subjects
Politics, Value judgment, media_common.quotation_subject, Counterintuitive, Accountability, Pedagogy, Ethical dilemma, Academic achievement, Psychology, Metropolitan area, Democracy, Education, media_common
Abstract

Teachers at eight elementary schools in a large metropolitan school district participated in a multi-year program of professional ethical dilemma discussions that took place at monthly school meetings over a two-year or three-year period and focused on real-life situations faced by elementary school teachers. Discussions were structured using the Four Component Model of Moral Judgment. The DIT-2 served as a measure of moral judgment. Results proved to be counterintuitive; teacher moral judgment did not improve over time. We discuss the implications of promoting moral and democratic sensibilities at a time when American classrooms are tightly controlled and teachers held accountable for student performance on high stakes tests.

Published
2011

32. Standardized Colleagues in Pharmacy Education

Author

Lucas A. Berenbrok and Meredith K. Sparks

Subjects
Medical education, Letter, 020205 medical informatics, business.industry, MEDLINE, Pharmacy education, Pharmacy, 02 engineering and technology, General Medicine, Pharmacists, Education, 03 medical and health sciences, 0302 clinical medicine, Students, Pharmacy, Education, Pharmacy, Pharmaceutical Services, 0202 electrical engineering, electronic engineering, information engineering, Humans, 030212 general & internal medicine, General Pharmacology, Toxicology and Pharmaceutics, business, Psychology, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Abstract

To the Editor: We would like to thank Gillette and colleagues for their enlightening study titled “Improving Pharmacy Student Communication Outcomes Using Standardized Patients,” published in the August 2017 issue of the American Journal of Pharmaceutical Education . Gillette and colleagues

Published
2018

34. Necessary and Sufficient Conditions for High-Dimensional Posterior Consistency under $g$ -Priors

Author

Malay Ghosh, Douglas K. Sparks, and Kshitij Khare

Subjects
Statistics and Probability, Bayesian probability, hyper-g-prior, Mathematics - Statistics Theory, posterior consistency, Statistics Theory (math.ST), High dimensional, Bayesian inference, 01 natural sciences, 010104 statistics & probability, Consistency (statistics), 0502 economics and business, Prior probability, FOS: Mathematics, Applied mathematics, 0101 mathematics, 050205 econometrics, Mathematics, Applied Mathematics, 05 social sciences, g-prior, 16. Peace & justice, Euclidean distance, Sample size determination, empirical Bayes
Abstract

We examine necessary and sufficient conditions for posterior consistency under $g$-priors, including extensions to hierarchical and empirical Bayesian models. The key features of this article are that we allow the number of regressors to grow at the same rate as the sample size and define posterior consistency under the sup vector norm instead of the more conventional Euclidean norm. We consider in particular the empirical Bayesian model of George and Foster (2000), the hyper-$g$-prior of Liang et al. (2008), and the prior considered by Zellner and Siow (1980)., Comment: Published at http://dx.doi.org/10.1214/14-BA893 in the Bayesian Analysis (http://projecteuclid.org/euclid.ba) by the International Society of Bayesian Analysis (http://bayesian.org/)

Published
2015

36. Sensitivity of HAWC to high-mass dark matter annihilations

Author

A. S. Barber, A. Imran, T. Oceguera-Becerra, Kevork N. Abazajian, E. C. Linares, Rodrigo Pelayo, B. Patricelli, Petra Hüntemeyer, S. Westerhoff, R. W. Ellsworth, U. Cotti, S. Silich, D. Zaborov, Z. Hampel-Arias, T. N. Ukwatta, D. W. Fiorino, Brenda Dingus, K. Tollefson, L. Villaseñor, J. A. Goodman, A. J. Smith, O. Martinez, E. De la Fuente, R. Luna-Garcia, G. B. Yodh, Anushka Udara Abeysekara, C. De León, M. Castillo, R. W. Springer, E. G. Pérez-Pérez, L. Nellen, Daniel Rosa-Gonzalez, A. Galindo, F. E. Sanchez, E. Belmont, L. Diaz-Cruz, P. W. Younk, J. Pretz, Dirk Lennarz, M. Longo, C. Alvarez, B. M. Baughman, Juan Carlos Diaz-Velez, R. Arceo, David Kieda, Varlen Grabski, R. A. Caballero-Lopez, James M. Ryan, Michael DuVernois, D. Berley, Maria Magdalena González, R. J. Lauer, E. Mendoza Torres, H. Martinez, Tyce DeYoung, P. A. Toale, F. Salesa, Nissim Illich Fraija, J. D. Álvarez, Karen S. Caballero-Mora, Jesús Martínez-Castro, H. A. Ayala Solares, I. Torres, Joshua Wood, Colas Rivière, J. T. Linnemann, M. Bonilla Rosales, Michael Newbold, J. A.J. Matthews, A. Zepeda, Segev BenZvi, Jorge Cotzomi, R. Alfaro, M. Gussert, Pedro Miranda-Romagnoli, Gerd Joachim Kunde, I. Taboada, G. Sinnis, J. Becerra González, A. Sandoval, Michael Schneider, I. G. Wisher, J. P. Harding, Julie McEnery, A. Marinelli, Fernando Garfias, Thomas Weisgarber, Alberto Carramiñana, H. León Vargas, K. Sparks Woodle, Humberto Ibarguen Salazar, J. Braun, Miguel Mostafa, J.C. Arteaga-Velázquez, R. Diaz Hernandez, Arturo Iriarte, N. Bautista-Elivar, C. M. Hui, Hao Zhou, P. Karn, Alejandro Lara, R. Noriega-Papaqui, William H. Lee, and E. Moreno

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Nuclear and High Energy Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Annihilation, Astrophysics::High Energy Astrophysical Phenomena, Hot dark matter, Dark matter, Scalar field dark matter, FOS: Physical sciences, Astronomy, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galaxy, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Observatory, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, Dwarf galaxy
Abstract

The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19 degrees North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Spring 2015. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi- TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from non-luminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dark matter annihilation channels. If no gamma-ray excess is observed, we show the limits HAWC can place on the dark matter cross-section from these sources. In particular, in the case of dark matter annihilation into gauge bosons, HAWC will be able to detect a narrow range of dark matter masses to cross-sections below thermal. HAWC should also be sensitive to non-thermal cross-sections for masses up to nearly 1000 TeV. The constraints placed by HAWC on the dark matter cross-section from known sources should be competitive with current limits in the mass range where HAWC has similar sensitivity. HAWC can additionally explore higher dark matter masses than are currently constrained., Comment: 15 pages, 4 figures, version to be published in PRD

Published
2014

37. LOCUS OF CONTROL AND WELL-BEING AT WORK: HOW GENERALIZABLE ARE WESTERN FINDINGS?

Author

P. E. Spector, C. L. Cooper, J. I. Sanchez, M. O'Driscoll, K. Sparks, P. Bernin, A. Bossing, P. Dewe, P. Hart, L. Lu, K. Miller, L. R. De Moraes, G. M. Ostrognay, M. Pagon, H. D. Pitariu, S. A. Y. Poelmans, P. Radhakrishnan, V. Russinova, V. Salamatov, and J. F. Salgado

Subjects
Management of Technology and Innovation, Strategy and Management, Business and International Management, General Business, Management and Accounting
Published
2002

38. Observation of Small-scale Anisotropy in the Arrival Direction Distribution of TeV Cosmic Rays with HAWC

Author

B. M. Baughman, A. Carraminana, A. S. Barber, D. W. Fiorino, R. W. Ellsworth, A. Galindo, Fernando Garfias, Dirk Lennarz, M. Castillo, C. De León, Thomas Weisgarber, E. Ruiz-Velasco, D. Zaborov, H. León Vargas, Brenda Dingus, Arturo Iriarte, A. Imran, R. W. Springer, Gus Sinnis, B. Patricelli, G. B. Yodh, E. G. Pérez-Pérez, J. T. Linnemann, N. Bautista-Elivar, Maria Magdalena González, R. J. Lauer, R. Luna-Garcia, and H. Zhou, C. Alvarez, F. Salesa Greus, C. M. Hui, R. Arceo, Lukas Nellen, David Kieda, Petra Hüntemeyer, C. Rivière, Rodrigo Pelayo, Ruben Alfaro, Jorge Cotzomi, Z. Hampel-Arias, T. N. Ukwatta, P. W. Younk, J. P. Harding, U. Cotti, S. Westerhoff, P. Karn, Nissim Illich Fraija, L. Villaseñor, J. A. Goodman, A. J. Smith, Daniel Rosa-Gonzalez, E. De la Fuente, Pedro Miranda-Romagnoli, D. Berley, James M. Ryan, E. Belmont, Segev BenZvi, A. Sandoval, Tyce DeYoung, P. A. Toale, Anushka Udara Abeysekara, M. Gussert, Juan Carlos Diaz-Velez, E. Mendoza Torres, Michael Schneider, I. G. Wisher, I. Torres, Gerd Joachim Kunde, Joshua Wood, H. Martinez, Karen S. Caballero-Mora, R. Noriega-Papaqui, Jesús Martínez-Castro, William H. Lee, Arnulfo Zepeda, H. A. Ayala Solares, A. Marinelli, Jennifer Pretz, Kirsten Tollefson, I. Taboada, J. A. Matthews, Kelly Malone, S. S. Marinelli, J.C. Arteaga-Velázquez, Alejandro Lara, M. Bonilla Rosales, J. D. Álvarez, Michael Newbold, Michael DuVernois, O. Martinez, Julie McEnery, R. Diaz Hernandez, T. Oceguera-Becerra, K. Sparks Woodle, Humberto Ibarguen Salazar, J. Braun, Miguel Mostafa, M. Longo, and E. Moreno

Subjects
media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, Flux, FOS: Physical sciences, Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astronomy & Astrophysics, Atomic, Physical Chemistry, Particle and Plasma Physics, cosmic rays, Observatory, Nuclear, Cherenkov radiation, media_common, Astroparticle physics, Physics, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, Molecular, Astronomy and Astrophysics, Space and Planetary Science, Sky, astroparticle physics, Milagro, Astrophysics - High Energy Astrophysical Phenomena, Astronomical and Space Sciences, Physical Chemistry (incl. Structural)
Abstract

The High-Altitude Water Cherenkov (HAWC) Observatory is sensitive to gamma rays and charged cosmic rays at TeV energies. The detector is still under construction, but data acquisition with the partially deployed detector started in 2013. An analysis of the cosmic-ray arrival direction distribution based on $4.9\times 10^{10}$ events recorded between June 2013 and February 2014 shows anisotropy at the $10^{-4}$ level on angular scales of about $10^\circ$. The HAWC cosmic-ray sky map exhibits three regions of significantly enhanced cosmic-ray flux; two of these regions were first reported by the Milagro experiment. A third region coincides with an excess recently reported by the ARGO-YBJ experiment. An angular power spectrum analysis of the sky shows that all terms up to $\ell=15$ contribute significantly to the excesses., Comment: 12 pages, 11 figures. Accepted by The Astrophysical Journal

Published
2014
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39. VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory

Author

D. W. Fiorino, N. Bautista-Elivar, F. Ángeles, C. M. Hui, Umberto Cotti, Hao Zhou, I. Taboada, I. Cabrera, Petra Hüntemeyer, E. Moreno, T. Oceguera-Becerra, Jorge Cotzomi, J. Nava, Z. Hampel-Arias, P. Karn, T. N. Ukwatta, J. A.J. Matthews, A. J. Smith, A. Zepeda, Erika Benítez, Nissim Illich Fraija, O. Martinez, K. Sparks Woodle, R. Arceo, Colas Rivière, S. Tinoco, M. Longo, Michael DuVernois, J. T. Linnemann, F. Ruiz-Sala, Fernando Garfias, Arturo Iriarte, J. D. Álvarez, A. Bernal, Thomas Weisgarber, Varlen Grabski, E. Ruiz-Velasco, E. Belmont, D. Zaborov, R. Langarica, Alberto Carramiñana, H. León Vargas, Karen S. Caballero-Mora, A. Imran, R. W. Springer, W. Wall, A. Rentería, A. González, C. De León, R. Noriega-Papaqui, C. Badillo, K. Tollefson, E. G. Pérez-Pérez, A. Tepe, L. Nellen, Juan Carlos Diaz-Velez, Gerd Joachim Kunde, William H. Lee, I. Ramírez, C. Alvarez, Jesús Martínez-Castro, David Kieda, P. W. Younk, Ibrahim Torres, J. R. Sacahui, H. A. Ayala Solares, M. Martos, A. Galindo, Elton J. G. Santos, Dirk Lennarz, J. F. Valdés Galicia, M. Bonilla Rosales, Dany Page, E. C. Linares, E. De la Fuente, Michael Newbold, L. Castañeda-Martínez, James M. Ryan, B. Patricelli, G. B. Yodh, R. A. Caballero-Lopez, Alejandro Lara, D. Berley, L. Hernandez-Cervantes, E. Mendoza Torres, H. Martinez, F. Salesa, Luis Xavier Gonzalez, Tyce DeYoung, P. A. Toale, L. A. Martínez, Maria Magdalena González, R. J. Lauer, A. Fernandez, Pedro Miranda-Romagnoli, C. Guzmán-Ceron, G. Sinnis, J. Becerra González, Jennifer Pretz, Anushka Udara Abeysekara, Guillermo Garcia-Torales, Rodrigo Pelayo, A. Sandoval, Michael Schneider, I. G. Wisher, S. Westerhoff, A. Marinelli, P. Vanegas, J. P. Harding, A. S. Barber, R. W. Ellsworth, Joshua Wood, F. Suarez, Ruben Alfaro, Daniel Rosa-Gonzalez, A. Avila-Aroche, R. Luna-Garcia, Deborah Dultzin, Segev BenZvi, S. Silich, Brenda Dingus, M. Castillo, A. Diaz-Azuara, L. Diaz-Cruz, M. Gussert, B. M. Baughman, L. Villaseñor, J. A. Goodman, J.C. Arteaga-Velázquez, Julie McEnery, R. Diaz Hernandez, A. Vázquez, Humberto Ibarguen Salazar, J. Braun, G. Lara, and Miguel Mostafa

Subjects
Physics, media_common.quotation_subject, Detector, Gamma ray, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Data acquisition, Pathfinder, Observatory, Sky, Forbush decrease, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Cherenkov radiation, Remote sensing, media_common
Abstract

VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l. in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design, construction techniques and data acquisition system of the HAWC observatory. HAWC is an air-shower array currently under construction at the same site of VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water Cherenkov detectors and two different data acquisition systems. It was in operation between October 2011 and May 2012 with an average live time of 30%. Besides the scientific verification purposes, the eight months of data were used to obtain the results presented in this paper: the detector response to the Forbush decrease of March 2012, and the analysis of possible emission, at energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B., Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages, 10 figures). Corresponding authors: A.Marinelli and D.Zaborov

Published
2014
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40. Sensitivity of the High Altitude Water Cherenkov Detector to Sources of Multi-TeV Gamma Rays

Author

F. Salesa, Gerd J. Kunde, James M. Ryan, N. Bautista-Elivar, Ruben Alfaro, Dirk Lennarz, E. Moreno, Pedro Miranda-Romagnoli, D. W. Fiorino, S. Silich, Daniel Rosa-Gonzalez, Alejandro Lara, A. Imran, Michael DuVernois, Miguel Mostafá, C. M. Hui, Lukas Nellen, Hao Zhou, E. C. Linares, Kirsten Tollefson, E. Belmont, J. T. Linnemann, Fernando Garfias, J. D. Álvarez, Humberto Ibarguen Salazar, Guillermo Garcia-Torales, R. A. Caballero-Lopez, D. Berley, K. Sparks, R. Noriega-Papaqui, J. Braun, Maria Magdalena González, R. J. Lauer, M. Castillo, William H. Lee, Juan Carlos Diaz-Velez, Thomas Weisgarber, J. Pretz, Luis Xavier Gonzalez, Tyce DeYoung, P. A. Toale, V. Grabski, P. Karn, J. A. Matthews, Arturo Iriarte, Segev BenZvi, M. Longo, R. Diaz Hernandez, I. Taboada, Jesús Martínez-Castro, H. A. Ayala Solares, S. Westerhoff, I. Torres, Joshua Wood, P. W. Younk, A. Fernandez, Elton J. G. Santos, A. Galindo, M. Bonilla Rosales, M. Gussert, Michael Newbold, E. De la Fuente, J.C. Arteaga-Velázquez, Colas Rivière, H. León Vargas, D. Zaborov, Jorge Cotzomi, G. B. Yodh, B. M. Baughman, Anushka Udara Abeysekara, L. Villaseñor, J. A. Goodman, R. Pelayo, A. Carraminana, A. S. Barber, G. Sinnis, B. Patricelli, R. W. Ellsworth, Jose Luis García-Luna, R. Luna-García, Brenda Dingus, Nissim Illich Fraija, R. W. Springer, E. G. Pérez-Pérez, C. Alvarez, David Kieda, Petra Hüntemeyer, J. Nava, Z. Hampel-Arias, T. N. Ukwatta, O. Martinez, U. Cotti, R. Arceo, A. J. Smith, C. De León, A. Sandoval, Michael Schneider, I. G. Wisher, Arnulfo Zepeda, A. Marinelli, and T. Oceguera-Becerra

Subjects
Cherenkov detector, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, Astrophysics, Atomic, law.invention, Particle and Plasma Physics, law, Observatory, Nuclear, Cherenkov radiation, media_common, Physics, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), Detector, Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Molecular, Astronomy and Astrophysics, Nuclear & Particles Physics, Particle acceleration, TeV gamma-ray astronomy, Water cherenkov, Sky, Astrophysics - High Energy Astrophysical Phenomena, Astronomical and Space Sciences
Abstract

The High Altitude Water Cherenkov (HAWC) observatory is an array of large water Cherenkov detectors sensitive to gamma rays and hadronic cosmic rays in the energy band between 100 GeV and 100 TeV. The observatory will be used to measure high-energy protons and cosmic rays via detection of the energetic secondary particles reaching the ground when one of these particles interacts in the atmosphere above the detector. HAWC is under construction at a site 4100 meters above sea level on the northern slope of the volcano Sierra Negra, which is located in central Mexico at 19 ° N latitude. It is scheduled for completion in 2014. In this paper we estimate the sensitivity of the HAWC instrument to point-like and extended sources of gamma rays. The source fluxes are modeled using both unbroken power laws and power laws with exponential cutoffs. HAWC, in one year, is sensitive to point sources with integral power-law spectra as low as 5 × 10 - 13 cm - 2 sec - 1 above 2 TeV (approximately 50 mCrab) over 5 sr of the sky. This is a conservative estimate based on simple event parameters and is expected to improve as the data analysis techniques are refined. We discuss known TeV sources and the scientific contributions that HAWC can make to our understanding of particle acceleration in these sources.

Published
2013
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41. First Measurement of theB→πℓνandB→ρ(ω)ℓνBranching Fractions

Author

R. Ammar, T. E. Coan, I. C. Lai, H. Severini, S. Chan, Anders Ryd, M. Athanas, Sz Márka, S. Nakanishi, D. He, C. O'Grady, E. H. Thorndike, W. R. Ross, D. Coppage, G. Bonvicini, J. P. Alexander, T. Liu, R. Wang, J. J. Thaler, S. Kotov, I. Volobouev, John Yelton, C. Bebek, Harold S. Park, Alice Bean, R. Janicek, N. Kwak, R. Kutschke, M. Bishai, M. Ogg, D. B. MacFarlane, A. J. Weinstein, Tomasz Skwarnicki, M. Lohner, V. Savinov, J. Urheim, A. Soffer, S. Menary, Daniel W. Bliss, M. Sung, D. Roberts, H. N. Nelson, S. J. Richichi, Kenneth Bloom, J. J. O'Neill, D. L. Kreinick, S. Anderson, D. Cinabro, B. Nemati, D. Fujino, Sheldon Stone, Dave Britton, M. Yurko, N. Katayama, J. Mevissen, A. Undrus, P. C. Kim, A. Freyberger, D. S. Crowcroft, J. Kandaswamy, B. Gittelman, G. Eigen, V. Shelkov, S. E. Csorna, Paul Avery, D. J. Dumas, M. Dickson, I. J. Kim, F. R. Wappler, Yurii V. Mukhin, T. E. Browder, Richard Wilson, Philip Baringer, H. A. Cho, M.A. Palmer, C.Y. Prescott, Jungil Lee, Shengfeng Yang, Karl Berkelman, A. Efimov, D. Peterson, C. Qiao, P. Skubic, A. H. Mahmood, A. Smith, K. Kinoshita, T. Lee, M. Schmidtler, G. W. Brandenburg, Xiangjun Xing, I. Narsky, Y. Kwon, L. Gibbons, K. W. McLean, Yurii Maravin, B. H. Behrens, C. Ward, D. L. Hartill, Jianqiao Ye, I. Korolkov, S. Roberts, N. Copty, R. Poling, D. Z. Besson, J. Gronberg, M. Battle, H. Kagan, Z. Ling, B. C. Barish, S.C. Timm, R. Mountain, I. P.J. Shipsey, M. Chadha, C. R. Ng, C. D. Jones, P. S. Drell, R. Elia, J. Roy, K. Lingel, M. Saulnier, D. G. Cassel, Michael S. Witherell, D. H. Miller, Dj Lange, J. L. Rodriguez, S. F. Schaffner, R. Greene, T. K. Nelson, Ryszard Stroynowski, J. Ernst, B. E. Berger, J. Staeck, I. Karliner, M. Goldberg, H. Yamamoto, R. Davis, P. Rankin, K. K. Gan, Sacha E Kopp, P. Gaidarev, Frank Würthwein, K. Cho, D. Gibaut, N. B. Mistry, M. M. Zoeller, R. J. Morrison, G. E. Gladding, B. I. Eisenstein, M. S. Alam, R. Wanke, Mats A Selen, M. Gao, S. Patton, H. P. Paar, G. Masek, F. Li, Juliet Ritchie Patterson, K. Honscheid, A. J. Sadoff, J. S. Miller, J. Masui, C. M. Korte, K. Sparks, J. Fast, H. Tajima, R. Fulton, J. E. Duboscq, D. Riley, Christopher G. White, H. Marsiske, Vivek Jain, A. Wolf, R. A. Briere, M. Lattery, D. M. Asner, E. Gerndt, V. Fadeyev, K. W. Edwards, E. Nordberg, Jeffrey Richman, W. T. Ford, J. Bartelt, R. D. Kass, Marina Artuso, R. Balest, G. S. Ludwig, N. Hancock, T. Bergfeld, D. M. Coffman, B. K. Heltsley, S. B. Athar, M. L. Perl, G. D. Gollin, Yuichi Kubota, R. Ehrlich, Alain Bellerive, S. L. Jones, P. M. Patel, W. S. Brower, P. Pomianowski, Ilya Kravchenko, Michael Wood, J. W. Hinson, T. Riehle, S. W. Gray, S. Schrenk, Yanwen Liu, J. G. Smith, C. P. Jessop, S. D. Johnson, G. C. Moneti, and E. I. Shibata

Subjects
Physics, Combinatorics, Isospin, General Physics and Astronomy, Omega
Abstract

CLEO has studied $B$ decays to $\ensuremath{\pi}\ensuremath{\ell}\ensuremath{\nu}$, $\ensuremath{\rho}\ensuremath{\ell}\ensuremath{\nu}$, and $\ensuremath{\omega}\ensuremath{\ell}\ensuremath{\nu}$, where $\ensuremath{\ell}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}eor\ensuremath{\mu}$, by incorporating the missing momentum into full $B$ reconstruction. With the ${B}^{0}$ and ${B}^{+}$ modes combined according to isospin predictions for the relative partial widths, we obtain $B({B}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}\ensuremath{\nu})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}(1.8\ifmmode\pm\else\textpm\fi{}0.4\ifmmode\pm\else\textpm\fi{}0.3\ifmmode\pm\else\textpm\fi{}0.2)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and $B({B}^{0}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{\ensuremath{-}}{\ensuremath{\ell}}^{+}\ensuremath{\nu})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}(2.5\ifmmode\pm\else\textpm\fi{}{0.4}_{\ensuremath{-}0.7}^{+0.5}\ifmmode\pm\else\textpm\fi{}0.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$, where the errors are statistical, systematic, and the estimated model dependence. We also estimate $|{V}_{\mathrm{ub}}|\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}(3.3\ifmmode\pm\else\textpm\fi{}{0.2}_{\ensuremath{-}0.4}^{+0.3}\ifmmode\pm\else\textpm\fi{}0.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$.

Published
1996

42. Rapid, Reliable Microwave Modification of Steiner Silver Impregnation Method for Diagnosis of Spirochetes and Non-filamentous Bacteria

Author

Candace K. Sparks, Christopher P. Crum, and David R. Genest

Subjects
Histology, Treponema, Chromatography, Materials science, biology, Segmented filamentous bacteria, biology.organism_classification, Microbiology, Staining, Medical Laboratory Technology, Microwave irradiation, Anatomy, Cat scratch, Silver impregnation, Microwave, Bacteria
Abstract

A microwave modification of the Steiner silver impregnation method is presented for the demonstration of spirochetes and non-filamentous bacteria. The technique, which uses a 45°C waterbath for reduction and microwave irradiation for sensitizing and impregnation, will consistently produce unequivocal staining of spirochetes and non-filamentous bacteria in less than 60 minutes. Consistency and speed are dependent upon the acid clean glassware, fresh solutions, exact timing and temperature of reduction step, and microwave technique. In view of the increased demand for excluding infections by treponema, borellia, and non-filamentous bacteria (such as cat scratch and Legionella pneumophilla), this technique has become an integral and routine procedure. It can be particularly useful in reducing technician and turn-around time in the laboratory. (The J Histotechnol 18:315, 1995).

Published
1995

43. Measurement of the cross section for γγ→pp¯

Author

J. Whitmore, K. Lingel, C. Bebek, Jungil Lee, M. Sivertz, T. E. Browder, Robert Wilson, David Sperka, H. Tajima, R. Ehrlich, J. S. Miller, S. L. Jones, H. Worden, M. Thulasidas, H. A. Cho, M. Kelly, D. G. Cassel, J. Dominick, Sheldon Stone, J. Mevissen, V. Shelkov, K. Sparks, S. J. Patton, Paul Avery, D. Cinabro, R. Kennett, Yoram Rozen, J. Kandaswamy, N. Horwitz, J. Masui, M. Chadha, Philip Baringer, S. Ball, V. Savinov, Cong Wang, Shengfeng Yang, J. A. Ernst, B. Gittelman, C. R. Ng, Shawn W. Henderson, Michael S. Witherell, J. Gronberg, H. P. Paar, R. Fulton, D. Peterson, X. Fu, Daniela Bortoletto, M. S. Alam, D. F. Cowen, M.K. Sung, I. J. Kim, D. H. Miller, J. Urheim, N. Katayama, Marina Artuso, R. Poling, D. S. Akerib, E. H. Thorndike, N. Hancock, Y. Skovpen, R. Davis, John Yelton, John E. Bartelt, G.R. Kalbfleisch, Robert K. Kutschke, G. Eigen, D. Z. Besson, P. Zadorozhny, R. L. Malchow, Christopher G. White, D. Coppage, Karl Berkelman, B. Ong, M. Daoudi, J. P. Alexander, M. Garcia-Sciveres, F. Muheim, D. L. Hartill, C. R. Sun, W. T. Ford, S. Sanghera, Pu Wang, J. L. Rodriguez, M. Sapper, S. Roberts, R. D. Kass, Anders Ryd, M. Athanas, R. Stephens, E. Nordberg, S. E. Csorna, Darin Acosta, Daniel Schmidt, G. S. Ludwig, D. R. Johnson, R. Balest, Frank Würthwein, Vipul Jain, K. Cho, G. Vasseur, J. Fast, B. Geiser, N. B. Mistry, F. Butler, B. Nemati, S. Schrenk, K. Kinoshita, R. S. Galik, N. Copty, Ryszard Stroynowski, W. R. Ross, D. Fujino, K. Honscheid, D. He, N. Kwak, G. Masek, Juliet Ritchie Patterson, P. Skubic, S. Nakanishi, T. Liu, M. Modesitt, E. I. Shibata, C. O'Grady, P. Rankin, Glen D. Crawford, Alice Bean, M. Procario, R. L. McIlwain, H. Kagan, M. Battle, H. N. Nelson, A. P. Freyberger, F. Shen, Horst Severini, A. J.R. Weinstein, S. Playfer, Ha Lam, J. D. Richman, M. Ogg, D. Riley, M. Lohner, J. J. O'Neill, R. J. Morrison, G. Zhu, Hubert Kroha, Mats A Selen, T. Miao, A. J. Sadoff, D. M. Coffman, M. Lattery, B. C. Barish, B. K. Heltsley, J. Snow, Paul Sheldon, Yuichi Kubota, H. Yamamoto, R. Ammar, P. L. Wang, T. K. Nelson, R. Wang, P. S. Drell, S. Chan, M. Saulnier, F. Morrow, Z. Egyed, Igor Volobouev, M. M. Zoeller, P. Wilson, K. K. Gan, T. Skwarnicki, P. C. Kim, S. Menary, M. Goldberg, G. C. Moneti, S.F. Schaffner, Yurii V. Mukhin, S. W. Gray, D. Perticone, M. Lambrecht, D. N. Brown, I. P. J. Shipsey, S. Salman, Janice Nelson, C. D. Jones, Michael Wood, J. G. Smith, C. M. Daubenmier, and D. L. Kreinick

Subjects
Nuclear physics, Physics, Cross section (physics), Particle physics
Published
1994

44. Measurement of two-photon production of theχc2

Author

T. Liu, M. Modesitt, A. P. Freyberger, H. N. Nelson, J. Snow, S. Roberts, N. Katayama, M. Garcia-Sciveres, Vipul Jain, D. S. Akerib, J. G. Smith, K. Lingel, M. Sivertz, G. Eigen, N. Kwak, Ryszard Stroynowski, D. Fujino, D. L. Kreinick, C. Bebek, H. Worden, D. G. Cassel, T. K. Nelson, Robert Wilson, K. Sparks, S. J. Patton, D. Perticone, P. Rankin, T. E. Browder, R. L. Malchow, D. Z. Besson, R. Poling, Igor Volobouev, M. M. Zoeller, J. Urheim, Marina Artuso, J. Dominick, M. Lambrecht, D. N. Brown, Christopher G. White, R. L. McIlwain, P. Zadorozhny, M. Daoudi, J. L. Rodriguez, J. Gronberg, I. P. J. Shipsey, V. Savinov, H. P. Paar, R. Fulton, B. Nemati, S. Menary, C. R. Sun, F. Shen, W. T. Ford, D. H. Miller, R. D. Kass, Anders Ryd, M. Athanas, S. Salman, Janice Nelson, C. D. Jones, Michael Wood, David Sperka, Frank Würthwein, K. Cho, P. S. Drell, M. Battle, R. Balest, A. J.R. Weinstein, N. B. Mistry, M. Daubenmeir, Shengfeng Yang, E. Nordberg, Ha Lam, J. D. Richman, M. S. Alam, W. R. Ross, S. Schrenk, G. S. Ludwig, M. Saulnier, F. Morrow, P. Wilson, D. F. Cowen, H. Kagan, R. Davis, D. He, M. Lattery, E. I. Shibata, M. Kelly, J. Mevissen, John E. Bartelt, G.R. Kalbfleisch, B. C. Barish, H. Yamamoto, E. H. Thorndike, D. M. Coffman, F. Muheim, D. R. Johnson, D. Cinabro, R. Kennett, B. K. Heltsley, J. Masui, J. Kandaswamy, J. A. Ernst, D. Peterson, D. Coppage, J. P. Alexander, B. Gittelman, T. Miao, R. Stephens, S. E. Csorna, D. Riley, S. Playfer, R. Wang, F. Butler, K. Kinoshita, I. J. Kim, N. Hancock, Y. Skovpen, Sheldon Stone, Paul Avery, R. Ammar, K. K. Gan, R. S. Galik, T. Skwarnicki, S. W. Gray, M. Sapper, S. Chan, R. J. Morrison, B. Geiser, Paul Sheldon, P. C. Kim, Yuichi Kubota, S. Sanghera, Pu Wang, M. Lohner, Darin Acosta, J. Whitmore, Jungil Lee, J. J. O'Neill, Mats A Selen, A. J. Sadoff, M. Goldberg, G. C. Moneti, N. Horwitz, M. Chadha, S.F. Schaffner, V. Shelkov, Cong Wang, John Yelton, M. Ogg, G. Zhu, Robert K. Kutschke, D. L. Hartill, Daniel Schmidt, J. Fast, Karl Berkelman, N. Copty, Glen D. Crawford, Z. Egyed, Shawn W. Henderson, X. Fu, B. Ong, G. Vasseur, Yurii V. Mukhin, P. Skubic, S. Nakanishi, G. Masek, Juliet Ritchie Patterson, M. Procario, K. Honscheid, P. L. Wang, Horst Severini, Hubert Kroha, H. A. Cho, Daniela Bortoletto, C. R. Ng, Michael S. Witherell, M.K. Sung, Yoram Rozen, Philip Baringer, S. Ball, H. Tajima, R. Ehrlich, S. L. Jones, J. S. Miller, M. Thulasidas, Alice Bean, and C. O'Grady

Subjects
Physics, Statistics::Theory, Particle physics, Particle decay, Muon, Statistics::Applications, Meson, Hadron, Perturbative QCD, High Energy Physics::Experiment, Production (computer science), Elementary particle, Quarkonium
Abstract

The CLEO II detector is used to search for the production of ${\mathrm{\ensuremath{\chi}}}_{\mathit{c}2}$ states in two-photon interactions. We use the signature ${\mathrm{\ensuremath{\chi}}}_{\mathit{c}2}$\ensuremath{\rightarrow}\ensuremath{\gamma}J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\gamma}${\mathit{l}}^{+}$${\mathit{l}}^{\mathrm{\ensuremath{-}}}$ with l=e,\ensuremath{\mu}. Using 1.49 ${\mathrm{fb}}^{\mathrm{\ensuremath{-}}1}$ of data taken with beam energies near 5.29 GeV, the two-photon width of the ${\mathrm{\ensuremath{\chi}}}_{\mathit{c}2}$ is determined to be \ensuremath{\Gamma}(${\mathrm{\ensuremath{\chi}}}_{\mathit{c}2}$\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma})=1.08\ifmmode\pm\else\textpm\fi{}0.30(stat)\ifmmode\pm\else\textpm\fi{}0.26(syst) keV, in agreement with predictions from perturbative QCD.

Published
1994

45. First measurement ofΓ(Ds+→μ+ν)Γ(Ds+→φπ+)

Author

D. Acosta, M. Athanas, G. Masek, H. Paar, A. Bean, J. Gronberg, R. Kutschke, S. Menary, R. J. Morrison, S. Nakanishi, H. N. Nelson, T. K. Nelson, J. D. Richman, A. Ryd, H. Tajima, D. Schmidt, D. Sperka, M. S. Witherell, M. Procario, S. Yang, R. Balest, K. Cho, M. Daoudi, W. T. Ford, D. R. Johnson, K. Lingel, M. Lohner, P. Rankin, J. G. Smith, J. P. Alexander, C. Bebek, K. Berkelman, D. Besson, T. E. Browder, D. G. Cassel, H. A. Cho, D. M. Coffman, P. S. Drell, R. Ehrlich, R. S. Galik, M. Garcia-Sciveres, B. Geiser, B. Gittelman, S. W. Gray, D. L. Hartill, B. K. Heltsley, C. D. Jones, S. L. Jones, J. Kandaswamy, N. Katayama, P. C. Kim, D. L. Kreinick, G. S. Ludwig, J. Masui, J. Mevissen, N. B. Mistry, C. R. Ng, E. Nordberg, M. Ogg, J. R. Patterson, D. Peterson, D. Riley, S. Salman, M. Sapper, H. Worden, F. Würthwein, P. Avery, A. Freyberger, J. Rodriguez, R. Stephens, J. Yelton, D. Cinabro, S. Henderson, K. Kinoshita, T. Liu, M. Saulnier, F. Shen, R. Wilson, H. Yamamoto, B. Ong, M. Selen, A. J. Sadoff, R. Ammar, S. Ball, P. Baringer, D. Coppage, N. Copty, R. Davis, N. Hancock, M. Kelly, N. Kwak, H. Lam, Y. Kubota, M. Lattery, J. K. Nelson, S. Patton, D. Perticone, R. Poling, V. Savinov, S. Schrenk, R. Wang, M. S. Alam, I. J. Kim, B. Nemati, J. J. O'Neill, H. Severini, C. R. Sun, M. M. Zoeller, G. Crawford, C. M. Daubenmier, R. Fulton, D. Fujino, K. K. Gan, K. Honscheid, H. Kagan, R. Kass, J. Lee, R. Malchow, F. Morrow, Y. Skovpen, M. Sung, C. White, J. Whitmore, P. Wilson, F. Butler, X. Fu, G. Kalbfleisch, M. Lambrecht, W. R. Ross, P. Skubic, J. Snow, P. L. Wang, M. Wood, D. Bortoletto, D. N. Brown, J. Fast, R. L. McIlwain, T. Miao, D. H. Miller, M. Modesitt, S. F. Schaffner, E. I. Shibata, I. P. J. Shipsey, P. N. Wang, M. Battle, J. Ernst, H. Kroha, S. Roberts, K. Sparks, E. H. Thorndike, C. H. Wang, J. Dominick, S. Sanghera, V. Shelkov, T. Skwarnicki, R. Stroynowski, I. Volobouev, P. Zadorozhny, M. Artuso, D. He, M. Goldberg, N. Horwitz, R. Kennett, G. C. Moneti, F. Muheim, Y. Mukhin, S. Playfer, Y. Rozen, S. Stone, M. Thulasidas, G. Vasseur, G. Zhu, J. Bartelt, S. E. Csorna, Z. Egyed, V. Jain, P. Sheldon, D. S. Akerib, B. Barish, M. Chadha, S. Chan, D. F. Cowen, G. Eigen, J. S. Miller, C. O'Grady, J. Urheim, and A. J. Weinstein

Subjects
Physics, Combinatorics, Particle physics, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Pi
Abstract

We present a measurement of [Gamma]([ital D][sub [ital s]][sup +][r arrow][mu][sup +][nu])/[Gamma]([ital D][sub [ital s]][sup +][r arrow][phi][pi][sup +])= 0.245[plus minus]0.052[plus minus]0.074. Using this ratio and [ital scrB]([ital D][sub [ital s]][sup +][r arrow][phi][pi][sup +])=(3.7[plus minus]0.9)% we extract [ital f][sub [ital D][ital s]]=344[plus minus]37[plus minus]52[plus minus]42 MeV, where the last error is due to the uncertainty in the [ital D][sub [ital s]][sup +][r arrow][phi][pi][sup +] absolute branching ratio. This result is larger than most theoretical predictions.

Published
1994

46. Observation ofΛc+ decays to Λπ+π0, Σ0π+, Σ0π+π0, and Σ0π−π+π+

Author

P. Zadorozhny, F. Muheim, B. Nemati, F. Morrow, D. Besson, T. K. Nelson, P. S. Drell, S. Nakanishi, H. Kagan, E. H. Thorndike, D. N. Brown, S. Playfer, Jorge Luis Rodriguez, D. Riley, M. Saulnier, D. Coppage, S. F. Schaffner, J. Bartelt, J. P. Alexander, Anders Ryd, M. Athanas, K. Sparks, R. J. Morrison, Mats A Selen, H. A. Cho, A. J. Sadoff, D. He, Yuichi Kubota, D. Fujino, J. J. O'Neill, D. L. Hartill, M. Sapper, T. E. Browder, W. R. Ross, Daniel Schmidt, Richard Wilson, R. Kennett, R. Poling, C. R. Ng, Yurii V. Mukhin, M. S. Alam, B. Gittelman, I. Volobouev, Michael S. Witherell, G. C. Moneti, Marina Artuso, P. Wilson, A. J. Weinstein, J. Ernst, I. J. Kim, R. Stephens, G. Crawford, M. Lattery, J. Urheim, H. N. Nelson, S. E. Csorna, E. I. Shibata, P. Skubic, D. M. Coffman, B. K. Heltsley, N. Kwak, K. Kinoshita, Daniela Bortoletto, N. Copty, I. P.J. Shipsey, C. R. Sun, F. Butler, W. T. Ford, K. Cho, R. Malchow, D. Cinabro, R. D. Kass, R. Balest, N. B. Mistry, J. Whitmore, Jungil Lee, S. Menary, B. Geiser, John Yelton, J. Gronberg, S. Patton, N. Horwitz, R. L. McIlwain, M. Chadha, D. H. Miller, F. Shen, R. Davis, H. P. Paar, R. Fulton, Maurice Garcia-Sciveres, R. Ammar, G. Masek, V. Shelkov, S. Schrenk, M. Lohner, D. Acosta, Juliet Ritchie Patterson, J. Mevissen, Daniel Johnson, X. Fu, T. Liu, T. Skwarnicki, M. Daoudi, J. Kandaswamy, Sheldon Stone, S. Sanghera, H. Severini, S. Chan, C. Bebek, Paul Avery, D. L. Kreinick, M. L. Kelly, K. K. Gan, Y. Skovpen, P. C. Kim, S. Henderson, N. Hancock, D. Peterson, A. P. Freyberger, C. O'Grady, George R. Kalbfleisch, S. W. Gray, K. Honscheid, H. Tajima, Hubert Kroha, S. Roberts, J. Snow, Pu Wang, M. Modesitt, M. Battle, M. Sung, E. Nordberg, Jeffrey Richman, G. S. Ludwig, M. M. Zoeller, Karl Berkelman, J. G. Smith, D. G. Cassel, M. Ogg, G. Zhu, T. Miao, K. Lingel, M. Procario, S. Salman, Michael Wood, H. Worden, M. Lambrecht, A. Bean, J. K. Nelson, S. Yang, B. Ong, J. Fast, Christopher G. White, Z. Egyed, D. Sperka, Ruifang Wang, D. F. Cowen, P. L. Wang, C. M. Daubenmier, Ryszard Stroynowski, P. Rankin, Chunjie Wang, D. Perticone, V. Savinov, Yoram Rozen, F. Würthwein, Philip Baringer, S. Ball, J. S. Miller, M. Thulasidas, R. Ehrlich, N. Katayama, S. L. Jones, D. S. Akerib, J. Dominick, G. Eigen, R. Kutschke, H. Yamamoto, Ha Lam, G. Vasseur, B. C. Barish, J. Masui, Vivek Jain, C. D. Jones, and M. Goldberg

Subjects
Nuclear physics, Baryon, Physics, Nuclear and High Energy Physics, Argus, Particle physics, Branching fraction, Branching (polymer chemistry), computer, computer.programming_language
Abstract

We have observed the previously unseen decay modes Λπ+π0, Σ0π+π0 and Σ0π−π+π+ of the charmed baryon Λc+, as well as Λc+→Σ0π+ observed previously by ARGUS. The branching ratios for these four decay modes relative to Λc+→pK−π+ are measured to be 0.73 ±0.09± 0.16, 0.36 ±0.09±0.10, 0.21±0.05±0.05, and 0.21±0.02 ±0.04, respectively. Using the recent CLEO measurement of the branching ratio for Λc+→pK− π+, these modes account for 6% of Λc+ decays.

Published
1994

47. Analysis of hadronic transitions inϒ(3S)decays

Author

M. Procario, D. Fujino, J. J. O'Neill, T. Liu, C. Bebek, B. Nemati, Yurii V. Mukhin, A. P. Freyberger, A. J. Weinstein, Z. Egyed, F. Morrow, D. Besson, George R. Kalbfleisch, H. N. Nelson, S. Salman, Michael Wood, F. Butler, I. P.J. Shipsey, J. Urheim, M. Daoudi, J. Snow, D. Sperka, Ruifang Wang, R. Malchow, R. Ehrlich, J. Mevissen, K. Cho, N. B. Mistry, J. Kandaswamy, D. Cinabro, John Yelton, D. Peterson, H. Tajima, Sheldon Stone, S. L. Jones, J. Dominick, Paul Avery, S. Patton, K. K. Gan, T. Skwarnicki, D. F. Cowen, H. Kagan, K. Lingel, M. Sivertz, S. Nakanishi, E. H. Thorndike, Daniela Bortoletto, N. Copty, P. C. Kim, S. Henderson, M. Goldberg, W. R. Ross, D. Acosta, G. C. Moneti, Daniel Johnson, D. Perticone, M. Modesitt, V. Savinov, K. Sparks, P. L. Wang, H. Worden, D. Coppage, J. P. Alexander, Yoram Rozen, F. Würthwein, C. M. Daubenmier, Y. I. Skovpen, R. J. Morrison, Mats A Selen, Ryszard Stroynowski, M. Lambrecht, T. K. Nelson, Philip Baringer, Marina Artuso, D. M. Coffman, B. Ong, A. J. Sadoff, C. R. Sun, W. T. Ford, H. P. Paar, R. D. Kass, B. K. Heltsley, J. G. Smith, R. Fulton, S. Ball, R. Balest, D. He, P. Rankin, M. Sapper, D. L. Hartill, M. Chandha, T. E. Browder, J. S. Miller, M. Ogg, G. Zhu, J. Fast, D. Riley, R. S. Galik, R. Kutschke, Christopher G. White, D. L. Kreinick, Chunjie Wang, E. Nordberg, Daniel Schmidt, M. Thulasidas, R. Davis, S. F. Schaffner, J. Bartelt, G. S. Ludwig, S. Sanghera, P. Wilson, S. Roberts, R. Ammar, M. Battle, N. Hancock, M. L. Kelly, H. Yamamoto, Paul Sheldon, Yuichi Kubota, G. Crawford, H. Severini, S. Chan, S. W. Gray, P. Skubic, K. Honscheid, Richard Wilson, C. O'Grady, M. M. Zoeller, T. Miao, N. Katayama, D. S. Akerib, G. Eigen, J. Whitmore, Jungil Lee, M. Sung, D. H. Miller, X. Fu, R. Stephens, S. E. Csorna, K. Kinoshita, E. I. Shibata, N. Kwak, S. Menary, R. L. McIlwain, F. Shen, S. Schrenk, F. Muheim, D. N. Brown, S. Playfer, M. S. Alam, J. Ernst, M. Lattery, Pu Wang, Karl Berkelman, Anders Ryd, M. Athanas, J. Gronberg, N. Horwitz, G. Masek, Juliet Ritchie Patterson, A. Bean, J. K. Nelson, S. Yang, Hubert Kroha, H. A. Cho, Ha Lam, J. D. Richman, R. Poling, C. R. Ng, Michael S. Witherell, G. Vasseur, B. C. Barish, C. D. Jones, Maurice Garcia-Sciveres, J. Masui, D. G. Cassel, Vivek Jain, P. S. Drell, Jorge Luis Rodriguez, M. Saulnier, R. Kennett, B. Gittelman, I. J. Kim, B. Geiser, and M. Lohner

Subjects
Physics, Particle physics, Angular distribution, ComputingMilieux_THECOMPUTINGPROFESSION, Meson, Stereochemistry, Branching fraction, Hadron
Abstract

Using the CLEO II detector, we have measured the branching fractions for [Upsilon](3[ital S])[r arrow][pi][pi][Upsilon](1[ital S]), [Upsilon](3[ital S])[r arrow][pi][pi][Upsilon](2[ital S]), and the cascade [Upsilon](3[ital S])[r arrow][Upsilon](2[ital S])+[ital X], [Upsilon](2[ital S])[r arrow][pi][sup +][pi][sup [minus]][Upsilon](1[ital S]), analyzing the exclusive mode where the daughter [Upsilon] state decays to a [ital e][sup +][ital e[minus]] or [mu][sup +][mu][sup [minus]] pair, as well as the inclusive [pi][sup +][pi][sup [minus]] transitions where the final [Upsilon] state decays into hadrons. Properties of the [pi][pi] system are analyzed. Searches for the cascade decay [Upsilon](3[ital S])[r arrow][pi][sup +][pi][sup [minus]][ital h][sub [ital b]], [ital h][sub [ital b]][r arrow][gamma][eta][sub [ital b]] and [Upsilon](3[ital S])[r arrow][pi][sup 0][ital h][sub [ital b]] were also performed.

Published
1994

48. Measurement of charmless semileptonic decays ofBmesons

Author

Richard Wilson, D. Cinabro, R. Kennett, Anders Ryd, David Sperka, B. Gittelman, I. J. Kim, M. Athanas, Shengfeng Yang, V. Chelkov, S. Schrenk, D. M. Coffman, D. G. Cassel, B. K. Heltsley, K. Lingel, Shawn W. Henderson, P. S. Drell, M. Saulnier, P. Wilson, M. Sivertz, D. Riley, D. F. Cowen, T. K. Nelson, X. Fu, E. H. Thorndike, T. Liu, M. Modesitt, Yoram Rozen, H. Yamamoto, B. Geiser, M. Ogg, G. Zhu, A. P. Freyberger, M. Lohner, J. J. O'Neill, D. Coppage, J. P. Alexander, Robert K. Kutschke, Philip Baringer, F. Muheim, R. Poling, M. Garcia-Sciveres, Igor Volobouev, M. M. Zoeller, Ha Lam, J. D. Richman, R. Wang, Yurii V. Mukhin, Karl Berkelman, S. Ball, Vipul Jain, D. N. Brown, S. Playfer, M. Lattery, R. Stephens, S. E. Csorna, D. Z. Besson, Ian Shipsey, M. Daoudi, F. Butler, J. Masui, J. Snow, F. Morrow, N. Horwitz, M. Chadha, J. S. Miller, Ryszard Stroynowski, D. Fujino, H. Worden, D. L. Kreinick, C. Bebek, K. Kinoshita, M. Thulasidas, P. Rankin, T. Miao, R. J. Morrison, B. Ong, Mats A Selen, T. E. Browder, K. Sparks, M. Daubenmeir, G. Vasseur, S. J. Patton, J. Dominick, M. S. Alam, H. Tajima, D. H. Miller, J. Urheim, K. K. Gan, T. Skwarnicki, A. J. Sadoff, V. Savinov, P. C. Kim, Yuichi Kubota, S. Menary, D. L. Hartill, M. Goldberg, G. C. Moneti, S. Roberts, R. Ehrlich, D. R. Johnson, S. W. Gray, P. Skubic, B. Nemati, Daniel Schmidt, N. Katayama, S.F. Schaffner, S. L. Jones, D. S. Akerib, N. Hancock, S. Nakanishi, J. Gronberg, J. Fast, Marina Artuso, G. Eigen, John E. Bartelt, Y. Skovpen, M. Battle, A. J.R. Weinstein, G.R. Kalbfleisch, P. Zadorozhny, H. P. Paar, R. Fulton, N. Copty, M. Sapper, R. Ammar, Harris Kagan, Alice Bean, Glen D. Crawford, S. Chan, J. G. Smith, E. Nordberg, Cong Wang, G. S. Ludwig, P. L. Wang, R. L. Malchow, Christopher G. White, John Yelton, C. O'Grady, D. Perticone, H. N. Nelson, Z. Egyed, N. Kwak, M. Lambrecht, S. Salman, Janice Nelson, C. D. Jones, Michael Wood, R. L. McIlwain, F. Shen, R. Davis, S. Sanghera, Pu Wang, Darin Acosta, D. He, Barry C. Barish, E. I. Shibata, J. Whitmore, Jungil Lee, J. L. Rodriguez, Frank Würthwein, K. Cho, N. B. Mistry, M. Kelly, J. Mevissen, J. Kandaswamy, J. A. Ernst, D. Peterson, W. R. Ross, K. Honscheid, Daniela Bortoletto, C. R. Sun, W. T. Ford, R. D. Kass, Sheldon Stone, Paul Avery, H. A. Cho, C. R. Ng, Michael S. Witherell, M.K. Sung, G. Masek, Juliet Ritchie Patterson, M. Procario, Horst Severini, and Hubert Kroha

Subjects
Combinatorics, Semileptonic decay, Physics, Particle physics, General Physics and Astronomy, B meson
Abstract

Using the CLEO II detector and a sample of 955 000 [Upsilon](4S) decays we have confirmed charmless semileptonic decays of [ital B] mesons. In the momentum interval 2.3--2.6 GeV/[ital c] we observe an excess of 107[plus minus]15[plus minus]11 leptons, which we attribute to [ital b][r arrow][ital ul][nu]. This result yields a model-dependent range of values for [vert bar][ital V][sub [ital u][ital b]]/[ital V][sub [ital c][ital b]][vert bar] that is lower than has been obtained in previous studies. For the inclusive spectator model of Altarelli [ital et] [ital al]. we find [vert bar][ital V][sub [ital u][ital b]]/[ital V][sub [ital c][ital b]][vert bar]=0.076[plus minus]0.008. Models that describe [ital b][r arrow][ital ul][nu] with a limited set of exclusive final states give [vert bar][ital V][sub [ital u][ital b]]/[ital V][sub [ital c][ital b]][vert bar]=0.06[minus]0.10.

Published
1993

49. Observation ofB0decay to two charmless mesons

Author

N. Hancock, Y. Skovpen, H. Tajima, F. Morrow, R. L. Malchow, Christopher G. White, K. Honscheid, P. Zadorozhny, E. H. Thorndike, R. Ehrlich, C. R. Sun, W. T. Ford, R. D. Kass, D. R. Johnson, J. Whitmore, Jungil Lee, D. Coppage, J. P. Alexander, S. L. Jones, M. Sapper, R. Balest, D. Riley, K. K. Gan, T. Skwarnicki, P. C. Kim, S. Menary, M. Goldberg, V. Shelkov, G. C. Moneti, S.F. Schaffner, S. Schrenk, J. G. Smith, C. M. Daubenmier, Cong Wang, Y. J. Kwon, T. Liu, M. Modesitt, N. Kwak, Robert Wilson, A. P. Freyberger, Alice Bean, Sheldon Stone, Daniela Bortoletto, J. Urheim, R. Ammar, John Yelton, T. Miao, K. Sparks, D. Perticone, S. J. Patton, J. Snow, David Sperka, M. Ogg, G. Zhu, Yoram Rozen, Paul Avery, M. Kelly, J. Mevissen, S. Chan, D. He, Barry C. Barish, E. I. Shibata, M. Lambrecht, Ian Shipsey, D. L. Kreinick, D. N. Brown, Robert K. Kutschke, C. Bebek, H. Kagan, Philip Baringer, S. Ball, Shengfeng Yang, Paul Sheldon, Yuichi Kubota, Marina Artuso, B. Nemati, Karl Berkelman, D. Z. Besson, R. L. McIlwain, J. Kandaswamy, T. E. Browder, Yurii V. Mukhin, S. Salman, Janice Nelson, C. D. Jones, S. Playfer, C. O'Grady, D. F. Cowen, Michael Wood, M. Daoudi, J. S. Miller, B. Ong, F. Shen, N. Katayama, H. Yamamoto, M. Garcia-Sciveres, D. S. Akerib, F. Muheim, G. Eigen, J. Dominick, M. Battle, M. Thulasidas, R. J. Morrison, Vipul Jain, John E. Bartelt, J. A. Ernst, Anders Ryd, Mats A Selen, G.R. Kalbfleisch, A. J. Sadoff, V. Savinov, M. Athanas, A. J.R. Weinstein, Ryszard Stroynowski, D. Fujino, R. Wang, D. L. Hartill, Daniel Schmidt, P. Rankin, G. Vasseur, J. Fast, D. Peterson, N. Copty, S. Nakanishi, S. Sanghera, Pu Wang, Darin Acosta, D. H. Miller, H. N. Nelson, Glen D. Crawford, T. K. Nelson, P. Skubic, S. W. Gray, Igor Volobouev, M. M. Zoeller, Shawn W. Henderson, X. Fu, Z. Egyed, W. R. Ross, D. M. Coffman, B. K. Heltsley, M. S. Alam, J. Gronberg, H. P. Paar, R. Fulton, E. Nordberg, G. S. Ludwig, K. Lingel, H. Worden, P. L. Wang, J. L. Rodriguez, Frank Würthwein, K. Cho, N. B. Mistry, R. Stephens, S. E. Csorna, F. Butler, G. Masek, K. Kinoshita, R. Davis, Juliet Ritchie Patterson, M. Procario, Horst Severini, Hubert Kroha, H. A. Cho, C. R. Ng, Michael S. Witherell, M.K. Sung, J. Masui, S. Roberts, Ha Lam, J. D. Richman, M. Lattery, B. Geiser, D. G. Cassel, R. Poling, M. Lohner, J. J. O'Neill, P. S. Drell, M. Saulnier, P. Wilson, D. Cinabro, R. Kennett, N. Horwitz, M. Chadha, B. Gittelman, and I. J. Kim

Subjects
Physics, Combinatorics, Particle physics, Particle decay, Meson, Branching fraction, Electron–positron annihilation, General Physics and Astronomy, B meson, Elementary particle
Abstract

We report results from a search for the decays ${\mathit{B}}^{0}$\ensuremath{\rightarrow}${\mathrm{\ensuremath{\pi}}}^{+}$${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$, ${\mathit{B}}^{0}$\ensuremath{\rightarrow}${\mathit{K}}^{+}$${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$, and ${\mathit{B}}^{0}$\ensuremath{\rightarrow}${\mathit{K}}^{+}$${\mathit{K}}^{\mathrm{\ensuremath{-}}}$. We find 90% confidence level upper limits on the branching fractions, ${\mathit{B}}_{\mathrm{\ensuremath{\pi}}\mathrm{\ensuremath{\pi}}}$2.9\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}5}$, ${\mathit{B}}_{\mathit{K}\mathrm{\ensuremath{\pi}}}$2.6\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}5}$, and ${\mathit{B}}_{\mathit{K}\mathit{K}}$0.7\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}5}$. While there is no statistically significant signal in the individual modes, the sum of ${\mathit{B}}_{\mathrm{\ensuremath{\pi}}\mathrm{\ensuremath{\pi}}}$ and ${\mathit{B}}_{\mathit{K}\mathrm{\ensuremath{\pi}}}$ exceeds zero with a significance of more than 4 standard deviations, indicating that we have observed charmless hadronic B decays.

Published
1993

50. Observation of the charmed baryonΣc+and measurement of the isospin mass splittings of theΣc

Author

K. Lingel, M. Sivertz, Y. I. Skovpen, J. Urheim, N. Horwitz, M. Chadha, J. Whitmore, F. Muheim, H. Worden, B. Ong, Ha Lam, J. D. Richman, B. Geiser, D. Riley, Sheldon Stone, M. Ogg, Daniela Bortoletto, N. Hancock, G. Zhu, Paul Avery, H. Kagan, James E. Fast, D. Z. Besson, R. Stoynowski, M. Lattery, M. Daoudi, David Sperka, B. C. Barish, J. Gronberg, S. Playfer, K. Sparks, C. P. O'Grady, M. S. Alam, K. K. Gan, T. Skwarnicki, R. L. Malchow, M. Lohner, J. G. Smith, S. J. Patton, H. P. Paar, R. Fulton, M. Sapper, S. Nakanishi, Paul Sheldon, Yuichi Kubota, C. M. Daubenmier, Christopher G. White, D. R. Johnson, J. Masui, J. L. Rodriguez, P. C. Kim, J. J. O'Neill, R. Ammar, B. Nemati, Jongmin Lee, Anders Ryd, M. Athanas, D. Cinabro, R. Kennett, S. Schrenk, Shengfeng Yang, C. R. Sun, W. T. Ford, S. Chan, Frank Würthwein, T. Liu, M. Modesitt, R. J. Morrison, Mats A Selen, B. Gittelman, K. Cho, R. D. Kass, M. Goldberg, G. C. Moneti, A. P. Freyberger, A. J. Sadoff, R. Balest, N. B. Mistry, P. Skubic, D. F. Cowen, I. J. Kim, S.F. Schaffner, M. Kelly, M. Battle, J. Mevissen, E. H. Thorndike, Z. Egyed, Cong Wang, A. J.R. Weinstein, M. Garcia-Sciveres, Yurii V. Mukhin, J. Kandaswamy, Yoram Rozen, J. Snow, Robert K. Kutschke, D. Coppage, Marina Artuso, R. J. Wilson, Vipul Jain, S. Roberts, Philip Baringer, John Yelton, John E. Bartelt, J. A. Ernst, K. Honscheid, J. P. Alexander, G.R. Kalbfleisch, S. Ball, S. Menary, Shawn W. Henderson, F. Morrow, E. Nordberg, Karl Berkelman, S. W. Gray, H. Tajima, T. Miao, D. Peterson, N. Kwak, D. He, D. L. Hartill, X. Fu, E. I. Shibata, Daniel Schmidt, D. Fujino, P. S. Drell, D. Perticone, G. S. Ludwig, R. Ehrlich, N. Copty, M. Lambrecht, R. S. Galik, R. Stephens, W. R. Ross, P. Rankin, S. L. Jones, S. E. Csorna, D. N. Brown, M. Saulnier, P. Wilson, Glen D. Crawford, T. K. Nelson, H. Yamamoto, I. P. J. Shipsey, N. Katayama, F. Butler, D. S. Akerib, H. N. Nelson, S. Salman, Janice Nelson, C. D. Jones, G. Eigen, Michael Wood, R. Davis, R. Wang, K. Kinoshita, G. Vasseur, J. S. Miller, R. L. McIlwain, M. Thulasidas, D. G. Cassel, P. L. Wang, M. M. Zoeller, F. Shen, Alice Bean, R. Poling, D. H. Miller, S. Sanghera, Pu Wang, Darin Acosta, G. Masek, Juliet Ritchie Patterson, M. Procario, Horst Severini, Hubert Kroha, H. A. Cho, C. R. Ng, D. M. Coffman, Michael S. Witherell, B. K. Heltsley, M.K. Sung, D. L. Kreinick, C. Bebek, T. E. Browder, J. Dominick, and V. Savinov

Subjects
Baryon, Physics, Charmed baryons, Particle physics, Particle properties, Stereochemistry, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Isospin, General Physics and Astronomy, Sigma baryon
Abstract

We observe the [Sigma][sub [ital c]][sup +] baryon decaying to [Lambda][sub [ital c]][sup +][pi][sup 0] and measure the mass difference [ital M]([Sigma][sub [ital c]][sup +])[minus][ital M]([Lambda][sub [ital c]][sup +]) to be 168.5[plus minus]0.2 MeV/[ital c][sup 2]. We also measure the mass differences [ital M]([Sigma][sub [ital c]][sup ++])[minus][ital M]([Lambda][sub [ital c]][sup +]) and [ital M]([Sigma][sub [ital c]][sup 0])[minus][ital M]([Lambda][sub [ital c]][sup +]) with improved precision and determine the isospin mass splittings [ital M]([Sigma][sub [ital c]][sup ++])[minus][ital M]([Sigma][sub [ital c]][sup 0]) and [ital M]([Sigma][sub [ital c]][sup +])[minus][ital M]([Sigma][sub [ital c]][sup 0]) to be 1.1[plus minus]0.4[plus minus]0.1 MeV/[ital c][sup 2] and 1.4[plus minus]0.5[plus minus]0.3 MeV/[ital c][sup 2], respectively. Our results indicate that the light quark mass difference does not dominate the isospin mass splitting in [Sigma][sub [ital c]].

Published
1993

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