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17 results on '"Cannon, B. E."'

1. Measurement of beam asymmetry for $\pi^-\Delta^{++}$ photoproduction on the proton at $E_\gamma$=8.5 GeV

Author

GlueX Collaboration, Adhikari, S., Akondi, C. S., Ali, A., Amaryan, M., Asaturyan, A., Austregesilo, A., Baldwin, Z., Barbosa, F., Barlow, J., Barriga, E., Barsotti, R., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Erbora, T., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Fitches, J., Foda, A. M., Furletov, S., Gan, L., Gao, H., Gasparian, A., Gleason, C., Goetzen, K., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jaegle, I., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Khachatryan, V., Khatchatryan, M., Kourkoumelis, C., Kuleshov, S., LaDuke, A., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W. B., Liu, B., Livingston, K., Lolos, G. J., Luckas, K., Lyubovitskij, V., Mack, D., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mizutani, K., Neelamana, V., Nerling, F., Ng, L., Ostrovidov, A. I., Papandreou, Z., Paudel, C., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Reinhold, J., Ritchie, B. G., Ritman, J., Rodriguez, G., Romanov, D., Romero, C., Salgado, C., Schadmand, S., Schertz, A. M., Schick, A., Schumacher, R. A., Schwiening, J., Shen, X., Shepherd, M. R., Smith, A., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Stevens, J. R., Strakovsky, I. I., Sumner, B., Suresh, K., Tarasov, V. V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Whitlatch, T., Wickramaarachchi, N., Williams, M., Yang, Y., Zarling, J., Zhang, Z., Zhao, Z., Zhou, J., Zhou, Q., Zhou, X., and Zihlmann, B.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

We report a measurement of the $\pi^-$ photoproduction beam asymmetry for the reaction $\vec{\gamma} p \rightarrow \pi^- \Delta^{++}$ using data from the GlueX experiment in the photon beam energy range 8.2--8.8 GeV. The asymmetry $\Sigma$ is measured as a function of four-momentum transfer $t$ to the $\Delta^{++}$ and compared to phenomenological models. We find that $\Sigma$ varies as a function of $t$: negative at smaller values and positive at higher values of $|t|$. The reaction can be described theoretically by $t$-channel particle exchange requiring pseudoscalar, vector, and tensor intermediaries. In particular, this reaction requires charge exchange, allowing us to probe pion exchange and the significance of higher-order corrections to one-pion exchange at low momentum transfer. Constraining production mechanisms of conventional mesons may aid in the search for and study of unconventional mesons. This is the first measurement of the process at this energy., Comment: 7 pages, 5 figures

Published
2020
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2. The GlueX Beamline and Detector

Author

Adhikari, S., Akondi, C. S., Ghoul, H. Al, Ali, A., Amaryan, M., Anassontzis, E. G., Austregesilo, A., Barbosa, F., Barlow, J., Barnes, A., Barriga, E., Barsotti, R., Beattie, T. D., Benesch, J., Berdnikov, V. V., Biallas, G., Black, T., Boeglin, W., Brindza, P., Briscoe, W. J., Britton, T., Brock, J., Brooks, W. K., Cannon, B. E., Carlin, C., Carman, D. S., Carstens, T., Cao, N., Chernyshov, O., Chudakov, E., Cole, S., Cortes, O., Crahen, W. D., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dickover, C., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Dzierba, A., Egiyan, H., Erbora, T., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Foda, A. M., Foote, J., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gerasimov, A., Gevorgyan, N., Gleason, C., Goetzen, K., Goryachev, A. Goncalves V. S., Guo, L., Hakobyan, H., Hamdi, A., Hardin, J., Henschel, C. L., Huber, G. M., Hutton, C., Hurley, A., Ioannou, P., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Katsaganis, S., Kalicy, G., Kamel, M., Keith, C. D., Klein, F. J., Kliemt, R., Kolybaba, D., Kourkoumelis, C., Krueger, S. T., Kuleshov, S., Larin, I., Lawrence, D., Leckey, J. P., Lersch, D. I., Leverington, B. D., Levine, W. I., Li, W., Liu, B., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Marukyan, H., Mattione, P. T., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., McIntyre, J., Meekins, D., Mendez, R., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mokaya, F., Moriya, K., Nerling, F., Ng, L., Ni, H., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Paudel, C., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pierce, J., Pooser, E., Popov, V., Pratt, B., Qiang, Y., Qin, N., Razmyslovich, V., Reinhold, J., Ritchie, B. G., Ritman, J., Robison, L., Romanov, D., Romero, C., Salgado, C., Sandoval, N., Satogata, T., Schertz, A. M., Schadmand, S., Schick, A., Schumacher, R. A., Schwarz, C., Schwiening, J., Semenov, A. Yu., Semenova, I. A., Seth, K. K., Shen, X., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Sparks, N., Staib, M. J., Stanislav, C., Stevens, J. R., Stewart, J., Strakovsky, I. I., Summner, B. C. L., Suresh, K., Tarasov, V. V., Taylor, S., Teigrob, L. A., Teymurazyan, A., Thiel, A., Tolstukhin, I., Tomaradze, A., Toro, A., Tsaris, A., Van Haarlem, Y., Vasileiadis, G., Vega, I., Visser, G., Voulgaris, G., Walford, N. K., Werthmüller, D., Whitlatch, T., Wickramaarachchi, N., Williams, M., Wolin, E., Xiao, T., Yang, Y., Zarling, J., Zhang, Z., Zhou, Q., Zhou, X., and Zihlmann, B.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

The GlueX experiment at Jefferson Lab has been designed to study photoproduction reactions with a 9-GeV linearly polarized photon beam. The energy and arrival time of beam photons are tagged using a scintillator hodoscope and a scintillating fiber array. The photon flux is determined using a pair spectrometer, while the linear polarization of the photon beam is determined using a polarimeter based on triplet photoproduction. Charged-particle tracks from interactions in the central target are analyzed in a solenoidal field using a central straw-tube drift chamber and six packages of planar chambers with cathode strips and drift wires. Electromagnetic showers are reconstructed in a cylindrical scintillating fiber calorimeter inside the magnet and a lead-glass array downstream. Charged particle identification is achieved by measuring energy loss in the wire chambers and using the flight time of particles between the target and detectors outside the magnet. The signals from all detectors are recorded with flash ADCs and/or pipeline TDCs into memories allowing trigger decisions with a latency of 3.3 $\mu$s. The detector operates routinely at trigger rates of 40 kHz and data rates of 600 megabytes per second. We describe the photon beam, the GlueX detector components, electronics, data-acquisition and monitoring systems, and the performance of the experiment during the first three years of operation., Comment: Accepted by Nuclear Instruments and Methods A, 78 pages, 54 figures

Published
2020
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3. Measurement of the Photon Beam Asymmetry in $\vec{\gamma} p\to K^+\Sigma^0$ at $E_{\gamma} = 8.5$ GeV

Author

The GlueX Collaboration, Adhikari, S., Ali, A., Amaryan, M., Austregesilo, A., Barbosa, F., Barlow, J., Barriga, E., Barsotti, R., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Cao, N., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Erbora, T., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Foda, A. M., Foote, J., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gleason, C., Goetzen, K., Goncalves, A., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Kourkoumelis, C., Kuleshov, S., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W., Liu, B., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., Meyer, C. A., Miskimen, R., Mitchell, R. E., Nerling, F., Ng, L., Ni, H., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Paudel, C., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Qin, N., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Romero, C., Salgado, C., Schertz, A. M., Schumacher, R. A., Schwiening, J., Seth, K. K., Shen, X., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Stevens, J. R., Strakovsky, I. I., Suresh, K., Tarasov, V. V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Whitlatch, T., Wickramaarachchi, N., Williams, M., Xiao, T., Yang, Y., Zarling, J., Zhang, Z., Zhou, Q., Zhou, X., and Zihlmann, B.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

We report measurements of the photon beam asymmetry $\Sigma$ for the reaction $\vec{\gamma} p\to K^+\Sigma^0$(1193) using the GlueX spectrometer in Hall D at Jefferson Lab. Data were collected using a linearly polarized photon beam in the energy range of 8.2-8.8 GeV incident on a liquid hydrogen target. The beam asymmetry $\Sigma$ was measured as a function of the Mandelstam variable $t$, and a single value of $\Sigma$ was extracted for events produced in the $u$-channel. These are the first exclusive measurements of the photon beam asymmetry $\Sigma$ for the reaction in this energy range. For the $t$-channel, the measured beam asymmetry is close to unity over the $t$-range studied, $-t=(0.1-1.4)~$(GeV/$c$)$^{2}$, with an average value of $\Sigma = 1.00\pm 0.05$. This agrees with theoretical models that describe the reaction via the natural-parity exchange of the $K^{*}$(892) Regge trajectory. A value of $\Sigma = 0.41 \pm 0.09$ is obtained for the $u$-channel integrated up to $-u=2.0$~(GeV/$c$)$^{2}$.

Published
2020
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4. Beam Asymmetry $\mathbf{\Sigma}$ for the Photoproduction of $\mathbf{\eta}$ and $\mathbf{\eta^{\prime}}$ Mesons at $\mathbf{E_{\gamma}=8.8}$GeV

Author

The GlueX Collaboration, Adhikari, S., Ali, A., Amaryan, M., Austregesilo, A., Barbosa, F., Barlow, J., Barnes, A., Barriga, E., Barsotti, R., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Boer, M., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Cao, N., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Erbora, T., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Foda, A. M., Foote, J., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gevorgyan, N., Gleason, C., Goetzen, K., Goncalves, A., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Kourkoumelis, C., Kuleshov, S., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W., Liu, B., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Marukyan, H., Mattione, P., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., Meyer, C. A., Miskimen, R., Mitchell, R. E., Nerling, F., Ng, L., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Paudel, C., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Qin, N., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Romero, C., Salgado, C., Schertz, A. M., Schumacher, R. A., Schwiening, J., Semenov, A. Yu., Semenova, I. A., Seth, K. K., Shen, X., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Staib, M., Stevens, J. R., Strakovsky, I. I., Suresh, K., Tarasov, V. V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Whitlatch, T., Wickramaarachchi, N., Williams, M., Xiao, T., Yang, Y., Zarling, J., Zhang, Z., Zhao, G., Zhou, Q., Zhou, X., and Zihlmann, B.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

We report on the measurement of the beam asymmetry $\Sigma$ for the reactions $\vec{\gamma}p\rightarrow p\eta$ and $\vec{\gamma}p \rightarrow p\eta^{\prime}$ from the GlueX experiment, using an 8.2--8.8 GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Lab. These measurements are made as a function of momentum transfer $-t$, with significantly higher statistical precision than our earlier $\eta$ measurements, and are the first measurements of $\eta^{\prime}$ in this energy range. We compare the results to theoretical predictions based on $t$--channel quasi-particle exchange. We also compare the ratio of $\Sigma_{\eta}$ to $\Sigma_{\eta^{\prime}}$ to these models, as this ratio is predicted to be sensitive to the amount of $s\bar{s}$ exchange in the production. We find that photoproduction of both $\eta$ and $\eta^{\prime}$ is dominated by natural parity exchange with little dependence on $-t$., Comment: 18 pages, 7 figures

Published
2019
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5. First measurement of near-threshold J/$\psi $ exclusive photoproduction off the proton

Author

The GlueX Collaboration, Ali, A., Amaryan, M., Anassontzis, E. G., Austregesilo, A., Baalouch, M., Barbosa, F., Barlow, J., Barnes, A., Barriga, E., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Boer, M., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Cao, N., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Foda, A. M., Foote, J., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gauzshtein, V., Gevorgyan, N., Gleason, C., Goetzen, K., Goncalves, A., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Han, S., Hardin, J., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Kourkoumelis, C., Kuleshov, S., Kuznetsov, I., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W., Liu, B., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., McIntyre, J., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mokaya, F., Nerling, F., Ng, L., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Qin, N., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Romero, C., Salgado, C., Schertz, A. M., Schumacher, R. A., Schwiening, J., Seth, K. K., Shen, X., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Stevens, J. R., Strakovsky, I. I., Suresh, K., Tarasov, V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Werthmueller, D., Whitlatch, T., Wickramaarachchi, N., Williams, M., Xiao, T., Yang, Y., Zarling, J., Zhang, Z., Zhao, G., Zhou, Q., Zhou, X., and Zihlmann, B.

Subjects
Nuclear Experiment
Abstract

We report on the measurement of the $\gamma p \rightarrow J/\psi p$ cross section from $E_\gamma = 11.8$ GeV down to the threshold at $8.2$ GeV using a tagged photon beam with the GlueX experiment. We find the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section $d\sigma /dt$ has an exponential slope of $1.67 \pm 0.39$ GeV$^{-2}$ at $10.7$ GeV average energy. The LHCb pentaquark candidates $P_c^+$ can be produced in the $s$-channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions $\mathcal{B}(P_c^+ \rightarrow J/\psi p)$ and cross sections $\sigma(\gamma p \to P_c^+)\times\mathcal{B}(P_c^+ \to J/\psi p) $., Comment: 12 pages, 7 figures

Published
2019
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6. Measurement of the beam asymmetry $\Sigma$ for $\pi^0$ and $\eta$ photoproduction on the proton at $E_\gamma = 9$ GeV

Author

GlueX Collaboration, Ghoul, H. Al, Anassontzis, E. G., Austregesilo, A., Barbosa, F., Barnes, A., Beattie, T. D., Bennett, D. W., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Brooks, W. K., Cannon, B. E., Chernyshov, O., Chudakov, E., Crede, V., Dalton, M. M., Deur, A., Dobbs, S., Dolgolenko, A., Dugger, M., Dzhygadlo, R., Egiyan, H., Eugenio, P., Fanelli, C., Foda, A. M., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gerasimov, A., Gevorgyan, N., Goetzen, K., Goryachev, V. S., Guo, L., Hakobyan, H., Hardin, J., Henderson, A., Huber, G. M., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kamel, M., Klein, F. J., Kliemt, R., Kourkoumeli, C., Kuleshov, S., Kuznetsov, I., Lara, M., Larin, I., Lawrence, D., Levine, W. I., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Mattione, P. T., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., McIntyre, J., Mendez, R., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mokaya, F., Moriya, K., Nerling, F., Nigmatkulov, G., Ochoa, N., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Pedroni, R., Pennington, M. R., Pentchev, L., Peters, K. J., Pooser, E., Pratt, B., Qiang, Y., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Salgado, C., Schumacher, R. A., Schwarz, C., Schwiening, J., Semenov, A. Yu., Semenova, I. A., Seth, K. K., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Sparks, N., Staib, M. J., Stevens, J. R., Strakovsky, I. I., Subedi, A., Tarasov, V., Taylor, S., Teymurazyan, A., Tolstukhin, I., Tomaradze, A., Toro, A., Tsaris, A., Vasileiadis, G., Vega, I., Walford, N. K., Werthmuller, D., Whitlatch, T., Williams, M., Wolin, E., Xiao, T., Zarling, J., Zhang, Z., Zihlmann, B., Mathieu, V., and Nys, J.

Subjects
Nuclear Experiment
Abstract

We report measurements of the photon beam asymmetry $\Sigma$ for the reactions $\vec{\gamma}p\to p\pi^0$ and $\vec{\gamma}p\to p\eta $ from the GlueX experiment using a 9 GeV linearly-polarized, tagged photon beam incident on a liquid hydrogen target in Jefferson Lab's Hall D. The asymmetries, measured as a function of the proton momentum transfer, possess greater precision than previous $\pi^0$ measurements and are the first $\eta$ measurements in this energy regime. The results are compared with theoretical predictions based on $t$-channel, quasi-particle exchange and constrain the axial-vector component of the neutral meson production mechanism in these models., Comment: 6 pages, 6 figures, Published in Physical Review C: Rapid Communication

Published
2017
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7. Measurement of beam asymmetry for π−Δ++ photoproduction on the proton at Eγ = 8.5 GeV

Author

Adhikari, S., Akondi, C. S., Ali, A., Amaryan, M., Asaturyan, A., Austregesilo, A., Baldwin, Z., Barbosa, F., Barlow, J., Barriga, E., Barsotti, R., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Erbora, T., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Fitches, J., Foda, A. M., Furletov, S., Gan, L., Gao, H., Gasparian, A., Gleason, C., Goetzen, K., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jaegle, I., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Khachatryan, V., Khatchatryan, M., Kourkoumelis, C., Kuleshov, S., LaDuke, A., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W. B., Liu, B., Livingston, K., Lolos, G. J., Luckas, K., Lyubovitskij, V., Mack, D., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mizutani, K., Neelamana, V., Nerling, F., Ng, L., Ostrovidov, A. I., Papandreou, Z., Paudel, C., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Reinhold, J., Ritchie, B. G., Ritman, J., Rodriguez, G., Romanov, D., Romero, C., Salgado, C., Schadmand, S., Schertz, A. M., Schick, A., Schumacher, R. A., Schwiening, J., Shen, X., Shepherd, M. R., Smith, A., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Stevens, J. R., Strakovsky, I. I., Sumner, B., Suresh, K., Tarasov, V. V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Whitlatch, T., Wickramaarachchi, N., Williams, M., Yang, Y., Zarling, J., Zhang, Z., Zhao, Z., Zhou, J., Zhou, Q., Zhou, X., and Zihlmann, B.

Subjects
High Energy Physics::Experiment, Nuclear Experiment
Abstract

We report a measurement of the \ud π\ud −\ud photoproduction beam asymmetry for the reaction \ud →\ud γ\ud p\ud →\ud π\ud −\ud Δ\ud +\ud +\ud using data from the GlueX experiment in the photon beam energy range 8.2–8.8 GeV. The asymmetry \ud Σ\ud is measured as a function of four-momentum transfer \ud t\ud to the \ud Δ\ud +\ud +\ud and compared to phenomenological models. We find that \ud Σ\ud varies as a function of \ud t\ud : negative at smaller values and positive at higher values of \ud |\ud t\ud |\ud . The reaction can be described theoretically by \ud t\ud -channel particle exchange requiring pseudoscalar, vector, and tensor intermediaries. In particular, this reaction requires charge exchange, allowing us to probe pion exchange and the significance of higher-order corrections to one-pion exchange at low momentum transfer. Constraining production mechanisms of conventional mesons may aid in the search for and study of unconventional mesons. This is the first measurement of the process at this energy.

Published
2021

8. Measurement of beam asymmetry for π − Δ + + photoproduction on the proton at E γ = 8.5 GeV

Author

GlueX Collaboration, Adhikari, S., Akondi, C. S., Ali, A., Amaryan, M., Asaturyan, A., Austregesilo, A., Baldwin, Z., Barbosa, F., Barlow, J., Barriga, E., Barsotti, R., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Erbora, T., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Fitches, J., Foda, A. M., Furletov, S., Gan, L., Gao, H., Gasparian, A., Gleason, C., Goetzen, K., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jaegle, I., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Khachatryan, V., Khatchatryan, M., Kourkoumelis, C., Kuleshov, S., LaDuke, A., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W. B., Liu, B., Livingston, K., Lolos, G. J., Luckas, K., Lyubovitskij, V., Mack, D., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mizutani, K., Neelamana, V., Nerling, F., Ng, L., Ostrovidov, A. I., Papandreou, Z., Paudel, C., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Reinhold, J., Ritchie, B. G., Ritman, J., Rodriguez, G., Romanov, D., Romero, C., Salgado, C., Schadmand, S., Schertz, A. M., Schick, A., Schumacher, R. A., Schwiening, J., Shen, X., Shepherd, M. R., Smith, A., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Stevens, J. R., Strakovsky, I. I., Sumner, B., Suresh, K., Tarasov, V. V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Whitlatch, T., Wickramaarachchi, N., Williams, M., Yang, Y., Zarling, J., Zhang, Z., Zhao, Z., Zhou, J., Zhou, Q., Zhou, X., and Zihlmann, B.

Subjects
Nuclear Theory, High Energy Physics::Experiment, ddc:530, Nuclear Experiment, High Energy Physics - Experiment
Abstract

We report a measurement of the $\pi^-$ photoproduction beam asymmetry for the reaction $\vec{\gamma} p \rightarrow \pi^- \Delta^{++}$ using data from the GlueX experiment in the photon beam energy range 8.2--8.8 GeV. The asymmetry $\Sigma$ is measured as a function of four-momentum transfer $t$ to the $\Delta^{++}$ and compared to phenomenological models. We find that $\Sigma$ varies as a function of $t$: negative at smaller values and positive at higher values of $|t|$. The reaction can be described theoretically by $t$-channel particle exchange requiring pseudoscalar, vector, and tensor intermediaries. In particular, this reaction requires charge exchange, allowing us to probe pion exchange and the significance of higher-order corrections to one-pion exchange at low momentum transfer. Constraining production mechanisms of conventional mesons may aid in the search for and study of unconventional mesons. This is the first measurement of the process at this energy., Comment: 7 pages, 5 figures

Published
2021

9. Measurement of the photon beam asymmetry in γ⃗p→K+Σ0 at Eγ = 8.5 GeV

Author

Adhikari, S., Ali, A., Amaryan, M., Austregesilo, A., Barbosa, F., Barlow, J., Barriga, E., Barsotti, R., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Cao, N., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Erbora, T., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Foda, A. M., Foote, J., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gleason, C., Goetzen, K., Goncalves, A., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Kourkoumelis, C., Kuleshov, S., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W., Liu, B., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., Meyer, C. A., Miskimen, R., Mitchell, R. E., Nerling, F., Ng, L., Ni, H., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Paudel, C., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Qin, N., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Romero, C., Salgado, C., Schertz, A. M., Schumacher, R. A., Schwiening, J., Seth, K. K., Shen, X., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Stevens, J. R., Strakovsky, I. I., Suresh, K., Tarasov, V. V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Whitlatch, T., Wickramaarachchi, N., Williams, M., Xiao, T., Yang, Y., Zarling, J., Zhang, Z., Zhou, Q., Zhou, X., and Zihlmann, B.

Subjects
High Energy Physics::Experiment, Nuclear Experiment
Abstract

We report measurements of the photon beam asymmetry \ud Σ\ud for the reaction \ud γ⃗p→K+Σ0\ud (1193) using the GlueX spectrometer in Hall D at Jefferson Lab. Data were collected by using a linearly polarized photon beam in the energy range of 8.2–8.8 GeV incident on a liquid hydrogen target. The beam asymmetry \ud Σ\ud was measured as a function of the Mandelstam variable \ud t\ud , and a single value of \ud Σ\ud was extracted for events produced in the \ud u\ud channel. These are the first exclusive measurements of the photon beam asymmetry \ud Σ\ud for the reaction in this energy range. For the \ud t\ud channel, the measured beam asymmetry is close to unity over the \ud t\ud range studied, \ud −\ud t\ud =\ud (\ud 0.1\ud –\ud 1.4\ud )\ud (\ud GeV\ud /\ud c\ud )\ud 2\ud , with an average value of \ud Σ\ud =\ud 1.00\ud ±\ud 0.05\ud . This agrees with theoretical models that describe the reaction via the natural-parity exchange of the \ud K\ud ∗\ud (892) Regge trajectory. A value of \ud Σ\ud =\ud 0.41\ud ±\ud 0.09\ud is obtained for the \ud u\ud channel integrated up to \ud −\ud u\ud =\ud 2.0\ud (\ud GeV\ud /\ud c\ud )\ud 2\ud .

Published
2020

10. Measurement of beam asymmetry for $��^-��^{++}$ photoproduction on the proton at $E_��$=8.5 GeV

Author

GlueX Collaboration, Adhikari, S., Akondi, C. S., Ali, A., Amaryan, M., Asaturyan, A., Austregesilo, A., Baldwin, Z., Barbosa, F., Barlow, J., Barriga, E., Barsotti, R., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Erbora, T., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Fitches, J., Foda, A. M., Furletov, S., Gan, L., Gao, H., Gasparian, A., Gleason, C., Goetzen, K., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jaegle, I., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Khachatryan, V., Khatchatryan, M., Kourkoumelis, C., Kuleshov, S., LaDuke, A., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W. B., Liu, B., Livingston, K., Lolos, G. J., Luckas, K., Lyubovitskij, V., Mack, D., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mizutani, K., Neelamana, V., Nerling, F., Ng, L., Ostrovidov, A. I., Papandreou, Z., Paudel, C., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Reinhold, J., Ritchie, B. G., Ritman, J., Rodriguez, G., Romanov, D., Romero, C., Salgado, C., Schadmand, S., Schertz, A. M., Schick, A., Schumacher, R. A., Schwiening, J., Shen, X., Shepherd, M. R., Smith, A., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Stevens, J. R., Strakovsky, I. I., Sumner, B., Suresh, K., Tarasov, V. V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Whitlatch, T., Wickramaarachchi, N., Williams, M., Yang, Y., Zarling, J., Zhang, Z., Zhao, Z., Zhou, J., Zhou, Q., Zhou, X., and Zihlmann, B.

Subjects
High Energy Physics - Experiment (hep-ex), Nuclear Theory, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

We report a measurement of the $��^-$ photoproduction beam asymmetry for the reaction $\vec�� p \rightarrow ��^- ��^{++}$ using data from the GlueX experiment in the photon beam energy range 8.2--8.8 GeV. The asymmetry $��$ is measured as a function of four-momentum transfer $t$ to the $��^{++}$ and compared to phenomenological models. We find that $��$ varies as a function of $t$: negative at smaller values and positive at higher values of $|t|$. The reaction can be described theoretically by $t$-channel particle exchange requiring pseudoscalar, vector, and tensor intermediaries. In particular, this reaction requires charge exchange, allowing us to probe pion exchange and the significance of higher-order corrections to one-pion exchange at low momentum transfer. Constraining production mechanisms of conventional mesons may aid in the search for and study of unconventional mesons. This is the first measurement of the process at this energy., 7 pages, 5 figures

Published
2020
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11. Beam asymmetry Σ for the photoproduction of η and η′ mesons at Eγ = 8.8GeV

Author

Adhikari, S., Ali, A., Amaryan, M., Austregesilo, A., Barbosa, F., Barlow, J., Barnes, A., Barriga, E., Barsotti, R., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Boer, M., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Cao, N., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Erbora, T., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Foda, A. M., Foote, J., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gevorgyan, N., Gleason, C., Goetzen, K., Goncalves, A., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Kourkoumelis, C., Kuleshov, S., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W., Liu, B., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Marukyan, H., Mattione, P., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., Meyer, C. A., Miskimen, R., Mitchell, R. E., Nerling, F., Ng, L., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Paudel, C., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Qin, N., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Romero, C., Salgado, C., Schertz, A. M., Schumacher, R. A., Schwiening, J., Semenov, A. Yu., Semenova, I. A., Seth, K. K., Shen, X., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Staib, M., Stevens, J. R., Strakovsky, I. I., Suresh, K., Tarasov, V. V., Teymurazyan, A., Thiel, A., Vasileiadis, G., Whitlatch, T., Wickramaarachchi, N., Williams, M., Xiao, T., Yang, Y., Zarling, J., Zhang, Z., Zhao, G., Zhou, Q., Zhou, X., and Zihlmann, B.

Abstract

We report on the measurement of the beam asymmetry \ud Σ\ud for the reactions \ud →\ud γ\ud p\ud →\ud p\ud η\ud and \ud →\ud γ\ud p\ud →\ud p\ud η\ud ′\ud from the GlueX experiment using an 8.2–8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Laboratory. These measurements are made as a function of momentum transfer \ud −\ud t\ud with significantly higher statistical precision than our earlier \ud η\ud measurements and are the first measurements of \ud η\ud ′\ud in this energy range. We compare the results to theoretical predictions based on \ud t\ud -channel quasiparticle exchange. We also compare the ratio of \ud Σ\ud η\ud to \ud Σ\ud η\ud ′\ud to these models as this ratio is predicted to be sensitive to the amount of \ud s\ud ¯\ud s\ud exchange in the production. We find that photoproduction of both \ud η\ud and \ud η\ud ′\ud is dominated by natural parity exchange with little dependence on \ud −\ud t\ud .

Published
2019

12. First Measurement of Near-Threshold J/ψ Exclusive Photoproduction off the Proton

Author

The GlueX Collaboration, Ali, A., Amaryan, M., Anassontzis, E. G., Austregesilo, A., Baalouch, M., Barbosa, F., Barlow, J., Barnes, A., Barriga, E., Beattie, T. D., Berdnikov, V. V., Black, T., Boeglin, W., Boer, M., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Cao, N., Chudakov, E., Cole, S., Cortes, O., Crede, V., Dalton, M. M., Daniels, T., Deur, A., Dobbs, S., Dolgolenko, A., Dotel, R., Dugger, M., Dzhygadlo, R., Egiyan, H., Ernst, A., Eugenio, P., Fanelli, C., Fegan, S., Foda, A. M., Foote, J., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gauzshtein, V., Gevorgyan, N., Gleason, C., Goetzen, K., Goncalves, A., Goryachev, V. S., Guo, L., Hakobyan, H., Hamdi, A., Han, S., Hardin, J., Huber, G. M., Hurley, A., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Kourkoumelis, C., Kuleshov, S., Kuznetsov, I., Larin, I., Lawrence, D., Lersch, D. I., Li, H., Li, W., Liu, B., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Marukyan, H., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., McIntyre, J., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mokaya, F., Nerling, F., Ng, L., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Pauli, P., Pedroni, R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Qin, N., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Romero, C., Salgado, C., Schertz, A. M., Schumacher, R. A., Schwiening, J., Seth, K. K., Shen, X., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Stevens, J. R., Strakovsky, I. I., Suresh, K., Tarasov, V., Taylor, S., Teymurazyan, A., Thiel, A., Vasileiadis, G., Werthmueller, D., Whitlatch, T., Wickramaarachchi, N., Williams, M., Xiao, T., Yang, Y., Zarling, J., Zhang, Z., Zhao, G., Zhou, Q., Zhou, X., and Zihlmann, B.

Subjects
Physics, Scattering cross-section, GlueX, General Physics and Astronomy, Exotic hadron, 01 natural sciences, 7. Clean energy, Pentaquark, Model exchange, Nuclear physics, Near threshold, 0103 physical sciences, High Energy Physics::Experiment, Photon beam, 010306 general physics, Nuclear Experiment
Abstract

We report on the measurement of the $\gamma p \rightarrow J/\psi p$ cross section from $E_\gamma = 11.8$ GeV down to the threshold at $8.2$ GeV using a tagged photon beam with the GlueX experiment. We find the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section $d\sigma /dt$ has an exponential slope of $1.67 \pm 0.39$ GeV$^{-2}$ at $10.7$ GeV average energy. The LHCb pentaquark candidates $P_c^+$ can be produced in the $s$-channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions $\mathcal{B}(P_c^+ \rightarrow J/\psi p)$ and cross sections $\sigma(\gamma p \to P_c^+)\times\mathcal{B}(P_c^+ \to J/\psi p) $., Comment: 12 pages, 7 figures

Published
2019

13. Measurement of the beam asymmetry Σ for π0 and η photoproduction on the proton at Eγ=9 GeV

Author

Al Ghoul, H., Anassontzis, E. G., Austregesilo, A., Barbosa, F., Beattie, T. D., Bennett, D. W., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Cannon, B. E., Chernyshov, O., Chudakov, E., Crede, V., Dalton, M. M., Deur, A., Dobbs, S., Dolgolenko, A., Dugger, M., Dzhygadlo, R., Egiyan, H., Eugenio, P., Fanelli, C., Foda, A. M., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gerasimov, A., Gevorgyan, N., Goetzen, K., Goryachev, V. S., Guo, L., Hakobyan, H., Hardin, J., Henderson, A., Huber, G. M., Ireland, D. G., Ito, M. M., Jarvis, N. S., Kakoyan, V., Kamel, M., Klein, F. J., Kliemt, R., Kourkoumeli, C., Kuleshov, S., Kuznetsov, I., Lara, M., Larin, I., Lawrence, D., Levine, W. I., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Mattione, P. T., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., McIntyre, J., Mendez, R., Meyer, C. A., Miskimen, R., Mokaya, F., Moriya, K., Nerling, F., Nigmatkulov, G., Ochoa, N., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Pedroni, R., Pennington, M. R., Pentchev, L., Peters, K. J., Pooser, E., Pratt, B., Qiang, Y., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Salgado, C., Schumacher, R. A., Schwarz, C., Schwiening, J., Semenov, A. Yu, Semenova, I. A., Seth, K. K., Shepherd, M. R., Sober, D. I., Somov, A., Somov, S., Soto, O., Sparks, N., Staib, M. J., Stevens, J. R., Strakovsky, I. I., Subedi, A., Tarasov, V., Teymurazyan, A., Tolstukhin, I., Tomaradze, A., Toro, A., Tsaris, A., Vasileiadis, G., Vega, I., Walford, N. K., Whitlatch, T., Wolin, E., Xiao, T., Zarling, J., Zihlmann, B., Mathieu, V., Nys, J., and Werthmüller, Dominik

Subjects
Nuclear Experiment
Abstract

We report measurements of the photon beam asymmetry Σ for the reactions γ - p→pπ0 and γ - p→pη from the GlueX experiment using a 9 GeV linearly polarized, tagged photon beam incident on a liquid hydrogen target in Jefferson Lab's Hall D. The asymmetries, measured as a function of the proton momentum transfer, possess greater precision than previous π0 measurements and are the first η measurements in this energy regime. The results are compared with theoretical predictions based on t-channel, quasiparticle exchange and constrain the axial-vector component of the neutral meson production mechanism in these models.

Published
2017

14. Measurement of the beam asymmetry Σ for π0 and η photoproduction on the proton at Eγ = 9GeV

Author

Anassontzis, E. G., Austregesilo, A., Barbosa, F., Barnes, A., Beattie, T. D., Bennett, D. W., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Brooks, W. K., Cannon, B. E., Chernyshov, O., Chudakov, E., Kuznetsov, I., Al Ghoul, H., and Lyubovitskij, Valery E.

Subjects
фотонные пучки, фоторождение, GlueX, Nuclear Experiment, нейтральные мезоны
Abstract

We report measurements of the photon beam asymmetry for the reactions γ p → pπ0 and γ p → pη from the GLUEX experiment using a 9 GeV linearly polarized, tagged photon beam incident on a liquid hydrogen target in Jefferson Lab’s Hall D. The asymmetries, measured as a function of the proton momentum transfer, possess greater precision than previous π0 measurements and are the first η measurements in this energy regime. The results are compared with theoretical predictions based on t-channel, quasiparticle exchange and constrain the axial-vector component of the neutral meson production mechanism in these models.

Published
2017

15. Measurement of the beam asymmetry $��$ for $��^0$ and $��$ photoproduction on the proton at $E_��= 9$ GeV

Author

GlueX Collaboration, Ghoul, H. Al, Anassontzis, E. G., Austregesilo, A., Barbosa, F., Barnes, A., Beattie, T. D., Bennett, D. W., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Brooks, W. K., Cannon, B. E., Chernyshov, O., Chudakov, E., Crede, V., Dalton, M. M., Deur, A., Dobbs, S., Dolgolenko, A., Dugger, M., Dzhygadlo, R., Egiyan, H., Eugenio, P., Fanelli, C., Foda, A. M., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gerasimov, A., Gevorgyan, N., Goetzen, K., Goryachev, V. S., Guo, L., Hakobyan, H., Hardin, J., Henderson, A., Huber, G. M., Ireland, D. G., Ito, M. M., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kamel, M., Klein, F. J., Kliemt, R., Kourkoumeli, C., Kuleshov, S., Kuznetsov, I., Lara, M., Larin, I., Lawrence, D., Levine, W. I., Livingston, K., Lolos, G. J., Lyubovitskij, V., Mack, D., Mattione, P. T., Matveev, V., McCaughan, M., McCracken, M., McGinley, W., McIntyre, J., Mendez, R., Meyer, C. A., Miskimen, R., Mitchell, R. E., Mokaya, F., Moriya, K., Nerling, F., Nigmatkulov, G., Ochoa, N., Ostrovidov, A. I., Papandreou, Z., Patsyuk, M., Pedroni, R., Pennington, M. R., Pentchev, L., Peters, K. J., Pooser, E., Pratt, B., Qiang, Y., Reinhold, J., Ritchie, B. G., Robison, L., Romanov, D., Salgado, C., Schumacher, R. A., Schwarz, C., Schwiening, J., Semenov, A. Yu., Semenova, I. A., Seth, K. K., Shepherd, M. R., Smith, E. S., Sober, D. I., Somov, A., Somov, S., Soto, O., Sparks, N., Staib, M. J., Stevens, J. R., Strakovsky, I. I., Subedi, A., Tarasov, V., Taylor, S., Teymurazyan, A., Tolstukhin, I., Tomaradze, A., Toro, A., Tsaris, A., Vasileiadis, G., Vega, I., Walford, N. K., Werthmuller, D., Whitlatch, T., Williams, M., Wolin, E., Xiao, T., Zarling, J., Zhang, Z., Zihlmann, B., Mathieu, V., and Nys, J.

Subjects
FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

We report measurements of the photon beam asymmetry $��$ for the reactions $\vec��p\to p��^0$ and $\vec��p\to p��$ from the GlueX experiment using a 9 GeV linearly-polarized, tagged photon beam incident on a liquid hydrogen target in Jefferson Lab's Hall D. The asymmetries, measured as a function of the proton momentum transfer, possess greater precision than previous $��^0$ measurements and are the first $��$ measurements in this energy regime. The results are compared with theoretical predictions based on $t$-channel, quasi-particle exchange and constrain the axial-vector component of the neutral meson production mechanism in these models., 6 pages, 6 figures, Published in Physical Review C: Rapid Communication

Published
2017
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16. Strange Hadron Spectroscopy with a Secondary KL Beam at GlueX

Author

Adhikari, S., Al Ghoul, H., Ali, A., Amaryan, M. J., Anassontzis, E. G., Anisovich, A. V., Austregesilo, A., Baalouch, M., Barbosa, F., Barnes, A., Bashkanov, M., Beattie, T. D., Bellwied, R., Berdnikov, V. V., Black, T., Boeglin, W., Briscoe, W. J., Britton, T., Brooks, W. K., Cannon, B. E., Chudakov, E., Cole, P. L., Crede, V., Dalton, M. M., Deur, A., Degtyarenko, P., Dobbs, S., Dodge, G., Dolgolenko, A. G., Döring, M., Dugger, M., Dzhygadlo, R., Edwards, R., Egiyan, H., Eidelman, S., Ernst, A., Eskandarian, A., Euginio, P., Fanelli, C., Fegan, S., Foda, A. M., Frye, J., Furletov, S., Gan, L., Gasparian, A., Gavalian, G., Gauzshtein, V., Gevorgyan, N., Glazier, D. I., Goetzen, K., Goity, J., Goryachev, V. S., Guo, L., Haberzettl, H., Hadžimehmedović, M., Hakobyan, H., Hamdi, A., Han, S., Hardin, J., Hayrapetyan, A., Horn, T., Huber, G. M., Hyde, C. E., Ireland, D. G., Ito, M. M., Jackson, B. C., Jarvis, N. S., Jones, R. T., Kakoyan, V., Kalicy, G., Kamel, M., Keith, C. D., Kim, C. W., Klein, F. J., Kourkoumeli, C., Kuleshov, S., Kuznetsov, I., Laptev, A. B., Larin, I., Lawrence, D., Levillain, M., Levine, W. I., Livingston, K., Lolos, G. J., Lyubovitskij, V. E., Mack, D., Mai, M., Manley, D. M., Meißner, U. -G, Marukyan, H., Mathieu, V., Mattione, P. T., Matveev, M., Matveev, V., Mccaughan, M., Mccracken, M., Mcginley, W., Mcintyre, J., Curtis Meyer, Miskimen, R., Mitchell, R. E., Mokaya, F., Mokeev, V., Nakayama, K., Nerling, F., Oh, Y., Osmanović, H., Ostrovidov, A. I., Omerović, R., Papandreou, Z., Park, K., Pasyuk, E., Patsyuk, M., Pauli, P., Pedroni, R., Pennington, M. R., Pentchev, L., Peters, K. J., Phelps, W., Pooser, E., Pratt, B., Price, J. W., Qin, N., Reinhold, J., Richards, D., Riska, D. -O, Ritchie, B. G., Ritman, J., Robison, L., Romanov, D., Ryu, H-Y, Salgado, C., Santopinto, E., Sarantsev, A. V., Schumacher, R. A., Schwarz, C., Schwiening, J., Semenov, A., Semenov, I., Seth, K. K., Shepherd, M. R., Smith, E. S., Sober, D. I., Sokhan, D., Somov, A., Somov, S., Soto, O., Sparks, N., Stahov, J., Staib, M. J., Stevens, J. R., Strakovsky, I. I., Subedi, A., Švarc, A., Szczepaniak, A., Tarasov, V., Taylor, S., Teymurazyan, A., Tomaradze, A., Tsaris, A., Vasileiadis, G., Watts, D., Werthmüller, D., Wickramaarachchi, N., Whitlatch, T., Williams, M., Wojtsekhowski, B., Workman, R. L., Xiao, T., Yang, Y., Zachariou, N., Zarling, J., Zhang, Z., Zou, B., Zhang, J., Zhou, X., and Zihlmann, B.

17. First Measurement of Near-Threshold J/ψ Exclusive Photoproduction off the Proton.

Author

Ali A, Amaryan M, Anassontzis EG, Austregesilo A, Baalouch M, Barbosa F, Barlow J, Barnes A, Barriga E, Beattie TD, Berdnikov VV, Black T, Boeglin W, Boer M, Briscoe WJ, Britton T, Brooks WK, Cannon BE, Cao N, Chudakov E, Cole S, Cortes O, Crede V, Dalton MM, Daniels T, Deur A, Dobbs S, Dolgolenko A, Dotel R, Dugger M, Dzhygadlo R, Egiyan H, Ernst A, Eugenio P, Fanelli C, Fegan S, Foda AM, Foote J, Frye J, Furletov S, Gan L, Gasparian A, Gauzshtein V, Gevorgyan N, Gleason C, Goetzen K, Goncalves A, Goryachev VS, Guo L, Hakobyan H, Hamdi A, Han S, Hardin J, Huber GM, Hurley A, Ireland DG, Ito MM, Jarvis NS, Jones RT, Kakoyan V, Kalicy G, Kamel M, Kourkoumelis C, Kuleshov S, Kuznetsov I, Larin I, Lawrence D, Lersch DI, Li H, Li W, Liu B, Livingston K, Lolos GJ, Lyubovitskij V, Mack D, Marukyan H, Matveev V, McCaughan M, McCracken M, McGinley W, McIntyre J, Meyer CA, Miskimen R, Mitchell RE, Mokaya F, Nerling F, Ng L, Ostrovidov AI, Papandreou Z, Patsyuk M, Pauli P, Pedroni R, Pentchev L, Peters KJ, Phelps W, Pooser E, Qin N, Reinhold J, Ritchie BG, Robison L, Romanov D, Romero C, Salgado C, Schertz AM, Schumacher RA, Schwiening J, Seth KK, Shen X, Shepherd MR, Smith ES, Sober DI, Somov A, Somov S, Soto O, Stevens JR, Strakovsky II, Suresh K, Tarasov V, Taylor S, Teymurazyan A, Thiel A, Vasileiadis G, Werthmüller D, Whitlatch T, Wickramaarachchi N, Williams M, Xiao T, Yang Y, Zarling J, Zhang Z, Zhao G, Zhou Q, Zhou X, and Zihlmann B

Abstract

We report on the measurement of the γp→J/ψp cross section from E_{γ}=11.8  GeV down to the threshold at 8.2 GeV using a tagged photon beam with the GlueX experiment. We find that the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section dσ/dt has an exponential slope of 1.67±0.39  GeV^{-2} at 10.7 GeV average energy. The LHCb pentaquark candidates P_{c}^{+} can be produced in the s channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions B(P_{c}^{+}→J/ψp) and cross sections σ(γp→P_{c}^{+})×B(P_{c}^{+}→J/ψp).

Published
2019
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