Author: "M Ehrhart" - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"M Ehrhart"' showing total 347 results

Start Over Author "M Ehrhart"

347 results on '"M Ehrhart"'

1. Beam spin asymmetry measurements of deeply virtual π0 production with CLAS12

Author: A. Kim, S. Diehl, K. Joo, V. Kubarovsky, P. Achenbach, Z. Akbar, J.S. Alvarado, Whitney R. Armstrong, H. Atac, H. Avakian, C. Ayerbe Gayoso, L. Barion, M. Battaglieri, I. Bedlinskiy, B. Benkel, A. Bianconi, A.S. Biselli, M. Bondi, F. Bossù, S. Boiarinov, K.T. Brinkmann, W.J. Briscoe, W.K. Brooks, S. Bueltmann, V.D. Burkert, R. Capobianco, D.S. Carman, J.C. Carvajal, A. Celentano, G. Charles, P. Chatagnon, V. Chesnokov, T. Chetry, G. Ciullo, B. Clary, G. Clash, P.L. Cole, M. Contalbrigo, G. Costantini, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, C. Dilks, C. Djalali, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, S. Fegan, A. Filippi, C. Fogler, G. Gavalian, G.P. Gilfoyle, G. Gosta, F.X. Girod, D.I. Glazier, A.A. Golubenko, R.W. Gothe, L. Guo, K. Hafidi, H. Hakobyan, M. Hattawy, F. Hauenstein, T.B. Hayward, D. Heddle, A. Hobart, M. Holtrop, Yu-Chun Hung, Y. Ilieva, D.G. Ireland, E. Isupov, H.S. Jo, R. Johnston, S. Joosten, M. Khachatryan, A. Khanal, W. Kim, V. Klimenko, A. Kripko, S.E. Kuhn, L. Lanza, M. Leali, M.L. Kabir, S. Lee, P. Lenisa, X. Li, I. .J.D. MacGregor, D. Marchand, V. Mascagna, B. McKinnon, D. Matamoros, S. Migliorati, T. Mineeva, M. Mirazita, V. Mokeev, P. Moran, C. Munoz Camacho, P. Naidoo, K. Neupane, D. Nguyen, S. Niccolai, G. Niculescu, M. Osipenko, M. Ouillon, P. Pandey, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, S.J. Paul, W. Phelps, N. Pilleux, M. Pokhrel, J. Poudel, J.W. Price, Y. Prok, A. Radic, N. Ramasubramanian, Trevor Reed, J. Richards, M. Ripani, J. Ritman, P. Rossi, F. Sabatié, C. Salgado, S. Schadmand, A. Schmidt, Y.G. Sharabian, E.V. Shirokov, U. Shrestha, D. Sokhan, N. Sparveris, M. Spreafico, S. Stepanyan, I.I. Strakovsky, S. Strauch, J. Tan, N. Trotta, R. Tyson, M. Ungaro, S. Vallarino, L. Venturelli, H. Voskanyan, E. Voutier, D.P. Watts, X. Wei, R. Wishart, M.H. Wood, M. Yurov, N. Zachariou, J. Zhang, V. Ziegler, and M. Zurek
Subjects: Physics, QC1-999
Abstract: The new experimental measurements of beam spin asymmetry were performed for the deeply virtual exclusive π0 production in a wide kinematic region with the photon virtualities Q2 up to 6.6 GeV2 and the Bjorken scaling variable xB in the valence regime. The data were collected by the CEBAF Large Acceptance Spectrometer (CLAS12) at Jefferson Lab with longitudinally polarized 10.6 GeV electrons scattered on an unpolarized liquid-hydrogen target. Sizable asymmetry values indicate a substantial contribution from transverse virtual photon amplitudes to the polarized structure functions. The interpretation of these measurements in terms of the Generalized Parton Distributions (GPDs) demonstrates their sensitivity to the chiral-odd GPD E¯T, which contains information on quark transverse spin densities in unpolarized and polarized nucleons and provides access to the nucleon's transverse anomalous magnetic moment. Additionally, the data were compared to a theoretical model based on a Regge formalism that was extended to the high photon virtualities.
Published: 2024
Full Text: View/download PDF

2. A multidimensional study of the structure function ratio σLT′/σ0 from hard exclusive π+ electro-production off protons in the GPD regime

Author: S. Diehl, A. Kim, K. Joo, P. Achenbach, Z. Akbar, M.J. Amaryan, H. Atac, H. Avagyan, C. Ayerbe Gayoso, L. Baashen, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, A.S. Biselli, M. Bondi, W.A. Booth, F. Bossù, S. Boiarinov, K.-Th. Brinkmann, W.J. Briscoe, S. Bueltmann, D. Bulumulla, V.D. Burkert, D.S. Carman, A. Celentano, P. Chatagnon, V. Chesnokov, T. Chetry, G. Ciullo, G. Clash, P.L. Cole, M. Contalbrigo, G. Costantini, A. D'Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, C. Djalali, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, L. Elouadrhiri, S. Fegan, A. Filippi, G. Gavalian, Y. Ghandilyan, G.P. Gilfoyle, D.I. Glazier, A.A. Golubenko, G. Gosta, R.W. Gothe, Y. Gotra, K.A. Griffioen, M. Guidal, K. Hafidi, H. Hakobyan, M. Hattawy, T.B. Hayward, D. Heddle, A. Hobart, M. Holtrop, Y. Ilieva, D.G. Ireland, E.L. Isupov, H.S. Jo, M. Khachatryan, A. Khanal, W. Kim, A. Kripko, V. Kubarovsky, V. Lagerquist, J.-M. Laget, L. Lanza, M. Leali, S. Lee, P. Lenisa, X. Li, K. Livingston, I. .J .D. MacGregor, D. Marchand, V. Mascagna, B. McKinnon, Z.E. Meziani, S. Migliorati, T. Mineeva, M. Mirazita, V. Mokeev, E. Molina, R.A. Montgomery, C. Munoz Camacho, P. Nadel-Turonski, P. Naidoo, K. Neupane, S. Niccolai, M. Nicol, G. Niculescu, M. Osipenko, M. Ouillon, P. Pandey, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, S.J. Paul, W. Phelps, N. Pilleux, M. Pokhrel, J. Poudel, J.W. Price, Y. Prok, T. Reed, J. Richards, M. Ripani, J. Ritman, P. Rossi, F. Sabatié, C. Salgado, S. Schadmand, A. Schmidt, Y. Sharabian, E.V. Shirokov, U. Shrestha, P. Simmerling, D. Sokhan, N. Sparveris, M. Spreafico, S. Stepanyan, I.I. Strakovsky, S. Strauch, J.A. Tan, N. Trotta, M. Turisini, R. Tyson, M. Ungaro, S. Vallarino, L. Venturelli, H. Voskanyan, E. Voutier, D.P. Watts, X. Wei, R. Williams, R. Wishart, M.H. Wood, N. Zachariou, J. Zhang, Z.W. Zhao, and M. Zurek
Subjects: Exclusive single pion, Eletroproduction, GPD, CLAS12, Physics, QC1-999
Abstract: A multidimensional extraction of the structure function ratio σLT′/σ0 from the hard exclusive e→p→e′nπ+ reaction above the resonance region has been performed. The study was done based on beam-spin asymmetry measurements using a 10.6 GeV incident electron beam on a liquid-hydrogen target and the CLAS12 spectrometer at Jefferson Lab. The measurements focus on the very forward regime (t/Q2 ≪ 1) with a wide kinematic range of xB in the valence regime (0.17 < xB < 0.55), and virtualities Q2 ranging from 1.5 GeV2 up to 6 GeV2. The results and their comparison to theoretical models based on Generalized Parton Distributions demonstrate the sensitivity to chiral-odd GPDs and the directly related tensor charge of the nucleon. In addition, the data is compared to an extension of a Regge formalism at high photon virtualities. It was found that the Regge model provides a better description at low Q2, while the GPD model is more appropriate at high Q2.
Published: 2023
Full Text: View/download PDF

3. Beam-spin asymmetry Σ for Σ− hyperon photoproduction off the neutron

Author: N. Zachariou, E. Munevar, B.L. Berman, P. Bydžovský, A. Cieplý, G. Feldman, Y. Ilieva, P. Nadel-Turonski, D. Skoupil, A.V. Sarantsev, D.P. Watts, M.J. Amaryan, G. Angelini, W.R. Armstrong, H. Atac, H. Avakian, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, F. Benmokhtar, A. Bianconi, L. Biondo, A.S. Biselli, M. Bondi, F. Bossù, S. Boiarinov, W.J. Briscoe, W.K. Brooks, D. Bulumulla, V.D. Burkert, D.S. Carman, J.C. Carvajal, A. Celentano, P. Chatagnon, T. Chetry, G. Ciullo, L. Clark, P.L. Cole, M. Contalbrigo, G. Costantini, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, S. Diehl, C. Djalali, R. Dupre, M. Dugger, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, P. Eugenio, G. Fedotov, S. Fegan, A. Filippi, A. Fradi, G. Gavalian, G.P. Gilfoyle, F.X. Girod, C. Gleason, A.A. Golubenko, R.W. Gothe, K.A. Griffioen, M. Guidal, K. Hafidi, H. Hakobyan, M. Hattawy, T.B. Hayward, D. Heddle, K. Hicks, A. Hobart, M. Holtrop, D.G. Ireland, E.L. Isupov, D. Jenkins, H.S. Jo, K. Joo, D. Keller, A. Khanal, M. Khandaker, A. Kim, F.J. Klein, A. Kripko, V. Kubarovsky, L. Lanza, M. Leali, K. Livingston, I.J.D. MacGregor, D. Marchand, N. Markov, L. Marsicano, V. Mascagna, B. McKinnon, S. Migliorati, T. Mineeva, M. Mirazita, V. Mokeev, C. Munoz Camacho, K. Neupane, S. Niccolai, G. Niculescu, T.R. O'Connell, M. Osipenko, A.I. Ostrovidov, P. Pandey, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, W. Phelps, O. Pogorelko, J.W. Price, Y. Prok, B.A. Raue, M. Ripani, J. Ritman, A. Rizzo, G. Rosner, J. Rowley, F. Sabatie, C. Salgado, A. Schmidt, R.A. Schumacher, Y.G. Sharabian, E.V. Shirokov, U. Shrestha, D. Sokhan, O. Soto, N. Sparveris, S. Stepanyan, P. Stoler, I.I. Strakovsky, S. Strauch, R. Tyson, M. Ungaro, L. Venturelli, H. Voskanyan, A. Vossen, E. Voutier, K. Wei, X. Wei, R. Wishart, M.H. Wood, B. Yale, J. Zhang, and Z.W. Zhao
Subjects: Physics, QC1-999
Abstract: We report a new measurement of the beam-spin asymmetry, Σ, for the γ→n→K+Σ− reaction using quasi-free neutrons in a liquid-deuterium target. The new dataset includes data at previously unmeasured photon energy and angular ranges, thereby providing new constraints on partial wave analyses used to extract properties of the excited nucleon states. The experimental data were obtained using the CEBAF Large Acceptance Spectrometer (CLAS), housed in Hall B of the Thomas Jefferson National Accelerator Facility (JLab). The CLAS detector measured reaction products from a liquid-deuterium target produced by an energy-tagged, linearly polarised photon beam with energies in the range 1.1 to 2.3 GeV. Predictions from an isobar model indicate strong sensitivity to N(1720)3/2+, Δ(1900)1/2−, and N(1895)1/2−, which corroborates results from a recent combined analysis of all KΣ channels. When our data are incorporated in the fits of partial-wave analyses, one observes significant changes in γ-n couplings of resonances which have small branching ratios to the πN channel.
Published: 2022
Full Text: View/download PDF

4. 12C(e,e'pN) measurements of short range correlations in the tensor-to-scalar interaction transition region

Author: I. Korover, J.R. Pybus, A. Schmidt, F. Hauenstein, M. Duer, O. Hen, E. Piasetzky, L.B. Weinstein, D.W. Higinbotham, S. Adhikari, K. Adhikari, M.J. Amaryan, Giovanni Angelini, H. Atac, L. Barion, M. Battaglieri, A. Beck, I. Bedlinskiy, Fatiha Benmokhtar, A. Bianconi, A.S. Biselli, S. Boiarinov, W.J. Briscoe, W.K. Brooks, D. Bulumulla, V.D. Burkert, D.S. Carman, A. Celentano, P. Chatagnon, T. Chetry, L. Clark, B. Clary, P.L. Cole, M. Contalbrigo, V. Crede, R. Cruz-Torres, A. D'Angelo, R. De Vita, M. Defurne, A. Denniston, A. Deur, S. Diehl, C. Djalali, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, R. Fersch, A. Filippi, T. Forest, G. Gavalian, F.X. Girod, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, K. Hafidi, H. Hakobyan, N. Harrison, M. Hattawy, T.B. Hayward, D. Heddle, K. Hicks, M. Holtrop, Y. Ilieva, D.G. Ireland, E.L. Isupov, D. Jenkins, H.S. Jo, K. Joo, S. Joosten, D. Keller, M. Khachatryan, A. Khanal, M. Khandaker, A. Kim, C.W. Kim, F.J. Klein, V. Kubarovsky, L. Lanza, M. Leali, P. Lenisa, K. Livingston, V. Lucherini, I.J.D. MacGregor, D. Marchand, N. Markov, L. Marsicano, V. Mascagna, B. McKinnon, S. Mey-Tal Beck, T. Mineeva, M. Mirazita, A. Movsisyan, C. Munoz Camacho, B. Mustapha, P. Nadel-Turonski, K. Neupane, G. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, W. Phelps, O. Pogorelko, J.W. Price, Y. Prok, D. Protopopescu, B.A. Raue, M. Ripani, J. Ritman, A. Rizzo, G. Rosner, J. Rowley, F. Sabatié, C. Salgado, R.A. Schumacher, E.P. Segarra, Y.G. Sharabian, U. Shrestha, D. Sokhan, O. Soto, N. Sparveris, S. Stepanyan, I.I. Strakovsky, S. Strauch, J.A. Tan, N. Tyler, M. Ungaro, L. Venturelli, H. Voskanyan, E. Voutier, T. Wang, D. Watts, X. Wei, M.H. Wood, N. Zachariou, J. Zhang, Z.W. Zhao, and X. Zheng
Subjects: Physics, QC1-999
Abstract: High-momentum configurations of nucleon pairs at short-distance are probed using measurements of the 12C(e,e′p) and 12C(e,e′pN) reactions (where N is either n or p), at high-Q2 and xB>1.1. The data span a missing-momentum range of 300–1000 MeV/c and are predominantly sensitive to the transition region of the strong nuclear interaction from a Tensor to Scalar interaction. The data are well reproduced by theoretical calculations using the Generalized Contact Formalism with both chiral and phenomenological nucleon-nucleon (NN) interaction models. This agreement suggests that the measured high missing-momentum protons up to 1000 MeV/c predominantly belong to short-ranged correlated (SRC) pairs. The measured 12C(e,e′pN) / 12C(e,e′p) and 12C(e,e′pp) / 12C(e,e′pn) cross-section ratios are consistent with a decrease in the fraction of proton-neutron SRC pairs and increase in the fraction of proton-proton SRC pairs with increasing missing momentum. This confirms the transition from an isospin-dependent tensor NN interaction at ∼400 MeV/c to an isospin-independent scalar interaction at high-momentum around ∼800 MeV/c as predicted by theoretical calculation.
Published: 2021
Full Text: View/download PDF

5. Double polarisation observable G for single pion photoproduction from the proton

Author: N. Zachariou, D.P. Watts, J. McAndrew, L. Zana, M. Bashkanov, I.I. Strakovsky, R. Workman, A.V. Sarantsev, V. Nikonov, K.P. Adhikari, S. Adhikari, M.J. Amaryan, G. Angelini, W.R. Armstrong, H. Atac, N.A. Baltzell, L. Barion, M. Battaglieri, I. Bedlinskiy, F. Benmokhtar, A. Bianconi, A.S. Biselli, M. Bondi, F. Bossù, S. Boiarinov, W.J. Briscoe, W.K. Brooks, D. Bulumulla, D.S. Carman, J.C. Carvajal, A. Celentano, P. Chatagnon, T. Chetry, G. Ciullo, B.A. Clary, P.L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, S. Diehl, C. Djalali, M. Dugger, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, S. Fegan, A. Filippi, G. Gavalian, G.P. Gilfoyle, F.X. Girod, D.I. Glazier, R.W. Gothe, K.A. Griffioen, L. Guo, K. Hafidi, H. Hakobyan, M. Hattawy, D. Heddle, K. Hicks, A. Hobart, M. Holtrop, Q. Huang, Y. Ilieva, D.G. Ireland, E.L. Isupov, D. Jenkins, H.S. Jo, K. Joo, S. Joosten, D. Keller, A. Khanal, M. Khandaker, A. Kim, F.J. Klein, A. Kripko, V. Kubarovsky, L. Lanza, M. Leali, P. Lenisa, K. Livingston, I.J.D. MacGregor, D. Marchand, L. Marsicano, V. Mascagna, B. McKinnon, Z.E. Meziani, T. Mineeva, V. Mokeev, A. Movsisyan, E. Munevar, C. Munoz Camacho, P. Nadel-Turonski, K. Neupane, A. Ni, S. Niccolai, G. Niculescu, T.R. O'Connell, M. Osipenko, A.I. Ostrovidov, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, O. Pogorelko, Y. Prok, D. Protopopescu, M. Ripani, B.G. Ritchie, J. Ritman, A. Rizzo, G. Rosner, J. Rowley, F. Sabatié, C. Salgado, A. Schmidt, R.A. Schumacher, Y.G. Sharabian, U. Shrestha, D. Sokhan, O. Soto, N. Sparveris, S. Stepanyan, S. Strauch, N. Tyler, M. Ungaro, L. Venturelli, H. Voskanyan, E. Voutier, X. Wei, B. Yale, J. Zhang, and Z.W. Zhao
Subjects: Physics, QC1-999
Abstract: We report measurements of π+ and π0 meson photoproduction from longitudinally spin-polarised protons by an energy tagged (0.73-2.3 GeV) and linearly polarised photon beam. A close to complete solid angle coverage for the reaction products was provided by the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The double-polarisation observable G is extracted from Maximum Likelihood fits to the data, enabling the first accurate determination for the reaction γ→p→→π+n, while also significantly extending the kinematic coverage for γ→p→→π0p. This large data set provides an important constraint on the properties and spectrum of excited nucleon states decaying to Nπ in the mass range from 1.4 to 2.2 GeV, as well as for background (non-resonant) photoproduction processes. The considerable improvement achieved in the description of the observable G within the SAID and Bonn-Gatchina approaches after implementation of our data, illustrates that the partial-wave analyses now significantly extend the knowledge on Nπ photoproduction amplitudes at W>1.8 GeV. A partial-wave analysis using the new high-precision data set has a large impact on the extracted properties of high-spin nucleon excited states.
Published: 2021
Full Text: View/download PDF

6. Beam–target helicity asymmetry E in K+Σ− photoproduction on the neutron

Author: N. Zachariou, D.P. Watts, J. Fleming, A.V. Sarantsev, V.A. Nikonov, A. D'Angelo, M. Bashkanov, C. Hanretty, T. Kageya, F.J. Klein, M. Lowry, H. Lu, A. Sandorfi, X. Wei, I. Zonta, K.P. Adhikari, S. Adhikari, M.J. Amaryan, G. Angelini, G. Asryan, H. Atac, L. Barion, C. Bass, M. Battaglieri, I. Bedlinskiy, F. Benmokhtar, A. Bianconi, A.S. Biselli, F. Bossù, S. Boiarinov, W.J. Briscoe, W.K. Brooks, D. Bulumulla, V. Burkert, D.S. Carman, J.C. Carvajal, A. Celentano, G. Charles, P. Chatagnon, T. Chetry, G. Ciullo, P.L. Cole, M. Contalbrigo, N. Dashyan, R. De Vita, A. Deur, S. Diehl, C. Djalali, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, P. Eugenio, S. Fegan, R. Fersch, A. Filippi, G. Gavalian, N. Gevorgyan, Y. Ghandilyan, G.P. Gilfoyle, F.X. Girod, W. Gohn, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, K. Hafidi, H. Hakobyan, M. Hattawy, D. Heddle, K. Hicks, D. Ho, M. Holtrop, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, H.S. Jo, K. Joo, S.J. Joosten, D. Keller, M. Khachatryan, A. Khanal, M. Khandaker, C.W. Kim, W. Kim, V. Kubarovsky, L. Lanza, M. Leali, P. Lenisa, K. Livingston, I.J.D. MacGregor, D. Marchand, N. Markov, L. Marsicano, V. Mascagna, M. Mayer, B. McKinnon, Z.E. Meziani, T. Mineeva, V. Mokeev, E. Munevar, C. Munoz Camacho, P. Nadel Turonski, T.R. O'Connell, M. Osipenko, A.I. Ostrovidov, M. Paolone, L.L. Pappalardo, K. Park, E. Pasyuk, P. Peng, W. Phelps, O. Pogorelko, J. Poudel, J.W. Price, Y. Prok, A.J.R. Puckett, B.A. Raue, M. Ripani, A. Rizzo, G. Rosner, C. Salgado, A. Schmidt, R.A. Schumacher, U. Shrestha, D. Sokhan, O. Soto, N. Sparveris, I.I. Strakovsky, S. Strauch, J.A. Tan, N. Tyler, M. Ungaro, L. Venturelli, H. Voskanyan, E. Voutier, N.K. Walford, C.S. Whisnant, M.H. Wood, J. Zhang, and Z.W. Zhao
Subjects: Physics, QC1-999
Abstract: We report a measurement of a beam–target double-polarisation observable (E) for the γ→n→(p)→K+Σ−(p) reaction. The data were obtained impinging the circularly-polarised energy-tagged photon beam of Hall B at Jefferson Lab on a longitudinally-polarised frozen-spin hydrogen deuteride (HD) nuclear target. The E observable for an effective neutron target was determined for centre-of-mass energies 1.70≤W≤2.30 GeV, with reaction products detected over a wide angular acceptance by the CLAS spectrometer. These new double-polarisation data give unique constraints on the strange decays of excited neutron states. Inclusion of the new data within the Bonn-Gatchina theoretical model results in significant changes for the extracted photocouplings of a number of established nucleon resonances. Possible improvements in the PWA description of the experimental data with additional “missing” resonance states, including the N(2120)3/2− resonance, are also quantified.
Published: 2020
Full Text: View/download PDF

7. Measurement of the beam spin asymmetry of e→p→e′p′η in the deep-inelastic regime with CLAS

Author: B. Zhao, A. Kim, K. Joo, I. Bedlinskiy, W. Kim, V. Kubarovsky, M. Ungaro, S. Adhikari, Z. Akbar, G. Angelini, H. Avakian, J. Ball, N.A. Baltzell, L. Barion, M. Bashkanov, M. Battaglieri, V. Batourine, A.S. Biselli, S. Boiarinov, W.J. Briscoe, W.K. Brooks, V.D. Burkert, D.S. Carman, A. Celentano, P. Chatagnon, T. Chetry, G. Ciullo, L. Clark, B.A. Clary, P.L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, M. Defurne, A. Deur, S. Diehl, C. Djalali, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, P. Eugenio, A. Filippi, T.A. Forest, G. Gavalian, Y. Ghandilyan, G.P. Gilfoyle, F.X. Girod, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, N. Harrison, M. Hattawy, D. Heddle, K. Hicks, M. Holtrop, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, H.S. Jo, S. Johnston, M.L. Kabir, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, A. Klein, F.J. Klein, S.E. Kuhn, S.V. Kuleshov, L. Lanza, P. Lenisa, K. Livingston, I.J.D. MacGregor, D. Marchand, N. Markov, B. McKinnon, C.A. Meyer, Z.E. Meziani, M. Mirazita, V. Mokeev, R.A. Montgomery, C. Munoz Camacho, P. Nadel-Turonski, S. Niccolai, G. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, O. Pogorelko, J.W. Price, Y. Prok, D. Protopopescu, M. Ripani, A. Rizzo, G. Rosner, P. Rossi, F. Sabatié, C. Salgado, R.A. Schumacher, Y.G. Sharabian, Iu. Skorodumina, G.D. Smith, D. Sokhan, N. Sparveris, S. Stepanyan, I.I. Strakovsky, S. Strauch, M. Taiuti, J.A. Tan, H. Voskanyan, E. Voutier, R. Wang, X. Wei, M.H. Wood, N. Zachariou, J. Zhang, and Z.W. Zhao
Subjects: Physics, QC1-999
Abstract: The beam spin asymmetry of the exclusive pseudoscalar channel e→p→e′p′η was measured for the first time in the deep-inelastic regime (W>2 GeV/c2 and Q2>1 GeV2/c2) using a longitudinally polarized 5.78 GeV electron beam at Jefferson Lab with the CEBAF Large Acceptance Spectrometer. The data were accumulated in 144 four-dimensional bins of Q2, xB, −t and ϕ over a wide kinematic range, where ϕ is the azimuthal angle between the lepton and hadron scattering planes, The measured azimuthal dependence with large amplitudes of the sin⁡ϕ moments is a clear indication of a substantial contribution to the polarized cross-section from transversely polarized virtual photons. In the framework of generalized parton distributions (GPDs) this contribution is expressed via longitudinal-transverse interference between chiral-even and chiral-odd GPDs. The experimental results are compared to the existing theoretical models demonstrating the sensitivity to the product of chiral-odd and chiral-even GPDs and provide new constraints to the existing GPD parameterizations. Keywords: Nucleon structure, CLAS collaboration, Deeply Virtual Meson Production, Chiral-odd generalized parton distributions
Published: 2019
Full Text: View/download PDF

8. First results on nucleon resonance photocouplings from the γp → π+π−p reaction

Author: E. Golovatch, V.D. Burkert, D.S. Carman, R.W. Gothe, K. Hicks, B.S. Ishkhanov, V.I. Mokeev, E. Pasyuk, S. Adhikari, Z. Akbar, M.J. Amaryan, H. Avakian, J. Ball, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, A.S. Biselli, S. Boiarinov, W.J. Briscoe, F. Cao, A. Celentano, P. Chatagnon, T. Chetry, G. Ciullo, L. Clark, B.A. Clary, P.L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, M. Defurne, A. Deur, S. Diehl, C. Djalali, M. Dugger, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, R. Fersch, A. Filippi, Y. Ghandilyan, G.P. Gilfoyle, K.L. Giovanetti, F.X. Girod, D.I. Glazier, K.A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, N. Harrison, M. Hattawy, D. Heddle, M. Holtrop, Y. Ilieva, D.G. Ireland, E.L. Isupov, D. Jenkins, H.S. Jo, S. Johnston, K. Joo, M.L. Kabir, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, W. Kim, A. Klein, F.J. Klein, V. Kubarovsky, L. Lanza, P. Lenisa, K. Livingston, I.J.D. MacGregor, D. Marchand, N. Markov, B. McKinnon, C.A. Meyer, R.A. Montgomery, A. Movsisyan, C. Munoz Camacho, P. Nadel-Turonski, S. Niccolai, G. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, O. Pogorelko, J.W. Price, Y. Prok, D. Protopopescu, M. Ripani, D. Riser, A. Rizzo, G. Rosner, F. Sabatié, C. Salgado, R.A. Schumacher, Y.G. Sharabian, Iu. Skorodumina, G.D. Smith, D.I. Sober, D. Sokhan, N. Sparveris, I.I. Strakovsky, S. Strauch, M. Taiuti, J.A. Tan, N. Tyler, M. Ungaro, H. Voskanyan, E. Voutier, R. Wang, X. Wei, M.H. Wood, N. Zachariou, J. Zhang, and Z.W. Zhao
Subjects: Physics, QC1-999
Abstract: We report the first experimental measurements of the nine 1-fold differential cross sections for the γp→π+π−p reaction, obtained with the CLAS detector at Jefferson Laboratory. The measurements cover the invariant mass range of the final state hadrons from 1.6 GeV
Published: 2019
Full Text: View/download PDF

9. Measurement of nuclear transparency ratios for protons and neutrons

Author: M. Duer, O. Hen, E. Piasetzky, L.B. Weinstein, A. Schmidt, I. Korover, E.O. Cohen, H. Hakobyan, S. Adhikari, G. Angelini, H. Avakian, C. Ayerbe Gayoso, L. Barion, M. Battaglieri, A. Beck, I. Bedlinskiy, A.S. Biselli, S. Boiarinov, W.J. Briscoe, W. Brooks, V.D. Burkert, F. Cao, D.S. Carman, A. Celentano, P. Chatagnon, T. Chetry, G. Ciullo, P.L. Cole, M. Contalbrigo, O. Cortes, V. Crede, R. Cruz Torres, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, S. Diehl, C. Djalali, R. Dupre, Burcu Duran, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, P. Eugenio, A. Filippi, T.A. Forest, G.P. Gilfoyle, F.X. Girod, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, L. Guo, K. Hafidi, C. Hanretty, N. Harrison, M. Hattawy, F. Hauenstein, T.B. Hayward, D. Heddle, M. Holtrop, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, H.S. Jo, S. Johnston, K. Joo, S. Joosten, D. Keller, G. Khachatryan, M. Khachatryan, A. Khanal, M. Khandaker, A. Kim, W. Kim, A. Klein, F.J. Klein, V. Kubarovsky, S.E. Kuhn, S.V. Kuleshov, L. Lanza, G. Laskaris, P. Lenisa, K. Livingston, I.J.D. MacGregor, D. Marchand, B. McKinnon, S. Mey-Tal Beck, T. Mineeva, M. Mirazita, V. Mokeev, R.A. Montgomery, A. Movsisyan, C. Munoz Camacho, B. Mustapha, P. Nadel-Turonski, S. Niccolai, G. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, M. Patsyuk, D. Payette, J. Price, D. Pocanic, O. Pogorelko, Y. Prok, D. Protopopescu, B.A. Raue, M. Ripani, D. Riser, A. Rizzo, G. Rosner, P. Rossi, F. Sabatié, C. Salgado, B.A. Schmookler, R.A. Schumacher, E.P. Segarra, Y.G. Sharabian, Iu. Skorodumina, D. Sokhan, O. Soto, N. Sparveris, S. Stepanyan, S. Strauch, M. Taiuti, J.A. Tan, M. Ungaro, H. Voskanyan, E. Voutier, R. Wang, X. Wei, N. Zachariou, J. Zhang, Z.W. Zhao, and X. Zheng
Subjects: Physics, QC1-999
Abstract: This paper presents, for the first time, measurements of neutron transparency ratios for nuclei relative to C measured using the (e,e′n) reaction, spanning measured neutron momenta of 1.4 to 2.4 GeV/c. The transparency ratios were extracted in two kinematical regions, corresponding to knockout of mean-field nucleons and to the breakup of Short-Range Correlated nucleon pairs. The extracted neutron transparency ratios are consistent with each other for the two measured kinematical regions and agree with the proton transparencies extracted from new and previous (e,e′p) measurements, including those from neutron-rich nuclei such as lead. The data also agree with and confirm the Glauber approximation that is commonly used to interpret experimental data. The nuclear-mass-dependence of the extracted transparencies scales as Aα with α=−0.289±0.007, which is consistent with nuclear-surface dominance of the reactions.
Published: 2019
Full Text: View/download PDF

10. Green turtle mitochondrial microsatellites indicate finer-scale natal homing to isolated islands than to continental nesting sites

Author: Llewellyn M. Ehrhart, Brian M. Shamblin, Campbell J. Nairn, Dean A. Bagley, Simona A. Ceriani, Katherine L. Mansfield, Kristen M. Hart, and Kelly J. Martin
Subjects: 0106 biological sciences, Ecology, Scale (ratio), 010604 marine biology & hydrobiology, Population structure, Aquatic Science, 010603 evolutionary biology, 01 natural sciences, law.invention, Geography, Natal homing, law, Nesting (computing), Microsatellite, Turtle (robot), Ecology, Evolution, Behavior and Systematics
Abstract: In highly mobile philopatric species, defining the scale of natal homing is fundamental to characterizing population dynamics and effectively managing distinct populations. Genetic tools have provided evidence of regional natal philopatry in marine turtles, but extensive sharing of maternally inherited mitochondrial control region (CR) haplotypes within regions (Chelonia mydasnesting sites detected at least 2 populations, but the ubiquity of haplotype CM-A3.1 among southern rookeries decreased the power to detect differentiation. We reassessed population structure by sequencing the mitochondrial microsatellite (short tandem repeat, mtSTR) in 786 samples from 11 nesting sites spanning 700 km from Canaveral National Seashore through Dry Tortugas National Park. The mtSTR marker subdivided CM-A3.1 into 12 haplotypes that were structured among rookeries, demonstrating independent female recruitment into the Dry Tortugas and Marquesas Keys nesting populations. Combined haplotypes provided support for recognition of at least 4 management units in Florida: (1) central eastern Florida, (2) southeastern Florida, (3) Key West National Wildlife Refuge, and (4) Dry Tortugas National Park. Recapture data indicated female nesting dispersal between islands
Published: 2020
Full Text: View/download PDF

11. Anandamide injected into the lateral ventricle of the brain inhibits submandibular salivary secretion by attenuating parasympathetic neurotransmission

Author: J. Fernandez-Solari, J.P. Prestifilippo, P. Vissio, M. Ehrhart-Bornstein, S.R. Bornstein, V. Rettori, and J.C. Elverdin
Subjects: Anandamide, Parasympathetic nervous system, Submandibular gland, Cannabinoid receptor type 1, Gamma-aminobutyric acid, Medicine (General), R5-920, Biology (General), QH301-705.5
Abstract: Our objective was to determine the effect of arachidonylethanolamide (anandamide, AEA) injected intracerebroventricularly (icv) into the lateral ventricle of the rat brain on submandibular gland (SMG) salivary secretion. Parasympathetic decentralization (PSD) produced by cutting the chorda tympani nerve strongly inhibited methacholine (MC)-induced salivary secretion while sympathetic denervation (SD) produced by removing the superior cervical ganglia reduced it slightly. Also, AEA (50 ng/5 µL, icv) significantly decreased MC-induced salivary secretion in intact rats (MC 1 µg/kg: control (C), 5.3 ± 0.6 vs AEA, 2.7 ± 0.6 mg; MC 3 µg/kg: C, 17.6 ± 1.0 vs AEA, 8.7 ± 0.9 mg; MC 10 µg/kg: C, 37.4 ± 1.2 vs AEA, 22.9 ± 2.6 mg). However, AEA did not alter the significantly reduced salivary secretion in rats with PSD, but decreased the slightly reduced salivary secretion in rats with SD (MC 1 µg/kg: C, 3.8 ± 0.8 vs AEA, 1.4 ± 0.6 mg; MC 3 µg/kg: C, 14.7 ± 2.4 vs AEA, 6.9 ± 1.2 mg; P < 0.05; MC 10 µg/kg: C, 39.5 ± 1.0 vs AEA, 22.3 ± 0.5 mg; P < 0.001). We showed that the inhibitory effect of AEA is mediated by cannabinoid type 1 CB1 receptors and involves GABAergic neurotransmission, since it was blocked by previous injection of the CB1 receptor antagonist AM251 (500 ng/5 µL, icv) or of the GABA A receptor antagonist, bicuculline (25 ng/5 µL, icv). Our results suggest that parasympathetic neurotransmission from the central nervous system to the SMG can be inhibited by endocannabinoid and GABAergic systems.
Published: 2009
Full Text: View/download PDF

12. Measurement of deeply virtual Compton scattering off He4 with the CEBAF Large Acceptance Spectrometer at Jefferson Lab

Author: T. A. Forest, D. P. Watts, H. Egiyan, F. Sabatié, D. Bulumulla, A. Filippi, Aditya R. Khanal, M. Khandaker, G. Rosner, Andrea Bianconi, D. Payette, Jo H. S., Y. Ghandilyan, H. Voskanyan, W. Kim, R. A. Schumacher, P. Lenisa, S. Bültmann, W. J. Briscoe, E. Pasyuk, Maxime Defurne, N. Markov, B. Torayev, R. Dupre, D. G. Ireland, Carlos A. Salgado, V. Crede, B. A. Clary, M. Contalbrigo, K. Livingston, M. Battaglieri, M. J. Amaryan, B. Yale, G. Costantini, S. Stepanyan, V. P. Kubarovsky, A. Kim, R. De Vita, J. Rowley, Whitney Armstrong, Simonetta Liuti, Krishna Neupane, J. Poudel, O. Pogorelko, K. Wei, S. Fegan, P. Eugenio, Dustin Keller, R. Paremuzyan, G. Khachatryan, Volker D. Burkert, M. L. Kabir, H. Atac, T. B. Hayward, Paolo Rossi, A. S. Biselli, R. Wishart, A. Celentano, R. W. Gothe, M. Guidal, K. Hafidi, V. Mokeev, Larry Weinstein, Gerard Gilfoyle, L. Venturelli, Michael Paolone, E. L. Isupov, D. Sokhan, M. Ehrhart, M. Caudron, M. Osipenko, S. Boiarinov, I. J. D. MacGregor, F. Bossu, A. Vossen, G. Ciullo, Fatiha Benmokhtar, Y. Prok, D. S. Carman, M. Holtrop, O. Soto, N. A. Baltzell, Nikos Sparveris, X. Wei, H. Hakobyan, M. H. Wood, E. Voutier, J. Ritman, S. Diehl, N. Dashyan, A. El Alaoui, B. McKinnon, Luciano Pappalardo, M. Bondì, K. A. Griffioen, Yordanka Ilieva, C. Ayerbe Gayoso, Nicholas Zachariou, J. C. Carvajal, Y. Perrin, V. Chesnokov, L. Barion, U. Shrestha, M. Mirazita, L. Lanza, K. Hicks, W. Phelps, V. Mascagna, D. Marchand, S. Niccolai, Alessandro Rizzo, Alexander Schmidt, I. Bedlinskiy, M. Ripani, P. Chatagnon, M. Ungaro, K. Joo, V. Sergeyeva, J. Zhang, F. X. Girod, N. Tyler, C. Djalali, T. Chetry, S. Strauch, L. Elouadrhiri, S. Joosten, I. I. Strakovsky, A. Deur, D. G. Jenkins, A. Hobart, M. Leali, T. R. O'Connell, N. Pivnyuk, A. D'Angelo, L. El Fassi, S. E. Kuhn, M. Hattawy, P. L. Cole, Martin K. Mayer, A. Kripko, and Y. G. Sharabian
Subjects: Nuclear physics, Physics, Spectrometer, 010308 nuclear & particles physics, 0103 physical sciences, Compton scattering, Perturbative QCD, 010306 general physics, 01 natural sciences
Published: 2021
Full Text: View/download PDF

13. Observation of Beam Spin Asymmetries in the Process ep→e′π+π−X with CLAS12

Author: G. Niculescu, D. Bulumulla, G. Ciullo, Aditya R. Khanal, A. El Alaoui, S. Niccolai, E. L. Isupov, D. S. Carman, F. X. Girod, Nikos Sparveris, K. A. Griffioen, D. G. Ireland, V. I. Mokeev, M. Contalbrigo, V. Crede, Nicholas Zachariou, J. C. Carvajal, Sung-Sik Lee, X. Wei, S. Boiarinov, Andrea Bianconi, P. Lenisa, C. Dilks, Fatiha Benmokhtar, O. Soto, T. B. Hayward, M. Osipenko, R. Paremuzyan, L. Marsicano, Maxime Defurne, B. A. Clary, Latifa Elouadrhiri, A. Movsisyan, N. Tyler, N. Markov, P. L. Cole, N. Dashyan, K. Hicks, I. J. D. MacGregor, S. Strauch, D. I. Glazier, V. P. Kubarovsky, Michael Paolone, Krishna Neupane, H. Hakobyan, F. Bossu, R. Tyson, J. Ritman, Eugene Pasyuk, R. De Vita, D. Marchand, H. S. Jo, H. Avakian, Eric Voutier, L. Lanza, S. Diehl, C. Salgado, A. A. Golubenko, H. Atac, H. Voskanyan, G. Costantini, W. J. Briscoe, L. Barion, S. E. Kuhn, M. Hattawy, A. Vossen, M. Guidal, A. D'Angelo, Dustin Keller, M Ehrhart, P. Naidoo, T. Chetry, D. P. Watts, P. Chatagnon, Y. Prok, U. Shrestha, Michael Wood, F. Sabatié, M. Holtrop, Chaden Djalali, L. El Fassi, V. Mascagna, G. Gavalian, K. Hafidi, A. Filippi, B. A. Raue, Luciano Pappalardo, C. Ayerbe Gayoso, I. Bedlinskiy, Michael Dugger, W. Phelps, G. Angelini, P. Rossi, K. Wei, S. Joosten, S. Fegan, M. Leali, A. Celentano, R. W. Gothe, P. Nadel-Turonski, M. Khachatryan, N. A. Baltzell, K. Livingston, Alessandro Rizzo, Axel Schmidt, T. R. O'Connell, William Brooks, I. I. Strakovsky, F. Hauenstein, A. Kim, L. Venturelli, Jie Zhang, Y. Gotra, Z. E. Meziani, A. Deur, B. Yale, E.P. Segarra, S. Nanda, A. Kripko, T. A. Forest, S. Stepanyan, Y. G. Sharabian, M. Ripani, R. Dupré, M. Bondì, M. Battaglieri, O. Pogorelko, J. Rowley, Volker D. Burkert, A. S. Biselli, A. Hobart, S. Adhikari, B. McKinnon, M. Mirazita, Gerard Gilfoyle, D. Sokhan, M. Arratia, Hovanes Egiyan, C. Munoz Camacho, M. Ungaro, K. Joo, A. Thornton, and W. Kim
Subjects: Quark, Physics, Spectrometer, Proton, Nuclear Theory, General Physics and Astronomy, Deep inelastic scattering, 01 natural sciences, Gluon, Nuclear physics, 0103 physical sciences, Cathode ray, Physics::Accelerator Physics, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Beam (structure), Spin-½
Abstract: The observation of beam spin asymmetries in two-pion production in semi-inclusive deep inelastic scattering off an unpolarized proton target is reported for the first time. The data presented here were taken in the fall of 2018 with the CLAS12 spectrometer using a 10.6 GeV longitudinally spin-polarized electron beam delivered by CEBAF at JLab. The measured asymmetries provide the first observation of a signal that can be used to extract the PDF $e(x)$ in a collinear framework and the helicity-dependent two-pion fragmentation function $G_1^\perp$.
Published: 2021
Full Text: View/download PDF

14. Photoproduction of the f2(1270) Meson Using the CLAS Detector

Author: V. Mokeev, P. Eugenio, Vincent Mathieu, D. Heddle, R. A. Schumacher, M. Battaglieri, K. A. Griffioen, R. Paremuzyan, Laura Clark, L. Marsicano, L. Lanza, M. J. Amaryan, M Carver, G. Angelini, D. P. Watts, Gerard Gilfoyle, M. Osipenko, N. Gevorgyan, P. Lenisa, M. Contalbrigo, H. Egiyan, K. Livingston, R. Tyson, D. Sokhan, S. Stepanyan, I. J. D. MacGregor, F. X. Girod, S. Adhikari, Dustin Keller, F. Sabatié, B. McKinnon, G. Niculescu, G. Rosner, B. A. Clary, D. G. Ireland, V. Crede, D. Bulumulla, William Brooks, E. Munevar, Jie Zhang, T. B. Hayward, K. Hafidi, A. Filippi, W. Phelps, Z. E. Meziani, B. Yale, Aditya R. Khanal, L. Venturelli, M. Ehrhart, M. Khandaker, E. L. Isupov, Friedrich Klein, Alessandro Rizzo, A. Kim, Michael Paolone, S. Boiarinov, Andrea Bianconi, G. Ciullo, A. Pilloni, C. W. Kim, A. Celentano, R. W. Gothe, Y. Prok, C. E. Hyde, I. Bedlinskiy, A. El Alaoui, N. A. Baltzell, F. Bossu, T. Chetry, D. S. Carman, Nicholas Zachariou, H. S. Jo, U. Shrestha, J. C. Carvajal, H. Voskanyan, Z. W. Zhao, Fatiha Benmokhtar, Nikos Sparveris, X. Wei, W. J. Briscoe, O. Soto, V. Mascagna, Maxime Defurne, M. Holtrop, S. Joosten, S. Niccolai, D. Protopopescu, E. Voutier, Luciano Pappalardo, A. Movsisyan, R. De Vita, H. Hakobyan, O. Pogorelko, S. Strauch, J. Ritman, J. Rowley, A. I. Ostrovidov, P. Chatagnon, K. Wei, S. Diehl, C. Salgado, S. Fegan, H. Atac, Volker D. Burkert, C. Munoz Camacho, Eugene Pasyuk, A. S. Biselli, G. Gavalian, V. P. Kubarovsky, Krishna Neupane, M. Ripani, M. Hattawy, K. Hicks, N. Dashyan, Michael Dugger, Yordanka Ilieva, L. Barion, Barry Ritchie, R. Dupre, D. Marchand, M. Ungaro, G. V. Fedotov, Q. Huang, K. P. Adhikari, K. Joo, D. G. Jenkins, M. Leali, Axel Schmidt, I. I. Strakovsky, P. Nadel-Turonski, A. Deur, Mark W. Bondi, M. E. McCracken, N. Tyler, C. Djalali, A. D'Angelo, L. El Fassi, A. Kripko, Y. G. Sharabian, and P. L. Cole
Subjects: Quark, Physics, Spectrometer, Meson, High Energy Physics::Lattice, Nuclear Theory, Quark model, Detector, General Physics and Astronomy, Quantum number, 01 natural sciences, 7. Clean energy, Resonance (particle physics), Nuclear physics, Pion, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics
Abstract: The quark structure of the f2(1270) meson has, for many years, been assumed to be a pure quark-antiquark (qq¯) resonance with quantum numbers JPC=2++. Recently, it was proposed that the f2(1270) is a molecular state made from the attractive interaction of two ρ mesons. Such a state would be expected to decay strongly to final states with charged pions due to the dominant decay ρ→π+π-, whereas decay to two neutral pions would likely be suppressed. Here, we measure for the first time the reaction γp→π0π0p, using the CEBAF Large Acceptance Spectrometer detector at Jefferson Lab for incident beam energies between 3.6 and 5.4 GeV. Differential cross sections, dσ/dt, for f2(1270) photoproduction are extracted with good precision due to low backgrounds and are compared to theoretical calculations.
Published: 2021
Full Text: View/download PDF

15. Beam Spin Asymmetry in Semi-Inclusive Electroproduction of Hadron Pairs

Author: K. Park, V. P. Kubarovsky, Krishna Neupane, C. W. Kim, H. Avakian, H. Voskanyan, W. J. Briscoe, Dustin Keller, P. Eugenio, Michael Wood, K. Hafidi, G. Gavalian, L. Marsicano, A Hobart, V. Mokeev, F. X. Girod, R. A. Schumacher, M. Battaglieri, I. I. Strakovsky, R. W. Gothe, T. Chetry, M. J. Amaryan, F. Sabatié, K. Wei, S. Fegan, N. Markov, L. Guo, Alessandro Rizzo, K. A. Griffioen, Fatiha Benmokhtar, Gerard Gilfoyle, R. Paremuzyan, E. L. Isupov, A. Deur, S. Pisano, V. Crede, Ross Milner, O. Soto, P. Lenisa, M. Contalbrigo, C. Dilks, L. Lanza, M. Ungaro, T. A. Forest, C. Mullen, W. K. Brooks, M. Guidal, Z. W. Zhao, S. Stepanyan, N. A. Baltzell, M. Holtrop, T. B. Hayward, Friedrich Klein, Andrea Celentano, O. Pogorelko, J. Poudel, A. Filippi, Brian Raue, K. Hicks, K. Joo, D. Marchand, M. Osipenko, Luciano Pappalardo, K. L. Giovanetti, Hovanes Egiyan, M. Ripani, C. Munoz Camacho, A. D'Angelo, B. Yale, S. Adhikari, L. Venturelli, B. McKinnon, M. Ehrhart, D. G. Ireland, Tim O'Connell, I. Bedlinskiy, D. I. Glazier, W. Phelps, D. G. Jenkins, N. Tyler, M. Leali, L. El Fassi, C. Djalali, Volker D. Burkert, W. Kim, T. Mineeva, D. Heddle, R. De Vita, G. Ciullo, V. Mascagna, H. S. Jo, A. S. Biselli, M. Mirazita, D. Bulumulla, Y. Prok, D. S. Carman, G. Niculescu, B. S. Ishkhanov, E. Pasyuk, Aditya R. Khanal, X. Wei, R. G. Fersch, Andrea Bianconi, H. Atac, P. L. Cole, N. Dashyan, G. Angelini, P. Chatagnon, B. A. Clary, P. Rossi, M. Defurne, Michael Paolone, L. Barion, Axel Schmidt, Aurore Courtoy, K. Livingston, M. Khandaker, Jie Zhang, I. J. D. MacGregor, E. Golovatch, R. Dupre, Y. Ghandilyan, Q. Huang, E. Voutier, A. Vossen, A. El Alaoui, Y. Ilieva, Nicholas Zachariou, J. C. Carvajal, S. Strauch, D. P. Watts, F. Bossu, Nikolaos Sparveris, Dinko Pocanic, S. E. Kuhn, M. Hattawy, Y. G. Sharabian, S. Boiarinov, H. Hakobyan, J. Ritman, S. Diehl, C. Salgado, U. Shrestha, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: High Energy Physics::Lattice, Nuclear Theory, Hadron, parton: distribution function, General Physics and Astronomy, Parton, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Economica, higher-twist, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), electron: beam, Nuclear Experiment, dimension: 1, Physics, Quantum chromodynamics, deep inelastic scattering: semi-inclusive reaction, Settore FIS/04, nucleon, kinematics, Quarks and Gluons, helicity distributions, quark: valence, Nucleon, Jefferson Lab, Quark, Particle physics, polarization: longitudinal, FOS: Physical sciences, Socio-culturale, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Transversity Distributions, hadron: electroproduction, hadron: pair production, Pion, CLAS, Hadron Physics, quantum chromodynamics, 0103 physical sciences, ddc:530, 010306 general physics, High Energy Physics::Phenomenology, Ambientale, Deep inelastic scattering, spin: asymmetry: measured, Distribution function, Elementary Particles and Fields, QCD Dynamics, High Energy Physics::Experiment, pi: pair production, experimental results
Abstract: Physical review letters 126(6), 062002 (2021). doi:10.1103/PhysRevLett.126.062002, Published by APS, College Park, Md.
Published: 2021
Full Text: View/download PDF

16. An experimental program with high duty-cycle polarized and unpolarized positron beams at Jefferson Lab

Author: Anthony W. Thomas, M. Battaglieri, R. De Vita, D. Marchand, Latifa Elouadrhiri, S. Habet, Hubert Spiesberger, P. Gueye, David Hamilton, Giovanni Salmè, A. Filippi, Pete Markowitz, D. Perera, G. Kalicy, M. Muhoza, N. Kalantarians, H. Atac, M. Khandaker, J. Xie, F. Sabatié, M. Mazouz, Ashot Gasparian, I.P. Fernando, V. Klimenko, T. A. Forest, D. McNulty, Z. E. Meziani, M. Boer, M. McCaughan, A. Asaturyan, J. P. Chen, V. Kozhuharov, S. Stepanyan, Simonetta Liuti, T. Patel, Alberto Accardi, M. Spata, Andrew Puckett, Andreas Metz, Salina Ali, V. Bellini, L. Barion, V. V. Berdnikov, Alexandre Camsonne, P. E. Reimer, M. Shabestari, P. Bisio, Simon Širca, T. Averett, J. Kim, Nikolaos Sparveris, M. Poelker, M. Spreafico, H. F. Ibrahim, Dipangkar Dutta, V. Bertone, Bogdan Wojtsekhowski, Ross Milner, H. Avakian, C. E. Hyde, P. M. King, Marc Vanderhaeghen, A. Somov, Yulia Furletova, Miha Mihovilovič, V. Tadevosyan, P. Sznajder, S. Migliorati, R. S. Beminiwattha, T. Chetry, M. Guidal, Olfred Hansen, T. Kutz, Z. W. Zhao, Barbara Pasquini, Eric Voutier, L. Lanza, M. J. Amaryan, J. R. M. Annand, Fatiha Benmokhtar, T. Gautam, H. Voskanyan, Richard Trotta, Ian L. Pegg, J. F. Owens, W. J. Briscoe, Jingyi Zhou, P. Valente, M. N. H. Rashad, Gordan Krnjaic, P. Lenisa, Elena Santopinto, Joseph Grames, M. Leali, S. Zhamkochyan, M. Caudron, Kai-Thomas Brinkmann, Elton Smith, L. Marsicano, Andrei Afanasev, Luciano Pappalardo, M. Carmignotto, Donal Day, L. Venturelli, Eugene Pasyuk, M. Ungaro, C. Peng, L. Causse, D. Hasell, G. Costantini, Douglas Higinbotham, N. D’Hose, J. Murphy, P. Chatagnon, R. Dupré, M. Bondì, Alexander Ilyichev, Matteo Rinaldi, P. Stoler, Brian Raue, G. N. Grauvogel, R. Santos Estrada, Kondo Gnanvo, K. Price, Q. Liu, S. Diehl, J. Nazeer, Y. G. Sharabian, X. Zheng, S. Niccolai, P. G. Blunden, J. Arrington, Riad Suleiman, J. Erler, S. Joosten, Andrea Bianconi, H.-S. Ko, P. L. Cole, Nilanga Liyanage, I. Albayrak, K. Joo, Jan C. Bernauer, F.-X. Girod, D. Gaskell, A. Kim, Juliette Mammei, A. Italiano, M. Hattawy, C. Ayerbe Gayoso, I. I. Strakovsky, M. Yurov, N. Randazzo, A. Deur, Wally Melnitchouk, H.-G. Zaunick, Michael Kohl, A. D'Angelo, E. Nardi, M. Paolone, C. Zorn, L. El Fassi, B. T. Kriesten, L. Darmé, M. Rathnayake, A. Shahinyan, Jie Zhang, Alessandro Rizzo, D. Flay, W. Xiong, H. Dutrieux, V. Sergeyeva, S. Zhang, E. R. Kinney, Hervé Moutarde, B. Dongwi, Axel Schmidt, Rolf Ent, S. Zhao, Volker D. Burkert, A. S. Tadepalli, A. S. Biselli, Tanja Horn, G. Niculescu, T. Cao, A. Celentano, P. Nadel-Turonski, Ethan Cline, J. Roche, B. Karky, M. Contalbrigo, H. Szumila-Vance, S. Fucini, O. Rondon-Aramayo, M. De Napoli, V. Mascagna, E. Fuchey, L. Cardman, G. Ciullo, Haiyan Gao, Cynthia Keppel, M. Ehrhart, A. Movsisyan, R. Novotny, A. Hobart, Sergio Scopetta, B. McKinnon, S. A. Wood, H. Mkrtchyan, M. Tiefenback, C. Munoz Camacho, Xinzhan Bai, R. Paremuzyan, B. Sawatzky, D. Sokhan, M. Suresh, Markus Diefenthaler, Z. Ye, Mauro Raggi, M. Kerver, Y. Roblin, A. Mkrtchyan, V. P. Kubarovsky, R. Capobianco, T. J. Hague, Dustin Keller, Sonny Mantry, Vladimir Khachatryan, Peter Schweitzer, Michael Wood, Maxime Defurne, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: cross-section, ratio, Photon, parton distributions, elastic scattering, Parton, polarized beam, Electron, Leptons Accelerators, Structure of Nucleons, 7. Clean energy, 01 natural sciences, Dark photon, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), Positron, Economica, electromagnetic form-factors, virtual compton-scattering, generalized, squared 4-momentum transfers, lepton-flavor, violation, electron-proton, parity violation, pair production, Physics, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), Nuclear Experiment, Elastic scattering, Dark sector, JLab, dark photon, Settore FIS/04, lepton: flavor: violation, nucleon: generalized parton distribution, 3. Good health, High Energy Physics - Phenomenology, Elastic and deep inelastic Scattering, Nucleon, Jefferson Lab, Nuclear and High Energy Physics, nucleon: form factor: electromagnetic, FOS: Physical sciences, Socio-culturale, helium: target, Context (language use), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear physics, PE2_2, PE2_1, deeply virtual Compton scattering, 0103 physical sciences, quantum chromodynamics, 010306 general physics, PE2_3, activity report, exchange: two-photon, electroweak interaction, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Ambientale, positron: beam, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], charge: asymmetry, Positron Beams, Physics::Accelerator Physics, proposal, High Energy Physics::Experiment
Abstract: Positron beams, both polarized and unpolarized, are identified as essential ingredients for the experimental programs at the next generation of lepton accelerators. In the context of the hadronic physics program at Jefferson Lab (JLab), positron beams are complementary, even essential, tools for a precise understanding of the electromagnetic structure of nucleons and nuclei, in both the elastic and deep-inelastic regimes. For instance, elastic scattering of polarized and unpolarized electrons and positrons from the nucleon enables a model independent determination of its electromagnetic form factors. Also, the deeply-virtual scattering of polarized and unpolarized electrons and positrons allows unambiguous separation of the different contributions to the cross section of the lepto-production of photons and of lepton-pairs, enabling an accurate determination of the nucleons and nuclei generalized parton distributions, and providing an access to the gravitational form factors. Furthermore, positron beams offer the possibility of alternative tests of the Standard Model of particle physics through the search of a dark photon, the precise measurement of electroweak couplings, and the investigation of charged lepton flavor violation. This document discusses the perspectives of an experimental program with high duty-cycle positron beams at JLab., Comment: 18 pages, 7 figures This version superseeds the previous version which scientific content was decomposed into several more elaborated articles. All of these articles will be collected in the EPJ A Topical Issue about "Positron beam and physics at Jefferson Lab (e+@Jlab)"
Published: 2021
Full Text: View/download PDF

17. Measurement of the proton spin structure at long distances

Author: P. Eugenio, J. Brock, N. Dashyan, I. Bedlinskiy, S. Choi, P. Nadel-Turonski, A. Hobart, M. Defurne, S. E. Kuhn, Latifa Elouadrhiri, P. Chatagnon, M. Ripani, C. D. Keith, D. Bulumulla, Aditya R. Khanal, S. Adhikari, B. McKinnon, T. Holmstrom, V. Mokeev, G. V. Fedotov, H. S. Jo, L. Guo, Alessandro Rizzo, Andrea Bianconi, L. Barion, M. Mirazita, K. Livingston, M. Hattawy, N. Markov, G. Rosner, Simon Širca, S. Fegan, Y. Ghandilyan, Jie Zhang, P. Bosted, Michael Paolone, C. Carlin, M. Guidal, M. L. Seely, E. Pasyuk, D. P. Watts, F. Bossu, Laura Clark, S. Niccolai, N. Guler, M. Holtrop, B. Yale, R. A. Schumacher, P. Rossi, W. Phelps, V. Mascagna, S. Joosten, Axel Schmidt, Alexandre Deur, Luciano Pappalardo, Nikolaos Sparveris, V. Crede, I. I. Strakovsky, W. Kim, Fatiha Benmokhtar, M. Ehrhart, D. I. Glazier, V. P. Kubarovsky, T. A. Forest, O. Pogorelko, Z. W. Zhao, J. Rowley, S. Stepanyan, A. I. Ostrovidov, K. Park, Krishna Neupane, R. De Vita, A. El Alaoui, Y. Ilieva, Nicholas Zachariou, D. G. Ireland, C. W. Kim, H. Avakian, C. Mullen, W. K. Brooks, A. Kripko, Andrea Celentano, Volker D. Burkert, A. S. Biselli, J. C. Carvajal, V. Sulkosky, H. Atac, Karl Slifer, M. Leali, F. Sabatié, L. Venturelli, Y. G. Sharabian, X. Zheng, M. Bondì, H. Voskanyan, P. Lenisa, W. J. Briscoe, I. J. D. MacGregor, M. Contalbrigo, S. K. Phillips, T. Mineeva, T. B. Hayward, Friedrich Klein, Brian Raue, J. Poudel, N. Tyler, C. Djalali, G. Ciullo, M. Osipenko, Y. Prok, D. S. Carman, X. Wei, K. A. Griffioen, E. Voutier, Dustin Keller, S. Strauch, L. Lanza, R. W. Gothe, Michael Wood, T. Chetry, K. Hafidi, R. Dupre, M. Battaglieri, Gerard Gilfoyle, E. L. Isupov, V. A. Drozdov, S. Boiarinov, H. Kang, U. Shrestha, F.-X. Girod, K. P. Adhikari, H. Hakobyan, J. Ritman, S. Diehl, C. Salgado, R. G. Fersch, M. Ungaro, E. Long, J. P. Chen, D. Heddle, P. L. Cole, D. G. Meekins, A. D'Angelo, K. Hicks, L. El Fassi, K. Joo, M. Khandaker, M. J. Amaryan, A. Filippi, K. L. Giovanetti, Larry Weinstein, L. Marsicano, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: polarizabilities, Photon, Proton, High Energy Physics::Lattice, Nuclear Theory, General Physics and Astronomy, polarized target, polarized beam, 01 natural sciences, 7. Clean energy, 010305 fluids & plasmas, High Energy Physics - Experiment, Theoretical Nuclear Physics, Experimental Nuclear Physics, High Energy Physics - Experiment (hep-ex), effective field theory, Economica, Proton spin crisis, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Experimental particle Physics, order, Nuclear Experiment (nucl-ex), Nuclear Experiment, Spin-½, Quantum chromodynamics, Physics, Settore FIS/04, nucleon, virtual compton-scattering, chiral perturbation-theory, sum-rule, moments, evolution, sum rule, kinematics, Quantum electrodynamics, nuclear matter, Nucleon, nucleon: structure, Strong interaction, FOS: Physical sciences, Socio-culturale, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], p: spin, PE2_2, momentum transfer: low, PE2_1, CLAS, 0103 physical sciences, quantum chromodynamics, ddc:530, 010306 general physics, PE2_3, quark gluon, Coupling constant, nuclear force, scattering, Ambientale, Physics::Accelerator Physics, nucleon: spin, High Energy Physics::Experiment, experimental results
Abstract: Measuring the spin structure of protons and neutrons tests our understanding of how they arise from quarks and gluons, the fundamental building blocks of nuclear matter. At long distances the coupling constant of the strong interaction becomes large, requiring non-perturbative methods to calculate quantum chromodynamics processes, such as lattice gauge theory or effective field theories. Here we report proton spin structure measurements from scattering a polarized electron beam off polarized protons. The spin-dependent cross-sections were measured at large distances, corresponding to the region of low momentum transfer squared between 0.012 and 1.0 GeV$^2$. This kinematic range provides unique tests of chiral effective field theory predictions. Our results show that a complete description of the nucleon spin remains elusive, and call for further theoretical works, e.g. in lattice quantum chromodynamics. Finally, our data extrapolated to the photon point agree with the Gerasimov-Drell-Hearn sum rule, a fundamental prediction of quantum field theory that relates the anomalous magnetic moment of the proton to its integrated spin-dependent cross-sections., Published version. 10 pages, 5 figures. 20 pages of supplementary material (data tables and a figure)
Published: 2021
Full Text: View/download PDF

18. Deeply virtual Compton scattering using a positron beam in Hall-C at Jefferson Lab

Author: Rolf Ent, M. Kerver, T. A. Forest, A. Mkrtchyan, M. J. Amaryan, P. Nadel-Turonski, Jie Zhang, M. McCaughan, V. V. Berdnikov, H. Rashad, J. Roche, Dustin Keller, A. Asaturyan, C. Munoz Camacho, K. Price, Donal Day, H.-S. Ko, B. McKinnon, S. A. Wood, I. Albayrak, V. Sergeyeva, A. Hobart, J. Murphy, S. Zhao, J. R. M. Annand, M. A. I. Fernando, Bogdan Wojtsekhowski, A. Somov, Tanja Horn, D. Marchand, S. Zhamkochyan, M. Defurne, H. Mkrtchyan, I. I. Strakovsky, S. Habet, V. Tadevosyan, R. Dupré, David Hamilton, Cynthia Keppel, R. Paremuzyan, H. Voskanyan, G. Kalicy, W. J. Briscoe, Dipangkar Dutta, P. Chatagnon, M. Caudron, S. Niccolai, V. Bellini, C. E. Hyde, Alexandre Camsonne, B. Sawatzky, Salina Ali, G. Niculescu, M. Ehrhart, Simon Širca, Eric Voutier, R. Rondon, E. R. Kinney, M. Muhoza, M. Guidal, P. Gueye, M. Mazouz, M. Carmignotto, Kai-Thomas Brinkmann, L. Causse, Carl Zorn, Andrei Afanasev, R. Novotny, S. Diehl, Richard Trotta, Ian L. Pegg, Joseph Grames, M. Boer, P. Markowitze, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: Nuclear and High Energy Physics, Photon, interference, FOS: Physical sciences, Parton, Bethe-Heitler, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], momentum transfer dependence, 01 natural sciences, Nuclear physics, p: target, Cross section (physics), deeply virtual Compton scattering, 0103 physical sciences, Nuclear Experiment (nucl-ex), 010306 general physics, Neutral particle, Nuclear Experiment, Physics, Spectrometer, 010308 nuclear & particles physics, Compton scattering, photon: electroproduction, nucleon: generalized parton distribution, positron: beam, neutral particle, kinematics, momentum: high, High Energy Physics::Experiment, spectrometer, Nucleon, Beam (structure), Jefferson Lab, experimental results
Abstract: We propose to use the High Momentum Spectrometer of Hall C combined with the Neutral Particle Spectrometer (NPS) to perform high precision measurements of the Deeply Virtual Compton Scattering (DVCS) cross section using a beam of positrons. The combination of measurements with oppositely charged incident beams is the only unambiguous way to disentangle the contribution of the DVCS $$^2$$ term in the photon electroproduction cross section from its interference with the Bethe-Heitler amplitude. This provides a stronger way to constrain the Generalized Parton Distributions of the nucleon. A wide range of kinematics accessible with an 11 GeV beam off an unpolarized proton target will be covered. The $$Q^2-$$ dependence of each contribution will be measured independently.
Published: 2021
Full Text: View/download PDF

19. Photoproduction of η mesons off the proton for 1.2<Eγ<4.7GeV using CLAS at Jefferson Laboratory

Author: I. Illari, R. A. Schumacher, U. Shrestha, M. Leali, S. Adhikari, B. McKinnon, C. A. Meyer, E. Munevar, P. Chatagnon, B. S. Ishkhanov, Aditya R. Khanal, G. V. Fedotov, P. Lenisa, J. Ritman, S. Stepanyan, N. Dashyan, D. P. Watts, Andrea Bianconi, M. Ungaro, K. P. Adhikari, A. El Alaoui, I. I. Strakovsky, G. Rosner, T. Chetry, A. Deur, C. W. Kim, Laura Clark, W. Phelps, M. Battaglieri, Nicholas Zachariou, J. C. Carvajal, Alexander Schmidt, M. J. Amaryan, William Brooks, Yordanka Ilieva, T. B. Hayward, V. Mascagna, B. A. Clary, E. L. Isupov, Y. G. Sharabian, H. Voskanyan, Friedrich Klein, W. J. Briscoe, P. Eugenio, S. Boiarinov, Brian Raue, G. Angelini, L. Barion, K. Joo, M. Guidal, Michael Paolone, Z. W. Zhao, F. X. Girod, F. Bossu, R. Cruz-Torres, E. Golovatch, M. Holtrop, R. Dupre, S. Strauch, Hovanes Egiyan, Maxime Defurne, K. A. Griffioen, Dustin Keller, C. Munoz Camacho, H. Hakobyan, Y. Prok, H. S. Jo, M. Hattawy, Michael Wood, K. Hafidi, D. G. Ireland, Luciano Pappalardo, V. Crede, A. Kim, D. I. Glazier, G. Ciullo, D. S. Carman, F. Sabatié, T. Hu, R. Paremuzyan, R. De Vita, D. Marchand, D. Protopopescu, Eugene Pasyuk, X. Wei, L. Venturelli, S. Diehl, Fatiha Benmokhtar, O. Soto, C. Salgado, E. Voutier, L. Lanza, Nicholas M. Harrison, Gerard Gilfoyle, A. Filippi, A. Movsisyan, J. W. Price, D. Sokhan, V. P. Kubarovsky, I. Bedlinskiy, M. Khandaker, M. Khachatryan, Nikolaos Sparveris, Z. E. Meziani, K. Wei, S. Niccolai, K. Livingston, N. Markov, Iu. Skorodumina, N. Tyler, C. Djalali, J. A. Tan, V. I. Mokeev, D. Heddle, Jie Zhang, G. Gavalian, D. G. Jenkins, R. Fersch, M. Ehrhart, M. Ripani, O. Pogorelko, P. L. Cole, J. Rowley, Tim O'Connell, A. I. Ostrovidov, Michael Dugger, T. Mineeva, P. Nadel-Turonski, H. Atac, A. S. Biselli, A. D'Angelo, L. Guo, Sylvester Joosten, Alessandro Rizzo, G. Asryan, L. El Fassi, C. Ayerbe Gayoso, M. E. McCracken, A. Hobart, C. Hanretty, W. Kim, G. Niculescu, P. Stoler, M. Osipenko, I. J. D. MacGregor, K. Hicks, M. Contalbrigo, J. Poudel, Z. Akbar, A. Celentano, and R. W. Gothe
Subjects: Physics, Particle physics, Range (particle radiation), Photon, Proton, Meson, 010308 nuclear & particles physics, Sigma, Photon energy, 01 natural sciences, 7. Clean energy, Resonance (particle physics), 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon
Abstract: Photoproduction cross sections are reported for the reaction $\gamma p\to p\eta$ using energy-tagged photons and the CLAS spectrometer at Jefferson Laboratory. The $\eta$ mesons are detected in their dominant charged decay mode, $\eta\to \pi^+\pi^-\pi^0$, and results on differential cross sections are presented for incident photon energies between 1.2 and 4.7 GeV. These new $\eta$ photoproduction data are consistent with earlier CLAS results but extend the energy range beyond the nucleon resonance region into the Regge regime. The normalized angular distributions are compared with the experimental results from several other experiments, and with predictions of $\eta$ MAID\,2018 and the latest solution of the Bonn-Gatchina coupled-channel analysis. Differential cross sections $d\sigma/dt$ are presented for incident photon energies $E_\gamma > 2.9$ GeV ($W > 2.5$ GeV), and compared with predictions which are based on Regge trajectories exchange in the $t$-channel (Regge models). The data confirm the expected dominance of $\rho$, $\omega$ vector-meson exchange in an analysis by the Joint Physics Analysis Center.
Published: 2020
Full Text: View/download PDF

20. Extraction of beam-spin asymmetries from the hard exclusive π+ channel off protons in a wide range of kinematics

Author: Y. G. Sharabian, K. Tezgin, S. E. Kuhn, M. Hattawy, S. Adhikari, M. Khachatryan, M. J. Amaryan, N. Tyler, P. Lenisa, C. Dilks, J. A. Tan, C. W. Kim, H. Avakian, B. McKinnon, Maxime Defurne, Laura Clark, K. A. Griffioen, Chaden Djalali, D. Bulumulla, T. Mineeva, L. Guo, G. Angelini, D. I. Glazier, B. S. Ishkhanov, S. Strauch, Aditya R. Khanal, F. X. Girod, T. B. Hayward, M. Guidal, D. P. Watts, K. L. Giovanetti, P. L. Cole, E. L. Isupov, E. Golovatch, G. Asryan, L. Lanza, R. De Vita, Alessandro Rizzo, Z. W. Zhao, V. Crede, R. Dupre, H. Voskanyan, Andrea Bianconi, N. Markov, Brian Raue, Y. Ghandilyan, S. Boiarinov, A. D'Angelo, M. Mirazita, M. Ehrhart, W. Phelps, W. J. Briscoe, A. Filippi, M. Holtrop, Victor Mokeev, U. Shrestha, L. El Fassi, H. Atac, P. Nadel-Turonski, M. Khandaker, Luciano Pappalardo, P. Eugenio, J. W. Price, O. Pogorelko, I. J. D. MacGregor, T. Chetry, M. Osipenko, J. Rowley, M. Ripani, Fatiha Benmokhtar, H. Hakobyan, O. Soto, M. Battaglieri, S. Diehl, Paolo Rossi, K. Park, Michael Paolone, A. Celentano, R. W. Gothe, D. Heddle, F. Bossu, D. G. Ireland, Hovanes Egiyan, C. Munoz Camacho, W. Kim, Axel Schmidt, G. Niculescu, P. Stoler, Volker D. Burkert, M. Contalbrigo, A. S. Biselli, M. Ungaro, I. I. Strakovsky, K. Hicks, A. Deur, Nicholas M. Harrison, Gerard Gilfoyle, D. Marchand, V. Mascagna, Eugene Pasyuk, W. K. Brooks, D. G. Jenkins, S. Joosten, L. Marsicano, V. P. Kubarovsky, K. P. Adhikari, M. Leali, D. Riser, Z. E. Meziani, Y. Prok, F. Sabatié, I. Bedlinskiy, P. Kroll, K. Joo, Dustin Keller, Michael Wood, A. Kim, K. Livingston, Jie Zhang, H. S. Jo, C. Salgado, A. El Alaoui, Y. Ilieva, P. Chatagnon, Nicholas Zachariou, J. C. Carvajal, K. Semenov-Tian-Shansky, N. Dashyan, E. Voutier, L. Venturelli, L. Barion, R. A. Schumacher, G. Ciullo, D. S. Carman, Nikos Sparveris, X. Wei, T. A. Forest, S. Stepanyan, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: Particle physics, generalized parton distribution, Partons, Nucleons, Compton Scattering, media_common.quotation_subject, General Physics and Astronomy, parton: distribution function, Socio-culturale, Parton, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Resonance (particle physics), Asymmetry, High Energy Physics - Experiment, Pion, PE2_2, PE2_1, CLAS, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], 010306 general physics, Nuclear Experiment, PE2_3, Spin-½, media_common, Physics, Settore FIS/04, electroproduction, moment, Moment (mathematics), distribution amplitude, High Energy Physics - Phenomenology, Amplitude, kinematics, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Elementary Particles and Fields, High Energy Physics::Experiment, Center of mass, asymmetry, experimental results
Abstract: We have measured beam-spin asymmetries to extract the \ud sin\ud ϕ\ud moment \ud A\ud sin\ud ϕ\ud L\ud U\ud from the hard exclusive \ud →\ud e\ud p\ud →\ud e\ud ′\ud n\ud π\ud +\ud reaction above the resonance region, for the first time with nearly full coverage from forward to backward angles in the center of mass. The \ud A\ud sin\ud ϕ\ud L\ud U\ud moment has been measured up to \ud 6.6\ud \ud \ud GeV\ud 2\ud in \ud −\ud t\ud , covering the kinematic regimes of generalized parton distributions (GPD) and baryon-to-meson transition distribution amplitudes (TDA) at the same time. The experimental results in very forward kinematics demonstrate the sensitivity to chiral-odd and chiral-even GPDs. In very backward kinematics where the TDA framework is applicable, we found \ud A\ud sin\ud ϕ\ud L\ud U\ud to be negative, while a sign change was observed near 90° in the center of mass. The unique results presented in this Letter will provide critical constraints to establish reaction mechanisms that can help to further develop the GPD and TDA frameworks.
Published: 2020
Full Text: View/download PDF

21. First measurement of direct photoproduction of the a2(1320)0 meson on the proton

Author: J. Rowley, A. I. Ostrovidov, Volker D. Burkert, A. S. Biselli, W. Phelps, K. A. Griffioen, V. Mascagna, N. Markov, M. E. McCracken, A. Hobart, Carlos A. Salgado, A. Filippi, A. Pilloni, Frank Klein, Dustin Keller, P. Eugenio, L. Marsicano, Sylvester Joosten, Maxime Defurne, M. Khandaker, M. Khachatryan, M. Osipenko, Pawel Nadel-Turonski, Michael Paolone, Alexander Schmidt, D. I. Glazier, D. Bulumulla, E. Munevar, B. S. Ishkhanov, Aditya R. Khanal, Nikolaos Sparveris, M. Ungaro, K. Hafidi, F. Bossu, M. Guidal, G. Niculescu, L. Lanza, D. G. Jenkins, I. J. D. MacGregor, R. De Vita, M. Leali, Laura Clark, M. J. Amaryan, Andrea Bianconi, C. W. Kim, W. Kim, W. Gohn, F. X. Girod, N. Tyler, C. Djalali, J. A. Tan, P. Chatagnon, G. V. Fedotov, H. Voskanyan, A. D'Angelo, T. Chetry, I. Bedlinskiy, L. Elouadrhiri, M. Holtrop, F. Hauenstein, W. J. Briscoe, E. Pasyuk, S. Strauch, K. Joo, H. Atac, D. P. Watts, H. Egiyan, G. Angelini, L. El Fassi, I. I. Strakovsky, R. Dupre, M. Battaglieri, F. Sabatié, Luciano Pappalardo, D. Heddle, A. Deur, M. Ripani, G. Gavalian, V. Mokeev, D. Marchand, V. Lucherini, V. P. Kubarovsky, Michael Dugger, Fatiha Benmokhtar, Krishna Neupane, R. G. Fersch, O. Pogorelko, O. Soto, S. Niccolai, Vincent Mathieu, P. L. Cole, Z. W. Zhao, Alessandro Rizzo, E. Golovatch, P. Lenisa, K. Hicks, M. Ehrhart, S. Adhikari, T. B. Hayward, J. Zhang, M. Hattawy, J. W. Price, N. Dashyan, Yordanka Ilieva, L. Barion, G. Rosner, William Brooks, G. Ciullo, Y. Prok, L. Venturelli, D. S. Carman, R. A. Schumacher, A. El Alaoui, X. Wei, Nicholas Zachariou, J. C. Carvajal, S. Stepanyan, E. Voutier, A. Movsisyan, Adam P. Szczepaniak, D. Sokan, Z. E. Meziani, K. Livingston, K. P. Adhikari, H. Hakobyan, H. S. Jo, A. Kim, J. Ritman, S. Diehl, D. G. Ireland, V. Crede, O. Cortes, E. L. Isupov, R. Paremuzyan, S. Boiarinov, R. Cruz-Torres, Nicholas M. Harrison, U. Shrestha, M. Contalbrigo, C. Munoz Camacho, M. H. Wood, B. McKinnon, A. Celentano, R. W. Gothe, M. Mirazita, and N. Gevorgyan
Subjects: Physics, Meson, 010308 nuclear & particles physics, Partial wave analysis, Hadron, Sigma, Photon energy, 01 natural sciences, Nuclear physics, Amplitude, 0103 physical sciences, Invariant mass, Nuclear Experiment, 010306 general physics, Phenomenology (particle physics)
Abstract: We present the first measurement of the exclusive reaction $\gamma p \rightarrow a_2(1320)^0 \, p$ in the photon energy range $3.5$-$5.5$ GeV and four-momentum transfer squared $0.2
Published: 2020
Full Text: View/download PDF

22. Inferring foraging areas of nesting loggerhead turtles using satellite telemetry and stable isotopes.

Author: Simona A Ceriani, James D Roth, Daniel R Evans, John F Weishampel, and Llewellyn M Ehrhart
Subjects: Medicine, Science
Abstract: In recent years, the use of intrinsic markers such as stable isotopes to link breeding and foraging grounds of migratory species has increased. Nevertheless, several assumptions still must be tested to interpret isotopic patterns found in the marine realm. We used a combination of satellite telemetry and stable isotope analysis to (i) identify key foraging grounds used by female loggerheads nesting in Florida and (ii) examine the relationship between stable isotope ratios and post-nesting migration destinations. We collected tissue samples for stable isotope analysis from 14 females equipped with satellite tags and an additional 57 untracked nesting females. Telemetry identified three post-nesting migratory pathways and associated non-breeding foraging grounds: (1) a seasonal continental shelf-constrained migratory pattern along the northeast U.S. coastline, (2) a non-breeding residency in southern foraging areas and (3) a residency in the waters adjacent to the breeding area. Isotopic variability in both δ(13)C and δ(15)N among individuals allowed identification of three distinct foraging aggregations. We used discriminant function analysis to examine how well δ(13)C and δ(15)N predict female post-nesting migration destination. The discriminant analysis classified correctly the foraging ground used for all but one individual and was used to predict putative feeding areas of untracked turtles. We provide the first documentation that the continental shelf of the Mid- and South Atlantic Bights are prime foraging areas for a large number (61%) of adult female loggerheads from the largest loggerhead nesting population in the western hemisphere and the second largest in the world. Our findings offer insights for future management efforts and suggest that this technique can be used to infer foraging strategies and residence areas in lieu of more expensive satellite telemetry, enabling sample sizes that are more representative at the population level.
Published: 2012
Full Text: View/download PDF

23. The Heavy Photon Search beamline and its performance

Author: F. X. Girod, M. Ungaro, C. Field, G. Kalicy, B. McKinnon, T. K. Nelson, T. Maruyama, A. P. Freyberger, S. Stepanyan, N. A. Baltzell, M. Holtrop, M. Ehrhart, K. Moffeit, S. Uemura, H. Vance, A. Odian, Hovanes Egiyan, R. Paremuzyan, J. Jaros, M. Oriunno, and M. Tiefenback
Subjects: Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Photon, Physics::Instrumentation and Detectors, FOS: Physical sciences, 01 natural sciences, Dark photon, High Energy Physics - Experiment, law.invention, Nuclear physics, High Energy Physics - Experiment (hep-ex), law, 0103 physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment, 010306 general physics, Instrumentation, Physics, Spectrometer, 010308 nuclear & particles physics, Detector, Collimator, Particle accelerator, Instrumentation and Detectors (physics.ins-det), Beamline, Cathode ray, Physics::Accelerator Physics
Abstract: The Heavy Photon Search (HPS) is an experiment to search for a hidden sector photon, aka a heavy photon or dark photon, in fixed target electroproduction at the Thomas Jefferson National Accelerator Facility (JLab). The HPS experiment searches for the e$^+$e$^-$ decay of the heavy photon with bump hunt and detached vertex strategies using a compact, large acceptance forward spectrometer, consisting of a silicon microstrip detector (SVT) for tracking and vertexing, and a PbWO$_4$ electromagnetic calorimeter for energy measurement and fast triggering. To achieve large acceptance and good vertexing resolution, the first layer of silicon detectors is placed just 10 cm downstream of the target with the sensor edges only 500 $\mu$m above and below the beam. Placing the SVT in such close proximity to the beam puts stringent requirements on the beam profile and beam position stability. As part of an approved engineering run, HPS took data in 2015 and 2016 at 1.05 GeV and 2.3 GeV beam energies, respectively. This paper describes the beam line and its performance during that data taking.
Published: 2017
Full Text: View/download PDF

24. Mexican origins for the Texas green turtle foraging aggregation: A cautionary tale of incomplete baselines and poor marker resolution

Author: Donna J. Shaver, Llewellyn M. Ehrhart, Luis Jaime Peña, Campbell J. Nairn, Katherine L. Mansfield, Brian M. Shamblin, Peter H. Dutton, Dean A. Bagley, and Nathan F. Putman
Subjects: 0106 biological sciences, mtDNA control region, Rookery, education.field_of_study, Ecology, 010604 marine biology & hydrobiology, Foraging, Population, Aquatic Science, Biology, 010603 evolutionary biology, 01 natural sciences, Oceanic dispersal, Natal homing, Habitat, education, Ecology, Evolution, Behavior and Systematics, Stock (geology)
Abstract: The green turtle ( Chelonia mydas ) foraging aggregation along the Texas coast has increased dramatically in recent years, but the source populations for these turtles have not been adequately resolved. Previous mixed stock analysis (MSA) based on 490 base pair (bp) mitochondrial control region haplotypes suggested a large Florida contribution, but widespread sharing of common haplotypes among potential source populations and incomplete source population baseline data precluded precise assessment. To test the hypothesis that Texas turtles may represent proximal western Gulf of Mexico (GoM) nesting populations, we analyzed novel rookery samples from Rancho Nuevo, Tamaulipas, Mexico (RNMX) and conducted oceanic connectivity simulations. The RNMX samples yielded haplotypes CM-A1.1 and CM-A3.1 in frequencies not significantly different from those of the central eastern Florida nesting population. However, mitogenomic sequencing identified a diagnostic mitochondrial SNP (mtSNP) variant that is fixed in RNMX relative to the Florida CM-A1.1 lineage. Pairwise comparisons indicate that the Tamaulipas rookery represents a discrete population relative to those previously described in the northern Greater Caribbean, warranting recognition of a western GoM management unit (MU). Contrary to previous findings, the Florida populations were ruled out as major contributors to the Texas aggregation through screening of the mtSNP. Mixed stock analysis incorporating the mtSNP data suggested a western GoM origin for approximately 70% of the Texas foraging aggregation, with Quintana Roo contributing the majority of the remainder. Backtracking simulations within an ocean circulation model were broadly congruent with genetic results in indicating substantial probability of oceanic transport from Mexican rookeries to the Texas coast (68%) while also dismissing the possibility of transport from the eastern Florida rookeries (0%). The mixed stock analyses and backtracking simulations are consistent with previous hypotheses implicating oceanic dispersal followed by natal homing by neritic juveniles to explain juvenile green turtle distributions. In contrast to a pattern of stepping stone connectivity across the remaining northern Greater Caribbean, the Texas foraging aggregation was distinct from all others analyzed in the region, including one in the eastern GoM. This isolation highlights the significance of Texas as developmental habitat for the proposed western GoM MU and reiterates the importance of continued international cooperation to facilitate recovery of this stock. This study also underscores the importance of satisfying underlying assumptions of mixed stock analysis in order to make robust inferences of connectivity.
Published: 2017
Full Text: View/download PDF

25. Exclusive π0p electroproduction off protons in the resonance region at photon virtualities 0.4GeV2≤Q2≤1GeV2

Author: P. Eugenio, M. Taiuti, Carlos A. Salgado, L. C. Smith, I. I. Strakovsky, B. S. Ishkhanov, R. Dupre, M. Battaglieri, Aditya R. Khanal, A. Deur, R. A. Schumacher, M. Contalbrigo, Michael Paolone, F. Bossu, C. Evans, Maxime Defurne, N. Tyler, C. Djalali, J. A. Tan, K. A. Griffioen, Pawel Nadel-Turonski, Fatiha Benmokhtar, O. Soto, R. De Vita, M. Ungaro, S. Niccolai, L. Lanza, A. D'Angelo, A. Kim, Alessandro Rizzo, T. Mineeva, S. Stepanyan, W. Kim, U. Shrestha, V. Crede, L. El Fassi, T. B. Hayward, H. Atac, R. Paremuzyan, P. Stoler, K. Joo, D. G. Jenkins, M. Leali, K. Hicks, G. Ciullo, William Brooks, N. Markov, M. Guidal, G. Niculescu, Y. Prok, L. Venturelli, W. Phelps, E. De Sanctis, V. Mascagna, I. Bedlinskiy, E. Golovatch, D. S. Carman, A. Celentano, R. W. Gothe, E. L. Isupov, M. Holtrop, Nikos Sparveris, C. W. Kim, Luciano Pappalardo, X. Wei, F. X. Girod, S. Boiarinov, G. Angelini, H. Avakian, J. W. Price, P. L. Cole, G. Rosner, N. A. Baltzell, T. Chetry, J. Rowley, K. Park, D. Sokhan, Y. Ghandilyan, F. Sabatié, Y. G. Sharabian, H. Hakobyan, H. S. Jo, E. Voutier, S. Diehl, D. G. Ireland, I. J. D. MacGregor, N. Dashyan, Volker D. Burkert, A. S. Biselli, S. Strauch, S. Adhikari, M. H. Wood, M. Osipenko, P. Chatagnon, B. McKinnon, Yordanka Ilieva, V. Mokeev, M. Mirazita, Rong Wang, M. Ehrhart, L. Barion, M. Hattawy, H. Voskanyan, S. K. Nanda, M. Ripani, M. Khachatryan, W. J. Briscoe, D. Marchand, E. Pasyuk, V. P. Kubarovsky, D. Riser, A. El Alaoui, C. Ayerbe Gayoso, Nicholas Zachariou, J. C. Carvajal, O. Pogorelko, D. Protopopescu, Frank Klein, Dustin Keller, K. Livingston, K. Hafidi, M. J. Amaryan, A. Filippi, and M. Khandaker
Subjects: Physics, Range (particle radiation), Photon, Proton, 010308 nuclear & particles physics, Resonance, 01 natural sciences, Nuclear physics, Cross section (physics), Isospin, 0103 physical sciences, Invariant mass, 010306 general physics, Legendre polynomials
Abstract: The exclusive electroproduction process ep→e′p′π0 was measured in the range of photon virtualities Q2=0.4–1.0GeV2 and the invariant mass range of the pπ0 system of W=1.1–1.8 GeV. These kinematics are covered in exclusive π0 electroproduction off the proton with nearly complete angular coverage in the pπ0 center-of-mass system and with high statistical accuracy. Nearly 36 000 cross-section points were measured, and the structure functions σT+eσL,σLT, and σTT, were extracted via fitting the ϕπ0 dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying N* and Δ* resonances with M>1.6 GeV. As part of a broad effort to determine the electrocouplings of the N* and Δ* resonances using both single- and double-pion electroproduction, this dataset is crucial for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the Nπ and π+π−p channels.
Published: 2020
Full Text: View/download PDF

26. Beam–target helicity asymmetry $E$ in $K^+$ $\Sigma^-$ photoproduction on the neutron

Author: R. De Vita, D. Marchand, H. Atac, H. S. Jo, A. Filippi, L. Marsicano, N. K. Walford, O. Soto, M. Khandaker, I. J. D. MacGregor, K. Hicks, W. Phelps, R. A. Schumacher, Michael Paolone, H. Hakobyan, W. Kim, G. Charles, F. Bossu, H. Lu, S. Joosten, J. W. Price, S. Diehl, C. Salgado, William Brooks, L. Venturelli, D. Heddle, V. P. Kubarovsky, I. Bedlinskiy, Z. E. Meziani, V. Mascagna, A. Celentano, R. W. Gothe, N. Markov, Alessandro Rizzo, W. Gohn, G. Asryan, Axel Schmidt, Dustin Keller, M. Ungaro, M. Guidal, M. Contalbrigo, M. Osipenko, Z. W. Zhao, Fatiha Benmokhtar, E. L. Isupov, Y. Prok, J. Poudel, O. Pogorelko, A. I. Ostrovidov, K. Park, M. J. Amaryan, Michael Wood, K. Hafidi, M. Holtrop, M. Ehrhart, C.D. Bass, V. A. Nikonov, A. D'Angelo, D. G. Jenkins, D. G. Ireland, G. Rosner, S. Boiarinov, E. Golovatch, P. Eugenio, K. Livingston, Luciano Pappalardo, K. Joo, M. Leali, Jie Zhang, T. Kageya, Volker D. Burkert, Y. Ghandilyan, A. S. Biselli, C. W. Kim, G. Gavalian, U. Shrestha, F.-X. Girod, Gerard Gilfoyle, M. Ripani, R. G. Fersch, H. Voskanyan, A. El Alaoui, G. Angelini, Nicholas Zachariou, J. C. Carvajal, W. J. Briscoe, P. L. Cole, T. Chetry, N. Gevorgyan, D. Ho, I. I. Strakovsky, A. M. Sandorfi, A. Deur, Victor Mokeev, D. Sokhan, T. R. O'Connell, Chaden Djalali, P. Nadel Turonski, T. Mineeva, M. Bashkanov, S. Adhikari, D. Bulumulla, E. Munevar, B. McKinnon, B. S. Ishkhanov, Aditya R. Khanal, Andrea Bianconi, I. Zonta, X. Wei, P. Peng, Hovanes Egiyan, C. Munoz Camacho, P. Lenisa, M. Hattawy, J. A. Fleming, Friedrich Klein, Brian Raue, Andrew Puckett, E. Voutier, Martin K. Mayer, M. Khachatryan, K. A. Griffioen, Nikolaos Sparveris, K. P. Adhikari, C. S. Whisnant, C. Hanretty, L. Lanza, R. Dupre, M. Battaglieri, M. Lowry, S. Strauch, Eugene Pasyuk, N. Dashyan, Yordanka Ilieva, L. Barion, G. Ciullo, D. S. Carman, S. Fegan, D. P. Watts, A. V. Sarantsev, N. Tyler, J. A. Tan, P. Chatagnon, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS
Subjects: Nuclear and High Energy Physics, Socio-culturale, nucleon resonance, Nucleons, Photoproduction, Mesons, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, K+: photoproduction, Particle identification, Nuclear physics, chemistry.chemical_compound, PE2_2, PE2_1, CLAS, 0103 physical sciences, Neutron, Hydrogen deuteride, n: target, 010306 general physics, Nuclear Experiment, PE2_3, photon: beam, Physics, 010308 nuclear & particles physics, nucleus: target, Settore FIS/04, Resonance, helicity: asymmetry, Observable, Sigma-: photoproduction, Helicity, lcsh:QC1-999, chemistry, Excited state, spectrometer, Nucleon, lcsh:Physics, Jefferson Lab, experimental results
Abstract: We report a measurement of a beam–target double-polarisation observable (E) for the γ→n→(p)→K+Σ−(p) reaction. The data were obtained impinging the circularly-polarised energy-tagged photon beam of Hall B at Jefferson Lab on a longitudinally-polarised frozen-spin hydrogen deuteride (HD) nuclear target. The E observable for an effective neutron target was determined for centre-of-mass energies 1.70≤W≤2.30 GeV, with reaction products detected over a wide angular acceptance by the CLAS spectrometer. These new double-polarisation data give unique constraints on the strange decays of excited neutron states. Inclusion of the new data within the Bonn-Gatchina theoretical model results in significant changes for the extracted photocouplings of a number of established nucleon resonances. Possible improvements in the PWA description of the experimental data with additional “missing” resonance states, including the N(2120)3/2− resonance, are also quantified.
Published: 2020
Full Text: View/download PDF

27. The CLAS12 Spectrometer at Jefferson Laboratory

Author: C. W. Kim, H. Avakian, D. Protopopescu, D. Heddle, M. Contalbrigo, M. L. Kabir, H. Voskanyan, E. Voutier, T. Chetry, M. Zarecky, J. Poudel, I. Illari, B. A. Clary, M. Osipenko, D. Insley, D. P. Watts, I. Bedlinskiy, Michael Paolone, V. Sergeyeva, D. Kashy, M. Khachatryan, F. Hauenstein, V. Mascagna, Nikolaos Sparveris, F. Bossu, D. Marchand, W. Kim, G. Niculescu, P. Bonneau, G. Charles, P. Hemler, Ruben J. Fair, P. Moran, Dustin Keller, C. Ayerbe Gayoso, Nicholas Zachariou, M. Ungaro, C. Munoz Camacho, M. J. Amaryan, G. Rosner, I. J. D. MacGregor, T. A. Forest, V. Lucherini, S. E. Kuhn, Y. Prok, M. Hattawy, S. Stepanyan, Michael Wood, K. Hafidi, M. D. Mestayer, S. Lee, M. Wiseman, F. Sabatié, R. Paremuzyan, N. Dashyan, A. Deur, K. Hicks, K. Joo, E. L. Isupov, N. A. Baltzell, R. W. Gothe, S. Christo, L. C. Smith, B. S. Ishkhanov, Latifa Elouadrhiri, V. Baturin, Nicholas M. Harrison, Gerard Gilfoyle, M. McMullen, G. E. Dodge, H. S. Jo, R. Johnston, A. Yegneswaran, K. Livingston, A. Lung, P. Stoler, M. Guidal, D. Sokhan, K. Price, Aditya R. Khanal, K. P. Adhikari, Jie Zhang, K. Bruhwel, S. Adhikari, S. Boyarinov, B. McKinnon, M. Ehrhart, M. Leali, Z. W. Zhao, S. Joosten, B. J. Roy, V. P. Kubarovsky, J. Newton, P. Chatagnon, G. V. Fedotov, D. Tilles, M.A. Antonioli, Renuka Rajput-Ghoshal, G. D. Smith, M. Holtrop, C. Cuevas, V. Gyurjyan, Probir K. Ghoshal, Yordanka Ilieva, H. Hakobyan, Alexander Schmidt, Luciano Pappalardo, Andrea Bianconi, W. J. Briscoe, M. Turisini, M. Mirazita, D. I. Glazier, M. Garçon, M. Ripani, F. X. Girod, A. Filippi, K. L. Giovanetti, R. Miller, J. Ritman, S. Diehl, R. De Vita, C. D. Keith, Y. G. Sharabian, M. Lowry, M. Defurne, E. Pasyuk, P. Naidoo, J. Hogan, N. Markov, Or Hen, C. Salgado, M. Taylor, G. Young, S. Strauch, Larry Weinstein, H. Atac, Chaden Djalali, A. Hobart, A. Kim, Z. E. Meziani, S. Schadmand, U. Shrestha, T. Ewing, T. Mineeva, O. Pogorelko, S. Nanda, L. Barion, G. Angelini, J. Rowley, P. Rossi, M. Leffel, William Brooks, I. Mandjavidze, L. Venturelli, Iu. Skorodumina, Y. Gotra, C. Mealer, J. W. Price, S. Aune, C. Wiggins, D. G. Ireland, G. Gavalian, G. Jacobs, V. Crede, Volker D. Burkert, A. S. Biselli, O. Pastor, Victor Mokeev, E.P. Segarra, Ross Milner, N. Tyler, J. A. Tan, E. Golovatch, R. Dupre, W. Phelps, Andrea Celentano, S. Procureur, M. Cook, G. Ciullo, M. Battaglieri, D. S. Carman, B. Raydo, A. Rizzo, X. Wei, R. Cruz-Torres, S. Niccolai, K. A. Griffioen, B. Eng, A. Movsisyan, P. L. Cole, L. Lanza, G. Christiaens, A. D'Angelo, T. Kageya, L. El Fassi, P. Lenisa, V. Ziegler, C. Hanretty, D. Anderson, T. B. Hayward, Brian Raue, Fatiha Benmokhtar, O. Soto, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics::Instrumentation and Detectors, data acquisition, magnet: solenoid, superconductivity: torus, Solenoid, 01 natural sciences, Particle identification, Luminosity, momentum resolution, electron: beam, Nuclear Experiment, Instrumentation, QC, Physics, Luminosity (scattering theory), Settore FIS/04, Detector, Magnetic spectrometer, magnet: torus, performance, Nuclear and High Energy Physics, Meson, vertex detector, nucleon: interaction, CLAS12, Electromagnetic physics, Large acceptance, Socio-culturale, fabrication, beam: energy, Nuclear physics, PE2_1, CLAS, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, PE2_3, scintillation counter, Cherenkov radiation, detector: design, activity report, Spectrometer, 010308 nuclear & particles physics, nucleus, CLAS12, Electromagnetic physics, Large acceptance, Luminosity, Magnetic spectrometer, magnet: superconductivity, magnetic spectrometer, electromagnetic physics, large acceptance, luminosity, neutral particle, Automatic Keywords, calorimeter: electromagnetic, Cherenkov counter, spectrometer, particle identification, Beam (structure)
Abstract: International audience; The CEBAF Large Acceptance Spectrometer for operation at 12 GeV beam energy (CLAS12) in Hall B at Jefferson Laboratory is used to study electro-induced nuclear and hadronic reactions. This spectrometer provides efficient detection of charged and neutral particles over a large fraction of the full solid angle. CLAS12 has been part of the energy-doubling project of Jefferson Lab’s Continuous Electron Beam Accelerator Facility, funded by the United States Department of Energy. An international collaboration of 48 institutions contributed to the design and construction of detector hardware, developed the software packages for the simulation of complex event patterns, and commissioned the detector systems. CLAS12 is based on a dual-magnet system with a superconducting torus magnet that provides a largely azimuthal field distribution that covers the forward polar angle range up to 35 ∘ , and a solenoid magnet and detector covering the polar angles from 35° to 125° with full azimuthal coverage. Trajectory reconstruction in the forward direction using drift chambers and in the central direction using a vertex tracker results in momentum resolutions of < 1% and < 3%, respectively. Cherenkov counters, time-of-flight scintillators, and electromagnetic calorimeters provide good particle identification. Fast triggering and high data-acquisition rates allow operation at a luminosity of 1035 cm −2 s −1 . These capabilities are being used in a broad program to study the structure and interactions of nucleons, nuclei, and mesons, using polarized and unpolarized electron beams and targets for beam energies up to 11 GeV. This paper gives a general description of the design, construction, and performance of CLAS12.
Published: 2020
Full Text: View/download PDF

28. First Measurements of the Double-Polarization Observables F , P , and H in ω Photoproduction off Transversely Polarized Protons in the N* Resonance Region

Author: Eberhard Klempt, O. Cortes, C. Hanretty, K. A. Griffioen, M. Ungaro, V. A. Nikonov, X. Wei, B. S. Ishkhanov, O. Soto, C. D. Keith, S. Strauch, G. Khachatryan, F. X. Girod, M. Osipenko, A. D'Angelo, Eugene Pasyuk, H. S. Jo, A. El Alaoui, W. J. Briscoe, Y. Ilieva, Aditya R. Khanal, Dustin Keller, L. Barion, F. Sabatié, I. I. Strakovsky, L. Guo, Alessandro Rizzo, A. V. Anisovich, L. Lanza, J. Brock, V. Mokeev, E. L. Isupov, Nicholas Zachariou, K Nakayama, M. C. Kunkel, P. Nadel-Turonski, Rong Wang, R. De Vita, A. Deur, R. A. Schumacher, Michael Wood, P. Lenisa, W. Phelps, Barry Ritchie, S. Boiarinov, K. Hafidi, G. Ciullo, Y. Prok, Iu. Skorodumina, S Niccolai, P. Eugenio, W. Kim, G. Niculescu, D. S. Carman, W. K. Brooks, I. Bedlinskiy, C. A. Meyer, D. Payette, K. Livingston, Sylvester Joosten, G. Rosner, H. Egiyan, Andrea Celentano, T. B. Hayward, J. Pierce, Jie Zhang, S. Adhikari, Friedrich Klein, D. G. Jenkins, M. Taiuti, K. P. Adhikari, Brian Raue, D. P. Watts, D. Marchand, Y. G. Sharabian, A. Movsisyan, S. Diehl, M. Ripani, C. Salgado, C. Carlin, S. Fegan, M. L. Kabir, A. V. Sarantsev, M. Battaglieri, N. Tyler, B. Duran, V. P. Kubarovsky, E. Voutier, J. A. Tan, U. Shrestha, V. Crede, D. Riser, Chaden Djalali, O. Pogorelko, M. Khachatryan, Michael Dugger, T. Mineeva, H. Avakian, E. Golovatch, A Fradi, R. Dupre, H. Voskanyan, Nikolaos Sparveris, F. Cao, P. Roy, N C Wei, N. K. Walford, R. A. Montgomery, M. Guidal, E. De Sanctis, N. Dashyan, A. Kim, P. Chatagnon, I. J. D. MacGregor, Michael Paolone, M. Holtrop, M. Hattawy, R. W. Gothe, M Ehrhart, K. Hicks, Luciano Pappalardo, S. Park, Taya Chetry, M. Contalbrigo, G. Angelini, Sergey Kuleshov, D. G. Meekins, L. El Fassi, A. I. Ostrovidov, D. G. Ireland, Volker D. Burkert, A. S. Biselli, M. Khandaker, B. McKinnon, D. Heddle, P. L. Cole, M. L. Seely, B. Torayev, Feng Huang, R. Paremuzyan, Sandra K. Johnston, D. Protopopescu, Z. W. Zhao, Nicholas M. Harrison, Gerard Gilfoyle, D. Sokhan, A. Filippi, and C. Munoz Camacho
Subjects: Physics, Photon, Spectrometer, Proton, Linear polarization, media_common.quotation_subject, Nuclear Theory, General Physics and Astronomy, Resonance, Polarization (waves), 01 natural sciences, Asymmetry, Nuclear physics, 0103 physical sciences, Physics::Accelerator Physics, Nuclear Experiment, 010306 general physics, Nucleon, media_common
Abstract: First measurements of double-polarization observables in ω photoproduction off the proton are presented using transverse target polarization and data from the CEBAF Large Acceptance Spectrometer (CLAS) FROST experiment at Jefferson Lab. The beam-target asymmetry F has been measured using circularly polarized, tagged photons in the energy range 1200-2700 MeV, and the beam-target asymmetries H and P have been measured using linearly polarized, tagged photons in the energy range 1200-2000 MeV. These measurements significantly increase the database on polarization observables. The results are included in two partial-wave analyses and reveal significant contributions from several nucleon (N^{*}) resonances. In particular, contributions from new N^{*} resonances listed in the Review of Particle Properties are observed, which aid in reaching the goal of mapping out the nucleon resonance spectrum.
Published: 2019
Full Text: View/download PDF

29. First results on nucleon resonance photocouplings from the γp → π+π−p reaction

Author: I. Bedlinskiy, J. Ball, F. Cao, E. De Sanctis, M. Guidal, R. Paremuzyan, N. Markov, Y. G. Sharabian, D. I. Sober, Maxime Defurne, D. I. Glazier, I. J. D. MacGregor, R. De Vita, P. Eugenio, I. I. Strakovsky, D. Protopopescu, G. D. Smith, M. Holtrop, Z. W. Zhao, Nicholas M. Harrison, Gerard Gilfoyle, M. Taiuti, E. Voutier, A. Deur, M. Contalbrigo, M. Khachatryan, D. Sokhan, Latifa Elouadrhiri, M. L. Kabir, M. J. Amaryan, G. Ciullo, C. A. Meyer, M. Khandaker, P. Chatagnon, Y. Prok, D. S. Carman, G. V. Fedotov, Z. Akbar, F. X. Girod, Sandra K. Johnston, K. Livingston, M. Hattawy, Nikos Sparveris, K. A. Griffioen, E. Golovatch, R. Dupre, A. I. Ostrovidov, K. Park, Jie Zhang, S. Niccolai, Hovanes Egiyan, Taya Chetry, C. Munoz Camacho, A. Movsisyan, D. G. Ireland, V. Crede, F. Sabatié, Volker D. Burkert, A. S. Biselli, P. Lenisa, M. Bashkanov, S. Adhikari, B. McKinnon, K. L. Giovanetti, S. Strauch, L. Lanza, J. W. Price, V. I. Mokeev, M. Ripani, R. A. Montgomery, D. Marchand, X. Wei, D. Heddle, A. El Alaoui, Y. Ilieva, M. Battaglieri, B. A. Clary, Nicholas Zachariou, Friedrich Klein, Iu. Skorodumina, H. Hakobyan, Michael Paolone, D. G. Jenkins, N. Dashyan, S. Diehl, C. Salgado, H. S. Jo, A. Filippi, Laura Clark, L. Barion, E. L. Isupov, Michael Dugger, S. Boiarinov, R. A. Schumacher, Avraham Klein, P. Nadel-Turonski, M. Ungaro, K. Joo, N. Tyler, C. Djalali, J. A. Tan, Dustin Keller, B. S. Ishkhanov, Michael Wood, K. Hafidi, H. Avakian, H. Voskanyan, E. Pasyuk, V. P. Kubarovsky, D. Riser, O. Pogorelko, G. Khachatryan, W. J. Briscoe, G. Rosner, Y. Ghandilyan, K. Hicks, L. Guo, Alessandro Rizzo, R. G. Fersch, P. L. Cole, A. D'Angelo, L. El Fassi, M. Osipenko, Rong Wang, M. Ehrhart, W. Kim, G. Niculescu, A. Celentano, and R. W. Gothe
Subjects: Nuclear and High Energy Physics, Meson, Nuclear Theory, Hadron, Two pion photoproduction, Socio-culturale, Elementary particle, 01 natural sciences, Settore FIS/04 - Fisica Nucleare e Subnucleare, Nuclear physics, Particle decay, Pion, 0103 physical sciences, Invariant mass, Resonance photocouplings, Nuclear Experiment, 010306 general physics, Physics, 010308 nuclear & particles physics, Resonance, lcsh:QC1-999, Baryon state, High Energy Physics::Experiment, Nucleon, lcsh:Physics
Abstract: We report the first experimental measurements of the nine 1-fold differential cross sections for the γp→π+π−p reaction, obtained with the CLAS detector at Jefferson Laboratory. The measurements cover the invariant mass range of the final state hadrons from 1.6 GeV Δ(1620)1/2−, Δ(1700)3/2−, N(1720)3/2+, and Δ(1905)5/2+ resonances, which have dominant decays into the ππN final states rather than the more extensively studied single meson decay channels.
Published: 2019

30. Exploring the Structure of the Bound Proton with Deeply Virtual Compton Scattering

Author: A. El Alaoui, Alessandro Rizzo, C. Ayerbe Gayoso, M. Khandaker, R. Paremuzyan, Nicholas Zachariou, O. Soto, Andrea Celentano, Nicholas M. Harrison, Gerard Gilfoyle, D. P. Watts, S. Fegan, D. Sokhan, V. Crede, K. Livingston, M. Garçon, Sandra K. Johnston, R. A. Montgomery, Jie Zhang, F. X. Girod, M. Battaglieri, M. Contalbrigo, G. Gavalian, E. Golovatch, S. Strauch, Aditya R. Khanal, S. Niccolai, A. Filippi, M. Ripani, R. Dupre, N A Baltzell, K. L. Giovanetti, A. D'Angelo, E. L. Isupov, G. Khachatryan, Dustin Keller, Larry Weinstein, P. Lenisa, Yordanka Ilieva, M. Defurne, N. Markov, Chaden Djalali, Michael Wood, Laura Clark, E. De Sanctis, F. Sabatié, D. Heddle, K. A. Griffioen, T. Mineeva, L. Barion, K. Hafidi, J. Poudel, Taya Chetry, C. Munoz Camacho, P. L. Cole, Iu. Skorodumina, G. Angelini, P. Rossi, T. B. Hayward, D. Protopopescu, Z. W. Zhao, B. McKinnon, F. Hauenstein, Friedrich Klein, L. Lanza, B. Torayev, A Fradi, S. Diehl, C. Salgado, V. P. Kubarovsky, D. Riser, G. Ciullo, O. Pogorelko, M. Mirazita, H. Egiyan, F. Bossu, G. Rosner, P. Eugenio, Y. Prok, D. S. Carman, L. El Fassi, E. Pasyuk, M. Taiuti, C. W. Kim, Zein-Eddine Meziani, F. Cao, M. L. Kabir, S. E. Kuhn, M. Hattawy, H. Voskanyan, A. I. Ostrovidov, D. G. Jenkins, I. J. D. MacGregor, M. Guidal, Rong Wang, N. Dashyan, D. G. Ireland, M Ehrhart, A. S. Biselli, N. Gevorgyan, R. W. Gothe, M. Holtrop, I. Bedlinskiy, Luciano Pappalardo, Martin K. Mayer, A. Deur, W. Kim, M. Khachatryan, Nikolaos Sparveris, W. K. Brooks, S. Adhikari, Y. G. Sharabian, R. De Vita, D. Marchand, H. S. Jo, X. Wei, R. A. Schumacher, S. Bültmann, T. A. Forest, S. Stepanyan, Simonetta Liuti, M. Ungaro, Y. Perrin, K. Hicks, P. Chatagnon, P. Nadel-Turonski, N. Tyler, J. A. Tan, E. Voutier, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CLAS, Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)
Subjects: generalized parton distribution, Proton, EMC effect, Nuclear Theory, General Physics and Astronomy, Virtual particle, parton: distribution function, Parton, Electron, 01 natural sciences, 7. Clean energy, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Electromagnetic probes, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), Form factors, Electromagnetic probes, Nuclear Structure, Deep Virtual Compton Scattering, Quark models, Electron-ion collisions, Nuclear structure & decays, Nucleon distribution, electron: beam, Nuclear Experiment, Physics, Settore FIS/04, Form factors, nucleon, matter: effect, kinematics, Quark models, Nucleon, spin: asymmetry, accelerator, FOS: Physical sciences, Socio-culturale, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Structure, Deep Virtual Compton Scattering, Nuclear physics, PE2_2, PE2_1, deeply virtual Compton scattering, CLAS, 0103 physical sciences, structure, 010306 general physics, PE2_3, Electron-ion collisions, Nuclear Physics, Scattering, Nuclear structure &amp, Compton scattering, Automatic Keywords, Physics::Accelerator Physics, High Energy Physics::Experiment, Nucleon distribution, spectrometer, decays, experimental results, photon: virtual
Abstract: In the past two decades, deeply virtual Compton scattering of electrons has been successfully used to advance our knowledge of the partonic structure of the free proton and investigate correlations between the transverse position and the longitudinal momentum of quarks inside the nucleon. Meanwhile, the structure of bound nucleons in nuclei has been studied in inclusive deep-inelastic lepton scattering experiments off nuclear targets, showing a significant difference in longitudinal momentum distribution of quarks inside the bound nucleon, known as the EMC effect. In this work, we report the first beam spin asymmetry (BSA) measurement of exclusive deeply virtual Compton scattering (DVCS) off a proton bound in $^4$He. The data used here were accumulated using a $6$ GeV longitudinally polarized electron beam incident on a pressurized $^4$He gaseous target placed within the CLAS spectrometer in Hall-B at the Thomas Jefferson National Accelerator Facility. The azimuthal angle ($\phi$) dependence of the BSA was studied in a wide range of virtual photon and scattered proton kinematics. The $Q^2$, $x_B$, and t dependencies of the BSA on the bound proton are compared with those on the free proton. In the whole kinematical region of our measurements, the BSA on the bound proton is smaller by 20\% to 40\%, indicating possible medium modification of its partonic structure.
Published: 2019
Full Text: View/download PDF

31. Ξ* photoproduction from threshold to W=3.3GeV

Author: Frank Klein, Dustin Keller, K. Hafidi, E. Golovatch, Y. G. Sharabian, K. Hicks, M. Ripani, C. Bookwalter, K. A. Griffioen, L. Lanza, H. Egiyan, V. Crede, I. J. D. MacGregor, M. Contalbrigo, S. Adhikari, M. Hattawy, C. Munoz Camacho, M. H. Wood, B. McKinnon, I. Bedlinskiy, D. Protopopescu, Michael Dugger, M. Osipenko, L. Elouadrhiri, M. Khachatryan, M. S. Saini, G. Ciullo, P. Eugenio, M. Taiuti, A. El Alaoui, Carlos A. Salgado, F. Cao, W. Kim, I. I. Strakovsky, Maxime Defurne, A. Deur, J. T. Goetz, Y. Prok, D. S. Carman, M. Mirazita, Nikos Sparveris, B. S. Ishkhanov, Nicholas Zachariou, M. L. Kabir, Diane Schott, Michael Paolone, C. A. Meyer, A. I. Ostrovidov, K. Park, X. Wei, N. Gevorgyan, D. I. Glazier, P. Chatagnon, G. V. Fedotov, D. G. Ireland, R. De Vita, M. Guidal, E. Voutier, A. Movsisyan, J. Zhang, F. Sabatié, G. Niculescu, S. Chandavar, V. P. Kubarovsky, Volker D. Burkert, A. S. Biselli, K. Livingston, J. W. Price, A. Celentano, R. W. Gothe, S. Anefalos Pereira, R. Paremuzyan, D. Riser, V. Mokeev, D. P. Weygand, A. Filippi, M. C. Kunkel, Brian Raue, O. Pogorelko, Nicholas M. Harrison, Rong Wang, M. Holtrop, S. Niccolai, R. Dupre, M. Battaglieri, M. Khandaker, Alessandro Rizzo, D. Sokhan, D. I. Sober, L. Guo, M. Ehrhart, M. Ungaro, Pawel Nadel-Turonski, H. Voskanyan, W. J. Briscoe, E. Pasyuk, Iu. Skorodumina, D. Heddle, Taya Chetry, William Brooks, P. L. Cole, Z. W. Zhao, R. A. Schumacher, A. D'Angelo, F. X. Girod, L. El Fassi, S. Strauch, E. L. Isupov, S. Boiarinov, H. Hakobyan, H. S. Jo, S. Diehl, Sylvester Joosten, C. Djalali, J. A. Tan, G. Khachatryan, N. Dashyan, A. Kim, G. Rosner, and Y. Ghandilyan
Subjects: Quark, Physics, Particle physics, 010308 nuclear & particles physics, Nuclear Theory, Quark model, Lattice field theory, 01 natural sciences, Xi baryon, Baryon, Lattice (order), Excited state, 0103 physical sciences, High Energy Physics::Experiment, Gauge theory, Nuclear Experiment, 010306 general physics
Abstract: The doubly strange Xi baryons provide an effective way to study a puzzle called the missing-baryons problem where both quark models and lattice guage theory predict more baryon excited states than are seen experimentally. However, few of these excited states have been observed with any certainty. Here, high-mass Xi* states have been searched for in photoproduction with the detector of the CLAS collaboration, and upper limits for the total cross sections have been established from threshold to W = 3.3 GeV. In addition, the total cross sections of the ground-state Xi(-)(1320) and first excited state Xi(-)(1530) are presented, extending significantly the centre-of-mass energy range of previous data.
Published: 2018
Full Text: View/download PDF

32. Beam-target helicity asymmetry E in K0Λ and K0Σ0 photoproduction on the neutron

Author: P. Lenisa, M. Ungaro, D. G. Ireland, C. A. Meyer, R. Dupre, V. Crede, C.D. Bass, V. A. Nikonov, M. Battaglieri, P. Chatagnon, G. V. Fedotov, R. A. Montgomery, Ron L. Workman, R. Paremuzyan, R. A. Schumacher, C. S. Whisnant, K. P. Adhikari, A. Fradi, M. Osipenko, D. G. Jenkins, Nicholas M. Harrison, N. Markov, Martin K. Mayer, K. A. Griffioen, I. Zonta, I. J. D. MacGregor, A. Kim, H. Hakobyan, M. Khachatryan, D. Sokhan, H. S. Jo, Tim O'Connell, D. Marchand, S. Diehl, M. Bashkanov, B. McKinnon, A. I. Ostrovidov, K. Park, V. Mokeev, G. Khachatryan, L. Lanza, Eberhard Klempt, P. Collins, S. Niccolai, F. X. Girod, M. Contalbrigo, Sandra K. Johnston, P. Eugenio, T. Chetry, Volker D. Burkert, A. S. Biselli, Pawel Nadel-Turonski, M. Mirazita, J. Zhang, Rong Wang, J. W. Price, Alessandro Rizzo, S. Strauch, Iu. Skorodumina, C. Hanretty, George Davey Smith, M. Taiuti, C. Djalali, J. A. Tan, E. Golovatch, Y. G. Sharabian, M. Lowry, G. Charles, K. L. Giovanetti, I. Bedlinskiy, M. Rehfuss, K. Hicks, S. Adhikari, M. L. Kabir, M. Ehrhart, F. Sabatié, Andreas Klein, V. Laine, F. Cao, D. Adikaram, M. Guidal, W. Kim, Larry Weinstein, Z. Akbar, G. Rosner, P. Peng, C. Munoz Camacho, M. H. Wood, M. Hattawy, G. Niculescu, J. A. Fleming, I. I. Strakovsky, M. Holtrop, A. Filippi, A. D'Angelo, M. Ripani, Y. Ghandilyan, Carlos A. Salgado, B. A. Clary, A. M. Sandorfi, B. S. Ishkhanov, M. Khandaker, D. I. Sober, A. Deur, Hong Lu, Michael Paolone, D. Ho, S. Fegan, A. Celentano, R. W. Gothe, D. Heddle, Maxime Defurne, E. L. Isupov, W. Gohn, S. Boiarinov, R. De Vita, T. Kageya, L. El Fassi, N. K. Walford, R. G. Fersch, Frank Klein, P. L. Cole, Z. W. Zhao, Dustin Keller, G. Ciullo, J. P. Ball, Y. Prok, D. S. Carman, Nikos Sparveris, X. Wei, K. Hafidi, E. Voutier, A. Movsisyan, Yordanka Ilieva, L. Barion, V. P. Kubarovsky, D. Riser, A. El Alaoui, Nicholas Zachariou, O. Pogorelko, K. Livingston, H. Voskanyan, D. Protopopescu, W. J. Briscoe, E. Pasyuk, D. P. Watts, H. Egiyan, A. V. Sarantsev, and S. Chandavar
Subjects: Physics, Strange quark, 010308 nuclear & particles physics, media_common.quotation_subject, Nuclear Theory, Quark model, Hyperon, 01 natural sciences, Helicity, Asymmetry, Pseudoscalar meson, Nuclear physics, 13. Climate action, Isospin, 0103 physical sciences, Neutron, Nuclear Experiment, 010306 general physics, media_common
Abstract: We report the first measurements of the E beam-target helicity asymmetry for the γn→K0Λ and K0Σ0 channels in the energy range 1.70≤W≤2.34 GeV. The CLAS system at Jefferson Lab uses a circularly polarized photon beam and a target consisting of longitudinally polarized solid molecular hydrogen deuteride with low background contamination for the measurements. The multivariate analysis method boosted decision trees is used to isolate the reactions of interest. Comparisons with predictions from the KaonMAID, SAID, and Bonn-Gatchina models are presented. These results will help separate the isospin I=0 and I=1 photocoupling transition amplitudes in pseudoscalar meson photoproduction.
Published: 2018
Full Text: View/download PDF

33. Center of Mass Motion of Short-Range Correlated Nucleon Pairs studied via the A(e,e′pp) Reaction

Author: D. Protopopescu, Z. W. Zhao, E. Voutier, M. Duer, D. Marchand, X. Wei, Dustin Keller, P. Eugenio, I. J. D. MacGregor, G. Ciullo, M. Taiuti, C. Djalali, J. A. Tan, W. Kim, Y. Prok, F. Sabatié, L. Lanza, J. P. Ball, D. S. Carman, G. Niculescu, M. L. Kabir, P. Lenisa, S. Strauch, Michael Wood, K. Hafidi, B. A. Clary, K. Livingston, D. G. Jenkins, S. Niccolai, A. Movsisyan, Jie Zhang, Michael Paolone, D. Heddle, A. Celentano, R. W. Gothe, N. Dashyan, Maxime Defurne, H. Avakian, S. E. Kuhn, Friedrich Klein, M. Contalbrigo, A. Beck, Hovanes Egiyan, C. Munoz Camacho, M. Osipenko, M. Ungaro, Eli Piasetzky, H. Voskanyan, R. Fersch, Or Hen, Z. Akbar, L. Barion, R. De Vita, P. Nadel-Turonski, V. Crede, Alessandro Rizzo, Eliahu Cohen, E. Golovatch, R. Dupre, W. J. Briscoe, E. Pasyuk, A. El Alaoui, R. A. Montgomery, R. Paremuzyan, V. Mokeev, M. Battaglieri, M. Ripani, F. Hauenstein, B. S. Ishkhanov, Nicholas M. Harrison, Nicholas Zachariou, Rong Wang, D. Sokhan, Alexander Schmidt, D. P. Watts, S. Adhikari, K. Hicks, B. McKinnon, E. De Sanctis, S. Mey-Tal Beck, A. Kim, V. P. Kubarovsky, Y. G. Sharabian, D. Riser, A. I. Ostrovidov, A. Filippi, P. Rossi, X. Zheng, M. Ehrhart, O. Pogorelko, M. Mirazita, A. Deur, D. G. Ireland, I. Bedlinskiy, M. Khachatryan, M. Khandaker, Nikolaos Sparveris, Volker D. Burkert, A. S. Biselli, M. J. Amaryan, Sandra K. Johnston, K. L. Giovanetti, Larry Weinstein, B. Schmookler, C. A. Meyer, P. Chatagnon, G. V. Fedotov, F. Cao, I. Korover, B. Mustapha, M. Holtrop, Taya Chetry, G. Charles, E. L. Isupov, S. Boiarinov, R. Cruz Torres, H. Hakobyan, S. Diehl, F. X. Girod, J. W. Price, R. A. Schumacher, S. Stepanyan, Avraham Klein, H. S. Jo, A. D'Angelo, L. El Fassi, G. Khachatryan, G. Rosner, Y. Ghandilyan, and K. A. Griffioen
Subjects: Physics, Range (particle radiation), 010308 nuclear & particles physics, Nuclear Theory, General Physics and Astronomy, 01 natural sciences, 7. Clean energy, Momentum, medicine.anatomical_structure, Quantum state, 0103 physical sciences, medicine, Nuclear force, Center of mass, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Nucleus, Fermi Gamma-ray Space Telescope
Abstract: Short-range correlated (SRC) nucleon pairs are a vital part of the nucleus, accounting for almost all nucleons with momentum greater than the Fermi momentum (k_{F}). A fundamental characteristic of SRC pairs is having large relative momenta as compared to k_{F}, and smaller center of mass (c.m.) which indicates a small separation distance between the nucleons in the pair. Determining the c.m. momentum distribution of SRC pairs is essential for understanding their formation process. We report here on the extraction of the c.m. motion of proton-proton (pp) SRC pairs in carbon and, for the first time in heavier and ansymetric nuclei: aluminum, iron, and lead, from measurements of the A(e,e^{'}pp) reaction. We find that the pair c.m. motion for these nuclei can be described by a three-dimensional Gaussian with a narrow width ranging from 140 to 170 MeV/c, approximately consistent with the sum of two mean-field nucleon momenta. Comparison with calculations appears to show that the SRC pairs are formed from mean-field nucleons in specific quantum states.
Published: 2018
Full Text: View/download PDF

34. Geometry tagging for heavy ions at JLEIC

Author: M.D. Baker, Amy Sy, Pawel Nadel-Turonski, T. Toll, C. E. Hyde, C. Fogler, A. Accardi, Guohui Wei, L. Zheng, R. Dupre, Vasiliy Morozov, M. Ehrhart, J. Stukes, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: experimental methods, geometry, parton: saturation, Geometry, Parton, electron nucleus, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, JLEIC, Neutron, Nuclear Experiment, attenuation, Physics, Attenuation, Detector, nucleus, gluon, parton: propagation, Collision, heavy ion, Hadronization, Gluon, Automatic Keywords, High Energy Physics::Experiment, Event (particle physics), statistical, hadronization, acceptance
Abstract: International audience; Geometry tagging is an experimental technique for selecting event samples where one can, on a statistical basis, control the geometry of the collision in order to make more incisive physics measurements. Several physics measurements at the EIC would benefit significantly from the use of this technique, including studies of gluon anti-shadowing, studies of parton propagation, attenuation and hadronization in the nucleus, and ultimately the search for parton saturation. The JLEIC full-acceptance detector, with full acceptance to forward-going neutrons, protons and nuclear fragments and a high data-taking rate is ideally suited to such geometry tagging. We improve, tune, and apply existing modeling codes, BeAGLE, Sartre, and GEMC, and detector descriptions to study this physics.
Published: 2018
Full Text: View/download PDF

35. Carry-over effects and foraging ground dynamics of a major loggerhead breeding aggregation

Author: Christopher R. Sasso, Llewellyn M. Ehrhart, Simona A. Ceriani, John F. Weishampel, Anton D. Tucker, James D. Roth, Daniel R. Evans, and David S. Addison
Subjects: Ecology, biology, Foraging, Aquatic Science, biology.organism_classification, Fecundity, Loggerhead sea turtle, Productivity (ecology), Abundance (ecology), Animal migration, Wildlife refuge, Bay, Ecology, Evolution, Behavior and Systematics
Abstract: Migratory animals spend different periods of their lives in widely separated and ecologically different locations; their experiences from one activity/period/site (e.g., foraging) can dramatically affect their success during another (e.g., breeding). Carry-over effects reflect the influence of foraging quality on reproductive behaviors of migratory species, such as nesting loggerhead sea turtle (Caretta caretta), which vary greatly in body size and reproductive parameters. We investigated carry-over effects on 330 loggerheads nesting at the Archie Carr National Wildlife Refuge (Melbourne Beach, Florida), one of the largest aggregations in the Western Hemisphere, using telemetry, stable isotope analysis and reproductive parameters. We assigned foraging locations used during the non-breeding period with discriminant function analysis and determined the relative contributions to different foraging regions from 2007 to 2012. Foraging regions significantly influenced female body size and fecundity. Loggerheads foraging southeast of the nesting beach in the vicinity of the Bahamas and Florida Keys laid larger clutches and had a shorter breeding frequency. On average, 47 % (±3 % SE) of the females foraged year-round in this area, while 33 % (±4 % SE) resided on the Southwest Florida continental shelf south of Tampa Bay and 18 % (±2 % SE) undertook seasonal migrations and foraged north of Cape Hatteras, North Carolina. Relative contributions to the foraging areas did not change over the 6-year period. The northern foraging area consistently contributed the fewest females despite being the most productive oceanographic region suggesting a trade-off between foraging area productivity and distance to the nesting beach. We reaffirm that the isotopic approach can be used to interpret trends in abundance at nesting beaches and demographic parameters affecting those trends. Understanding geospatial linkages and relative importance of foraging areas is critical to fostering appropriate management and conservation strategies for migratory species.
Published: 2015
Full Text: View/download PDF

36. Sea turtle hatchling production from Florida (USA) beaches, 2002-2012, with recommendations for analyzing hatching success

Author: Blair E. Witherington, Beth Brost, Llewellyn M. Ehrhart, Erin H. Leone, Dean A. Bagley, and Anne B. Meylan
Subjects: Avian clutch size, education.field_of_study, Ecology, biology, Hatching, Population, Botany, biology.organism_classification, law.invention, Predation, Fishery, Sea turtle, QL1-991, Nest, law, QK1-989, Turtle (robot), education, Zoology, Hatchling, Nature and Landscape Conservation
Abstract: We measured sea turtle hatchling production on 16 sea turtle nesting beaches (219.6 km) in Florida (USA) from 2002 to 2012. A standard protocol was used to sample 19 701 loggerhead Caretta caretta, 3809 green turtle Chelonia mydas, and 664 leatherback Dermochelys coriacea nest contents, representing all Florida nesting beaches. We assessed (1) annual variation in hatching (hatched eggs/total eggs) and emergence (emerged hatchlings/total eggs) successes, (2) annual hatchling production, and (3) sources of egg and hatchling mortality. Emergence success rates were extrapolated to all Florida sea turtle nesting beaches using means weighted by each beach’s nesting contribution. Weighted mean emergence success was 51.6% for loggerheads, 50.0% for green turtles, and 38.7% for leatherbacks. These estimates represent survivorship to the time hatchlings emerge from the nest. The estimated annual mean number of hatchlings produced on Florida beaches during the study period was 3 528 180 loggerheads (SD = 1 155 701), 568 098 green turtles (SD = 327 156), and 33 014 leatherbacks (SD = 17 574). Beach erosion from storms and nest predation by mammals were the principal identified sources of egg and hatchling mortality. Average emergence success ranged from 38.8 to 65.0% between years and 41.8 to 61.7% between study beaches, suggesting that a single sample year or location would not adequately represent a sea turtle population in demographic analyses of multiple year classes. We provide recommendations for analyzing hatching success and present a method of analysis that allows the inclusion of partially depredated nests. These nests are typically excluded because the original clutch size and the number of eggs removed by predators may not be known.
Published: 2015
Full Text: View/download PDF

37. Foraging and recruitment hotspot dynamics for the largest Atlantic loggerhead turtle rookery

Author: John F. Weishampel, Katherine L. Mansfield, Michael B. Wunder, Simona A. Ceriani, and Llewellyn M. Ehrhart
Subjects: 0106 biological sciences, Conservation of Natural Resources, Population Dynamics, Foraging, lcsh:Medicine, 010603 evolutionary biology, 01 natural sciences, Article, Hotspot (geology), Animals, Telemetry, lcsh:Science, Atlantic Ocean, Hatchling, Isotope analysis, Carbon Isotopes, geography, Rookery, Multidisciplinary, geography.geographical_feature_category, Nitrogen Isotopes, Reproductive success, Satellite telemetry, Continental shelf, Ecology, Reproduction, 010604 marine biology & hydrobiology, lcsh:R, Satellite Communications, Turtles, Fishery, Isotope Labeling, lcsh:Q, Animal Migration, Female
Abstract: Determining patterns of migratory connectivity for highly-mobile, wide-ranging species, such as sea turtles, is challenging. Here, we combined satellite telemetry and stable isotope analysis to estimate foraging locations for 749 individual loggerheads nesting along the east central Florida (USA) coast, the largest rookery for the Northwest Atlantic population. We aggregated individual results by year, identified seven foraging hotspots and tracked these summaries to describe the dynamics of inter-annual contributions of these geographic areas to this rookery over a nine-year period. Using reproductive information for a subset of turtles (n = 513), we estimated hatchling yields associated with each hotspots. We found considerable inter-annual variability in the relative contribution of foraging areas to the nesting adults. Also reproductive success differed among foraging hotspots; females using southern foraging areas laid nests that produced more offspring in all but one year of the study. These analyses identified two high priority areas for future research and conservation efforts: the continental shelf adjacent to east central Florida and the Great Bahama Bank, which support higher numbers of foraging females that provide higher rates of hatchling production. The implementation of the continuous-surface approach to determine geographic origins of unknown migrants is applicable to other migratory species.
Published: 2017
Full Text: View/download PDF

38. Genetic structure of Florida green turtle rookeries as indicated by mitochondrial DNA control region sequences

Author: Brian M. Shamblin, Thomas J. Wilmers, Dean A. Bagley, Eugenia Naro-Maciel, Kirt Rusenko, Kristen M. Hart, Laura J. Wright, Nicole A. Desjardin, John C. Stiner, Llewellyn M. Ehrhart, Campbell J. Nairn, Chris Johnson, R. Erik Martin, and Debra Sobel
Subjects: Rookery, biology, Ecology, Biodiversity, biology.organism_classification, law.invention, Sea turtle, Habitat, law, Caribbean region, Cape, Genetic structure, Genetics, Turtle (robot), Ecology, Evolution, Behavior and Systematics
Abstract: Green turtle (Chelonia mydas) nesting has increased dramatically in Florida over the past two decades, ranking the Florida nesting aggregation among the largest in the Greater Caribbean region. Individual beaches that comprise several hundred kilometers of Florida’s east coast and Keys support tens to thousands of nests annually. These beaches encompass natural to highly developed habitats, and the degree of demographic partitioning among rookeries was previously unresolved. We characterized the genetic structure of ten Florida rookeries from Cape Canaveral to the Dry Tortugas through analysis of 817 base pair mitochondrial DNA (mtDNA) control region sequences from 485 nesting turtles. Two common haplotypes, CM-A1.1 and CM-A3.1, accounted for 87 % of samples, and the haplotype frequencies were strongly partitioned by latitude along Florida’s Atlantic coast. Most genetic structure occurred between rookeries on either side of an apparent genetic break in the vicinity of the St. Lucie Inlet that separates Hutchinson Island and Jupiter Island, representing the finest scale at which mtDNA structure has been documented in marine turtle rookeries. Florida and Caribbean scale analyses of population structure support recognition of at least two management units: central eastern Florida and southern Florida. More thorough sampling and deeper sequencing are necessary to better characterize connectivity among Florida green turtle rookeries as well as between the Florida nesting aggregation and others in the Greater Caribbean region.
Published: 2014
Full Text: View/download PDF

39. Long-Term Trends in Loggerhead (Caretta caretta) Nesting and Reproductive Success at an Important Western Atlantic Rookery

Author: Llewellyn M. Ehrhart, Dean A. Bagley, William E. Redfoot, and Katherine L. Mansfield
Subjects: Avian clutch size, Morphometrics, Rookery, biology, Reproductive success, Ecology, Hatching, Storm, biology.organism_classification, Fishery, Sea turtle, Wildlife refuge, Animal Science and Zoology, human activities, Ecology, Evolution, Behavior and Systematics
Abstract: The Archie Carr National Wildlife Refuge (ACNWR), located along the central east coast of Florida (USA) in the western North Atlantic, hosts one of the largest loggerhead (Caretta caretta) nesting assemblages in the western Hemisphere. Sea turtle nesting activity has been continuously monitored on this beach for > 31 yrs, representing one of the longest sea turtle reproductive data sets in the world. Between 1982 and 2012, an estimated 358,243 nests were deposited on the ACNWR with an estimated annual mean plus 95% confidence interval of 11,556 ± 1,129 nests. This constitutes 25.4% ± 0.8% of the mean annual Florida Index Nesting Beach Survey loggerhead complement. Mean annual clutch size was 113.9 ± 1.4, resulting in a 55.1% ± 4.0% mean annual hatching success rate and a mean emerging success rate of 53.3% ± 3.7%. The only egg-fate that was statistically correlated with emerging success were eggs washed out by erosion. The loss of eggs by erosion was significantly greater during storm and poststo...
Published: 2014
Full Text: View/download PDF

40. Developing a common currency for stable isotope analyses of nesting marine turtles

Author: John F. Weishampel, James D. Roth, Pedro F. Quintana-Ascencio, Simona A. Ceriani, and Llewellyn M. Ehrhart
Subjects: Ecology, biology, Stable isotope ratio, Foraging, Sampling (statistics), Aquatic Science, biology.organism_classification, Sea turtle, Taxon, Nesting (computing), Nesting season, Ecology, Evolution, Behavior and Systematics, Isotope analysis
Abstract: Understanding geospatial linkages is critical to the development of appropriate management and conservation strategies for migratory species. Stable isotope analysis is a powerful tool that is performed routinely across taxa to unravel migratory connectivity. Marine turtles are a highly migratory and widely distributed taxon, but are largely studied at breeding areas. Isotopic values of several slow turnover rate tissues have been used to identify often distant foraging areas. However, as more isotopic data from various tissues become available, the relationships between tissues need to be calculated to permit meta-analyses to elucidate isotopic patterns across broader spatiotemporal scales. We used several commonly collected tissues (blood, skin, fresh eggs and unhatched eggs) collected simultaneously from loggerhead turtles (Caretta caretta) to develop a common currency for stable isotope analysis studies conducted on the nesting beach. We found highly significant relationships between the tissue signatures (r 2 ranged from 0.83 to 0.96) and developed equations to convert isotopic values from one tissue to another. We examined inter- and intra-clutch isotopic variability and found that a single sampling event over the 4-month nesting season adequately defined the loggerhead female foraging area. Consequently, we propose using unhatched eggs as a common currency in stable isotope studies of nesting loggerheads. Unhatched eggs represent a noninvasive and nondestructive method that enables more extensive (both numerically and spatially) sampling. Given similar physiologies, analogous relationships might be derived in other sea turtle species.
Published: 2014
Full Text: View/download PDF

41. A Defined, Controlled Culture System for Primary Bovine Chromaffin Progenitors Reveals Novel Biomarkers and Modulators

Author: Triantafyllos Chavakis, Graeme Eisenhofer, Stefan R. Bornstein, M Ehrhart-Bornstein, Ian Levenfus, Steve W. Poser, Jimmy Masjkur, Nan Qin, Sven Lange, Vladimir Vukicevic, Carina Arps-Forker, and Andreas Androutsellis-Theotokis
Subjects: Cholera Toxin, Time Factors, Chromaffin Cells, Cellular differentiation, Basic fibroblast growth factor, Cell Culture Techniques, Biology, Angiopoietin-2, chemistry.chemical_compound, Catecholamines, Neural Stem Cells, medicine, Animals, Progenitor cell, Protein Kinase Inhibitors, Cells, Cultured, Cell Proliferation, Janus Kinases, Cell growth, Intracellular Signaling Peptides and Proteins, Gene Expression Regulation, Developmental, Membrane Proteins, Cell Differentiation, Cell Biology, General Medicine, Tissue-Specific Progenitor and Stem Cells, Molecular biology, Neural stem cell, medicine.anatomical_structure, chemistry, Adrenal Medulla, Cell culture, Catecholamine, Cattle, Fibroblast Growth Factor 2, Adrenal medulla, Biomarkers, Signal Transduction, Transcription Factors, Developmental Biology, medicine.drug
Abstract: We present a method to efficiently culture primary chromaffin progenitors from the adult bovine adrenal medulla in a defined, serum-free monolayer system. Tissue is dissociated and plated for expansion under support by the mitogen basic fibroblast growth factor (bFGF). The cultures, although not homogenous, contain a subpopulation of cells expressing the neural stem cell marker Hes3 that also propagate. In addition, Hes3 is also expressed in the adult adrenal medulla from where the tissue is taken. Differentiation is induced by bFGF withdrawal and switching to Neurobasal medium containing B27. Following differentiation, Hes3 expression is lost, and cells acquire morphologies and biomarker expression patterns of chromaffin cells and dopaminergic neurons. We tested the effect of different treatments that we previously showed regulate Hes3 expression and cell number in cultures of fetal and adult rodent neural stem cells. Treatment of the cultures with a combination of Delta4, Angiopoietin2, and a Janus kinase inhibitor increases cell number during the expansion phase without significantly affecting catecholamine content levels. Treatment with cholera toxin does not significantly affect cell number but reduces the ratio of epinephrine to norepinephrine content and increases the dopamine content relative to total catecholamines. These data suggest that this defined culture system can be used for target identification in drug discovery programs and that the transcription factor Hes3 may serve as a new biomarker of putative adrenomedullary chromaffin progenitor cells.
Published: 2014
Full Text: View/download PDF

42. Trends in Size Class Distribution, Recaptures, and Abundance of Juvenile Green Turtles (Chelonia mydas) Utilizing a Rock Riprap Lined Embayment at Port Canaveral, Florida, USA, as Developmental Habitat

Author: William E. Redfoot and Llewellyn M. Ehrhart
Subjects: education.field_of_study, biology, Ecology, Foraging, Population, biology.organism_classification, law.invention, Fishery, Sea turtle, Habitat, Abundance (ecology), law, Juvenile, Animal Science and Zoology, Carapace, Turtle (robot), education, Ecology, Evolution, Behavior and Systematics
Abstract: Despite great advances in the understanding of marine turtle biology over the past 60 yrs, there is still a paucity of demographic data on the juvenile stage of their life history. These data are required to adequately predict population trends for these long-lived marine turtle species. In the early 1990s, juvenile green turtles (Chelonia mydas) were observed in the Trident Turning Basin at Port Canaveral, Brevard County, Florida. We began a study in 1993 to assess the species composition, size class distribution, and degree of residency of the marine turtles utilizing this man-made embayment as developmental habitat. The results of the first 18 yrs of that study are related here. Juvenile green turtles constituted 99.4% of the marine turtle captures. Straight carapace lengths (SCL) of turtles ranged from 20.0 to 52.0 cm with a mean of 31.7 cm, smaller than those observed in other known green turtle developmental habitats in Florida. The mean SCL of the green turtles in the basin has declined ov...
Published: 2013
Full Text: View/download PDF

43. Sea level rise, land use, and climate change influence the distribution of loggerhead turtle nests at the largest USA rookery (Melbourne Beach, Florida)

Author: Reed F. Noss, S. Wolf, Allison Whitney Hays, John F. Weishampel, Matthew V. Bilskie, C. Long, B. Von Holle, C. Sanchez, MV Schwoerer, Llewellyn M. Ehrhart, Davina L. Passeri, Joshua S. Reece, and Scott C. Hagen
Subjects: Shore, Rookery, geography, geography.geographical_feature_category, Ecology, biology, Global warming, Climate change, Aquatic Science, biology.organism_classification, Coastal erosion, Sea turtle, Oceanography, Habitat destruction, Nest, Environmental science, Ecology, Evolution, Behavior and Systematics
Abstract: Anthropogenic climate change adds to the existing suite of threats to species, such as habitat degradation, by increasing extinction risk and compromising the ability of species to respond adaptively to these stressors. Because threats from anthropogenic climate change often interact synergistically with other threats, integrated assessments of the factors and processes that affect species persistence and distribution are required. We assessed the influence of coastal land use and climate change (specifically sea level rise) on the spatial distribution of nests within the largest loggerhead Caretta caretta marine turtle rookery in the Atlantic Ocean, at Melbourne Beach, Florida, from 1986 to 2006. We generated a multiple regression model based on climate change, sea-level rise and land use that describes 47% of the spatial variation in loggerhead nest- ing. Nests have shifted northward (likely in response to warming temperatures), away from inten- sive coastal development, and, surprisingly, toward areas of increased erosion. Using the Bruun Rule (an approximation of the response of the shoreline profile to sea level rise), we modeled the impacts of sea level rise of 0.25 and 0.5 m in conjunction with extrapolations of coastal develop- ment and a continued northward shift in nest distribution. We project up to a 43% decrease in beach area from 1986 to a future with 0.5 m of sea level rise and predict that loggerhead nesting will shift northward and become increasingly crowded on narrowing beaches. An implication of this study is that areas currently protected for large rookeries may not overlap with their future distributions.
Published: 2013
Full Text: View/download PDF

44. The HPS electromagnetic calorimeter

Author: M. Battaglieri, B. Raydo, Jeremy McCormick, L. Colaneri, R. Dupré, M. Bondì, I. Balossino, N. A. Baltzell, A. D'Angelo, M. Garçon, R. Paremuzyan, M. De Napoli, P. Rosier, A. Celentano, M. Ehrhart, A. Filippi, R. De Vita, N. Gevorgyan, V. P. Kubarovsky, G. Charles, S. Stepanyan, E. Rauly, Larry Weinstein, H. Szumila-Vance, E. Buchanan, A. Rizzo, Daniela Calvo, Valeria Sipala, M. Guidal, E. Rindel, M. Holtrop, N. Randazzo, M. Osipenko, B. McKinnon, K. Livingston, K. McCarty, F. X. Girod, Hovanes Egiyan, V. Iurasov, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), HPS, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Istituto Nazionale di Fisica Nucleare, Sezione di Torino (INFN, Sezione di Torino), Istituto Nazionale di Fisica Nucleare (INFN), Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay ( IPNO ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire AIM, and Université Paris Diderot - Paris 7 ( UPD7 ) -Centre d'Etudes de Saclay
Subjects: tungsten: oxygen, Photon, Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, Elementary particle, Tracking (particle physics), 7. Clean energy, 01 natural sciences, Dark photon, Settore FIS/04 - Fisica Nucleare e Subnucleare, High Energy Physics - Experiment, 99-00, High Energy Physics - Experiment (hep-ex), [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], [ PHYS.PHYS.PHYS-INS-DET ] Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Instrumentation, Nuclear Experiment, Heavy photon, Electromagnetic calorimeter, Lead-tungstate crystals, Avalanche photodiodes, Physics, Detector, Nuclear and High Energy Physics, Instrumentation and Detectors (physics.ins-det), 00-01, Calorimeter, performance, Jefferson Lab, Author Keywords:Heavy photon, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Linear particle accelerator, NO, Nuclear physics, [ PHYS.HEXP ] Physics [physics]/High Energy Physics - Experiment [hep-ex], 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, lead, 010308 nuclear & particles physics, calorimeter: design, Avalanche photodiode, calorimeter: electromagnetic, photon: heavy, scintillation counter: crystal, High Energy Physics::Experiment
Abstract: The Heavy Photon Search experiment (HPS) is searching for a new gauge boson, the so-called "heavy photon." Through its kinetic mixing with the Standard Model photon, this particle could decay into an electron-positron pair. It would then be detectable as a narrow peak in the invariant mass spectrum of such pairs, or, depending on its lifetime, by a decay downstream of the production target. The HPS experiment is installed in Hall-B of Jefferson Lab. This article presents the design and performance of one of the two detectors of the experiment, the electromagnetic calorimeter, during the runs performed in 2015-2016. The calorimeter's main purpose is to provide a fast trigger and reduce the copious background from electromagnetic processes through matching with a tracking detector. The detector is a homogeneous calorimeter, made of 442 lead-tungstate (PbWO4) scintillating crystals, each read out by an avalanche photodiode coupled to a custom trans-impedance amplifier., 34 pages, 25 figures
Published: 2017
Full Text: View/download PDF

45. Lipoprotein apheresis reduces adipocyte fatty acid-binding protein serum levels

Author: Stefan R. Bornstein, M. Ehrhart-Bornstein, V Lamounier-Zepter, Sabine Fischer, Ulrich Julius, and Christiane Look
Subjects: Male, medicine.medical_specialty, Time Factors, Lipoproteins, Hypercholesterolemia, Type 2 diabetes, Fatty Acid-Binding Proteins, Risk Assessment, Body Mass Index, Pathogenesis, chemistry.chemical_compound, Risk Factors, Adipocyte, Internal medicine, Internal Medicine, medicine, Humans, Immunoadsorption, Triglycerides, Aged, business.industry, Cholesterol, HDL, Cholesterol, LDL, General Medicine, Middle Aged, medicine.disease, Obesity, Treatment Outcome, Endocrinology, Adipocyte fatty acid binding protein, Apheresis, chemistry, Cardiovascular Diseases, Blood Component Removal, Female, Cardiology and Cardiovascular Medicine, business, Lipoprotein apheresis, Biomarkers, Lipoprotein(a)
Abstract: Background and methods Adipocyte fatty acid-binding protein (FABP4) is a member of the intracellular lipid-binding protein family highly expressed in adipocytes and macrophages. Recent studies indicate a key role for circulating FABP4 in the pathogenesis of atherosclerosis and type 2 diabetes. We described an additional role for FABP4 in the development of cardiac dysfunction in obesity. Therefore, FABP4 seems to be a target in the prevention and treatment of metabolic and cardiovascular disorders in obesity with high potential for future therapeutic applications. However, a safe pharmacological therapy is not yet available. Lipoprotein apheresis is an established therapy for severe and otherwise untreatable hypercholesterolemia which increases life expectancy in patients at high-risk for cardiovascular events. We therefore investigated the acute effect of lipoprotein apheresis on FABP4 serum levels in 64 high-risk patients (25 women, 39 men) under regular apheresis treatment. Results FABP4 levels were significantly reduced by 23.2 ± 1.8% by apheresis treatment. Although women had higher FABP4 levels than men (53.5 ± 8.3 ng/ml vs. 30.7 ± 4.3 ng/ml), reduction rate after lipoprotein apheresis was similar in both genders. Among the apheresis methods investigated, immunoadsorption of lipoproteins was most effective in lowering circulating FABP4. Conclusion These data suggest that the reduction of FABP4 serum levels may contribute to the preventive effect of lipoprotein apheresis on cardiovascular events.
Published: 2013
Full Text: View/download PDF

46. Expanded mitochondrial control region sequences increase resolution of stock structure among North Atlantic loggerhead turtle rookeries

Author: Anton D. Tucker, Mark G. Dodd, Janne T. Nielsen, Chris Johnson, Alejandro Arenas, Brian M. Shamblin, Dean A. Bagley, Karen A. Bjorndal, Alan B. Bolten, Erin L. LaCasella, Peter H. Dutton, Blair E. Witherington, Margaret M. Lamont, Raymond R. Carthy, F. Alberto Abreu-Grobois, Michael S. Gaines, Llewellyn M. Ehrhart, Campbell J. Nairn, Kimberly J. Reich, and David S. Addison
Subjects: mtDNA control region, Rookery, Genetic diversity, education.field_of_study, Ecology, Population structure, Population, Aquatic Science, Analysis of molecular variance, Cape verde, Geography, education, Ecology, Evolution, Behavior and Systematics, Stock (geology)
Abstract: The southeastern USA hosts the largest nesting concentration of loggerhead turtles Caretta caretta in the Atlantic. Regionally significant nesting also occurs along the Caribbean coast of Mexico, in Cuba, and in the Bahamas. Previous studies of North Atlantic loggerhead turtle rookeries based on a 380 bp fragment of the mitochondrial control region supported recognition of 8 demographically independent nesting populations (management units) in the Northwest Atlantic in addition to Cape Verde in the eastern Atlantic. Recent analysis of expanded mitochon- drial control region sequences revealed additional genetic diversity and increased population structure between western and eastern Atlantic loggerhead turtle rookeries. We se quenced an 817 bp mitochondrial DNA fragment in 2427 samples from nesting beaches in the southeastern USA, Cay Sal Bank, Bahamas, and Quintana Roo, Mexico. Pairwise FST comparisons, pairwise exact tests of population differentiation, and analysis of molecular variance support previously proposed management unit designations and additionally indicate that southeastern and south- western Florida rookeries should be recognized as distinct management units. Therefore, North- west Atlantic loggerhead turtle rookeries can be subdivided into 10 management units, corre- sponding to the beaches from (1) Virginia through northeastern Florida, (2) central eastern Florida, (3) southeastern Florida, (4) Dry Tortugas, Florida, (5) Cay Sal, Bahamas, (6) southwestern Cuba, (7) Quintana Roo, Mexico, (8) southwestern Florida, (9) central western Florida, and (10) northwestern Florida. We confirmed increased resolution of stock structure between many North- west Atlantic management units and the Cape Verde rookery with the expanded control region haplotypes.
Published: 2012
Full Text: View/download PDF

47. Differentiation of Chromaffin Progenitor Cells to Dopaminergic Neurons

Author: Marius Ader, M Ehrhart-Bornstein, Graeme Eisenhofer, Sven Lange, Kuei-Fang Chung, Vladimir Vukicevic, Linda Gebauer, Stefan R. Bornstein, Ursula Ravens, Nan Qin, Janine Schmid, Andreas Hermann, and Alexander Storch
Subjects: endocrine system, Parkinson's disease, Chromaffin Cells, metabolism [Stem Cells], Biomedical Engineering, Retinoic acid, lcsh:Medicine, Tretinoin, metabolism [Tretinoin], Biology, cytology [Stem Cells], chemistry.chemical_compound, medicine, Animals, ddc:610, Progenitor cell, Cells, Cultured, Cell Proliferation, cytology [Dopaminergic Neurons], Transplantation, Dopaminergic Neurons, Stem Cells, lcsh:R, metabolism [Dopaminergic Neurons], Dopaminergic, Cell Differentiation, metabolism [Chromaffin Cells], Cell Biology, medicine.disease, Ascorbic acid, physiology [Cell Differentiation], chemistry, cytology [Chromaffin Cells], Cattle, Neural differentiation, Neuroscience
Abstract: The differentiation of dopamine-producing neurons from chromaffin progenitors might represent a new valuable source for replacement therapies in Parkinson's disease. However, characterization of their differentiation potential is an important prerequisite for efficient engraftment. Based on our previous studies on isolation and characterization of chromaffin progenitors from adult adrenals, this study investigates their potential to produce dopaminergic neurons and means to enhance their dopaminergic differentiation. Chromaffin progenitors grown in sphere culture showed an increased expression of nestin and Mash1, indicating an increase of the progenitor subset. Proneurogenic culture conditions induced the differentiation into neurons positive for neural markers β-III-tubulin, MAP2, and TH accompanied by a decrease of Mash1 and nestin. Furthermore, Notch2 expression decreased concomitantly with a downregulation of downstream effectors Hes1 and Hes5 responsible for self-renewal and proliferation maintenance of progenitor cells. Chromaffin progenitor-derived neurons secreted dopamine upon stimulation by potassium. Strikingly, treatment of differentiating cells with retinoic and ascorbic acid resulted in a twofold increase of dopamine secretion while norepinephrine and epinephrine were decreased. Initiation of dopamine synthesis and neural maturation is controlled by Pitx3 and Nurr1. Both Pitx3 and Nurr1 were identified in differentiating chromaffin progenitors. Along with the gained dopaminergic function, electrophysiology revealed features of mature neurons, such as sodium channels and the capability to fire multiple action potentials. In summary, this study elucidates the capacity of chromaffin progenitor cells to generate functional dopaminergic neurons, indicating their potential use in cell replacement therapies.
Published: 2012
Full Text: View/download PDF

48. Isolation and characterization of tetranucleotide microsatellites from the leatherback turtle (Dermochelys coriacea)

Author: Brian M. Shamblin, Dean A. Bagley, Llewellyn M. Ehrhart, Campbell J. Nairn, and Travis I. Alstad
Subjects: Ecology, Biodiversity, Endangered species, Zoology, Locus (genetics), Biology, law.invention, Loss of heterozygosity, law, Genetics, Wildlife refuge, Microsatellite, Life history, Ecology, Evolution, Behavior and Systematics, Polymerase chain reaction
Abstract: The leatherback turtle (Dermochelys coriacea) is a globally endangered marine species. Numerous questions regarding life history and demographics that are of conservation interest remain and many of these can be addressed through the use of highly polymorphic nuclear markers. We describe primers and polymerase chain reaction conditions to amplify 19 tetranucleotide microsatellite loci from the leatherback turtle. The primers were tested on samples from 22 females that nested at Archie Carr National Wildlife Refuge, Melbourne Beach, Florida, USA. The primers developed in this study yielded an average of 9.4 alleles per locus (range of 5–19) and an average observed heterozygosity of 0.84 (range 0.36–1.00). These markers should prove useful in supplementing existing markers for individual and population level analyses.
Published: 2011
Full Text: View/download PDF

49. Genetic barcoding of marine leeches (Ozobranchus spp.) from Florida sea turtles and their divergence in host specificity

Author: Llewellyn M. Ehrhart, Steven T. Weege, Michael J. Bresette, Audrey E. McGowin, Dave Clark, Dean A. Bagley, Adrian M. Corbett, and Triet Minh Truong
Subjects: animal structures, Fibropapillomatosis, Ecology, Leech, Zoology, Ozobranchus branchiatus, Biology, DNA barcoding, Phylogenetics, GenBank, Genetics, Taxonomy (biology), Ecology, Evolution, Behavior and Systematics, Host specificity, Biotechnology
Abstract: Ozobranchus margoi and Ozobranchus branchiatus are the only two species of marine turtle leeches (Ozobranchus spp.) known to inhabit the Atlantic coast of the United States and the Gulf of Mexico. In early reports of fibropapillomatosis (FP) in green turtles (Chelonia mydas), O. branchiatus was implicated as a vector in the transmission of Fibropapilloma-associated turtle herpesvirus (FPTHV). It is imperative that the leech species be identified to elucidate the role Ozobranchus spp. may play in disease transmission. In this study, Ozobranchus branchiatus has been identified for the first time on a loggerhead (Caretta caretta) turtle, and the molecular data for this species is now available for the first time in GenBank. Both species of leeches were also found infecting a single C. mydas. Using morphological taxonomy combined with distance- and character-based genetic sequence analyses, this study has established a DNA barcode for both species of Ozobranchus spp. leech and has shown it can be applied successfully to the identification of leeches at earlier stages of development when morphological taxonomy cannot be employed. The results suggest a different haplotype may exist for O. branchiatus leeches found on C. caretta versus C. mydas. Leech cocoon residue collected from a C. mydas was identified using the new method.
Published: 2010
Full Text: View/download PDF

50. Genetic structure of the southeastern United States loggerhead turtle nesting aggregation: evidence of additional structure within the peninsular Florida recovery unit

Author: David S. Addison, Kristina L. Williams, Russell A. Scarpino, Sally R. Murphy, Dean A. Bagley, Raymond R. Carthy, Chris Johnson, Stefanie Ouellette, Mark G. Dodd, Michael G. Frick, Anton D. Tucker, Anne B. Meylan, Brian M. Shamblin, Erin McMichael, Matthew H. Godfrey, Llewellyn M. Ehrhart, and Campbell J. Nairn
Subjects: mtDNA control region, Rookery, education.field_of_study, Ecology, Population, Population genetics, Aquatic Science, Biology, Analysis of molecular variance, law.invention, law, Genetic variation, Genetic structure, Turtle (robot), education, Ecology, Evolution, Behavior and Systematics
Abstract: The southeastern United States supports one of two large loggerhead turtle (Caretta caretta) nesting aggregations worldwide and is therefore critical to global conservation and recovery efforts for the species. Previous studies have established the presence of four demographically distinct nesting populations (management units) corresponding to beaches from (1) North Carolina through northeastern Florida, (2) peninsular Florida, (3) the Dry Tortugas, and (4) northwest Florida. Temporal and geographic genetic structure of the nesting aggregation was examined utilizing partial mitochondrial control region haplotype frequencies from 834 samples collected over the 2002 through 2008 nesting seasons from 19 beaches as well as previously published haplotype data. Most rookeries did not exhibit interannual genetic variation. However, the interannual variation detected did significantly impact the interpretation of spatial genetic structure in northeastern Florida. Based on pairwise F ST comparisons, exact tests of population differentiation, and analysis of molecular variance, the present study upholds the distinctiveness of the four currently recognized management units and further supports recognition of discrete central eastern, southern (southeastern and southwestern), and central western Florida management units. Further subdivision may be warranted, but more intensive genetic sampling is required. In addition, tools such as telemetry and mark-recapture are needed to complement genetic data and overcome limitations of genetic markers in resolving loggerhead turtle rookery connectivity in the southeastern USA.
Published: 2010
Full Text: View/download PDF

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Publication Type

Journal

Database

Publisher

347 results on '"M Ehrhart"'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources