Adjunct Instructional Faculty
Physics
Dennis Weygand
215 OCEANOGRAPHY & PHYSICS BLDG
NORFOLK, 23529
Ph.D. in Nuclear Physics, Syracuse University, (1979)
B.S. in Physics & Mathematics, Hofstra University, (1973)
Articles
- Gavalian, G., Stepanyan, S., Amaryan, M., Bagdasaryan, H., Brooks, W., Bueltmann, S. L., Careccia, S. L. ., Dharmavardane, K. V. ., Dodge, G. E., Guler, N., Hyde, C. E., Juengst, H. G. ., Kalantarians, N., Klein, A., Kuhn, S., Lachniet, J., Sabatie, F., Niroula, M. R. ., Tkachenko, S., Weinstein, L. B., Weygand, D., Yun, J. and Zhang, J. (2009). Beam Spin Asymmetries in deeply virtual Compton scattering (DVCS) with CLAS at 4.8-GeV. Phys. Rev. C 80 , pp. 035206.
- Aznauryan, I. G.., Adhikari, K. P. ., Brooks, W., Careccia, S. L.., Forest, T. A. ., Hyde, C. E., Klein, A., Kuhn, S., Nepali, C., Niroula, M. R. ., Sabatie, F., Seradaryan, H., Stepanyan, S., Tkachenko, S., Weinstein, L. B., Weygand, D. and Zhang, J. (2009). Electroexcitation of nucleon resonances from CLAS data on single pion electroproduction. Phys. Rev. C 80 , pp. 055203.
- Fedotov, G. V. ., Amaryan, M., Bagdasaryan, H., Bektasoglu, M., Brooks, W., Bueltmann, S. L., Careccia, S. L. ., Dharmavardane, K. V. ., Dodge, G. E., Forest, T. A. ., Gavalian, G., Guler, N., Hyde, C. E., Juengst, H. G. ., Klimenko, A., Klein, A., Kuhn, S., Lachniet, J., Sabatie, F., Stepanyan, S., Tkachenko, S., Weinstein, L. B., Weygand, D. and Zhang, J. (2009). Electroproduction of pπ⁺π¯ off protons at 0.2
Phys. Rev. C 79 , pp. 015204.
- Chen, W., Mibe, T., Dutta, D., Gao, H., Laget, J. M.., Mirazita, M., Rossi, P., Stepanyan, S., Strakovsky, I. I.., Amaryan, M., Anghinolfi, M., Bagdasaryan, H., Battaglieri, M., Bellis, M., Berman, B. L. ., Biselli, A. S.., Bookwalter, C., Branford, D., Briscoe, W. J.., Brooks, W. K.., Burkert, V. D.., Careccia, S. L.., Carman, D. S.., Casey, L., Cole, P. L. ., Collins, P., Crede, V., Daniel, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Dhamija, S., Dickson, R., Djalali, C., Dodge, G. E., Doughty, D., Egiyan, H., Eugenio, P., Fedotov, G., Fradi, A., Garcon, M., Gilfoyle, G. P.., Giovanetti, K. L.., Girod, F. X.., Gohn, W., Gothe, R. W. ., Griffioen, K. A.., Guidal, M., Hakobyan, H., Hanretty, C., Hassall, N., Heddle, D., Hicks, K., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G. ., Ishkhanov, B. S.., Isupov, E. L. ., Jo, H. S.., Johnstone, J. R. ., Joo, K., Keller, D., Khandaker, M., Kim, W., Klein, A., Klein, F. J.., Kramer, L. H.., Kubarovsky, V., Kuhn, S., Kuleshov, S. V.., Kuznetsov, V., Livingston, K., Lu, H. Y.., Markov, N., McCracken, M. E.., McKinnon, B., Meyer, C. A.., Mineeva, T., Mokeev, V., Moreno, B., Moriya, K., Nadel-Turonski, P., Nasseripour, R., Niccolai, S., Niculescu, I., Niroula, M. R. ., Osipenko, M., Ostorovidov, A. I.., Park, K., Park, S., Anefalos Pereira, S., Pogorelko, O., Pozdniakov, S., Price, J. W. ., Procureur, S., Protoposescu, D., Raue, B. A.., Ricco, G., Ripani, M., Ritchie, B. G.., Rosner, G., Sabatie, F., Saini, M. S.., Salamanca, J., Salgado, C., Schumacher, R. A.., Sharabian, Y. G.., Sober, D. I.., Sokhan, D., Stepanyan, S. S.., Strauch, S., Taiuti, M., Tedescchi, D. J.., Tkachenko, S., Ungaro, M., Vineyard, M. F.., Watts, D. P.., Weinstein, L. B., Weygand, D., Wood, M. H.., Yegneswaran, A., Zhang, J. and Zhao, B. (2009). Measurement of the Differential Cross Section for the Reaction gamman-->pi-p from Deuterium. Phys. Rev. Lett. 103 (1) , pp. 012301 [6 pages].
- Nasseripour, N., Adhikari, K. P. ., Amaryan, M., Brooks, W., Careccia, S. L. ., Dodge, G. E., Hyde, C. E., Klein, A., Kuhn, S., Mayer, M., Nepali, C. S. ., Niroula, M. R. ., Seradaryan, H., Tkachenko, S., Weinstein, L. B., Weygand, D. and Zhang, J. (2009). Photodisintegration of ⁴He into p+t. Phys. Rev. C 80 , pp. 044603.
- Battaglieri, M., Adhikari, K. P. ., Amaryan, M., Careccia, S. L. ., Dodge, G. E., Hyde, C. E., Klein, A., Mayer, M., Nepali, C. S. ., Niroula, M. R. ., Seradaryan, H., Stepanyan, S., Tkachenko, S., Weinstein, L. B., Weygand, D. and Zhang, J. (2009). Photoproduction of pi+ pi- meson pairs on the proton.. Phys. Rev. D 80 , pp. 072005.
- Dugger, M., Amaryan, M., Brooks, W., Careccia, S. L. ., Dodge, G. E., Hyde, C. E., Klein, A., Niroula, M. R. ., Stepanyan, S., Tkachenko, S., Weinstein, L. B. and Weygand, D. (2009). pi+ photoproduction on the proton for photon energies from 0.725 to 2.875-GeV. Phys. Rev. C 79 , pp. 065206.
- Lachniet, J., Afanasev, A., Arenhovel, H., Brooks, W. K.., Gilfoyle, G. P.., Higinbotham, D., Jeschonnek, S., Quinn, B., Vineyard, M. F.., Adams, G., Adhikari, K. P.., Amaryan, M., Anghinolfi, M., Asavapibhop, B., Asryan, G., Avakian, H., Bagdasaryan, H., Baillie, N., Ball, J. P.., Baltzell, N. A.., Barrow, S., Batourine, V., Battaglieri, M., Beard, K., Bedlinskiy, I., Bektasolgu, M., Bellis, M., Benmouna, N., Berman, B. L.., Biselli, A. S.., Bonner, B. E.., Bookwalter, C., Bouchigny, S., Boiarinov, S., Bradford, R., Briscoe, W. J.., Bueltmann, S. L., Burkett, V. D.., Calarco, J. R.., Careccia, S. L.., Carman, D. S.., Casey, L., Cheng, L., Cole, P. L.., Coleman, A., Collins, P., Cords, D., Corvisiero, P., Crabb, D., Crede, V., Cummings, J. P.., Dale, D., Daniel, A., Dashyan, N., De Masi, R., De Vita, R., De Sanctis, E., Degtyarenko, P. V.., Denizli, H., Dennis, L., Deur, A., Dhamija, S., Dharmawardane, K. V.., Dhuga, K. S.., Dickson, R., Djalali, C., Dodge, G. E., Doughty, D., Dragovitsch, P., Dugger, M., Dytman, S., Dzyubak, O. P.., Egiyan, H., Egiyan, K. S.., El Fassi, L., Elouadrhiri, L., Emplo, A., Eugenio, P., Fatemi, R., Fedotov, G., Fersch, R., Feurerbach, R. J. ., Forest, T. A. ., Fradi, A., Gabrielyan, M. Y. ., Garcon, M., Gavalian, G., Gevorgyan, N., Giovanetti, K. L. ., Girod, F. X. ., Goetz, J. T. ., Gohn, W., Golovatch, E., Gothe, R. W. ., Graham, L., Griffioen, K. A. ., Guidal, M., Guillo, M., Guler, N., Guo, L., Gyurjyan, V., Hadjidakis, C., Hafidi, K., Hakobayan, H., Hanretty, C., Hardie, J., Hassall, N., Heddle, D., Hersman, F. W.., Hicks, K., Hleiqawi, I., Holtrop, M., Hu, J., Huertas, M., Hyde, C. E., Ilieva, Y., Ireland, D. G. ., Ishkhanov, S., Isupov, E. L. ., Ito, M. M. ., Jenkins, D., Joh, H. S. ., Johnstone, J. R. ., Joo, K., Juengst, H. G. ., Kageya, T., Kalantarians, N., Keller, D. D. ., Kellie, J. D. ., Khandaker, M., Khetarpal, P., Kim, K. Y. ., Kim, K., Kim, W., Klein, A., KIein, F. J. ., Klusman, M., Konczykowski, P., Kossov, M., Kramer, L. H. ., Kubarovsky, V., Kuhn, J., Kuhn, S., Kuleshov, S., Kuznetsov, V., Laget, J. M.., Langheinrich, J., Lawrence, D., Lima, C. S.., Livingston, K., Livingston, M., Lu, H. Y.., Lukashin, K., MacCormick, M., Malace, S., Manak, J. J.., Markov, N., Mattione, P., McAleer, S., McCracken, M. E.., McKinnon, B., McNabb, J. C.., Mecking, B. A.., Mestayer, M. D.., Meyer, C. A.., Mibe, T., Mikhailov, K., Mineeva, T., Minehart, R., Mirazita, M., Miskimen, R., Mokeev, V., Moreno, B., Moriya, K., Morrow, S. A.., Moteabbed, M., Mueller, J., Munevar, E., Mutchler, G. S.., Nadel-Turonski, P., Nasseripour, R., Niccolai, S., Niculescu, G., Niczyporuk, B. B.., Niroula, M. R.., Niyazov, R. A.., Nozar, M., O'Rielly, G. V.., Osipenko, M., Ostrovidov, A. I.., Park, K., Park, S., Pasyuk, E., Paterson, C., Anefalos Pereira, S., Philips, S. A.., Pierce, J., Pivnyuk, N., Pocanic, D., Pogorelko, O., Polli, E., Popa, I., Pozdniakov, S., Preedom, B. M.., Price, J. W.., Prok, Y., Protopopescu, D., Qin, L. M. ., Raue, B. A. ., Riccardi, G., Ricco, G., Ripani, M., Ritchie, B. G.., Rosner, G., Rossi, P., Rowntree, D., Rubin, P. D.., Sabatié, F., Saini, M. S.., Salamanca, J., Salgado, C., Sandorfi, A., Santoro, J. P.., Sapunenko, V., Schott, D., Schumacher, R. A.., Serov, V. S.., Sharabian, Y. G.., Sharov, D., Shaw, J., Shvedunov, N. V.., Skabelin, A. V.., Smith, E. S.., Smith, L. C.., Sober, D. I.., Sokhan, D., Starostin, A., Stavinsky, A., Stepanyan, S., Stepanyan, S. S.., Stokes, B. E.., Stoler, P., Stopani, K. A.., Strakovsky, I. I.., Strauch, S., Suleiman, R., Taiuti, M., Taylor, S., Tedeschi, D. J.., Thompson, R., Tkabladze, A., Tkachenko, S., Ungaro, M., Vlassov, A. V.., Watts, D. P.., Wei, X., Weinstein, L. B., Weygand, D., Williams, M., Wolin, E., Wood, M. H.., Yegneswaran, A., Yun, J., Yurov, M., Zana, L., Zhang, J., Zhao, B. and Zhao, Z. W.. (2009). Precise Measurement of the Neutron Magnetic Form Factor GMn in the Few-GeV2 Region. Phys. Rev. Lett. 102 (19) , pp. 192001 [6 pages].
- Qian, X., Stepanyan, S., Adhikari, K. P. ., Amaryan, M., Brooks, W., Careccia, S. L. ., Dodge, G. E., Hyde, C. E., Klein, A., Mayer, M., Nepali, C. S. ., Niroula, M. R. ., Seradaryan, H., Tkachenko, S., Weinstein, L. B., Weygand, D. and Zhang, J. (2009). The Extraction of phi - N total cross section from d(gamma, pK⁺ K¯n CLAS Collaboration. Phys. Rev. B 680 (5) , pp. 417-422.
- Battaglieri, M., De Vita, R., Szczepaniak, A. P.., Adhikari, K. P.., Amaryan, M., Ambrozewicz, P., Anghinolfi, M., Asryan, G., Avakian, H., Bagdasaryan, H., Baillie, N., Ball, J. P.., Baltzell, N. A.., Batourine, V., Bedlinskiy, I., Bektasolgu, M., Bellis, M., Benmouna, N., Berman, B. L.., Bibrizycki, L., Biselli, A. S.., Bookwalter, C., Bouchigny, S., Boiarinov, S., Bradford, R., Branford, D., Briscoe, W. J.., Brooks, W. K. ., Bueltmann, S. L., Burkett, V. D.., Calarco, J. R.., Careccia, S. L.., Carman, D. S.., Casey, L., Cheng, L., Chen, S., Clinton, E., Cole, P. L.., Collins, P., Crabb, D., Crannell, H., Crede, V., Cummings, J. P.., Dale, D., Daniel, A., Dashyan, N., De Masi, R., De Sanctis, E., Degtyarenko, P. V.., Deur, A., Dhamija, S., Dharmawardane, K. V.., Dickson, R., Djalali, C., Dodge, G. E., Donnelly, J., Doughty, D., Dugger, M., Dzyubak, O. P.., Egiyan, H., Egiyan, K. S.., El Fassi, L., Elouadrhiri, L., Eugenio, P., Fedotov, G., Fersch, R., Forest, T. A. ., Fradi, A., Gabrielyan, M. Y. ., Gan, L., Garcon, M., Gasparian, A., Gavalian, G., Gevorgyan, N., Giovanetti, K. L. ., Girod, F. X. ., Glamazdin, O., Goett, J., Goetz, J. T. ., Gohn, W., Golovatch, E., Gordon, C. O.., Gothe, R. W. ., Graham, L., Griffioen, K. A. ., Guidal, M., Guillo, M., Guler, N., Guo, L., Gyurjyan, V., Hadjidakis, C., Hafidi, K., Hakobayan, H., Hakobayan, R. S.., Hanretty, C., Hardie, J., Hassall, N., Heddle, D., Hersman, F. W.., Hicks, K., Hleiqawi, I., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G. ., Ishkhanov, S., Isupov, E. L. ., Ito, M. M. ., Jenkins, D., Jo, H. S. ., Johnstone, J. R. ., Joo, K., Juengst, H. G. ., Kageya, T., Kalantarians, N., Keller, D. D. ., Kellie, J. D. ., Khandaker, M., Khetarpal, P., Kim, W., Klein, A., KIein, F. J. ., Klimenko, A. V.., Konczykowski, P., Kossov, M., Krahn, Z., Kramer, L. H. ., Kubarovsky, V., Kuhn, J., Kuhn, S., Kuleshov, S., Kuznetsov, V., Lachniet, J., Laget, J. M.., Langheinrich, J., Lawrence, D., Lee, T., Lesniak, L., Li, J., Livingston, K., Lowry, M., Lu, H. Y.., MacCormick, M., Malace, S., Markov, N., Mattione, P., McCracken, M. E.., McKinnon, B., Mecking, B. A.., Melone, J. J.., Mestayer, M. D.., Meyer, C. A.., Mibe, T., Mikhailov, K., Mineeva, T., Minehart, R., Mirazita, M., Miskimen, R., Mochalov, V., Mokeev, V., Moreno, B., Moriya, K., Morrow, S. A.., Moteabbed, M., Mueller, J., Munevar, E., Mutchler, G. S.., Nadel-Turonski, P., Nakagawa, I., Nasseripour, R., Niccolai, S., Niculescu, G., Niczyporuk, B. B.., Niroula, M. R.., Niyazov, R. A.., Nozar, M., Osipenko, M., Ostrovidov, A. I.., Park, K., Park, S., Pasyuk, E., Paris, M., Paterson, C., Anefalos Pereira, S., Pierce, J., Pivnyuk, N., Pocanic, D., Pogorelko, O., Pozdniakov, S., Price, J. W.., Prok, Y., Protopopescu, D., Raue, B. A. ., Riccardi, G., Ricco, G., Ripani, M., Ritchie, B. G.., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S.., Salamanca, J., Salgado, C., Sandorfi, A., Santoro, J. P.., Sapunenko, V., Schott, D., Schumacher, R. A.., Serov, V. S.., Sharabian, Y. G.., Sharov, D., Shvedunov, N. V.., Smith, E. S.., Smith, L. C.., Sober, D. I.., Sokhan, D., Starostin, A., Stavinsky, A., Stepanyan, S., Stepanyan, S. S.., Stokes, B. E.., Stoler, P., Stopani, K. A.., Strakovsky, I. I.., Strauch, S., Taiuti, M., Tedeschi, D. J.., Teymurazyan, A., Tkabladze, A., Tkachenko, S., Todor, L., Tur, C., Ungaro, M., Vineyard, M. F. ., Vlassov, A., Watts, D. P.., Wei, X., Weinstein, L. B., Weygand, D., Williams, M., Wolin, E., Wood, M. H.., Yegneswaran, A., Yurov, M., Zana, L., Zhang, J., Zhao, B. and Zhao, Z. W.. (2009). First measurement of Direct f₀(980) Photoproduction on the Proton. Phys. Rev. Lett. 102 (19) , pp. 102001 [6 pages].
- Ireland, D. G., Bagdasaryan, H., Brooks, W., Careccia, S., Dodge, G. E., Gavalian, G., Guler, N., Hyde, C. E., Juengst, H., Kalantarians, N., Klein, A., Lachniet, J., Niroula, M. R. ., Sabatie, F., Stepanyan, S., Tkachenko, S., Weinstein, L. B., Weygand, D. and Zhang, J. (2008). Bayesian analysis of pentaquark signals from CLAS data. Phys. Rev. Lett. 100 , pp. 052001.
- Park, K., Amaryan, M., Bagdasaryan, H., Bektasoglu, M., Brooks, W., Careccia, S., Dharmawardane, K., Dodge, G. E., Forest, T. A.., Gavalian, G., Guler, N., Hyde, C. E., Juengst, H., Kalantarians, N., Klein, A., Klimenko, A., Kuhn, S., Lachniet, J., Niroula, M., Niyazov, R., Sabatie, F., Stepanyan, S., Tkachenko, S., Weinstein, L. B., Weygand, D. and Zhang, J. (2008). Cross sections and beam asymmetries for ep → enπ+ in the nuclear resonance region for 1.7 ≤ Q² ≤ 4.5 GeV² . Phys. Rev. C 77 (1) , pp. 015208.
- Aznauryan, I. G., Bagdasaryan, H., Bektasoglu, M., Bueltmann, S. L., Careccia, S. L., Dharmawardane, K. V., Dodge, G. E., Forest, T. A., Gavalian, G., Guler, N., Hyde, C. E., Juengst, H. G., Kuhn, S., Lachniet, J., Niroula, M. R., Niyazov, R. A., Qin, L. M., Sabatie, F., Tkachenko, S., Weinstein, L. B., Yun, J., Weygand, D. and Zhang, J. (2008). Electroexcitation of the Roper resonance at 1.7
Physical Review C 78 (045209).
- Wood, M. H., Weygand, D., Amaryan, M., Bektasoglu, M., Careccia, S., Dharmawardane, K., Dodge, G. E., Gavalian, G., Guler, N., Hyde, C. E., Juengst, H., Kalantarians, N., Klein, A., Kuhn, S., Niroula, M., Niyazov, R., Sabatie, F., Stepanyan, S., Tkachenko, S., Weinstein, L. B. and Zhang, J. (2008). Light vector mesons in the nuclear medium . Phys. Rev. C 78 , pp. 015201.
- Masi, R. De., Amaryan, M., Bagdasaryan, H., Brooks, W. K. ., Bueltmann, S. L., Careccia, S., Dharmawardane, K., Dodge, G. E., Gavalian, G., Guler, N., Hyde, C. E., Juengst, H., Kalantarians, N., Klein, A., Klimenko, A., Kuhn, S., Lachniet, J., Niroula, M., Niyazov, R., Sabatie, F., Stepanyan, S., Tkachenko, S., Weinstein, L. B., Weygand, D. and Zhang, J. (2008). Measurement of ep → epπ⁰ beam spin asymmetries above the resonance region. Phys. Rev. C 77 , pp. 042201.
- Nasseripour, R., Amaryan, M., Bagdasaryan, H., Burkert, W., Careccia, S., Dodge, G. E., Forest, T. A. ., Gavalian, G., Guler, N., Hyde, C. E., Juengst, H., Kalantarians, N., Klein, A., Kuhn, S., Lachniet, J., Niroula, M., Niyazov, R., Qin, L., Sabatie, F., Stepanyan, S., Tkachenko, S., Weinstein, L. B., Weygand, D., Yun, J. and Zhang, J. (2008). Polarized structure function σLT' for 1H(e⃗,e'K+)Λ in the nucleon resonance region. Phys. Rev. C 77 , pp. 065208.
- Nasseripour, R., Amaryan, M., Bagdasaryan, H., Bueltmann, S. L., Careccia, C., Dharmawardane, K. V., Dodge, G. E., Gavalian, G., Guler, N., Hyde, C. E., Juengst, H. G., Klimenko, A. V., Kuhn, S., Lachniet, J., Niroula, M. R., Niyazov, R. A., Tkachenko, S., Weinstein, L. B. and Weygand, D. (2007). Search for Medium Modifications of the rho meson. Phys. Rev. Lett 99 , pp. 262302.
- Dugger, M., Amaryan, M., Bagdasaryan, H., Careccia, S. L., Dharmawardane, K. V., Dodge, G. E., Forest, T. A., Gavalian, G., Guler, N., Hyde, C. E., Juengst, H. G., Klimenko, A. V., Kuhn, S., Lachniet, J., Niroula, M., Qin, L. M., Sabatie, F., Tkachenko, S., Yun, J., Weinstein, L. B., Weygand, D. and Zhang, J. (2007). π⁰ photoproduction on the proton for photon energies from 0.675 to 2.875 GeV. Phys Rev C 76 , pp. 025211.
- Klimenko, A. V., Bagdasaryan, H., Bueltmann, S. L., Careccia, S. L., Dharmawardane, K. V., Dodge, G. E., Gavalian, G., Guler, N., Hyde, C. E., Klein, A., Kuhn, S., Lachniet, J., Niyazov, R. A., Sabatie, F., Stepanyan, S., Tkachenko, S., Weinstein, L. B., Weygand, D. and Zhang, J. (2006). Electron Scattering From High-Momentum Neutrons in Deuterium. Phys Rev C 73 , pp. 035212.
- Niccolai, S., Bagdasaryan, H., Bueltmann, S. L., Careccia, S. L., Dharmawardane, K. V., Dodge, G. E., Gavalian, G., Guler, N., Hyde, C. E., Juengst, H. G., Klimenko, A. V., Kuhn, S., Lachniet, J., Weinstein, L. B., Weygand, D. and Zhang, J. (2006). Search for the Θ ⁺ pentaquark in the γd → ΛnK⁺ Rection measured with CLAS . Phys Rev Lett 97 , pp. 032001.
- Strauch, S., Bagdasaryan, H., Bektasoglu, M., Careccia, S., Dodge, G. E., Forest, T., Gavalian, G., Guler, N., Hyde, C. E., Juengst, H., Klien, A., Klimenko, A., Kuhn, S., Niyazov, R., Lachniet, J., Sabatie, F., Stepanyan, S., Tkachenko, S., Weinstein, L. B., Weygand, D., Yun, J. and Zhang, J. (2005). Beam-Helicity Asymmetries in Double-Charged-Pion Photoproduction on the Proton . Phys Rev Lett 95 , pp. 162003.
- Hadjidakis, C., Bagdasaryan, H., Bektasoglu, M., Dharmawardane, K., Forest, T., Gavalian, G., Guler, N., Hyde, C. E., Dodge, G. E., Kuhn, S., Juengst, H., Klein, A., Klimenko, A., Lachniet, J., Niyazov, R., Qin, L., Sabatie, F., Stepanyan, S., Weinstein, L. B., Weygand, D. and Yun, J. (2005). Exclusive ρ0 meson electroproduction from hydrogen at CLAS . Phys Lett B 605 , pp. 256-264.