المؤلفون: Ambrozewicz, P., Ye, L., Prok, Y., Larin, I., Ahmidouch, A., Baker, K., Baturin, V., Benton, L., Bernstein, A., Burkert, V., Clinton, E., Cole, P. L., Collins, P., Dale, D., Danagoulian, S., Davidenko, G., Demirchyan, R., Deur, A., Dolgolenko, A., Dutta, D., Dzyubenko, G., Evdokimov, A., Fedotov, G., Feng, J., Gabrielyan, M., Gan, L., Gao, H., Gasparian, A., Gevorkyan, N., Gevorkyan, S., Glamazdin, A., Goryachev, V., Guo, L., Gyurjyan, V., Hardy, K., He, J., Isupov, E., Ito, M., Jiang, L., Kang, H., Kashy, D., Khandaker, M., Kingsberry, P., Klein, F., Kolarkar, A., Konchatnyi, M., Korchin, O., Korsch, W., Kosinov, O., Kowalski, S., Kubantsev, M., Kubarovsky, A., Kubarovsky, V., Lawrence, D., Li, X., Levillain, M., Lu, H., Ma, L., Martel, P., Matveev, V., McNulty, D., Mecking, B., Micherdzinska, A., Milbrath, B., Minehart, R., Miskimen, R., Mochalov, V., Morrison, B., Mtingwa, S., Nakagawa, I., Overby, S., Pasyuk, E., Payen, M., Park, K., Pedroni, R, Phelps, W., Protopopescu, D., Rimal, D., Ritchie, B. G., Romanov, D., Salgado, C, Shahinyan, A., Sitnikov, A, Sober, D., Stepanyan, S., Stephens, W., Tarasov, V., Taylor, S., Teymurazyan, A., Underwood, J., Vasiliev, A., Vishnyakov, V., Weygand, D. P., Wood, M., Zhang, Y., Zhou, S., Zihlmann, B.

المصدر: Phys. Lett B797, 134884 (2019)

مصطلحات موضوعية: Nuclear Experiment, High Energy Physics - Phenomenology, Nuclear Theory

الوصف: The cross section of atomic electron Compton scattering $\gamma + e \rightarrow \gamma^\prime + e^\prime $ was measured in the 4.40--5.475 GeV photon beam energy region by the {\em PrimEx} collaboration at Jefferson Lab with an accuracy of 2\% and less. The results are consistent with theoretical predictions that include next-to-leading order radiative corrections. The measurements provide the first high precision test of this elementary QED process at beam energies greater than 0.1 GeV.
Comment: 6 pages, 4 figures

الوصول الحر: http://arxiv.org/abs/1903.05529Test

المؤلفون: DIANA Collaboration, Barmin, V. V., Asratyan, A. E., Curceanu, C., Davidenko, G. V., Guaraldo, C., Kubantsev, M. A., Larin, I. F., Matveev, V. A., Shebanov, V. A., Shishov, N. N., Sokolov, L. I., Tarasov, V. V.

مصطلحات موضوعية: High Energy Physics - Experiment, Nuclear Experiment

الوصف: Using the DIANA data on the charge-exchange reaction $K^+n \rightarrow pK^0$ on a bound neutron, in which the s-channel formation of the pentaquark baryon $\Theta^+(1538)$ has been observed, we analyze the dependence of the background-subtracted $\Theta^+ \rightarrow pK^0$ signal on the $K^0$ emission angle in the $pK^0$ rest frame. In order to describe the observed $\cos\Theta_K^\mathrm{cms}$ distribution, invoking the interference between the nonresonant s-wave and the $\Theta^+$-mediated higher-wave contributions to the amplitude of the charge-exchange reaction is required at a 2.8$\sigma$ level. The spin--parity assignment of 1/2$^-$ for the $\Theta^+$ baryon is ruled out at a statistical level of 2.9 standard deviations. A physically-meaningful selection in $\cos\Theta_K^\mathrm{cms}$ based on the observed angular dependence of the $\Theta^+ \rightarrow pK^0$ signal allows to boost the statistical significance of the signal up to 7.1 standard deviations. This is far in excess of previously reported signals and renders the $\Theta^+$ existence more credible.
Comment: 13 pages, 7 figures

الوصول الحر: http://arxiv.org/abs/1507.06001Test

المؤلفون: SELEX Collaboration, Nigmatkulov, G. A., Ponosov, A. K., Akgun, U., Alkhazov, G., Amaro-Reyes, J., Asratyan, A., Atamantchouk, A. G., Ayan, A. S., Balatz, M. Y., Blanco-Covarrubias, A., Bondar, N. F., Cooper, P. S., Dauwe, L. J., Davidenko, G. V., Dersch, U., Dolgolenko, A. G., Dzyubenko, G. B., Edelstein, R., Emediato, L., Endler, A. M. F., Engelfried, J., Eschrich, I., Escobar, C. O., Estrada, N., Evdokimov, A. V., Filimonov, I. S., Flores-Castillo, A., Garcia, F. G., Golovtsov, V. L., Gouffon, P., Gülmez, E., Iori, M., Jun, S. Y., Kaya, M., Kilmer, J., Kim, V. T., Kochenda, L. M., Konorov, I., Kozhevnikov, A. P., Krivshich, A. G., Krüger, H., Kubantsev, M. A., Kubarovsky, V. P., Kulyavtsev, A. I., Kuropatrkin, N. P., Kurshetsov, V. F., Kushnirenko, A., Lach, J., Landsberg, L. G., Larin, I., Leikin, E. M., López-Hinojosa, G., Lungov, T., Maleev, V. P., Mao, D., Mathew, P., Mattson, M., Matveev, V., McCliment, E., Moinester, M. A., Molchanov, V. V., Morelos, A., Nemitkin, A. V., Neoustroev, P. V., Newsom, C., Nilov, A. P., Nurushev, S. B., Ocherashvili, A., Onel, Y., Ozkorucuklu, S., Penzo, A., Petrenko, S. V., Procario, M., Prutskoi, V. A., Razmyslovich, B. V., Romanov, D. A., Rud, V. I., Russ, J., Sánchez-López, J. L., Savchenko, A. A., Simon, J., Sinev, G. V., Sitnikov, A. I., Smith, V. J., Srivastava, M., Steiner, V., Stepanov, V., Stutte, L., Svoiski, M., Tarasov, V. V., Terentyev, N. K., Torres, I., Uvarov, L. N., Vasiliev, A. N., Vavilov, D. V., Vázquez-Jáuregui, E., Verebryusov, V. S., Victorov, V. A., Vishnyakov, V. E., Vorobyov, A. A., Vorwalter, K., You, J., Zukanovich-Funchal, R.

مصطلحات موضوعية: High Energy Physics - Experiment, Nuclear Experiment

الوصف: We report on the measurement of the one-dimensional charged kaon correlation functions using 600~GeV/{\it c} $\Sigma^-$, $\pi^-$ and 540~GeV/{\it c} $p$ beams from the SELEX~(E781) experiment at the Fermilab Tevatron. $K^{\pm}K^{\pm}$ correlation functions are studied for three transverse pair momentum, $k_T$, ranges and parameterized by a Gaussian form. The emission source radii, $R$, and the correlation strength, $\lambda$, are extracted. The analysis shows a decrease of the source radii with increasing kaon transverse pair momentum for all beam types.
Comment: 8 pages, 4 figures, 1 table

الوصول الحر: http://arxiv.org/abs/1501.04316Test

المؤلفون: DIANA Collaboration, Barmin, V. V., Asratyan, A. E., Borisov, V. S., Curceanu, C., Davidenko, G. V., Dolgolenko, A. G., Guaraldo, C., Kubantsev, M. A., Larin, I. F., Matveev, V. A., Shebanov, V. A., Shishov, N. N., Sokolov, L. I., Tarasov, V. V., Tumanov, G. K., Verebryusov, V. S.

المصدر: Phys. Rev. C89, 045204 (2014)

مصطلحات موضوعية: Nuclear Experiment, High Energy Physics - Experiment

الوصف: The charge-exchange reaction K^+ Xe --> K^0 p Xe' is investigated using the data of the DIANA experiment. The distribution of the pK^0 effective mass shows a prominent enhancement near 1538 MeV formed by \sim 80 events above the background, whose width is consistent with being entirely due to the experimental resolution. Under the selections based on a simulation of K^+Xe collisions, the statistical significance of the signal reaches 5.5\sigma. We interpret this observation as strong evidence for formation of a pentaquark baryon with positive strangeness, \Theta^+(uudd\bar{s}), in the charge-exchange reaction K^+ n --> K^0 p on a bound neutron. The mass of the \Theta^+ baryon is measured as m(\Theta^+) = 1538+-2 MeV. Using the ratio between the numbers of resonant and non-resonant charge-exchange events in the peak region, the intrinsic width of this baryon resonance is determined as \Gamma(\Theta^+) = 0.34+-0.10 MeV.
Comment: 19 pages, 8 figures

الوصول الحر: http://arxiv.org/abs/1307.1653Test

المؤلفون: Larin, I., McNulty, D., Clinton, E., Ambrozewicz, P., Lawrence, D., Nakagawa, I., Prok, Y., Teymurazyan, A., Ahmidouch, A., Asratyan, A., Baker, K., Benton, L., Bernstein, A. M., Burkert, V., Cole, P., Collins, P., Dale, D., Danagoulian, S., Davidenko, G., Demirchyan, R., Deur, A., Dolgolenko, A., Dzyubenko, G., Ent, R., Evdokimov, A., Feng, J., Gabrielyan, M., Gan, L., Gasparian, A., Gevorkyan, S., Glamazdin, A., Goryachev, V., Gyurjyan, V., Hardy, K., He, J., Ito, M., Jiang, L., Kashy, D., Khandaker, M., Kingsberry, P., Kolarkar, A., Konchatnyi, M., Korchin, A., Korsch, W., Kowalski, S., Kubantsev, M., Kubarovsky, V., Li, X., Martel, P., Matveev, V., Mecking, B., Milbrath, B., Minehart, R., Miskimen, R., Mochalov, V., Mtingwa, S., Overby, S., Pasyuk, E., Payen, M., Pedroni, R., Ritchie, B., Rodrigues, T. E., Salgado, C., Shahinyan, A., Sitnikov, A., Sober, D., Stepanyan, S., Stephens, W., Underwood, J., Vasiliev, A., Vishnyakov, V., Wood, M., Zhou, S.

المصدر: Phys.Rev.Lett.106:162303,2011

مصطلحات موضوعية: Nuclear Experiment

الوصف: High precision measurements of the differential cross sections for $\pi^0$ photoproduction at forward angles for two nuclei, $^{12}$C and $^{208}$Pb, have been performed for incident photon energies of 4.9 - 5.5 GeV to extract the ${\pi^0 \to \gamma\gamma}$ decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The ${\pi^0 \to \gamma\gamma}$ decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is $\Gamma{(\pi^0 \to \gamma\gamma)} = 7.82 \pm 0.14 ~({\rm stat.}) \pm 0.17 ~({\rm syst.}) ~{\rm eV}$. With the 2.8% total uncertainty, this result is a factor of 2.5 more precise than the current PDG average of this fundamental quantity and it is consistent with current theoretical predictions.
Comment: 4 pages, 5 figures

الوصول الحر: http://arxiv.org/abs/1009.1681Test

المؤلفون: Ahmed, S. N., Angstadt, R., Aoki, M., Åsman, B., Austin, S., Bagby, L., Barberis, E., Baringer, P., Bean, A., Bischoff, A., Blekman, F., Bolton, T. A., Boswell, C., Bowden, M., Browning, F., Buchholz, D., Burdin, S., Butler, D., Cease, H., Choi, S., Clark, A. R., Clutter, J., Cooper, A., Cooper, W. E., Corcoran, M., de Jong, S. J., Demarteau, M., Demina, R., Desai, S., Derylo, G., Ellison, J., Ermolov, P., Fagan, J., Fast, J., Filthaut, F., Foglesong, J., Fox, H., Galea, C. F., Gardner, J., Genik II, R. J., Gerber, C. E., Gershtein, Y., Gounder, K., Grinstein, S., Gu, W., Gutierrez, P., Haggerty, H., Hall, R. E., Hagopian, S., Hance, R., Harder, K., Heger, P., Heinson, A. P., Heintz, U., Hesketh, G., Hover, D., Howell, J., Hrycyk, M., Iashvili, I., Johnson, M., Jöstlein, H., Juste, A., Kahl, W., Kajfasz, E., Karmanov, D., Kesisoglou, S., Khanov, A., King, J., Kleinfelder, S., Kowalski, J., Krempetz, K., Kubantsev, M., Kulik, Y., Landsberg, G., Leflat, A., Lehner, F., Lipton, R., Mao, H. S., Martin, M., Mateski, J., Matulik, M., McKenna, M., Melnitchouk, A., Merkin, M., Mihalcea, D., Milgrome, O., Montgomery, H. E., Moua, S., Naumann, N. A., Nomerotski, A., Olis, D., O'Neil, D. C., Garzón, G. J. Otero y, Parua, N., Pawlak, J., Petteni, M., Quinn, B., Rapidis, P. A., Ratzmann, P., Rizatdinova, F., Roco, M., Rucinski, R., Rykalin, V., Schellman, H., Schmitt, W., Sellberg, G., Serritella, C., Shabalina, E., Sidwell, R. A., Simak, V., Smith, E., Squires, B., Stanton, N. R., Steinbrück, G., Strandberg, J., Strandberg, S., Strauss, M., Stredde, S., Toukhtarov, A., Tripathi, S. M., Trippe, T. G., Tsybychev, D., Utes, M., van Gemmeren, P., Vaz, M., Weber, M., Wijngaarden, D. A., Wish, J., Womersley, J., Yarema, R., Ye, Z., Zieminski, A., Zimmerman, T., Zverev, E. G.

المصدر: Nucl.Instrum.Meth.A634:8-46,2011

مصطلحات موضوعية: Physics - Instrumentation and Detectors, High Energy Physics - Experiment

الوصف: This paper describes the mechanical design, the readout chain, the production, testing and the installation of the Silicon Microstrip Tracker of the D0 experiment at the Fermilab Tevatron collider. In addition, description of the performance of the detector during the experiment data collection between 2001 and 2010 is provided.

الوصول الحر: http://arxiv.org/abs/1005.0801Test

المؤلفون: Barmin, V. V., Asratyan, A. E., Borisov, V. S., Curceanu, C., Davidenko, G. V., Dolgolenko, A. G., Guaraldo, C., Kubantsev, M. A., Larin, I. F., Matveev, V. A., Shebanov, V. A., Shishov, N. N., Sokolov, L. I., Tumanov, G. K., Verebryusov, V. S.

المصدر: Phys.Atom.Nucl.73:1164-1167,2010

مصطلحات موضوعية: High Energy Physics - Experiment

الوصف: The data on the reactions K^+Xe --> K^0 \gamma X and K^+Xe --> K^+ \gamma X, obtained with the bubble chamber DIANA, have been analyzed for possible radiative decays of the \Theta^+(1540) baryon: \Theta^+ --> K^0 p \gamma and \Theta^+ --> K^+ n \gamma. No signals have been observed, and we derive the upper limits \Gamma(\Theta^+ --> K^0 p \gamma) / \Gamma(\Theta^+ --> K^0 p) < 0.032 and \Gamma(\Theta^+ --> K^+ n \gamma) / \Gamma(\Theta^+ --> K^+ n) < 0.041 which, using our previous measurement of \Gamma(\Theta^+ --> KN) = (0.39+-0.10) MeV, translate to \Gamma(\Theta^+ --> K^0 p \gamma) < 8 keV and \Gamma(\Theta^+ --> K^+ n \gamma) < 11 keV at 90% confidence level. We have also measured the cross sections of K^+ -induced reactions involving emission of a neutral pion: \sigma(K^+n --> K^0 p \pi^0) = (68+-18) \mub and \sigma(K^+N --> K^+ N \pi^0) = (30+-8) \mub for incident K^+ momentum of 640 MeV.
Comment: 8 pages

الوصول الحر: http://arxiv.org/abs/0909.4666Test

المؤلفون: Barmin, V. V., Asratyan, A. E., Borisov, V. S., Curceanu, C., Davidenko, G. V., Dolgolenko, A. G., Guaraldo, C., Kubantsev, M. A., Larin, I. F., Matveev, V. A., Shebanov, V. A., Shishov, N. N., Sokolov, L. I., Tumanov, G. K., Verebryusov, V. S.

المصدر: Phys.Atom.Nucl.73:1168-1175,2010

مصطلحات موضوعية: High Energy Physics - Experiment

الوصف: The data on the charge-exchange reaction K^+Xe --> K^0 p Xe, obtained with the bubble chamber DIANA, are reanalyzed using increased statistics and updated selections. Our previous evidence for formation of a narrow pK^0 resonance with mass near 1538 MeV is confirmed and reinforced. The statistical significance of the signal reaches some 8\sigma (6\sigma) when estimated as S/\sqrt{B} (S/\sqrt{B+S}). The mass and intrinsic width of the \Theta^+ baryon are measured as m = (1538+-2) MeV and \Gamma = (0.39+-0.10) MeV.
Comment: 13 pages, 9 figures

الوصول الحر: http://arxiv.org/abs/0909.4183Test

المؤلفون: Martel, P., Clinton, E., McWilliams, R., Lawrence, D., Miskimen, R., Ahmidouch, A., Ambrozewicz, P., Asratyan, A., Baker, K., Benton, L., Bernstein, A., Cole, P., Collins, P., Dale, D., Danagoulian, S., Davidenko, G., Demirchyan, R., Deur, A., Dolgolenko, A., Dzyubenko, G., Evdokimov, A., Feng, J., Gabrielyan, M., Gan, L., Gasparian, A., Glamazdin, O., Goryachev, V., Gyurjyan, V., Hardy, K., Ito, M., Khandaker, M., Kingsberry, P., Kolarkar, A., Konchatnyi, M., Korchin, O., Korsch, W., Kowalski, S., Kubantsev, M., Kubarovsky, V., Larin, I., Matveev, V., McNulty, D., Milbrath, B., Minehart, R., Mochalov, V., Mtingwa, S., Nakagawa, I., Overby, S., Pasyuk, E., Payen, M., Pedroni, R., Prok, Y., Ritchie, B., Salgado, C., Sitnikov, A., Sober, D., Stephens, W., Teymurazyan, A., Underwood, J., Vasiliev, A., Verebryusov, V., Vishnyakov, V., Wood, M.

المصدر: Nucl.Instrum.Meth.A612:46-49,2009

مصطلحات موضوعية: Nuclear Experiment

الوصف: A technique is presented for precision measurements of the area densities, density * T, of approximately 5% radiation length carbon and 208Pb targets used in an experiment at Jefferson Laboratory to measure the neutral pion radiative width. The precision obtained in the area density for the carbon target is +/- 0.050%, and that obtained for the lead target through an x-ray attenuation technique is +/- 0.43%.

الوصول الحر: http://arxiv.org/abs/0811.2132Test

المؤلفون: Kubantsev, M., Larin, I., Gasparyan, A.

المصدر: AIP Conf.Proc.867:51-58,2006

مصطلحات موضوعية: Physics - Instrumentation and Detectors

الوصف: We report the design and performance of the hybrid electromagnetic calorimeter consisting of 1152 $PbWO_4$ crystals and 576 lead glass blocks for the PrimEx experiment at the Jefferson Laboratory. The detector was built for high precision measurement of the neutral pion lifetime via the Primakoff effect. Calorimeter installation and commissioning was completed with the first physics run in fall of 2004. We present the energy and position resolution of the calorimeter. Obtained $\pi^0$ mass resolution of $1.3 \mathrm{MeV/c^2}$ and its production angle resolution of $0.34 \mathrm{mrad}$ demonstrate the ability of the experiment to extract the $\pi^0$ lifetime on one percent level.
Comment: 8 pages, 7 figures, talk on the CALOR06 Conference, Chicago

الوصول الحر: http://arxiv.org/abs/physics/0609201Test