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Title: Study of the Process e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -} in the Energy Region 400 < {radical}(s)< 1000 MeV

Abstract

The cross section of the process e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -} was measured in the spherical neutral detector experiment at the VEPP-2M collider in the energy region 400 < {radical}(s)< 1000 MeV. This measurement was based on about 12.4 x 10{sup 6} selected collinear events, which include 7.4 x 10{sup 6} e{sup +}e{sup -} {yields} e{sup +}e{sup -}, 4.5 x 10{sup 6} e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -}, and 0.5 x 10{sup 6} e{sup +}e{sup -} {yields} {mu}{sup +}{mu}{sup -} selected events. The systematic uncertainty of cross section determination is 1.3%. The {rho}-meson parameters were determined as m{sub {rho}} = 774.9 {+-} 0.4 {+-} 0.5 MeV, {gamma}{sub {rho}} = 146.5 {+-} 0.8 {+-} 1.5 MeV, and {sigma}({rho} {yields} {pi}{sup +}{pi}{sup -}) = 1220 {+-} 7 {+-} 16 nb and the parameters of the G-parity suppressed decay {omega} {yields} {pi}{sup +}{pi}{sup -} as {sigma}({omega} {yields} {pi}{sup +}{pi}{sup -}) = 29.9 {+-} 1.4 {+-} 1.0 nb and {phi}{sub {rho}}{sub {omega}} = 113.5 {+-} 1.3 {+-} 1.7 deg.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;  [1] more »;  [2] « less
  1. Budker Institute of Nuclear Physics, Siberian Division, Russian Academy of Sciences, Novosibirsk, 630090 (Russian Federation)
  2. (Russian Federation) (and others)
Publication Date:
OSTI Identifier:
20768704
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Experimental and Theoretical Physics; Journal Volume: 101; Journal Issue: 6; Other Information: Translated from Zhurnal Ehksperimental'noj i Teoreticheskoj Fiziki, ISSN 0044-4510, 128, 1201-1219 (No. 6, 2005); DOI: 10.1134/1.2163921; (c) 2005 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA); TN:
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ANNIHILATION; CROSS SECTIONS; ELECTRON-POSITRON INTERACTIONS; ELECTRONS; ELECTROPRODUCTION; G PARITY; HADRONIC PARTICLE DECAY; MEV RANGE 100-1000; MUONS MINUS; MUONS PLUS; OMEGA BARYONS; PAIR PRODUCTION; PIONS MINUS; PIONS PLUS; POSITRONS; RHO-770 MESONS; SPHERICAL CONFIGURATION

Citation Formats

Achasov, M.N., Beloborodov, K.I., Berdyugin, A.V., Bogdanchikov, A.G., Bozhenok, A.V., Bukin, A.D., Bukin, D.A., Dimova, T.V., Druzhinin, V.P., Golubev, V.B., Koop, I.A., Korol, A.A., Koshuba, S.V., Lysenko, A.P., Otboev, A.V., Pakhtusova, E.V., Serednyakov, S.I., Shatunov, Yu.M., Sidorov, V.A., Silagadze, Z.K., and Novosibirsk State University, Novosibirsk, 630090. Study of the Process e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -} in the Energy Region 400 < {radical}(s)< 1000 MeV. United States: N. p., 2005. Web. doi:10.1134/1.2163921.
Achasov, M.N., Beloborodov, K.I., Berdyugin, A.V., Bogdanchikov, A.G., Bozhenok, A.V., Bukin, A.D., Bukin, D.A., Dimova, T.V., Druzhinin, V.P., Golubev, V.B., Koop, I.A., Korol, A.A., Koshuba, S.V., Lysenko, A.P., Otboev, A.V., Pakhtusova, E.V., Serednyakov, S.I., Shatunov, Yu.M., Sidorov, V.A., Silagadze, Z.K., & Novosibirsk State University, Novosibirsk, 630090. Study of the Process e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -} in the Energy Region 400 < {radical}(s)< 1000 MeV. United States. doi:10.1134/1.2163921.
Achasov, M.N., Beloborodov, K.I., Berdyugin, A.V., Bogdanchikov, A.G., Bozhenok, A.V., Bukin, A.D., Bukin, D.A., Dimova, T.V., Druzhinin, V.P., Golubev, V.B., Koop, I.A., Korol, A.A., Koshuba, S.V., Lysenko, A.P., Otboev, A.V., Pakhtusova, E.V., Serednyakov, S.I., Shatunov, Yu.M., Sidorov, V.A., Silagadze, Z.K., and Novosibirsk State University, Novosibirsk, 630090. Thu . "Study of the Process e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -} in the Energy Region 400 < {radical}(s)< 1000 MeV". United States. doi:10.1134/1.2163921.
@article{osti_20768704,
title = {Study of the Process e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -} in the Energy Region 400 < {radical}(s)< 1000 MeV},
author = {Achasov, M.N. and Beloborodov, K.I. and Berdyugin, A.V. and Bogdanchikov, A.G. and Bozhenok, A.V. and Bukin, A.D. and Bukin, D.A. and Dimova, T.V. and Druzhinin, V.P. and Golubev, V.B. and Koop, I.A. and Korol, A.A. and Koshuba, S.V. and Lysenko, A.P. and Otboev, A.V. and Pakhtusova, E.V. and Serednyakov, S.I. and Shatunov, Yu.M. and Sidorov, V.A. and Silagadze, Z.K. and Novosibirsk State University, Novosibirsk, 630090},
abstractNote = {The cross section of the process e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -} was measured in the spherical neutral detector experiment at the VEPP-2M collider in the energy region 400 < {radical}(s)< 1000 MeV. This measurement was based on about 12.4 x 10{sup 6} selected collinear events, which include 7.4 x 10{sup 6} e{sup +}e{sup -} {yields} e{sup +}e{sup -}, 4.5 x 10{sup 6} e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -}, and 0.5 x 10{sup 6} e{sup +}e{sup -} {yields} {mu}{sup +}{mu}{sup -} selected events. The systematic uncertainty of cross section determination is 1.3%. The {rho}-meson parameters were determined as m{sub {rho}} = 774.9 {+-} 0.4 {+-} 0.5 MeV, {gamma}{sub {rho}} = 146.5 {+-} 0.8 {+-} 1.5 MeV, and {sigma}({rho} {yields} {pi}{sup +}{pi}{sup -}) = 1220 {+-} 7 {+-} 16 nb and the parameters of the G-parity suppressed decay {omega} {yields} {pi}{sup +}{pi}{sup -} as {sigma}({omega} {yields} {pi}{sup +}{pi}{sup -}) = 29.9 {+-} 1.4 {+-} 1.0 nb and {phi}{sub {rho}}{sub {omega}} = 113.5 {+-} 1.3 {+-} 1.7 deg.},
doi = {10.1134/1.2163921},
journal = {Journal of Experimental and Theoretical Physics},
number = 6,
volume = 101,
place = {United States},
year = {Thu Dec 15 00:00:00 EST 2005},
month = {Thu Dec 15 00:00:00 EST 2005}
}
  • The corrected cross section of the e{sup +}e{sup -} {sup {yields}} {pi}{sup +}{pi}{sup -} process measured in the spherical neutral detector experiment at the VEPP-2M e{sup +}e{sup -} collider is presented. The update is necessary due to a flaw in the e{sup +}e{sup -} {sup {yields}} {pi}{sup +}{pi}{sup -} and e{sup +}e{sup -} {sup {yields}} {mu}{sup +}{mu}{sup -} Monte Carlo event generators used previously in data analysis.
  • The cross section of the process e{sup +}e{sup -}{yields}{mu}{sup +}{mu}{sup -} was measured in the spherical neutral detector experiment at the VEPP-2M e{sup +}e{sup -} collider in the energy region {radical}(s)=980, 1040-1380 MeV. The event numbers of the process e{sup +}e{sup -}{yields}{mu}{sup +}{mu}{sup -} were normalized to the integrated luminosity measured using e{sup +}e{sup -}{yields}e{sup +}e{sup -} and e{sup +}e{sup -}{yields}{gamma}{gamma} processes. The ratio of the measured cross section to the theoretically predicted value is 1.006{+-}0.007{+-}0.016 and 1.005{+-}0.007{+-}0.018 in the first and second case, respectively. Using results of the measurements, the electromagnetic running coupling constant {alpha} in the energy regionmore » {radical}(s)=1040-1380 MeV was obtained <1/{alpha}>=134.1{+-}0.5{+-}1.2 and this is in agreement with theoretical expectation.« less
  • A search for lepton-flavor-violating process e{sup +}e{sup -{yields}}e{mu} in the energy region {radical}(s)=984-1060 MeV with the SND detector at the VEPP-2M e{sup +}e{sup -} collider is reported. The model independent 90% C.L. upper limits on the e{sup +}e{sup -{yields}}e{mu} cross section, {sigma}{sub e{mu}<}8 pb, as well as on the corresponding {phi}{yields}e{mu} branching fraction, B({phi}{yields}e{mu})<2x10{sup -6} have been obtained, for the polar angles 55 deg. <{theta}<125 deg. of the final particles.
  • Experiment E949 at Brookhaven National Laboratory has observed three new events consistent with the decay K{sup +}{yields}{pi}{sup +}{nu}{nu} in the pion momentum region 140<P{sub {pi}}<199 MeV/c in an exposure of 1.71x10{sup 12} stopped kaons with an estimated total background of 0.93{+-}0.17(stat){sub -0.24}{sup +0.32}(syst) events. This brings the total number of observed K{sup +}{yields}{pi}{sup +}{nu}{nu} events to seven. Combining this observation with previous results, assuming the pion spectrum predicted by the standard model, results in a branching ratio of B(K{sup +}{yields}{pi}{sup +}{nu}{nu})=(1.73{sub -1.05}{sup +1.15})x10{sup -10}. An interpretation of the results for alternative models of the decay K{sup +}{yields}{pi}{sup +}+nothing is alsomore » presented.« less
  • The total cross section for the process {pi}{sup +}{pi{minus}}{r arrow}{pi0}{pi0} in the dipion mass region 0.55{lt}{ital M}{lt}2.0 GeV is determined from the peripheral transitions {pi}{sup {minus}}{r arrow}{pi0}{pi0} in carbon and propanediol targets at an initial {pi}{sup {minus}}-meson momentum 39.1 GeV/{ital c}.