Author: Robert Bruce Bacastow
Publisher:
ISBN:
Category :
Languages : en
Pages : 62
Book Description
Branching Ratio for Pion-beta Decay: [pi]+ --> [pi]0 + [epsilon]+ + [gamma]
Author: Robert Bruce Bacastow
Publisher:
ISBN:
Category :
Languages : en
Pages : 62
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 62
Book Description
Branching Ratio for Pion-beta Decay
A Precise Determination of the Pion Beta Decay Rate
Author: Kétévi Adiklè Assamagan
Publisher:
ISBN:
Category :
Languages : en
Pages : 500
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 500
Book Description
A Measurement of the Branching Ratio of the [pi]0 Dalitz Decay Using K[subscript]L [arrow] 3[pi]0 Decays from KTeV
Author: Erin E. Abouzaid
Publisher:
ISBN:
Category : Kaons
Languages : en
Pages : 328
Book Description
Publisher:
ISBN:
Category : Kaons
Languages : en
Pages : 328
Book Description
Measuring the Branching Ratio of the Rare Decay Pi0 --] E+ E-
Author: Rune Niclasen
Publisher:
ISBN:
Category :
Languages : en
Pages : 124
Book Description
A precise branching ratio measurement of the rare decay {pi}{sup 0} {yields} e{sup +}e{sup -} has been made. The measurement was made with the rare kaon decay experiment KTeV at Fermilab where the source of {pi}{sup 0}s was K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{pi}{sup 0} decaying in flight. A total of 794 fully reconstructed K{sub L} {yields} 3{pi}{sup 0} events consistent with two of the intermediate {pi}{sup 0}s decaying into {gamma}{gamma} and one into e{sup +}e{sup -} were collected. An estimated 53.2 {+-} 11.0 of these events were expected to be background. Normalizing to the {pi}{sup 0} Dalitz decay they found Br({pi}{sup 0} {yields} e{sup +}e{sup -}, (m{sub e{sup +}e{sup -}}/m{sub {pi}{sup 0}}){sup 2}> 0.95) = (6.44 {+-} 0.25(stat) {+-} 0.22(syst)) x 10{sup -8} where internal radiation, {pi}{sup 0} {yields} e{sup +}e{sup -}({gamma}), was limited by the requirement (m{sub e{sup +}e{sup -}}/m{sub {pi}{sup 0}}){sup 2}> 0.95 which separated it from the tree level Dalitz decay, {pi}{sup 0} {yields} e{sup +}e{sup -}P{gamma}.
Publisher:
ISBN:
Category :
Languages : en
Pages : 124
Book Description
A precise branching ratio measurement of the rare decay {pi}{sup 0} {yields} e{sup +}e{sup -} has been made. The measurement was made with the rare kaon decay experiment KTeV at Fermilab where the source of {pi}{sup 0}s was K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{pi}{sup 0} decaying in flight. A total of 794 fully reconstructed K{sub L} {yields} 3{pi}{sup 0} events consistent with two of the intermediate {pi}{sup 0}s decaying into {gamma}{gamma} and one into e{sup +}e{sup -} were collected. An estimated 53.2 {+-} 11.0 of these events were expected to be background. Normalizing to the {pi}{sup 0} Dalitz decay they found Br({pi}{sup 0} {yields} e{sup +}e{sup -}, (m{sub e{sup +}e{sup -}}/m{sub {pi}{sup 0}}){sup 2}> 0.95) = (6.44 {+-} 0.25(stat) {+-} 0.22(syst)) x 10{sup -8} where internal radiation, {pi}{sup 0} {yields} e{sup +}e{sup -}({gamma}), was limited by the requirement (m{sub e{sup +}e{sup -}}/m{sub {pi}{sup 0}}){sup 2}> 0.95 which separated it from the tree level Dalitz decay, {pi}{sup 0} {yields} e{sup +}e{sup -}P{gamma}.
Determination of the Axial-vector Form Factor in the Radiative Decay of the Pion. [Phase Space, Branching Ratio].
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The branching ratio for the decay .pi. .-->. e.nu gamma. was measured in a counter experiment in which the e was detected in a magnetic spectrometer and the .gamma.-ray in a lead glass hodoscope. The number of observed events is 226.2 +- 22.4. The branching ratio into the phase space with electron momentum above 56 MeV/c and the electron/photon opening angle greater than 132° is found to be (5.6 +- 0.7) x 10−8. From the measured branching ratio one determines .gamma., the ratio of the axial vector to vector form factor. The vector form factor is computed using CVC and the .pi.° lifetime. For T/sub .pi./° = 0.828 x 10−16 sec, .gamma. = 0.44 +- 0.12 or .gamma. = --2.36 +- 0.12 is obtained. A comparison between the measured values of .gamma. and various theories is made.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The branching ratio for the decay .pi. .-->. e.nu gamma. was measured in a counter experiment in which the e was detected in a magnetic spectrometer and the .gamma.-ray in a lead glass hodoscope. The number of observed events is 226.2 +- 22.4. The branching ratio into the phase space with electron momentum above 56 MeV/c and the electron/photon opening angle greater than 132° is found to be (5.6 +- 0.7) x 10−8. From the measured branching ratio one determines .gamma., the ratio of the axial vector to vector form factor. The vector form factor is computed using CVC and the .pi.° lifetime. For T/sub .pi./° = 0.828 x 10−16 sec, .gamma. = 0.44 +- 0.12 or .gamma. = --2.36 +- 0.12 is obtained. A comparison between the measured values of .gamma. and various theories is made.
Measuring Pion Beta Decay with High-energy Pion Beams
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 14
Book Description
Improved measurements of the pion beta decay rate are possible with an intense high-energy pion beam. The rate for the decay [pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon] is predicted by the Standard Model (SM) to be R([pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon]) = 0.3999[plus minus]0.0005 s[sup [minus]1]. The best experimental number, obtained using in-flight decays, is R([pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon]) = 0.394 [plus minus] 0.015 s[sup [minus]1]. A precise measurement would test the SM by testing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix for which one analysis of the nuclear beta decay data has shown a 0.4% discrepancy. Several nuclear correction factors, needed for nuclear decay, are not present for pion beta decay, so that an experiment at the 0.2% level would be a significant one. Detailed study of possible designs will be needed, as well as extensive testing of components. The reduction of systematic errors to the 0.1% level can only be done over a period of years with a highly stable apparatus and beam. At a minimum, three years of occupancy of a beam line, with 800 hours per year, would be required.
Publisher:
ISBN:
Category :
Languages : en
Pages : 14
Book Description
Improved measurements of the pion beta decay rate are possible with an intense high-energy pion beam. The rate for the decay [pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon] is predicted by the Standard Model (SM) to be R([pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon]) = 0.3999[plus minus]0.0005 s[sup [minus]1]. The best experimental number, obtained using in-flight decays, is R([pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon]) = 0.394 [plus minus] 0.015 s[sup [minus]1]. A precise measurement would test the SM by testing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix for which one analysis of the nuclear beta decay data has shown a 0.4% discrepancy. Several nuclear correction factors, needed for nuclear decay, are not present for pion beta decay, so that an experiment at the 0.2% level would be a significant one. Detailed study of possible designs will be needed, as well as extensive testing of components. The reduction of systematic errors to the 0.1% level can only be done over a period of years with a highly stable apparatus and beam. At a minimum, three years of occupancy of a beam line, with 800 hours per year, would be required.
A Measurement of the Branching Ratio of the [pi]0 Dalitz Decay Using K(L) 2!3 [pi]0 Decays from KTeV.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 183
Book Description
The authors present a measurement of B([pi]0 2!e+e-[gamma])/B([pi]0 2![gamma][gamma]) using data taken in 1999 by the E832 KTeV experiment at Fermilab. The [pi]0s were produced by KL decays in flight that are fully reconstructed. They find 63,693 KL 2!3[pi]0 2![gamma][gamma] [gamma][gamma] e+e-[gamma] decays in KTeV data (an increase of a factor of ~ 20 in event statistics over previous experiments), and normalize to KL 2!3[pi]0 2!6[gamma], to extract B([pi]0 2!e+e-[gamma], me+e-> 15 MeV/c2
Publisher:
ISBN:
Category :
Languages : en
Pages : 183
Book Description
The authors present a measurement of B([pi]0 2!e+e-[gamma])/B([pi]0 2![gamma][gamma]) using data taken in 1999 by the E832 KTeV experiment at Fermilab. The [pi]0s were produced by KL decays in flight that are fully reconstructed. They find 63,693 KL 2!3[pi]0 2![gamma][gamma] [gamma][gamma] e+e-[gamma] decays in KTeV data (an increase of a factor of ~ 20 in event statistics over previous experiments), and normalize to KL 2!3[pi]0 2!6[gamma], to extract B([pi]0 2!e+e-[gamma], me+e-> 15 MeV/c2
Measurement of the Branching Ratio for Eta-meson Decay Into a Neutral Pion and Two Photons
Author: Jason William Brudvik
Publisher:
ISBN: 9780549130093
Category :
Languages : en
Pages : 240
Book Description
This dissertation presents the results of a measurement of the branching ratio for the rare decay eta → pi0gammagamma. The experiment was carried out in the A2 hall of the Mainz Microtron facility at the Institut fur Kernphysik, on the campus of Johannes Gutenberg Universitat Mainz, in Mainz, Germany. The experiment used the Glasgow-Mainz Tagger, which is a recoil-electron spectrometer, to determine the energy of the incident photons. The principal detector is the Crystal Ball, a highly segmented multiphoton spectrometer covering nearly 4pi steradians surrounding the experimental target. There is also a forward detector, TAPS, which is a multiphoton spectrometer arranged as a downstream wall of detectors. Furthermore, our setup includes an instrument used to differentiate between charged and neutral particles called the Particle Identification Detector, and a liquid hydrogen target. The kinematic-fit technique was used to select the eta → pi 0gammagamma events. The major backgrounds, namely eta → 3pi0 and eta → gammagamma decay and 2pi 0 production were measured simultaneously. The result for the branching ratio is BR(eta → pi0gammagamma) = (2.0+/-0.7) x 10-4. This corresponds to a partial width of Gamma (eta → pi0gammagamma) = 0.26 +/- 0.10 eV. This result is somewhat smaller than the result of recent experiments, it is consistent with theoretical calculations based on Chiral Perturbation Theory.
Publisher:
ISBN: 9780549130093
Category :
Languages : en
Pages : 240
Book Description
This dissertation presents the results of a measurement of the branching ratio for the rare decay eta → pi0gammagamma. The experiment was carried out in the A2 hall of the Mainz Microtron facility at the Institut fur Kernphysik, on the campus of Johannes Gutenberg Universitat Mainz, in Mainz, Germany. The experiment used the Glasgow-Mainz Tagger, which is a recoil-electron spectrometer, to determine the energy of the incident photons. The principal detector is the Crystal Ball, a highly segmented multiphoton spectrometer covering nearly 4pi steradians surrounding the experimental target. There is also a forward detector, TAPS, which is a multiphoton spectrometer arranged as a downstream wall of detectors. Furthermore, our setup includes an instrument used to differentiate between charged and neutral particles called the Particle Identification Detector, and a liquid hydrogen target. The kinematic-fit technique was used to select the eta → pi 0gammagamma events. The major backgrounds, namely eta → 3pi0 and eta → gammagamma decay and 2pi 0 production were measured simultaneously. The result for the branching ratio is BR(eta → pi0gammagamma) = (2.0+/-0.7) x 10-4. This corresponds to a partial width of Gamma (eta → pi0gammagamma) = 0.26 +/- 0.10 eV. This result is somewhat smaller than the result of recent experiments, it is consistent with theoretical calculations based on Chiral Perturbation Theory.