Author: Alan Strelzoff
Publisher:
ISBN:
Category : Branching ratios (Nuclear physics)
Languages : en
Pages : 66
Book Description
The ratio of the pion decay rates for the processes, pi yields e + nu and pi yields mu + nu was measured. A large NaI (tl) crystal was used to separate the high energy pion decay electrons from the continuous spectrum of the pi-mu-e chain. Counting decay electrons immediately following a pion stop, the ratio by a direct comparison of pi-e and pi-mu-e electrons was determined. From an observed 10,891 pi-e electrons a precision of 1.8% was attained in the guantity (pion lifetime x branching ratio). Considering the present uncertainty in the pion lifetime the branching ratio, (1.247 = 0.028) x 10 to the -4 power is obtained. This is in good agreement with the theoretical value, 1.233 x 10 to the -4 power, required by the V-A theory when radiative corrections are included. (Author).
Electron Decay Branching Ratio of the Pion
Author: Alan Strelzoff
Publisher:
ISBN:
Category : Branching ratios (Nuclear physics)
Languages : en
Pages : 66
Book Description
The ratio of the pion decay rates for the processes, pi yields e + nu and pi yields mu + nu was measured. A large NaI (tl) crystal was used to separate the high energy pion decay electrons from the continuous spectrum of the pi-mu-e chain. Counting decay electrons immediately following a pion stop, the ratio by a direct comparison of pi-e and pi-mu-e electrons was determined. From an observed 10,891 pi-e electrons a precision of 1.8% was attained in the guantity (pion lifetime x branching ratio). Considering the present uncertainty in the pion lifetime the branching ratio, (1.247 = 0.028) x 10 to the -4 power is obtained. This is in good agreement with the theoretical value, 1.233 x 10 to the -4 power, required by the V-A theory when radiative corrections are included. (Author).
Publisher:
ISBN:
Category : Branching ratios (Nuclear physics)
Languages : en
Pages : 66
Book Description
The ratio of the pion decay rates for the processes, pi yields e + nu and pi yields mu + nu was measured. A large NaI (tl) crystal was used to separate the high energy pion decay electrons from the continuous spectrum of the pi-mu-e chain. Counting decay electrons immediately following a pion stop, the ratio by a direct comparison of pi-e and pi-mu-e electrons was determined. From an observed 10,891 pi-e electrons a precision of 1.8% was attained in the guantity (pion lifetime x branching ratio). Considering the present uncertainty in the pion lifetime the branching ratio, (1.247 = 0.028) x 10 to the -4 power is obtained. This is in good agreement with the theoretical value, 1.233 x 10 to the -4 power, required by the V-A theory when radiative corrections are included. (Author).
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
The Branching Ratio for Pion Beta Decay
Author: David F. Bartlett
Publisher:
ISBN:
Category : Beta rays
Languages : en
Pages : 116
Book Description
The conserved vector current theory predicts that the branching ratio for the decay of a charged pion into a neutral pion is (1.05=0.02)x10 to the -8th power, if the coupling constant is derived from muon decay, or (1.00=0.02)x10 to the -8th power, if the coupling constant is derived from nuclear beta decay. Using spark chambers to distinguish the nearly anticollinear gamma rays from pi(+) beta decay from a background of other gamma rays, we have found 36 events and have measured the branching ratio to be (0.97=0.20)x10 to the -8th power, in agreement with the theoretical prediction and previous measurements. The method of background subtraction (approximately 10%) depends only on knowing that the background is isotropic for gamma rays having opening angles between 160 degrees and 180 degrees. (Author).
Publisher:
ISBN:
Category : Beta rays
Languages : en
Pages : 116
Book Description
The conserved vector current theory predicts that the branching ratio for the decay of a charged pion into a neutral pion is (1.05=0.02)x10 to the -8th power, if the coupling constant is derived from muon decay, or (1.00=0.02)x10 to the -8th power, if the coupling constant is derived from nuclear beta decay. Using spark chambers to distinguish the nearly anticollinear gamma rays from pi(+) beta decay from a background of other gamma rays, we have found 36 events and have measured the branching ratio to be (0.97=0.20)x10 to the -8th power, in agreement with the theoretical prediction and previous measurements. The method of background subtraction (approximately 10%) depends only on knowing that the background is isotropic for gamma rays having opening angles between 160 degrees and 180 degrees. (Author).
Determination of the Parity of the Neutral Pion Via the Four-Electron Decay
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
We present a new determination of the parity of the neutral pion via the double Dalitz decay [pi]° 2!ee−ee−. Our sample, which consists of 30 511 candidate decays, was collected from K{sub L} 2![pi]°[pi]°[pi]° decays in flight at the KTeV-E799 experiment at Fermi National Accelerator Laboratory. We confirm the negative [pi]° parity, and place a limit on scalar contributions to the [pi]° 2!e+e−e+e− decay amplitude of less than 3.3% assuming CPT conservation. The [pi]°[gamma]*[gamma]* form factor is well described by a momentum-dependent model with a slope parameter fit to the final state phase space distribution. Additionally, we have measured the branching ratio of this mode to be B([pi]° 2!e+e−e+e−) = (3.26 ± 0.18) x 10−5.
Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
We present a new determination of the parity of the neutral pion via the double Dalitz decay [pi]° 2!ee−ee−. Our sample, which consists of 30 511 candidate decays, was collected from K{sub L} 2![pi]°[pi]°[pi]° decays in flight at the KTeV-E799 experiment at Fermi National Accelerator Laboratory. We confirm the negative [pi]° parity, and place a limit on scalar contributions to the [pi]° 2!e+e−e+e− decay amplitude of less than 3.3% assuming CPT conservation. The [pi]°[gamma]*[gamma]* form factor is well described by a momentum-dependent model with a slope parameter fit to the final state phase space distribution. Additionally, we have measured the branching ratio of this mode to be B([pi]° 2!e+e−e+e−) = (3.26 ± 0.18) x 10−5.
A New Branching Ratio Measurement of the Pion Beta-decay [pi]+[right Arrow][pi]0+e++[nu]e
Author: Francois Charles Gaille
Publisher:
ISBN:
Category : Branching ratios (Nuclear physics)
Languages : en
Pages : 560
Book Description
Publisher:
ISBN:
Category : Branching ratios (Nuclear physics)
Languages : en
Pages : 560
Book Description
Branching Ratio for Pion-beta Decay
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.
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.
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
Branching Ratio Measurement of the Neutral Pion Dalitz Decay at NA62
Author: Thomas W. Bache
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
This note is part of Quality testing.
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
This note is part of Quality testing.