Author: Peter Gumplinger
Publisher:
ISBN:
Category : Pions
Languages : en
Pages : 240
Book Description
A Measurement of the Neutral Pion Form Factor by Means of the Reaction [pi]0 --> Ee−[gamma]
Author: Peter Gumplinger
Publisher:
ISBN:
Category : Pions
Languages : en
Pages : 240
Book Description
Publisher:
ISBN:
Category : Pions
Languages : en
Pages : 240
Book Description
On the Physical Relevance of the Study of Gamma* Gamma -] Pi Pi at Small T and Large Q2
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 7
Book Description
We discuss the relevance of a dedicated measurement of exclusive production of a pair of neutral pions in a hard [gamma]*[gamma] scattering at small momentum transfer. In this case, the virtuality of one photon provides us with a hard scale in the process, enabling us to perform a QCD calculation of this reaction rate using the concept of Transition Distribution Amplitudes (TDA). Those are related by sum rules to the pion axial form factor F{sub A}{sup [pi]} and, as a direct consequence, a cross-section measurement of this process at intense beam electron-positron colliders such as CLEO, KEK-B and PEP-II, or Super-B would provide us with a unique measurement of the neutral pion axial form factor F{sub A}{sup [pi]0} at small scale. We believe that our models for the photon to meson transition distribution amplitudes are sufficiently constrained to give reasonable orders of magnitude for the estimated cross sections. Cross sections are large enough for quantitative studies to be performed at high luminosity ee− colliders. After verifying the scaling and the [phi] independence of the cross section, one should be able to measure these new hadronic matrix elements, and thus open a new gate to the understanding of the hadronic structure. In particular, we argued here that the study of [gamma]*[gamma] 2![pi]°{pi}° in the TDA regime could provide with a unique experimental measurement of the {pi}° axial form factor.
Publisher:
ISBN:
Category :
Languages : en
Pages : 7
Book Description
We discuss the relevance of a dedicated measurement of exclusive production of a pair of neutral pions in a hard [gamma]*[gamma] scattering at small momentum transfer. In this case, the virtuality of one photon provides us with a hard scale in the process, enabling us to perform a QCD calculation of this reaction rate using the concept of Transition Distribution Amplitudes (TDA). Those are related by sum rules to the pion axial form factor F{sub A}{sup [pi]} and, as a direct consequence, a cross-section measurement of this process at intense beam electron-positron colliders such as CLEO, KEK-B and PEP-II, or Super-B would provide us with a unique measurement of the neutral pion axial form factor F{sub A}{sup [pi]0} at small scale. We believe that our models for the photon to meson transition distribution amplitudes are sufficiently constrained to give reasonable orders of magnitude for the estimated cross sections. Cross sections are large enough for quantitative studies to be performed at high luminosity ee− colliders. After verifying the scaling and the [phi] independence of the cross section, one should be able to measure these new hadronic matrix elements, and thus open a new gate to the understanding of the hadronic structure. In particular, we argued here that the study of [gamma]*[gamma] 2![pi]°{pi}° in the TDA regime could provide with a unique experimental measurement of the {pi}° axial form factor.
The Form Factor of the Neutral Pion
Author: Peter Nemethy
Publisher:
ISBN:
Category : Mesons
Languages : en
Pages : 76
Book Description
In an experiment performed at Columbia University's Nevis Cyclotron, the decay 'neutral-pion to gamma photon + electron + positron' was observed. Using a system of counters and spark chambers 2200 events were recorded with an opening angle of the Dalitz pair near 120 deg. The effect of pi-zero structure on the invariant mass spectrum of the pair is interpreted as an electromagnetic form factor for the neutral-pion. The form factor is a linear function, (gamma)(x) = 1 + ax, of the invariant mass squared, x. The experimental result for the form factor slope is a = (+0.01 plus or minus 0.11) (1/(pion mass)sq.).
Publisher:
ISBN:
Category : Mesons
Languages : en
Pages : 76
Book Description
In an experiment performed at Columbia University's Nevis Cyclotron, the decay 'neutral-pion to gamma photon + electron + positron' was observed. Using a system of counters and spark chambers 2200 events were recorded with an opening angle of the Dalitz pair near 120 deg. The effect of pi-zero structure on the invariant mass spectrum of the pair is interpreted as an electromagnetic form factor for the neutral-pion. The form factor is a linear function, (gamma)(x) = 1 + ax, of the invariant mass squared, x. The experimental result for the form factor slope is a = (+0.01 plus or minus 0.11) (1/(pion mass)sq.).
Measurement of the Neutral Pion Form Factor Slope from the Dalitz Pair Spectrum
Author: Joseph Burger
Publisher:
ISBN:
Category : Form factor (Nuclear physics)
Languages : en
Pages : 133
Book Description
Publisher:
ISBN:
Category : Form factor (Nuclear physics)
Languages : en
Pages : 133
Book Description
Measurement of the Gamma Gamma* -] Pi0 Transition Form Factor
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 19
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 19
Book Description
_63r0 - Γ [rho 0 - Gamma] Mixing in the Neutral Channel Pion Form Factor F(e) Π (s) [F (e) Pi] (s)] and Its Role in Comparing E+e- with _63t [tau] Spectral Functions
Author: Fred Jegerlehner
Publisher:
ISBN:
Category :
Languages : en
Pages : 19
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 19
Book Description
Measurement of the Charged Pion Form Factor Slope from the Reaction [pi]−p --> Ne+e− at Rest
Author: Richard Garland
Publisher:
ISBN:
Category : Pions
Languages : en
Pages : 126
Book Description
Publisher:
ISBN:
Category : Pions
Languages : en
Pages : 126
Book Description
Measurement of the Charged Pion Form Factor Slope from the Reaction [pi]−p --> Nee− at Rest
Author: Richard Garland
Publisher:
ISBN:
Category : Form factor (Nuclear physics)
Languages : en
Pages : 126
Book Description
Publisher:
ISBN:
Category : Form factor (Nuclear physics)
Languages : en
Pages : 126
Book Description
Rho 0 - Gamma Mixing in the Neutral Channel Pion Form Factor F (e) Pi (s) and Its Role in Comparing E + E - with Tau Spectral Functions
Author: Fred Jegerlehner
Publisher:
ISBN:
Category :
Languages : en
Pages : 19
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 19
Book Description
Measurement of the Gamma Gamma* to Pi0 Transition Form Factor
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Book Description