scholarly journals Measurement of the Pion Polarizability at COMPASS

2014 ◽  
Author(s):  
Stefan Huber
Keyword(s):  
Pion Polarizability

scholarly journals Lower bound to the pion polarizability from QCD sum rules

1996 ◽  
Vol 366 (1-4) ◽  
pp. 354-359 ◽  
Author(s):  
M. Benmerrouche ◽  
G. Orlandini ◽  
T.G. Steele
Keyword(s):  
Lower Bound ◽  
Sum Rules ◽  
Qcd Sum Rules ◽  
Pion Polarizability

scholarly journals Measurement of the Charged-Pion Polarizability

2015 ◽  
Vol 114 (6) ◽  
Author(s):  
C. Adolph ◽  
R. Akhunzyanov ◽  
M. G. Alexeev ◽  
G. D. Alexeev ◽  
A. Amoroso ◽  
...  
Keyword(s):  
Charged Pion ◽  
Pion Polarizability

scholarly journals Radiative corrections for pion polarizability experiments

1995 ◽  
Vol 66 (1-2) ◽  
pp. 279-284 ◽  
Author(s):  
A. A. Akhundov ◽  
S. Gerzon ◽  
S. Kananov ◽  
M. A. Moinester
Keyword(s):  
Radiative Corrections ◽  
Pion Polarizability

scholarly journals Compton scattering off pions and electromagnetic polarizabilities

2019 ◽  
Vol 34 (16) ◽  
pp. 1930008 ◽  
Author(s):  
Murray Moinester ◽  
Stefan Scherer
Keyword(s):  
Compton Scattering ◽  
Cross Sections ◽  
Charged Pion ◽  
Chiral Symmetry Breaking ◽  
Goldstone Boson ◽  
Text Data ◽  
Two Photon ◽  
Pion Polarizability ◽  
Theoretical Predictions ◽  
Stringent Test

The electric [Formula: see text] and magnetic [Formula: see text] Compton polarizabilities of both the charged and the neutral pion are of fundamental interest in the low-energy sector of quantum chromodynamics (QCD). Pion polarizabilities affect the shape of the [Formula: see text] Compton scattering angular distribution at back scattering angles and [Formula: see text] absolute cross sections. Theory derivations are given for the [Formula: see text] Compton scattering differential cross section, dispersion relations, and sum rules in terms of the polarizabilities. We review experimental charged and neutral polarizability studies and theoretical predictions. The [Formula: see text] polarizabilities were deduced from DESY Crystal Ball [Formula: see text] data, but with large uncertainties. The charged pion polarizabilities were deduced most recently from (1) radiative pion Primakoff scattering [Formula: see text] at CERN COMPASS, (2) two-photon pion pair production [Formula: see text] at SLAC Mark II, and (3) radiative pion photoproduction [Formula: see text] from the proton at MAMI in Mainz. A stringent test of chiral perturbation theory (ChPT) is possible based on comparisons of precision experimental charged pion polarizabilities with ChPT predictions. Only the CERN COMPASS charged pion polarizability measurement has acceptably small uncertainties. Its value [Formula: see text] agrees well with the two-loop ChPT prediction [Formula: see text], strengthening the identification of the pion with the Goldstone boson of chiral symmetry breaking in QCD.

scholarly journals Exotic meson decays and polarization asymmetry in hadron environment with chiral imbalance

2018 ◽  
Vol 191 ◽  
pp. 05014 ◽  
Author(s):  
A.E. Putilova ◽  
A.V. Iakubovich ◽  
A.A. Andrianov ◽  
V.A. Andrianov ◽  
D. Espriu
Keyword(s):  
Chemical Potential ◽  
Photon Polarization ◽  
Polarization Asymmetry ◽  
Exotic Meson ◽  
Scalar Mesons ◽  
Pseudoscalar Mesons ◽  
Pion Polarizability ◽  
Vacuum States ◽  
Light Scalar ◽  
The Difference

The possibility of the formation of a local parity breaking in a quark-hadron medium is described as a result of a violation of chiral symmetry, i.e, the difference between the average numbers of right and left -handing quarks in the fireball after HIC.The phenomenology of LPB in the fireball induces the introduction of a topological charge and, accordingly, a topological (chiral) chemical potential. Using the effective meson Lagrangian motivated by QCD in the chiral medium the properties of light scalar and pseudoscalar mesons are analyzed. It is establish that exotic decays of scalar mesons arise as a result of mixing of π and a0 vacuum states in the presence of chiral imbalance. The pion electromagnetic formfactor obtains a parity-odd supplement which generates a photon polarization asymmetry in pion polarizability. We consider that the above-mentioned properties of LPB can be revealed in experiments on LHC, RHIC, CBM FAIR and NICA accelerators.

Pion polarizability in a chiral quark model

1981 ◽  
Vol 101 (4) ◽  
pp. 252-254 ◽  
Author(s):  
D. Ebert ◽  
M.K. Volkov
Keyword(s):  
Quark Model ◽  
Chiral Quark Model ◽  
Pion Polarizability
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