منابع مشابه
ηcγ TRANSITION FORM FACTOR
The ηcγ transition form factor is calculated in a model based on a modified hard scattering approach to exclusive reactions, in which transverse degrees of freedom are taken into account. For the ηc-meson a distribution amplitude of the Bauer-Stech-Wirbel type is used, where the two free parameters, namely the decay constant fηc and the transverse size of the wave function, are related to the F...
متن کاملDπ Form Factor Revisited
The D * Dπ form factor is evaluated in a QCD sum rule calculation for both D and π off-shell mesons. We study the Borel sum rule for the three point function of one pseudoscalar, one axial and one vector meson currents. We find that the momentum dependence of the form factors is very different if the D or the π meson is off-shell, but they lead to the same coupling constant in the D * Dπ vertex.
متن کاملForm Factor Dark Matter
We present a dynamical alternative to inelastic dark matter as a way of reconciling the modulating signal seen at DAMA with null results at other direct detection experiments. The essential ingredient is a new form factor which introduces momentum dependence in the interaction of dark matter with nuclei. The role of the form factor is to suppress events at low momentum transfer. We find that a ...
متن کاملThe Pion Form Factor
The pion, and specifically its charge form factor, is of key interest in the study of the quark-gluon structure of hadrons. This is exemplified by the many calculations that treat the pion as one of their prime examples. One of the reasons is that the valence structure of the pion, being 〈qq̄〉, is relatively simple. Hence it is expected that the value of the four-momentum transfer squared Q, dow...
متن کاملRemarks on Form Factor Bounds
Improved model independent upper bounds on the weak transition form factors are derived using inclusive sum rules. Comparison of the new bounds with the old ones is made for the form factors hA1 and hV in B → D decays. [email protected] 1 A set of model independent bounds has been derived to provide a restriction on the shape of weak transition form factors [1–3]. They have been extensive...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physical Review D
سال: 2012
ISSN: 1550-7998,1550-2368
DOI: 10.1103/physrevd.86.016001