40,414 research outputs found
Polarization amplitudes in decay beyond the standard model
We use a recent formalism of the weak hadronic reactions to study the helicity amplitudes in decay. This recent formalism maps the transition matrix elements at the
quark level into hadronic matrix elements, and finally writes the weak matrix
elements in terms of easy analytical formulas evaluated by means of an
elaborate angular momentum algebra. The formalism provides directly the
amplitudes for the different spin third components of the vector mesons
involved. We extend the formalism to a general case, with the operator
, that can account for different models
beyond the standard model and study in detail the reaction for the different helicities of the . The results are
shown in terms of the parameter that differs for each model. We find
that is very different for
the different components and in particular the magnitude is very sensitive to the parameter,
which makes the investigation of this magnitude a most welcome initiative to
test different models beyond the standard model.Comment: 20 pages, 6 figures, add some discussion
Helicity amplitudes in decay
We use a recent formalism of the weak hadronic reactions that maps the
transition matrix elements at the quark level into hadronic matrix elements,
evaluated with an elaborate angular momentum algebra that allows finally to
write the weak matrix elements in terms of easy analytical formulas. In
particular they appear explicitly for the different spin third components of
the vector mesons involved. We extend the formalism to a general case, with the
operator , that can accommodate
different models beyond the standard model and study in detail the reaction for the different helicities of the . The results
are shown for each amplitude in terms of the parameter that is
different for each model. We show that is very different for the different components and in
particular the magnitude is very sensitive to the
parameter, which suggest to use this magnitude to test different
models beyond the standard model. We also compare our results with the standard
model and find very similar results, and practically identical at the end point
of .Comment: 25 pages, 10 figure
Three pseudoscalar meson production in annihilation
We study, at leading order in the large number of colours expansion and
within the Resonance Chiral Theory framework, the odd-intrinsic-parity cross-sections in the energy regime
populated by hadron resonances, namely 3 \, m_{\pi} \lsim E \lsim 2 \,
\mbox{GeV}. In addition we implement our results in the Monte Carlo generator
PHOKHARA 7.0 and we simulate hadron production through the radiative return
method.Comment: 39 pages, 5 figure
Transport equation for 2D electron liquid under microwave radiation plus magnetic field and the Zero Resistance State
A general transport equation for the center of mass motion is constructed to
study transports of electronic system under uniform magnetic field and
microwave radiation. The equation is applied to study 2D electron system in the
limit of weak disorder where negative resistance instability is observed when
the radiation field is strong enough. A solution of the transport equation with
spontaneous AC current is proposed to explain the experimentally observed
Radiation-Induced Zero Resistance State.Comment: 9 pages, 1 figur
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