160 research outputs found
Lifetime Differences in Heavy Mesons With Time Independent Measurements
Heavy meson pairs produced in the decays of heavy quarkonium resonances at e+
e- machines (beauty and tau-charm factories) have the useful property that the
two mesons are in the CP-correlated states. By tagging one of the mesons as a
CP eigenstate, a lifetime difference of heavy neutral meson mass eigenstates
width difference may be determined by measuring the leptonic branching ratio of
the other meson. We discuss the use of this and related methods both in the
case where time dependent mixing is small and when it is significant. We
consider the impact of possible CP-violating effects and present the complete
results for CP-entangled decay rates with CP-violation taken into account.Comment: 14 pages, 0 figures; 2 references added, results unchange
Exclusive Electro-Disintegration of 3He at high Q2: II. Decay Function Formalism
Based on the theoretical framework of generalized eikonal approximation we
study the two-nucleon emission reactions in high electro-disintegration
of . Main aim is to investigate those features of the reaction which can
be unambiguously identified with the short range properties of the ground state
nuclear wave function. To evaluate the differential cross section we work in
the formalism of the decay function which characterizes the property of the
ground state wave function as well as the decay properties of final two nucleon
spectator system. Our main motivation here is to explore the accessibility of
two-- and three--nucleon short range correlations in He as well as to
isolate unambiguously single and double rescattering processes in the reaction
dynamics. Our analysis allowed us also to identify new approaches for
investigating the role of the practically unknown three-nucleon forces in the
ground state wave function of .Comment: 37 pages, 28 figure
Modern technologies of waste utilization from industrial tire production
The innovative technology of waste tire production recovery from JSC "Nizhnekamskshina", which determines the possibility of obtaining a new type of composite material in the form fiber filled rubber compound (FFRC) as the raw material, production of rubber products with high technical and operational characteristics
Detecting new physics contributions to the D0-D0bar mixing through their effects on B decays
New physics effects may yield a detectable mass difference in the D0-D0bar
system, Delta m_D. Here we show that this has an important impact on some B -->
D decays. The effect involves a new source of CP violation, which arises from
the interference between the phases in the B --> D decays and those in the
D0-D0bar system. This interference is naturally large. New physics may well
manifest itself through Delta m_D contributions to these B decays.Comment: 10 pages, Revtex, no figures. To appear in PR
Hidden gauge formalism for the radiative decays of axial-vector mesons
The radiative decay of the axial-vector resonances into a pseudoscalar meson
and a photon is studied using the vector meson Lagrangian obtained from the
hidden gauge symmetry (HGS) formalism. The formalism is well suited to study
this problem since it deals with pseudoscalar and vector mesons in a unified
way, respecting chiral invariance. We show explicitly the gauge invariance of
the set of diagrams that appear in the approach and evaluate the radiative
decay width of the a1(1260) and b1(1235) axial vector meson resonances into pi
gamma. We also include the contribution of loops involving anomalous couplings
and compare the results to those obtained previously within another formalism.Comment: 24 pages, 6 tables, 11 figure
Properties of the Resonance Lambda(1520) as seen in the Forward Electroproduction at JLab Hall A
High-resolution spectrometer measurements of the reaction H(e,e' K+)X at
small Q2 are used to extract the mass and width of the Lambda(1520). We
investigate dependence of the resonance parameters on different
parametrizations of the background and the resonance peak itself. Our final
values for the Breit-Wigner parameters are M=1520.4+-0.6(stat)+-1.5(syst) MeV
and Gamma=18.6+-1.9(stat)+-1(syst) MeV. The width appears to be more sensitive
to the assumptions than the mass. We also estimate, for the first time, the
pole position for this resonance and find that both the pole mass and width
seem to be smaller than their Breit-Wigner values.Comment: 4 pages, 1 figure, to appear in the proceedings of MENU 201
B-Decay CP Asymmetries, Discrete Ambiguities and New Physics
The first measurements of CP violation in the system will likely probe
, and . Assuming that the CP angles
, and are the interior angles of the unitarity
triangle, these measurements determine the angle set
except for a twofold discrete ambiguity. If one allows for the possibility of
new physics, the presence of this discrete ambiguity can make its discovery
difficult: if only one of the two candidate solutions is consistent with
constraints from other measurements in the and systems, one is not sure
whether new physics is present or not. We review the methods used to resolve
the discrete ambiguity and show that, even in the presence of new physics, they
can usually be used to uncover this new physics. There are some exceptions,
which we describe in detail. We systematically scan the parameter space and
present examples of values of and the new-physics
parameters which correspond to all possibilities. Finally, we show that if one
relaxes the assumption that the bag parameters \BBd and \BK are positive,
one can no longer definitively establish the presence of new physics.Comment: 29 pages, LaTeX, 1 figures, presentation substantially reworked,
physics conclusions unchanged. This version will be published in Phys. Rev.
CP Violation in \tau ->\nu\pi K_S and D->\pi K_S: The Importance of K_S-K_L Interference
The -factories have measured CP asymmetries in the and
modes. The state is identified by its decay to two pions at
a time that is close to the lifetime. Within the Standard Model and many
of its extensions, the asymmetries in these modes come from CP violation in
mixing. We emphasize that the interference between the
amplitudes of intermediate and is as important as the pure
amplitude. Consequently, the measured asymmetries depend on the times over
which the relevant decay rates are integrated and on features of the
experiment.Comment: 4 pages, 4 figure
New CP-violating parameters in cascade decays
We consider decay chains of the type P -> M + ... -> f + ..., where M is a
neutral meson that may mix with its antiparticle Mbar, before decaying into the
final state f. P may be either a heavier neutral meson or a charged meson. We
perform a rephasing-invariant analysis of the quantities that show up in such
cascade decays. If the decay P -> M + ... (or the decay P -> Mbar + ...) is
forbidden, we find the usual lambda_f parameters describing the interference
between the mixing of a neutral meson system and the decay from that system
into the final state f. However, when both the P -> M + ... and P -> Mbar + ...
decays are allowed, we find a new class of rephasing-invariant parameters,
xi_i, that measure the interference between the mixing of a neutral meson
system and the decay from the initial state *into that system*. We show that
the quantities lambda_f and xi_i are necessary and sufficient to describe all
the interference effects present in the most general cascade decay. We discuss
the various cascade decays in turn, highlighting the special features of each
one.Comment: 22 pages, latex, 5 figures, corrected missing signs in the discussion
of the CP conservation limi
Relativistic Aharonov-Casher Phase in Spin One
The Aharonov-Casher (AC) phase is calculated in relativistic wave equations
of spin one. The AC phase has previously been calculated from the Dirac-Pauli
equation using a gauge-like technique \cite{MK1,MK2}. In the spin-one case, we
use Kemmer theory (a Dirac-like particle theory) to calculate the phase in a
similar manner. However the vector formalism, the Proca theory, is more widely
known and used. In the presence of an electromagnetic field, the two theories
are `equivalent' and may be transformed into one another. We adapt these
transformations to show that the Kemmer theory results apply to the Proca
theory. Then we calculate the Aharonov-Casher phase for spin-one particles
directly in the Proca formalism.Comment: 12 page
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