1,836 research outputs found
New generalized fuzzy metrics and fixed point theorem in fuzzy metric space
In this paper, in fuzzy metric spaces (in the sense of Kramosil and Michalek (Kibernetika 11:336-344, 1957)) we introduce the concept of a generalized fuzzy metric which is the extension of a fuzzy metric. First, inspired by the ideas of Grabiec (Fuzzy Sets Syst. 125:385-389, 1989), we define a new G-contraction of Banach type with respect to this generalized fuzzy metric, which is a generalization of the contraction of Banach type (introduced by M Grabiec). Next, inspired by the ideas of Gregori and Sapena (Fuzzy Sets Syst. 125:245-252, 2002), we define a new GV-contraction of Banach type with respect to this generalized fuzzy metric, which is a generalization of the contraction of Banach type (introduced by V Gregori and A Sapena). Moreover, we provide the condition guaranteeing the existence of a fixed point for these single-valued contractions. Next, we show that the generalized pseudodistance J:X×X→[0,∞) (introduced by Włodarczyk and Plebaniak (Appl. Math. Lett. 24:325-328, 2011)) may generate some generalized fuzzy metric NJ on X. The paper includes also the comparison of our results with those existing in the literature
CP violation in the inclusive b -> s g decay in the framework of multi Higgs doublet models
We study the decay width and CP asymmetry of the inclusive process b--> s g
(g denotes gluon) in the multi Higgs doublet models with complex Yukawa
couplings, including next to leading QCD corrections. We analyse the
dependencies of the decay width and CP asymmetry on the scale \mu and CP
violating parameter \theta. We observe that there exist an enhancement in the
decay width and CP asymmetry is at the order of 10^{-2}.Comment: 11 pages, 8 Figure
Decay constants, semi-leptonic and non-leptonic decays in a Bethe-Salpeter Model
We evaluate the decay constants for the B and mesons and the form factors
for the semileptonic decays of the B meson to and mesons in a
Bethe-Salpeter model. From data we extract from and from decays. The form factors are then used to obtain non-leptonic
decay partial widths for and in the
factorization approximation.Comment: 15 Pages, 3 Postscript figures (available also from [email protected]
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.
An analysis of two-body non-leptonic B decays involving light mesons in the standard model
We report a theoretical analysis of the exclusive non-leptonic decays of B
mesons into two light mesons,some of which have been measured recently by the
CLEO collaboration. Our analysis is carried out in the context of an effective
Hamiltonian based on the Standard Model using next-to-leading order
perturbative QCD calculations. Using a factorization ansatz for the hadronic
matrix elements, we show that existing data are accounted for in this approach.
Thus, theoretical scenarios with a substantially enhanced Wilson coefficient of
the chromomagnetic dipole operator (as compared to the SM) and/or those with a
substantial color-singlet component in the wave function of
are not required by these data. Implications of some of these
measurements for the parameters of the CKM matrix are presented.Comment: 42 pages including 21 postscript figures; uses epsfig, some ref.
added; improved mixing scheme for (eta,eta') system implemented; error
corrected in (3.61) as explained below eq. (3.64) in the present version.
Figs. 17-20 update
Measurements of Charmless Hadronic b->s Penguin Decays in the pi+pi-K+pi- Final State and First Observation of B0 -> rho0K+pi-
We report measurements of charmless hadronic B^0 decays into the pi+pi-K+pi+
final state. The analysis uses a sample of 657x10^6 BBbar pairs collected with
the Belle detector at the KEKB asymmetric-energy e+e- collider at the Y(4S)
resonance. The decay B^0 -> rho0 Kpi is observed for the first time; the
significance is 5.0sigma and the corresponding partial branching fraction for
M_Kpi in (0.75,1.20) GeV/c^2 is [2.8 +- 0.5(stat) +-0.5(syst)] x 10^{-6}. We
also obtain the first evidence for B^0 -> f0Kpi with 3.5sigma significance and
for B^0 -> pi+pi-K*0 with 4.5sigma significance. For the two-body decays B^0 ->
rho0K*0 and B^0 -> f0K*0, the significances are 2.7sigma and 2.5sigma,
respectively, and the upper limits on the branching fractions are 3.4x10^{-6}
and 2.2x10^{-6} at 90% confidence level.Comment: 6 pages, 3 figures. accepted by PRD(RC
First Measurement of Inclusive B -> X_s eta Decays
We report a first measurement of inclusive B -> X_s eta decays, where X_s is
a charmless state with unit strangeness. The measurement is based on a
pseudo-inclusive reconstruction technique and uses a sample of 657 x 10^6
BB-bar pairs accumulated with the Belle detector at the KEKB e^+e^- collider.
For M_{X_s} < 2.6 GeV/c^2, we measure a branching fraction of (26.1 +/- 3.0
(stat) +1.9 -2.1 (syst) +4.0 -7.1 (model)) x 10^-5 and a direct CP asymmetry of
A_{CP} = -0.13 +/- 0.04 +0.02 -0.03. Over half of the signal occurs in the
range M_{X_s} > 1.8 GeV/c^2.Comment: 6 pages, 1 figure, 1 table, submitted to Physical Review Letter
Evidence for a new resonance and search for the Y(4140) in
The process \gamma \gamma \to \phi \jpsi is measured for \phi \jpsi
masses between threshold and 5 GeV/, using a data sample of 825
fb collected with the Belle detector. A narrow peak of
events, with a significance of 3.2 standard deviations
including systematic uncertainty, is observed. The mass and natural width of
the structure (named X(4350)) are measured to be
and
, respectively. The
product of its two-photon decay width and branching fraction to \phi\jpsi is
for , or
for . No
signal for the Y(4140)\to \phi \jpsi structure reported by the CDF
Collaboration in B\to K^+ \phi \jpsi decays is observed, and limits of
\Gamma_{\gamma \gamma}(Y(4140)) \BR(Y(4140)\to\phi \jpsi)<41 \hbox{eV} for
or for are determined at the 90% C.L. This
disfavors the scenario in which the Y(4140) is a molecule.Comment: 9 pages, 3 figures, publication in Phys. Rev. Lett. 104, 112004, 201
Bounds on the width, mass difference and other properties of X(3872) --> pi+pi-J/psi decays
We present results from a study of X(3872) --> pi+pi- J/psi decays produced
via exclusive B--> K X(3872) decays. We determine the mass to be M_X(3872)=
(3871.84\pm 0.27 (stat)\pm 0.19 (syst)) MeV, a 90% CL upper limit on the
natural width of Gamma_X(3872)
K+X(3872))xBf(X(3872)-->pi+pi-J/psi)=(8.61 \pm 0.82(stat) \pm 0.52 (syst))
x10^{-6}, and a ratio of branching fractions Bf(B0--> K0 X(3872))/BF(B+--> K+
X(3872))=0.50\pm 0.14(stat)\pm0.04(syst). The difference in mass between the
X(3872)-->pi+pi-J/psi signals in B+ and B0 decays is Delta M_{X(3872)= (-0.69
\pm 0.97 (stat)} \pm 0.19 (syst)) MeV. A search for a charged partner of the
X(3872) in the decays Bbar0-->K- X+ or B+-->K0X+, X+-->pi+pi0 J/psi resulted in
upper limits on the product branching fractions for these processes that are
well below expectations for the case that the X(3872) is the neutral member of
an isospin triplet. In addition, we examine possible J^{PC} quantum number
assignments for the X(3872) based on comparisons of angular correlations
between final state particles in X(3872)-->pi+pi-J/psi decays with simulated
data for J^{PC} values of 1^{++} and 2^{-+}. We examine the influence of
rho-omega interference in the M(pi+pi-) spectrum. The analysis is based on a
711fb^{-1} data sample that contains 772 million BBbar meson pairs collected at
the Upsilon(4S) resonance in the Belle detector at the KEKB e+e- collider.Comment: 15 pages, 10 figures and 6 tables. Submitted to Physical Review
- …