213 research outputs found
Assessing the Triple Deficit Hypothesis for Major South Asian Countries: A Panel Data Analysis
The paper examines the ‘triple deficit hypothesis'-an extension of the ‘twin deficit hypothesis' with inclusion of private saving gap for a panel of five South Asian countries, namely India, Pakistan, Bangladesh, Srilanka and Nepal for the period 1985-2015. The results based on first and second generation panel cointegration tests indicate long-run relationship among budget balance (BB), current account balance (CAB) and private saving gap. The long-run coefficients obtained using MG-DOLS, MG-FMOLS and CCEMG indicate positive impact of BB and private saving gap on CAB thus confirming triple deficit hypothesis. The causality analysis reveals feedback relationship between CAB and BB implying that improvement in CAB requires fiscal austerity but fiscal adjustment is not fully policy controlled and requires adjustment in current account. Further, the causation also runs from saving gap to CAB and BB implying that plugging the saving gap would help improve both current account and budget balance.
Keywords: Triple Deficit Hypothesis, South Asia, Panel Cointegration, Panel Causality, GM-DOLS, GM- FMOLS, CCEMG Estimator
JEL Classifications: E60, F32, H6
Effect of FCNC mediated Z boson on lepton flavor violating decays
We study the three body lepton flavor violating (LFV) decays , and the semileptonic decay in the flavor changing neutral current (FCNC) mediated boson
model. We also calculate the branching ratios for LFV leptonic B decays,
, , and the
conversion of muon to electron in Ti nucleus. The new physics parameter space
is constrained by using the experimental limits on and
. We find that the branching ratios for and processes could be as large as and . For other LFV B decays the branching ratios are found to be too
small to be observed in the near future.Comment: 15 pages, 8 figures, typos corrected, one more section added, version
to appear in EPJ
Signature of new physics in B -> phi pi decay
We investigate the effect of an extra fourth quark generation and FCNC
mediated and bosons on the rare decay mode . In
the standard model, this mode receives only penguin contributions and
therefore, highly suppressed with branching ratio . This
in turn makes this mode a very sensitive probe for new physics. We find that
due to the above mentioned new physics contributions there is a significant
enhancement in its branching ratio. Furthermore, the direct CP violation
parameter which is identically zero in the SM is found to be quite significant.
If this mode will be observed in the upcoming LHCb experiment, it will not only
provide a clear signal of new physics but also can be used to constrain the new
physics parameter space.Comment: 13 pages, 3 figures, version to appear in Phys. Lett.
Possibility of extracting the weak phase from decays
We explore the possibility of extracting the weak phase from pure
tree decays in a model
independent way. The CP violating weak phase can be determined
cleanly, without any hadronic uncertainties, as these decay modes are free from
the penguin pollutions. Furthermore, neither tagging nor time dependent studies
are required to extract the angle with these modes.Comment: 12 pages, LaTex, Minor changes in the text, version to appear in
Phys. Rev.
Probing the unparticle signal in penguin processes
We investigate the effect of unparticles in the pure penguin
processes and . Since
these processes receive dominant contributions due to the {\it top} quark in
the loop, direct and mixing-induced CP asymmetry parameters in these processes
are expected to be vanishingly small in the standard model. We find that due to
the unparticle effect sizable nonzero CP violation could be possible in these
channels.Comment: 12 pages, 4 figures, version to appear in Phys. Lett.
Exploring the Unitarity Triangle through CP violation observables in
We discuss the determination of the CKM parameters from the forthcoming
violation observables in decays. Combining the information on
mixing induced CP violation in , with the
precision observable and the -- mixing phase
, we propose a determination of the unitarity triangle . Computing the penguin parameters within QCD
factorization yield precise determination of , reflected
by a weak dependence on the which is shown as a second order effect.
The impact of the direct CP violation observable on the penguin
parameters are investigated and a lower bound on is extracted. We also
discuss the effect of the -- new physics mixing phase on
the penguin parameters and . Using the SU(3)-flavour
symmetry argument and the current -factories data provided by the modes, we complement the CP-violating
observables in a variety of ways, in particular we find that .
Finally we analyze systematically the SU(3)-symmetry breaking factor within QCD
factorization.Comment: 22 pages, 6 figures, typos corrected, reference and some remarks
adde
Study of f_0(980) and f_0(1500) from B_s \to f_0(980)\pi, f_0(1500)\pi Decays
In this paper, we analyze the scalar mesons and from
the decays within Perturbative
QCD approach. From the leading order calculations, we find that (a) in the
allowed mixing angle ranges, the branching ratio of is about , which is smaller than
that of (the difference is a few times even one
order); (b) the decay is better to distinguish
between the lowest lying state or the first excited state for ,
because the branching ratios for two scenarios have about one-order difference
in most of the mixing angle ranges; and (c) the direct CP asymmetries of for two scenarios also exists great difference. In
scenario II, the variation range of the value according to the mixing angle is very small, except for
the values corresponding to the mixing angles being near or
, while the variation range of in scenario I is very large. Compared with the future data for
the decay , it is ease to determine the nature
of the scalar meson .Comment: 16 pages, 3 figures, Revte
Analysis of \Lambda_b \rar \Lambda \ell^+ \ell^- transition in SM4 using form factors from Full QCD
Using the responsible form factors calculated via full QCD, we analyze the
transition in the standard
model containing fourth generation quarks (SM4). We discuss effects of the
presence of fourth family quark on related observables like branching
ratio, forward-backward asymmetry, baryon polarization as well as double lepton
polarization asymmetries. We also compare our results with those obtained in
the SM as well as with predictions of the SM4 but using form factors calculated
within heavy quark effective theory. The obtained results on branching ratio
indicate that the transition
is more probable in full QCD comparing to the heavy quark effective theory. It
is also shown that the results on all considered observables in SM4 deviate
considerably from the SM predictions when .Comment: 22 Pages and 21 Figure
B --> Phi K_S and Supersymmetry
The rare decay B --> Phi K_S is a well-known probe of physics beyond the
Standard Model because it arises only through loop effects yet has the same
time-dependent CP asymmetry as B --> Psi K_S. Motivated by recent data
suggesting new physics in B --> Phi K_S, we look to supersymmetry for possible
explanations, including contributions mediated by gluino loops and by Higgs
bosons. Chirality-preserving LL and RR gluino contributions are generically
small, unless gluinos and squarks masses are close to the current lower bounds.
Higgs contributions are also too small to explain a large asymmetry if we
impose the current upper limit on B(B_s --> mu mu). On the other hand,
chirality-flipping LR and RL gluino contributions can provide sizable effects
and while remaining consistent with related results in B --> Psi K_S, Delta
M_s, B --> X_s gamma and other processes. We discuss how the LR and RL
insertions can be distinguished using other observables, and we provide a
string-based model and other estimates to show that the needed sizes of mass
insertions are reasonable.Comment: 33 pages, 32 figures, Updated version for PRD. Includes discussions
of other recent works on this topic. Added discussions & plots for gluino
mass dependence and effects of theoretical uncertaintie
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