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Proposal to study inelastic high energy proton-proton collisions in the diffractive region
B-physics constraints on baryon number violating couplings: grand unification or R-parity violation
We investigate the role that baryon number violating interactions may play in
phenomenology. Present in various grand unified theories, supersymmetric
theories with R-parity violation and composite models, a diquark state could be
quite light. Using the data on B decays as well as mixing, we
find strong constraints on the couplings that such a light diquark state may
have with the Standard Model quarks.Comment: 19 pages, latex, no figures, 13 tables include
Sneutrino Mixing Phenomena
In any model with nonzero Majorana neutrino masses, the sneutrino and
antisneutrino of the supersymmetric extended theory mix. We outline the
conditions under which sneutrino-antisneutrino mixing is experimentally
observable. The mass-splitting of the sneutrino mass eigenstates and sneutrino
oscillation phenomena are considered.Comment: 12 pages, revtex + axodraw, 1 figure included. Minor change
Testing the Standard Model and Schemes for Quark Mass Matrices with CP Asymmetries in B Decays
The values of and , where and
are angles of the unitarity triangle, will be readily measured in a B
factory (and maybe also in hadron colliders). We study the standard model
constraints in the plane. We use the results
from recent analyses of and which take into account
heavy quark symmetry considerations. We find and
most likely \sin (2 \beta) \roughly{>} 0.6, and emphasize the strong
correlations between and . Various schemes
for quark mass matrices allow much smaller areas in the plane. We study the schemes of Fritzsch, of Dimopoulos, Hall and
Raby, and of Giudice, as well as the ``symmetric CKM'' idea, and show how CP
asymmetries in B decays will crucially test each of these schemes.Comment: 11 pages and 4 postscript figures available on request, LaTeX,
WIS-92/52/Jun-PH, LBL-3256
Leptonic Flavor and CP Violation
We discuss how neutrino oscillation experiments can probe new sources of
leptonic flavor and CP violation.Comment: 8 pages, latex, no figures. Invited talk given at KAON 2001, Pisa,
Italy, June 12 - 17, 200
Phenomenology of Decays
Using the QCD sum rules technique we study several aspects of the
phenomenology of the b-flavoured strange meson . In particular, we
evaluate the mass of the particle, the leptonic constant and the form factors
of the decays , , . We also calculate, in the factorization approximation, a number of
two-body non leptonic decays.Comment: 19 pages, 2 figures (not included) available upon request, LaTex,
BARI-TH/93-139, UTS-DFT-93-1
Measurement of the K_L \to \pi\mu\nu form factor parameters with the KLOE detector
Using 328 pb^{-1}of data collected at DAFNE corresponding to 1.8
million decays, we have measured the form factor
parameters. The structure of the vector-current provides information
about the dynamics of the strong interaction; its knowledge is necessary for
evaluation of the phase-space integral required for measuring the CKM matrix
element and for testing lepton universality in kaon decays. Using a
new parametrization for the vector and scalar form factors, we find
=\pt(25.7\pm 0.6),-3, and =\pt(14.0\pm 2.1),-3,. Our
result for , together with recent lattice calculations of ,
and , satisfies the Callan-Trieman relatio
Very light CP-odd scalar in the Two-Higgs-Doublet Model
We show that a general two-Higgs-doublet model (THDM) with a very light
CP-odd scalar (A) can be compatible with the rho parameter, Br(b --> s\gamma),
R_b, A_b, (g-2) of muon, Br(Upsilon --> A gamma), and the direct search via the
Yukawa process at LEP. For its mass around 0.2 GeV, the muon (g-2) and
Br(Upsilon --> A \gamma) data require tan(beta) to be about 1. Consequently, A
can behave like a fermiophobic CP-odd scalar and predominantly decay into a
photon pair ("gamma gamma"), which registers in detectors of high energy
collider experiments as a single photon signature when the momentum of A is
large. We compute the partial decay width of Z --> A A A and the production
rate of f \bar{f} --> Z A A --> Z +"gamma gamma", f^' {\bar f} --> W^{\pm} A A
--> W^\pm + "gamma gamma" and f \bar f --> H^+ H^- --> W^+ W^- A A --> W^+ W^-
+ "gamma gamma" at high energy colliders such as LEP, Tevatron, LHC, and future
Linear Colliders. Other production mechanisms of a light A, such as gg --> h
--> AA --> "gamma gamma", are also discussed.Comment: Some improvementes, references updated, 3 new figures, one new
appendix, abstract and conclusions unchaged. Version to appear in Physical
Review
Chiral Perturbation Theory for SU(3) Breaking in Heavy Meson Systems
The SU(3) breaking effects due to light quark masses on heavy meson masses,
decay constants () and the form factor for semileptonic
transitions are formulated
in chiral perturbation theory, using a heavy meson effective Lagrangian and
expanding in inverse powers of the heavy meson mass. To leading order in this
expansion, the leading chiral logarithms and the required counterterms are
determined. At this level, a non-analytic correction to the mass splittings of
appears, similar the the one found in light baryons. The
correction to is roughly estimated to be of the order of
and, therefore, experimentally accessible, while the correction to the
form factor is likely to be substantially smaller. We explicitly check that the
heavy quark symmetry is preserved by the chiral loops.Comment: 21 page
A global fit to determine the pseudoscalar mixing angle and the gluonium content of the eta' meson
We update the values of the eta-eta' mixing angle and of the eta' gluonium
content by fitting our measurement R_phi = BR(phi to eta' gamma)/ BR(phi to eta
gamma) together with several vector meson radiative decays to pseudoscalars (V
to P gamma), pseudoscalar mesons radiative decays to vectors (P to V gamma) and
the eta' to gamma gamma, pi^0 to gamma gamma widths. From the fit we extract a
gluonium fraction of Z^2_G = 0.12 +- 0.04, the pseudoscalar mixing angle psi_P
= (40.4 +- 0.6) degree and the phi-omega mixing angle psi_V = (3.32 +- 0.09)
degree. Z^2_G and psi_P are fairly consistent with those previously published.
We also evaluate the impact on the eta' gluonium content determination of
future experimental improvements of the eta' branching ratios and decay width.Comment: 13 pages, 7 figures to submit to JHE
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