44 research outputs found
Detecting Gluino-Containing Hadrons
When SUSY breaking produces only dimension-2 operators, gluino and photino
masses are of order 1 GeV or less. The gluon-gluino bound state has mass
1.3-2.2 GeV and lifetime > 10^{-5} - 10^{-10} s. This range of mass and
lifetime is largely unconstrained because missing energy and beam dump
techniques are ineffective. With only small modifications, upcoming K^0 decay
experiments can study most of the interesting range. The lightest
gluino-containing baryon (uds-gluino) is long-lived or stable; experiments to
find it and the uud-gluino are also discussed.Comment: 13 pp, 1 figure (uuencoded). Descendant of hep-ph/9504295,
hep-ph/9508291, and hep-ph/9508292, focused on experimental search
techniques. To be published in Phys Rev Let
Impact of D0-D0bar mixing on the experimental determination of gamma
Several methods have been devised to measure the weak phase gamma using
decays of the type B+- --> D K+-, where it is assumed that there is no mixing
in the D0-D0bar system. However, when using these methods to uncover new
physics, one must entertain the real possibility that the measurements are
affected by new physics effects in the D0-D0bar system. We show that even
values of x_D and/or y_D around 10^{-2} can have a significant impact in the
measurement of sin^2{gamma}. We discuss the errors incurred in neglecting this
effect, how the effect can be checked, and how to include it in the analysis.Comment: 18 pages, Latex with epsfig, 8 figure
Tau and Charm physics highlights
In tau physics, we are at the frontier between the completion of the LEP
program and the start of analyses from b-factories, which are expected to
produce results in the coming years. Nice results from CLEO are steadily
delivered in the meantime. For charm, impressive progress have been achieved by
fixed target experiments in the search for CP violation and D^0 - \bar D^0
oscillations. First results from b-factories demonstrate the power of these
facilities in such areas. The novel measurement of the D* width by CLEO happens
to be rather different from current expectations. The absence of a charm
factory explains the lack or the very slow progress in the absolute scale
determinations for charm decays.Comment: "Typos corrected and references added
Experiments to Find or Exclude a Long-Lived, Light Gluino
Gluinos in the mass range ~1 1/2 - 3 1/2 GeV are absolutely excluded. Lighter
gluinos are allowed, except for certain ranges of lifetime. Only small parts of
the mass-lifetime parameter space are excluded for larger masses unless the
lifetime is shorter than ~ 2 10^{-11} (m_{gluino}/ GeV) sec. Refined mass and
lifetime estimates for R-hadrons are given, present direct and indirect
experimental constraints are reviewed, and experiments to find or definitively
exclude these possibilities are suggested.Comment: 27 pp, latex with 1 uufiled figure, RU-94-35. New version amplifies
discussion of some points and corresponds to version for Phys. Rev.
Leptogenesis and low energy observables in left-right symmetric models
In the context of left-right symmetric models we study the connection of
leptogenesis and low energy parameters such as neutrinoless double beta decay
and leptonic CP violation. Upon imposition of a unitarity constraint, the
neutrino parameters are significantly restricted and the Majorana phases are
determined within a narrow range, depending on the kind of solar solution. One
of the Majorana phases gets determined to a good accuracy and thereby the
second phase can be probed from the results of neutrinoless double beta decay
experiments. We examine the contributions of the solar and atmospheric mass
squared differences to the asymmetry and find that in general the solar scale
dominates. In order to let the atmospheric scale dominate, some finetuning
between one of the Majorana phases and the Dirac CP phase is required. In this
case, one of the Majorana phases is determined by the amount of CP violation in
oscillation experiments.Comment: 18 pages, 6 figures. Matches version to appear in PR
Are ultrahigh energy cosmic rays signals of supersymmetry?
We investigate the possibility that cosmic rays of energy larger than the
Greisen-Zatsepin-Kuzmin cutoff are not nucleons, but a new stable, massive,
hadron that appears in many extensions of the standard model. We focus
primarily on the S^0, a uds-gluino bound state. The range of the S^0 through
the cosmic background radiation is significantly longer than the range of
nucleons, and therefore can originate from sources at cosmoglogical distances.Comment: 20 page LaTeX file with 5 PostScript figures included with epsf.
Discussion of acceleration mechanisms has been elaborated and some new
references have been added. No change in conclusions or figure
Leptogenesis and Neutrino Oscillations Within A Predictive G(224)/SO(10)-Framework
A framework based on an effective symmetry that is either G(224)= SU(2)_L x
SU(2)_R xSU(4)^c or SO(10) has been proposed (a few years ago) that
successfully describes the masses and mixings of all fermions including
neutrinos, with seven predictions, in good accord with the data. Baryogenesis
via leptogenesis is considered within this framework by allowing for natural
phases (~ 1/20-1/2) in the entries of the Dirac and Majorana mass-matrices. It
is shown that the framework leads quite naturally, for both thermal as well as
non-thermal leptogenesis, to the desired magnitude for the baryon asymmetry.
This result is obtained in full accord with the observed features of the
atmospheric and solar neutrino oscillations, as well as with those of the quark
and charged lepton masses and mixings, and the gravitino-constraint. Hereby one
obtains a unified description of fermion masses, neutrino oscillations and
baryogenesis (via leptogenesis) within a single predictive framework.Comment: Efficiency factor updated, some clarifications and new references
added. 19 page
Measurement of CP asymmetry in Cabibbo suppressed D0 decays
We measure the CP-violating asymmetries in decays to the D0 -> K+K- and D0 ->
pi+pi- CP eigenstates using 540 fb^{-1} of data collected with the Belle
detector at or near the Upsilon(4S) resonance. Cabibbo-favored D0 -> K-pi+
decays are used to correct for systematic detector effects. The results,
A_{CP}^{KK} = (-0.43 +- 0.30 +- 0.11)% and A_{CP}^{pipi} = (+0.43 +- 0.52 +-
0.12)%, are consistent with no CP violation.Comment: Submitted to Phys. Lett.
Estimation By Means of Wavelet Analysis of the Signal-to-Noise Ratio of Dysphonic Voices
The objective is to explore a procedure for isolating additive noise in vowels, and estimating the signal-to-noise ratio. The method is founded on the wavelet transform, which is a family of multi-resolution analysis methods. The breakdown of sonorants into a noise and a signal constituent relates to the observation that additive noise is mostly high-frequency or low-amplitude. The segregation of the noise is therefore based on the isolation of the wavelets of the highestresolution scale or, alternatively, on those whose amplitude is below a critical threshold. The analysis method was tested on a corpus of [a],[i],[u] vowels sustained by healthy and dysphonic speakers. Results suggest that isolating noise via thresholding is preferable to assigning high-resolution scales to noise and low-resolution scales to the signal. Keywords--- Signal-to-noise ratio, Wavelet Transform. I. Introduction The article is concerned with gauging the amount of noise in vowels in view of the description ..