1,328 research outputs found
Strong Phases in the Decays B to pi pi
Two sources of strong phases in the decays to are identified:
(1) "quasi-elastic scattering" corresponding to intermediate states like
and , (2) ``'' corresponding to intermediate
states like and . Possibilities of using data to
identify these two sources are discussed and illustrated. Present data suggests
both sources may be significant.Comment: 6 pages, 1 figure
Neutrino Masses and Oscillations in Models with Large Extra Dimensions
We discuss the profile of neutrino masses and mixings in models with large
extra dimensions when right handed neutrinos are present in the branes along
with the usual standard model particles. In these models, string scale must be
bigger than GeV to have desired properties for the neutrinos at low
energies. The lightest neutrino mass is zero and there is oscillations to
sterile neutrinos that are different from other models with the bulk neutrino.Comment: Minor changes. 9 pages, latex file, uses epsf style, two figures
included. To appear at Phys. Lett.
Bounds on sterile neutrino mixing for cosmologically interesting mass range
This talk summarizes our recent work which studied the impact of resonant
and ( is a sterile
neutrino) conversions on supernova physics, under the assumption that the mass
of the sterile state is in the few eV -cosmologically significant range.Comment: Latex file, 3 pages including 4 ps figures, Talk given by H. Nunokawa
in TAUP97, Gran Sasso, Italy, 7-11 September, 199
Non-leptonic B-decays, CP violation & the UT
We study the implication of the time-dependent CP asymmetry in
decays on the extraction of weak phases taking into account
the precise measurement of , obtained from the ``gold-plated''mode
. Predictions and uncertainties for the hadronic parameters
are investigated in QCD factorization. Furthermore, independent theoretical and
experimental tests of the factorization framework are briefly discussed.
Finally, a model-independent bound on the unitarity triangle from CP violation
in and is derived.Comment: 4 pages; 4 figures (requires epsfig, psfrag); To appear in the
proceedings of the 11th International Conference on Quantum Chromodynamics
(QCD 04), Montpellier, France, 5--10th July 200
Comment on ``Neutrino masses and mixing angles in a predictive theory of fermion masses''
In the extension of the Dimopoulos--Hall--Raby model of the fermion mass
matrices to the neutrino sector, there is an entry in the up-quark and neutrino
Dirac mass matrices which can be assumed to arise from the Yukawa coupling of a
{\bf 120}, instead of a {\bf 10} or a {\bf 126}, of SO(10). Although this
assumption leads to an extra undetermined complex parameter in the model, the
resulting lepton mixing matrix exhibits the remarkable feature that the does not mix with the other two neutrinos. Making a reasonable
assumption about the extra parameter, we are able to fit the large-mixing-angle
MSW solution of the solar-neutrino problem, and we obtain eV, the right mass range to close the Universe. Other possibilities for
explaining the solar-neutrino deficit are also discussed.Comment: standard LATEX, 6 pages, 2 figures available from the authors, report
No. CMU-HEP93-20 and DOE-ER/40682-4
Neutrinoless Double Beta Decay and CP Violation
We study the relation between the Majorana neutrino mass matrices and the
neutrinoless double beta decay when CP is not conserved. We give an explicit
form of the decay rate in terms of a rephasing invariant quantity and
demonstrate that in the presence of CP violation it is impossible to have
vanishing neutrinoless double beta decay in the case of two neutrino
generations (or when the third generation leptons do not mix with other leptons
and hence decouple).Comment: 9 pages, UTPT-93-1
Crowdsourcing Digital Public History
The generation of communal knowledge is not a new phenomenon. In the late nineteenth century, the Oxford English Dictionary solicited volunteers to submit words and their usage for inclusion in the dictionary ( 1 ). Carl Becker, writing in 1932 on what was already an old discussion in the historical profession, noted that if the essence of history is the memory of things said and done, then it is obvious that every normal person, Mr. Everyman, knows some history (2). The historian Jo Guldi\u27s work on participatory mapping shows that urban planners in the middle of the twentieth century attempted to learn from and listen to members of a community.
There is plenty of precedent, then, for harnessing participatory knowledge. Today, the digital turn has offered new technologies to engage with communities and significantly widened the number of possible participants. The success of recent digital crowdsourcing projects, including Flickr Commons, the National Archive\u27s Citizen Archivist Dashboard, History Harvest, and Transcribe Bentham have demonstrated the degree of success that crowdsourcing offers to cultural heritage and public digital history. Like any research, a crowdsourcing project requires careful planning and an understanding of what is meant by crowdsourcing in a specific project. In this essay we discuss the importance of these definitions, describe a few successful and well-known crowdsourced projects, and discuss one of the projects we are working on here at Stanford\u27s Center for Spatial and Textual Analysis (CESTA)
Desperately Seeking Non-Standard Phases via Direct CP Violation in Process
Attributing the recent CLEO discovery of to originate
(primarily) from the fragmentation of an off-shell gluon () via , , we emphasize that many such states () should
materialize. Indeed the hadronic fragments () of states are closely
related to those seen in . A particular
final state of considerable interest is . Signals from such states
in decays can be combined to provide a very sensitive search for CP
violating phase(s) from non-standard physics. The method should work even if
the contribution of these source(s) to the rates is rather small () to
the point that a comparison between theory and experiment may find it extremely
difficult to reveal the presence of such a new physics.Comment: 16 pages, 5 figure
Electroweak Radiative Corrections to Muon Capture
Electroweak radiative corrections to muon capture on nuclei are computed and
found to be sizable. They enhance the capture rates for hydrogen and helium by
2.8% and 3.0% respectively. As a result, the value of the induced pseudoscalar
coupling, g_P^exp, extracted from a recent hydrogen 1S singlet capture
experiment is increased by about 21% to g_P^exp = 7.3 +/- 1.2 and brought into
good agreement with the prediction of chiral perturbation theory,
g_P^theory=8.2 +/- 0.2. Implications for helium capture rate predictions are
also discussed.Comment: 6 page
Probing neutrino oscillations jointly in long and very long baseline experiments
We examine the prospects of making a joint analysis of neutrino oscillation
at two baselines with neutrino superbeams. Assuming narrow band superbeams and
a 100 kt water Cerenkov calorimeter, we calculate the event rates and
sensitivities to the matter effect, the signs of the neutrino mass differences,
the CP phase and the mixing angle \theta_{13}. Taking into account all possible
experimental errors under general consideration, we explored the optimum cases
of narrow band beam to measure the matter effect and the CP violation effect at
all baselines up to 3000 km. We then focus on two specific baselines, a long
baseline of 300 km and a very long baseline of 2100 km, and analyze their joint
capabilities. We found that the joint analysis can offer extra leverage to
resolve some of the ambiguities that are associated with the measurement at a
single baseline.Comment: 23 pages, 11 figure
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