5,674 research outputs found
Puzzles in Hyperon, Charm and Beauty Physics
Puzzles awaiting better experiments and better theory include: (1) the
contradiction between good and bad SU(3) baryon wave functions in fitting
Cabibbo theory for hyperon decays, strangeness suppression in the sea and the
violation of the Gottfried Sum rule - no model fits all; (2) Anomalously
enhanced Cabibbo-suppressed decays; (3) anomalously
enhanced and suppressed decays; (4) the OZI rule in weak
decays; (5) Vector dominance () in weak
decays (6) Puzzles in doubly-cabibbo-suppressed charm decays.(7) Problems in
obtaining spin structure from polarization measurements of produced
's.Comment: 5 page
Theoretical Summary of the HADRON99 conference
The Constituent Quark Model has provided a remarkable description of the
experimentally observed hadron spectrum but still has no firm theoretical
basis. Attempts to provide a QCD justification discussed at Hadron99 include
QCD Sum Rules, instantons, relativistic potential models and the lattice.
Phenomenological analyses to clarify outstanding problems like the nature of
the scalar and pseudoscalar mesons and the low branching ratio for were presented. New experimental puzzles include the observation of
.Comment: 10 pages, espcrc1.st
What is coherent in neutrino oscillations
Simple rigorous quantum mechanics with no hand waving nor loopholes clarifies
the confusion between three contradictory descriptions of neutrino
oscillations: (1)The time oscillations shown in standard textbooks produced by
neutrino eigenstates with different masses and different energies. (2) That
time oscillations and interference between states having different energies
cannot be observed in realistic experiments. (3) That interference between
different neutrino mass eigenstates is not observable in "missing mass"
experiments where information determining the neutrino mass is available from
other particles measured in production or detection vertices.
Quantum-mechanical ignorance of the neutrino momentum is rigorously shown to be
imposed by all realistic detectors and to produce coherence between amplitudes
from neutrino states with the same energy and different masses. Conditions are
precisely formulated for the loss of coherence when mass eigenstate wave
packets moving with different velocities separate. The example of Bragg
scattering shows how quantum-mechanically imposed ignorance produces coherence.Comment: 13 pages, Abstract and text of original contribution completely
revise
Systematics of Large Axial Vector Meson Production in Heavy Flavor Weak Decays
Branching ratios observed for and B decays to final states
are comparable to those for corresponding decays to
and and much larger than those for all other
decays. Implications are discussed of a "vector-dominance model" in which a
is produced and immediately turns into an axial vector, vector or pseudoscalar
meson. Data for decays to all such final states are shown to have large
branching ratios and satisfy universality relations. Upper limits on small
strong phase differences between amplitudes relevant to CP violation models are
obtained from analysis of the predicted and observed suppression of
decays into neutral final states , and . .
Branching ratios of are predicted for the as yet unobserved
presence of the charmed-strange axial vector in B decays.Comment: 14 page
Penguins, Trees and Final State Interactions in B Decays in Broken SU3
The availability of data on decays to strange quasi-two-body final
states, either with or without charmonium opens new possibilities for
understanding different contributions of weak diagrams and in particular the
relative contributions of tree and penguin diagrams. Corresponding and
decays to charge conjugate final states are equal in the SU(3) symmetry
limit and the dominant SU(3) breaking mechanism is given by ratios of CKM
matrix elements. Final State Interactions effects should be small, because
strong interactions conserve and should tend to cancel in ratios between
charge conjugate states. Particularly interesting implications of decays into
final states containing and are discussed.Comment: special macro - phyzz
FSI Rescattering in Decays via States with and
New results going beyond those obtained from isospin and flavor symmetry and
subject to clear experimental tests are obtained for effects of FSI in
decays to charmless strange final states containing neutral flavor-mixed mesons
like , , and . The most general strong-interaction
diagrams containing arbitrary numbers of quarks and gluons are included with
the assumptions that any pair created by gluons must be a flavor
singlet, and that there are no hairpin diagrams in which a final meson contains
a pair from the same gluon vertex. The smallness of
suggests that it might have a large CP violation. A sum rule is derived to test
whether the large requires the addition of an additional glueball
or charm admixture. Further analysis from decay systematics supports this
picture of FSI and raises questions about charm admixture in the
Puzzles in Cabibbo-Suppressed Charm Decays
We identify two Cabibbo suppressed decay modes with anomalously high
branching ratios which are not simply explained by any model. All standard
model diagrams that can contribute to these decays are related by symmetries to
diagrams for other decays that do not show any such enhancement. If these high
branching ratios are confirmed by more precise experiments, they may require
new physics to explain them. Anomalies in decays and tests for possible
violation of G-parity are discussed.Comment: 12 pages, additional clarification at eq. (13), correction of error
in eq. (18) and subsequent discussio
Sieving Through the Data to Find the Person: HRâs Imperative for Balancing Big Data with People Centricity
[Excerpt] With âbig dataâ and âanalyticsâ atop human resources (HR) professionalsâ dictionaries, it is no wonder that some are calling it time to think of employees as data points and to scientifically make people decisions. These beget horrific images of what many employees already believe HR promotes: incessant change and downsizing solely for profit maximization.
Yet, for HR to genuinely transition into the world of data-driven people solutions, it must leverage its roots in employee advocacy, understanding, and development. To best do this, HR must undertake three actions. First, HR can ease into people analytics, using the necessary time and effort to gain employee buy-in. Second, HR should stress the objectivity of data-driven decision making. Third, HR practitioners must exhibit empathy for those affected by such decisions
- âŠ