19,792 research outputs found
Is it possible to Measure the Weak Phase of a Penguin Diagram?
The penguin amplitude receives contributions from internal ,
and -quarks. We show that it is impossible to measure the weak phase of any
of these penguin contributions without theoretical input. However, a single
assumption involving the hadronic parameters makes it possible to obtain the
weak phase and test for the presence of new physics in the
flavour-changing neutral current.Comment: 4 pages, latex, no figures, talk given by R. Sinha at the 3rd
International Conference on B Physics and CP Violation, Taipei, Taiwan,
December 3-7, 1999, to appear in the Proceeding
Tau contribution and precision measurement of theta23 at a neutrino factory
We discuss precision measurements of the leading atmospheric parameters at a
standard neutrino factory. The oscillation of the muon and electron neutrinos
(anti-neutrinos) to tau neutrinos (anti-neutrinos) adds to the muon events
sample (both right sign and wrong sign) via leptonic decays of the taus
produced through charge-current interactions in the detector. We focus on how
this contribution affects a precision measurement of the atmospheric mixing
parameters and the deviation of muon neutrino -- tau neutrino mixing from
maximality.Comment: 4 pages, 5 figures, presented by NS at the 11th International
Workshop on Neutrino Factories, Superbeams and Beta Beams (Nufact09), July
20-25, 2009, Illinois Institute of Technology, Chicago, US
The Leggett-Garg inequality and Page-Wootters mechanism
Violation of the Leggett-Garg inequality (LGI) implies quantum phenomena. In
this light we establish that the Moreva \textit{et al.} \cite{moreva}
experiment demonstrating the Page-Wootter's mechanism \cite{wootters} falls in
the quantum domain. An observer outside a 2-photons world does not detect any
change in the photons state,i.e. there is no time parameter for the outside
observer. But an observer attached to one of the photons sees the other photon
evolving and this means there is an "internal" time. The LGI is violated for
the clock photon whose state evolves with the internal time as measured by the
system photon. Conditional probabilities in this 2-photons system are computed
for both sharp and unsharp measurements. The conditional probability increases
for entangled states as obtained by Page and Wootters for both ideal and also
unsharp measurements. We discuss how the conditional probabilities can be used
to distinguish between massless and massive gravitons. This is important in the
context of gravitational waves.Comment: 5 pages, Late
Brownian motion at absolute zero
We derive a general quantum formula giving the mean-square displacement of a
diffusing particle as a function of time. Near {\bf 0 K} we find a universal
logarithmic behavior (valid for times longer than the relaxation time), and
deviations from classical behavior can also be significant at larger values of
time and temperature. Our derivation depends neither on the specific
composition of the heat bath nor on the strength of the coupling between the
bath and the particle. An experimental regime of microseconds and microdegrees
Kelvin would elicit the pure logarithmic diffusion.Comment: Publishe
Understanding Job Stress among Healthcare Staff
Introduction: Job life is an important part of a person’s daily life. There are many aspects of a job. A person may be satisfied with one or more aspects of his/her job but at the same time may be unhappy with other things related to the job. Objective: To evaluate the sources of job stress (stressful aspects of work) among the staff of a super specialty hospital & to suggest measures to decrease level of job stress. Methodology: Descriptive study employing 381 staff members of a super specialty hospital using a structured personal interview questionnaire consisting of 21 sources of stress. The hospital staff was asked to rate each item according to the extent to which it had contributed to their stress as experienced in their jobs in the past few months on a scale of 0 (not at all),1(a little), 2(quite a bit), 3 (a lot). A global rating of stress was also obtained. Result: The prime sources of stress were found to be underpayment (76%), excessive workload (70.3%), inadequate staff (48.6), & being involved in the emotional distress of patients (46.7%). Conclusion: The staffs of the hospital were in moderate stress due to the prime stressors so adequate measures should be taken to alleviate these stressors. This could be achieved through workload management, job redesign, & by offering occupational health education
Octet baryon magnetic moments from QCD sum rules
A comprehensive study is made for the magnetic moments of octet baryons in
the method of QCD sum rules. A complete set of QCD sum rules is derived using
the external field method and generalized interpolating fields. For each
member, three sum rules are constructed from three independent tensor
structures. They are analyzed in conjunction with the corresponding mass sum
rules. The performance of each of the sum rules is examined using the criteria
of OPE convergence and ground-state dominance, along with the role of the
transitions in intermediate states. Individual contributions from the u, d and
s quarks are isolated and their implications in the underlying dynamics are
explored. Valid sum rules are identified and their predictions are obtained.
The results are compared with experiment and previous calculations.Comment: 21 pages, 11 figures, 6 figures; added a reference, minor change in
tex
Probing New Physics via an Angular Analysis of B --> V1 V2 decays
We show that an angular analysis of B --> V1 V2 decays yields numerous tests
for new physics in the decay amplitudes. Unlike direct CP asymmetries, many of
these new-physics observables are nonzero even if the strong phase differences
vanish. For certain observables, neither time-dependent measurements nor
tagging is necessary. Should a signal for new physics be found, one can place a
lower limit on the size of the new-physics parameters, as well as on their
effect on the measurement of the phase of B0--Bbar0 mixing.Comment: 9 pages, plain latex, no figures. Title modified slightly. Paragraph
added about viability of method. Conclusions unchanged. To be published in
Europhysics Letter
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