17,625 research outputs found
The Prediction of Mass of Z'-Boson from Mixing
B_q^0-B_^0 bar mixing offers a profound probe into the effects of new
physics beyond the Standard Model. In this paper, and
mass differences are considered taking the effect of both
Z-and Z' -mediated flavour-changing neutral currents in the
mixing (q = d, s). Our estimated mass of Z' boson is accessible at the
experiments LHC and B-factories in near future.Comment: 11 pages, 02 Figure
Quantum advantage by relational queries about physically realizable equivalence classes
Relational quantum queries are sometimes capable to effectively decide
between collections of mutually exclusive elementary cases without completely
resolving and determining those individual instances. Thereby the set of
mutually exclusive elementary cases is effectively partitioned into equivalence
classes pertinent to the respective query. In the second part of the paper, we
review recent progress in theoretical certifications (relative to the
assumptions made) of quantum value indeterminacy as a means to build quantum
oracles for randomness.Comment: 8 Pages, one figure, invited contribution to TopHPC2019, Tehran,
Iran, April 22-25, 201
Effects of the R-parity violation in the minimal supersymmetric standard model on dilepton pair production at the CERN LHC
We investigate in detail the effects of the R-parity lepton number violation
in the minimal supersymmetric standard model (MSSM) on the parent process at the CERN Large Hadron Collider (LHC). The numerical
comparisons between the contributions of the R-parity violating effects to the
parent process via the Drell-Yan subprocess and the gluon-gluon fusion are
made. We find that the R-violating effects on pair production at the
LHC could be significant. The results show that the cross section of the pair productions via gluon-gluon collision at the LHC can be of the order
of fb, and this subprocess maybe competitive with the production
mechanism via the Drell-Yan subprocess. We give also quantitatively the
analysis of the effects from both the mass of sneutrino and coupling strength
of the R-parity violating interactions.Comment: 18 pages, 10 figures, accepted by Phys. Rev.
Continuous Spin Representations of the Poincar\'e and Super-Poincar\'e Groups
We construct Wigner's continuous spin representations of the Poincar\'e
algebra for massless particles in higher dimensions. The states are labeled
both by the length of a space-like translation vector and the Dynkin indices of
the {\it short little group} , where is the space-time dimension.
Continuous spin representations are in one-to-one correspondence with
representations of the short little group. We also demonstrate how combinations
of the bosonic and fermionic representations form supermultiplets of the
super-Poincar\'e algebra. If the light-cone translations are nilpotent, these
representations become finite dimensional, but contain zero or negative norm
states, and their supersymmetry algebra contains a central charge in four
dimensions.Comment: 19 page
Increased Yield of ttbb at Hadron Colliders in Low-Energy Supersymmetry
Light bottom squarks and gluinos have been invoked to explain the b quark
pair production excess at the Tevatron. We investigate the associated
production of ttbb at hadron colliders in this scenario, and find that the
rates for this process are enhanced over the Standard Model prediction. If
light gluinos exist, it may be possible to detect them at the Tevatron, and
they could easily be observed at the LHC.Comment: 5p, references added, version accepted to PR
Vegetation above a feral pig barrier fence in rain forests of Kilauea's East Rift, Hawaii Volcanoes National Park
Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.Immediately after the 1993 construction of a barrier fence to block the movements of feral pigs in forests of Kilauea's East Rift within Hawaii Volcanoes National Park (HAVO), a systematic framework of transects and plots was established for collection of baseline vegetation data upslope of the fence. Distribution and estimated abundance of the most invasive alien plant species were determined. The most widespread alien grass species was Hilo grass (Paspalum conjugatum); although it typically had low estimated cover values, this grass was almost ubiquitous. The most common invasive alien tree species was strawberry guava (Psidium cattleianum); it was found along transects in the western half of the study area, where its cover was estimated as 5-25% or 25-50%. Firetree (Myrica faya) occurred less frequently and had lower cover values than strawberry guava. Two other invasive woody species were found at low frequency or in limited areas; yellow Himalayan raspberry (Rubus ellipticus) was restricted to the slopes of Kane Nui o Hamo, and cane tibouchina (Tibouchina herbacea) occurred infrequently at widely scattered localities. Alien plant frequencies from the current survey were compared with those from a previous plant survey in 1988. A third of the alien plant species along transects, including firetree, yellow raspberry, and strawberry guava, had very similar frequencies on both surveys. Frequency of Hilo grass and scaly swordfern (Nephrolepis
multiflora) increased greatly in the study area between the two surveys. Some of the observed changes in vegetation may have been influenced by recent disturbance to the forests by cinder deposits from Pu'u '0'o, in an earlier phase of the current eruption. The locations of rare native plants were mapped along transects, and numbers were compared with those from the previous survey of 1988. The endangered pendent kihi fern (Adenophorus periens) was not relocated on Park transects; this species may have disappeared from the slopes of Kane Nui o Hamo in the last five years. Koli'i (Trematolobelia grandifolia), a "species of concern" has persisted on Kane Nui o Hamo, and its current size class structure indicates a stable population. The 12 rare plant species that were observed on East Rift transects were concentrated in several sites, including Kane Nui o Hamo, forests south and west of Napau crater, relatively open forest southeast of the 1840 flow, and the southwest corner of the study area near the Naulu Trail. Frequencies of 'oha (Clermontia spp.), indicator species for pig damage in Hawai'i, were relatively high overall in the study area, although the impact of pig predation was indicated by the paucity of terrestrial plants and a low freqeuncy of large Clermontia. Remonitoring a subset of transects after 1.5 years revealed that terrestrial Clermontia declined in frequency, while epiphytic plants increased over the same period. Tree fern density in the study area was 38/100m2, and the trunk height class of 1-2 m was well represented in East Rift forests. A higher density of tree ferns was observed in the western half of the study area, primarily due to the greater number of tree ferns >1m. There were fewer tree ferns on the lower halves of three main transects than were found on the upper reaches, farthest away from the barrier fence and upslope from uluhe-dominated forest. 'Olapa (Cheirodendron trigynum) appeared to be an inconsistent indicator species for pig activity. This important rain forest tree was maintaining a stable population in East Rift forests, despite the long-term presence of feral pigs there. Differences in 'olapa density were noted in the western versus the eastern, unprotected part of the study area, where lower numbers of terrestrial 'olapa saplings were seen. When compared with the upper transect reaches, fewer 'olapa saplings were found along the lower portions of the three main transects, in the area near the open end of the barrier fence. Vegetation cover and woody plant density of recently pig-disturbed sites were examined in 1994 using 39 vegetation plots, and a subset of 26 plots was remonitored 1.5-2 years later. The vegetation of disturbed East Rift forests was found to be poor in native woody plant species, and ground cover was very sparse. In the interval between monitoring, the cover of two alien species (Hilo grass and scaly swordfern) increased dramatically. Early succession indicates that these two plants will become dominant components of ground cover in pig-disturbed areas. Little change was noted in native woody plant density overall, but several native species, including tree ferns, displayed increases over the 1.5 year monitoring period. Feral pig density, estimated from frequency of pig activity, was low in the East Rift study area (averaging 1.9 pig/km2), even before systematic control efforts began. Quarterly pig activity monitoring revealed an increase in activity along Park transects until the end of 1993, followed by a steady decline to 2.4 pig/km2 by the end of the study in January 1996. Data from this study suggest that the park's snaring efforts reduced the feral pig population in the most protected, interior part of the forest upslope of the barrier fence within two years of the project initiation. Success in lowering pig density was not observed on transects at or beyond the open terminus of the barrier fence, indicating that pig ingress continued throughout the study. The current survey may only be considered a baseline study of vegetation and pig activity in managed East Rift forests. Future remonitoring may be needed to evaulate the success of this management effort in promoting long-term recovery of native vegetation.National Park Service Cooperative Agreement
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Primordial Gravitational Waves From Open Inflation
We calculate the spectrum of gravitational waves generated during inflation
in open inflationary models. In such models an initial epoch of
old inflation solves the horizon and flatness problems, and during this first
epoch of inflation the quantum state of the graviton field rapidly approaches
the Bunch-Davies vacuum. Then old inflation ends by the nucleation of a single
bubble, inside of which there is a shortened epoch of slow-roll inflation
giving today. In this paper we re-express the Bunch-Davies vacuum
for the graviton field in terms of the hyperbolic modes inside the bubble and
propagate these modes forward in time into the present era. We derive the
expression for the contribution from these gravity waves to the cosmic
microwave background anisotropy including the effect of a finite energy
difference across the bubble wall.Comment: 40 pages, TEX with phyzzx macro, 5 figure
Searches for Gravitational Waves from Binary Neutron Stars: A Review
A new generation of observatories is looking for gravitational waves. These
waves, emitted by highly relativistic systems, will open a new window for ob-
servation of the cosmos when they are detected. Among the most promising
sources of gravitational waves for these observatories are compact binaries in
the final min- utes before coalescence. In this article, we review in brief
interferometric searches for gravitational waves emitted by neutron star
binaries, including the theory, instru- mentation and methods. No detections
have been made to date. However, the best direct observational limits on
coalescence rates have been set, and instrumentation and analysis methods
continue to be refined toward the ultimate goal of defining the new field of
gravitational wave astronomy.Comment: 30 pages, 5 Figures, to appear in "Short-Period Binary Stars:
Observations, Analyses, and Results", Ed.s Eugene F. Milone, Denis A. Leahy,
David W. Hobil
Flight investigation of cockpit-displayed traffic information utilizing coded symbology in an advanced operational environment
Traffic symbology was encoded to provide additional information concerning the traffic, which was displayed on the pilot's electronic horizontal situation indicators (EHSI). A research airplane representing an advanced operational environment was used to assess the benefit of coded traffic symbology in a realistic work-load environment. Traffic scenarios, involving both conflict-free and conflict situations, were employed. Subjective pilot commentary was obtained through the use of a questionnaire and extensive pilot debriefings. These results grouped conveniently under two categories: display factors and task performance. A major item under the display factor category was the problem of display clutter. The primary contributors to clutter were the use of large map-scale factors, the use of traffic data blocks, and the presentation of more than a few airplanes. In terms of task performance, the cockpit-displayed traffic information was found to provide excellent overall situation awareness. Additionally, mile separation prescribed during these tests
Contribution of Long Wavelength Gravitational Waves to the CMB Anisotropy
We present an in depth discussion of the production of gravitational waves
from an inflationary phase that could have occurred in the early universe,
giving derivations for the resulting spectrum and energy density. We also
consider the large-scale anisotropy in the cosmic microwave background
radiation coming from these waves. Assuming that the observed quadrupole
anisotropy comes mostly from gravitational waves (consistent with the
predictions of a flat spectrum of scalar density perturbations and the measured
dipole anisotropy) we describe in detail how to derive a value for the scale of
inflation of GeV, which is at a particularly interesting
scale for particle physics. This upper limit corresponds to a 95\% confidence
level upper limit on the scale of inflation assuming only that the quadrupole
anisotropy from gravitational waves is not cancelled by another source. Direct
detection of gravitational waves produced by inflation near this scale will
have to wait for the next generation of detectors.Comment: (LaTeX 16 pages), 2 figures not included, YCTP-P16-9
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