How broad is a neutrino? Banks, Hannah; Kelly, Kevin J.; McCullough, Matthew
The journal of high energy physics,
02/2023, Letnik:
2023, Številka:
2
Journal Article
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A
bstract
Canonical neutrino oscillations arise due to the propagation of three mass eigenstates from production to detection. We aspire to capture, in one simple framework, a broad range of new ...physics effects on neutrino propagation beyond this canonical picture — this can be done by promoting the neutrino propagators to the general Källén-Lehmann form. In this work we demonstrate how models predicting additional light propagating species of neutrino are naturally accommodated in this language and propose a simple model spectrum composed of just three ‘broadened’ states as a flexible ansatz by which to explore the phenomenology of new physics in neutrino propagation. Reinterpreting existing neutrino oscillation measurements, we illustrate how this framework provides the capacity to probe deviations from the standard three-neutrino scenario systematically and generally. Whilst current data allows for relatively strong constraints on broadened neutrinos, we find the upcoming JUNO experiment will yield significant improvements, particularly for the heaviest neutrino, paving the way to a clearer understanding of how neutrinos propagate in vacuum.
A
bstract
Significant evidence exists for the apparent disappearance of electron-type neutrinos in radioactive source experiments. Yet, interpreted within the standard ‘3+1 sterile neutrino ...scenario’, precision short-baseline measurements of electron antineutrinos from nuclear reactors strongly disagree with these results. Recently, it has been demonstrated that allowing for a finite wavepacket size for the reactor neutrinos can ameliorate such a tension, however the smallness of the required wavepackets is a subject of intense debate. In this work, we demonstrate that a ‘broad’ sterile neutrino may relax this tension in much the same way. Such a phenomenological possibility can arise in plausible hidden sector scenarios, such as a clockwork-style sector, for which we provide a concrete microscopic model.
Living organisms can use minute structures to manipulate the reflection of light and display colours based on interference. There has been debate in recent literature over whether the diffractive ...optical effects produced by epoxy replicas of petals with folded cuticles persist and induce iridescence in the original flowers when the effects of petal pigment and illumination are taken into account.
We explored the optical properties of the petal of Hibiscus trionum by macro-imaging, scanning and transmission electron microscopy, and visible and ultraviolet (UV) angle-resolved spectroscopy of the petal.
The flower of Hibiscus trionum is visibly iridescent, and the iridescence can be captured photographically. The iridescence derives from a diffraction grating generated by folds of the cuticle. The iridescence of the petal can be quantitatively characterized by spectrometric measurements with several square-millimetres of sample area illuminated.
The flower of Hibiscus trionum has the potential to interact with its pollinators (honeybees, other bees, butterflies and flies) through iridescent signals produced by its cuticular diffraction grating.
Croton scarciesii (Euphorbiaceae-Crotonoideae), a rheophytic shrub from West Africa, is shown to have been misplaced in Croton for 120 years, having none of the diagnostic characters of that genus, ...but rather a set of characters present in no known genus of the family. Pollen analysis shows that the new genus Karima belongs to the inaperturate crotonoid group. Analysis of a concatenated molecular dataset combining trnL-F and rbcL sequences positioned Karima as sister to Neoholstia from south eastern tropical Africa in a well-supported clade comprised of genera of subtribes Grosserineae and Neoboutonieae of the inaperturate crotonoid genera. Several morphological characters support the relationship of Karima with Neoholstia, yet separation is merited by numerous characters usually associated with generic rank in Euphorbiaceae. Quantitative ecological data and a conservation assessment supplement illustrations and descriptions of the taxon.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Charting the fifth force landscape Banks, Hannah; McCullough, Matthew
Physical review. D,
04/2021, Letnik:
103, Številka:
7
Journal Article
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Fifth forces arising from hidden sector scalar operator exchange, as probed in a variety of present and planned experiments, can be captured by a general dispersion relation involving one real, ...positive, spectral density function. Previously considered scalar fifth forces, from tree-level to more exotic loop-level possibilities, are derived in this formalism, without explicitly performing conventional loop calculations. A variety of experimental observables commonly used in fifth force searches are also presented in the same formalism, allowing the straightforward extraction of limits on any specific model. The speculative possibility of probing hidden sector violations of unitarity, causality, or locality, manifested as a breakdown of the positivity of the spectral density, is also discussed.
Harry Styles is one of the most popular faces in the music industry, yet the scholarly discourse around him is lacking. Perhaps he is seen to be not worthy of study given his 'artificial' beginnings ...in a boy band created for the X Factor. However, the evolution of Styles has been a complex journey and his current presentation of fluid masculinity and fashion, undefined sexuality, and political activation, seem to demonstrate an original self. This article is a counter claim to the many ways that Styles has been constructed, instead presenting him as a cultural figure worthy of study. The discussion also contains discourse about the phenomenon and gender performance of boy bands, to explore Styles's evolution from a teenage heartthrob in chinos and polo shirts in 2010, to becoming the 2019 host of the Met Gala in a sheer blouse, heeled boots, and a pearl earring.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
For much of the last thirty years, the caesalpinioid genus Bauhinia has been recognised by numerous authors as a broadly circumscribed, ecologically, morphologically and palynologically diverse ...pantropical taxon, comprising several subgenera. One of these, Bauhinia subg. Phanera has recently been reinstated at generic rank based on a synthesis of morphological and molecular data. Nevertheless, there remains considerable diversity within Phanera. Following a review of palynological and molecular studies of Phanera in conjunction with a careful re-examination of the morphological heterogeneity within the genus, we have found strong evidence that the species of Phanera subsect. Corymbosae are a natural group that warrant generic status. We describe here the genus Cheniella R.Clark & Mackinder gen. nov. to accommodate them. It comprises 10 species and 3 subspecies, one newly described here. Generic characters include leaves that are simple and emarginate or bilobed; flowers with elongate hypanthia which are as long as or much longer than the sepals; pods that are glabrous, compressed, oblong, indehiscent or tardily dehiscent; and with numerous seeds, the seeds bearing an unusually long funicle extending most of the way around their circumference. A further distinctive floral character was found to be a fleshy disc on which the staminodes are mounted. An analysis carried out for this study reveals Cheniella to be characterised by a pollen type that is unique to the genus and previously unknown in the Leguminosae. Species diversity is richest in southern China, the full distribution extending westward to India and south- and eastward through Indochina into Malesia.
The Third Family Hypercharge Model predicts a Formula omitted gauge boson with flavour dependent couplings which has been used to explain anomalies in meson decay processes which involve the Formula ...omitted transition. The model predicts that a TeV-scale Formula omitted should decay to particle-antiparticle pairs of muons, taus, top quarks and bottom quarks with appreciable branching ratios. We reinterpret various ATLAS and CMS search limits for Formula omitted production followed by such decays at the LHC over a parameter space of the model that results from a successful combined fit to the Formula omitted data and precision electroweak observables. Current exclusions in parameter space and expected sensitivities of the various different channels in the high-luminosity run are compared. We find that the high-luminosity run of the LHC will significantly increase the sensitivity to the model beyond the existing empirical limits, which we find to be surprisingly weak.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract The Third Family Hypercharge Model predicts a $$Z^\prime $$ Z ′ gauge boson with flavour dependent couplings which has been used to explain anomalies in meson decay processes which involve ...the $$b\rightarrow s\mu ^+\mu ^-$$ b → s μ + μ - transition. The model predicts that a TeV-scale $$Z^\prime $$ Z ′ should decay to particle-antiparticle pairs of muons, taus, top quarks and bottom quarks with appreciable branching ratios. We reinterpret various ATLAS and CMS search limits for $$Z^\prime $$ Z ′ production followed by such decays at the LHC over a parameter space of the model that results from a successful combined fit to the $$b\rightarrow s l^+ l^-$$ b → s l + l - data and precision electroweak observables. Current exclusions in parameter space and expected sensitivities of the various different channels in the high-luminosity run are compared. We find that the high-luminosity run of the LHC will significantly increase the sensitivity to the model beyond the existing empirical limits, which we find to be surprisingly weak.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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