"Criticar já é distinguir"

Gabrielli, Beatriz

doi:10.47749/t/unicamp.2018.1060959

Cited by 5 publications

(7 citation statements)

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“…However the excluded regions in the m LQ and λ 1i LQ λ 2i LQ plane could be analyzed, for example, by means of contour plots. A complete study for this scenario will be presented elsewhere [28].…”

Section: Numerical Results For the Boundsmentioning

confidence: 99%

Model-independent constraints on leptoquarks from rareμandτlepton processes

Gabrielli

2000

Phys. Rev. D

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We perform a model independent analysis so as to constrain the leptoquark (LQ) models from negative searches for µ → eγ, µ → 3e decays (and analogous processes in the τ sector), and coherent µ − e conversion in nuclei. We considerably improve some constraints obtained by analyses known in the literature, analyses which we show have by far underestimated the LQ contributions to the µ → 3e. In particular we find that the coherent µ − e conversion in nuclei mediated by the photon-conversion mechanism and the µ → 3e decay are golden plates where the flavor changing leptoquark couplings, involving the second and third quark generations, can be strongly constrained. This is due to the fact that these processes get the enhancements by large log(m 2 q /m 2 LQ ) terms which are induced by the so-called "photon-penguin" diagrams. These enhancements, which produce a mild GIM suppression in the amplitudes, have not been taken into account in the previous analyses. We show that the µ → eγ decay can set weaker constraints on the LQ models and this is because its amplitude is strongly GIM suppressed by the terms of order O(m 2 q /m 2 LQ ). We also present the results for the corresponding constraints in the τ sector. Finally the prospects of the future muon experiments for the improvement of the present bounds are analyzed and discussed.

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Section: Numerical Results For the Boundsmentioning

confidence: 99%

Model-independent constraints on leptoquarks from rareμandτlepton processes

Gabrielli

2000

Phys. Rev. D

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“…It is interesting to check whether UHE photon propagation could be affected by the presence of axions or scalar bosons. The formal requirements for photon-axion conversion regarding photon energy and magnetic field strength, appear to be fulfilled [35,36]. Photon conversions to non-electromagnetic channels may differ from the standard QED process due to an absence of electromagnetic sub-cascade.…”

Section: Possible Impact Of Uhe Photon Searchesmentioning

confidence: 99%

Review of the Multimessenger Working Group at UHECR-2012

Álvarez-Muñiz

Risse

Рубцов

et al. 2013

EPJ Web of Conferences

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The current status of searches for ultra-high energy neutrinos and photons using air showers is reviewed. Regarding both physics and observational aspects, possible future research directions are indicated. Introduction1 What is the status of searches for ultra-high energy neutrinos and photons using air showers? What 2 might be the future prospects, in particular in the next couple of years? What is (are) the physics 3 case(s) for multimessenger observations, and what are the observational experiences and challenges? 4 These questions may summarize the main objective of the Multimessenger Working Group that was 5 formed, together with four other Working Groups, a few months before the UHECR-2012 sympo-6 sium. At this symposium, possible future directions of the field of ultra-high energy cosmic rays were 7 discussed, bringing the major collaborations from air-shower experiments as well as colleagues from 8 theory together. 9Given this objective, one can think of many issues to inspect. In particular, one can compare neutri-10 nos versus photons; neutrinos and photons versus charged cosmic rays; air shower observations versus 11 other techniques; shower observations from ground versus those from space; ground shower tech-12 niques versus each other; current data versus models; various models versus each other; and, above 13 all, the present status versus future directions. Given these many aspects in a highly dynamic field, it 14 is evident this review does not claim to be complete, or even finished. Rather, certain considerations 15 of possible relevance to the aim of the symposium are compiled and highlighted. 16 We start with both neutrinos and photons before each one is examined individually. 17 2 UHE Neutrinos and photons 18 Multimessenger observations are a key ingredient for discovering and for better understanding various 19 phenomena in the Universe. Boosted by the invention of the telescope about 400 years ago, photon 20observations cover now an impressive energy range from radio wavelengths up to about 100 TeV. The 21 discovery of (charged) cosmic rays dates back (at the time of writing these proceedings quite precisely) 22 100 years ago, with cosmic rays being measured now from sub-GeV to more than 100 EeV in energy. 23First non-terrestrial neutrinos were observed about 40 years ago, in the MeV energy range. 24 Various efforts are underway for opening new observational windows to the Universe and for 25 deeper observations of already accessible energy regimes of the different particle types. Examples of 26 significant discoveries in new windows are the cosmic microwave background or gamma-ray bursts 27 arXiv:1306.4199v1 [astro-ph.HE] 18 Jun 2013 EPJ Web of Conferencesfor the case of photon messengers, the muon for the case of cosmic-ray messengers via the air show-28 ers they produce, or the discovery of neutrinos from SN 1987A in the case of neutrino messengers. 29Two things can be seen from this small list. Firstly, some of the discoveries were not expected or 30 predicted beforehand; they gave t...

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“…supersymmetric seesaw mechanism model [22], R-parity violating SUSY [23], the CMSSMseesaw and NUHM-seesaw [24]. Within an effective field theory framework, the predictions on BR(τ → P l) or constraints from these LFV decays on the Wilson coefficients of LFV operators are studied [11,[25][26][27][28][29][30][31][32][33][34]. An overview on status of τ physics can be found in Ref.…”

Section: Decaymentioning

confidence: 99%

Searching for lepton flavor violating decays tau to Pl in Minimal R-symmetric Supersymmetric Standard Model

Sun,

Guo,

et al. 2020

Preprint

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Considering the constraints from the experimental data on branching ratios of τ → eγ and τ → µγ, we analyze the lepton flavor violating decays τ → P l (P = π 0 , η, η ; l = e, µ) in the scenario of the minimal R-symmetric supersymmetric standard model. The numerical results show that the theoretical predictions on branching ratios of τ → P l can be enhanced close to the upper experimental bounds or future sensitivities, meanwhile the theoretical predictions on branching ratios of τ → eγ and τ → µγ satisfy the present experimental bounds.

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"Criticar já é distinguir"

Cited by 5 publications

References 0 publications

Model-independent constraints on leptoquarks from rareμandτlepton processes

Model-independent constraints on leptoquarks from rareμandτlepton processes

Review of the Multimessenger Working Group at UHECR-2012

Searching for lepton flavor violating decays tau to Pl in Minimal R-symmetric Supersymmetric Standard Model

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