scholarly journals The Impact of Excited Neutrinos onνν¯→γγProcess

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
S. C. İnan ◽  
M. Köksal
Keyword(s):  
Standard Model ◽  
Ultrahigh Energy ◽  
The Standard Model ◽  
The Impact

We examine the effect of excited neutrinos on the annihilation of relic neutrinos with ultrahigh energy cosmic neutrinos for theνν¯→γγprocess. The contributions of the excited neutrinos to the neutrino-photon decoupling temperature are calculated. We see that photon-neutrino decoupling temperature can be significantly reduced below the obtained value of the Standard Model with the impact of excited neutrinos.

scholarly journals ULTRAHIGH ENERGY NEUTRINOS

2003 ◽  
Vol 18 (22) ◽  
pp. 4085-4096 ◽  
Author(s):  
SHARADA IYER DUTTA ◽  
MARY HALL RENO ◽  
INA SARCEVIC
Keyword(s):  
Black Hole ◽  
Standard Model ◽  
Cross Section ◽  
Neutrino Oscillations ◽  
Ultrahigh Energy ◽  
Nonstandard Model ◽  
Air Shower ◽  
Energy Neutrino ◽  
The Standard Model ◽  
Event Rates

The ultrahigh energy neutrino cross section is well understood in the standard model for neutrino energies up to 1012 GeV, Tests of neutrino oscillations (νμ ↔ ντ) from extragalactic sources of neutrinos are possible with large underground detectors. Measurements of horizontal air shower event rates at neutrino energies above 1010 GeV will be able to constrain nonstandard model contributions to the neutrino-nucleon cross section, e.g., from mini-black hole production.

A Note on Licenses in the Presence of Corruption

2017 ◽  
Vol 14 (3) ◽  
Author(s):  
Amy Farmer ◽  
Fabio Méndez ◽  
Andrew Samuel
Keyword(s):  
Standard Model ◽  
Regulatory Policies ◽  
The Standard Model ◽  
The Impact

Abstract We study the effectiveness of licenses in environments with corruption. We expand the standard model so that bribery is feasible not only when licenses are granted but also when enforced or verified. This modification alters many prior results on bribery and licensing significantly. Specifically, we show that in some cases penalties for bribery at the license-granting stage complement penalties for bribery at the permit-enforcement stage. In other cases, they act as substitutes for each other. These results are especially important for often used regulatory policies in which licenses are used in conjunction with some form of subsequent license verification. Thus, our model suggests that studying the impact of bribery at the license-granting stage should not be conducted without simultaneously studying bribery at the permit verification stage.

scholarly journals Flavor physics: Precision as an avenue to discovery

2020 ◽  
Vol 35 (01) ◽  
pp. 1930018
Author(s):  
Diego Guadagnoli
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
Flavor Physics ◽  
Standard Model Prediction ◽  
New Physics ◽  
Effective Theory ◽  
Theory Approach ◽  
Long Distance ◽  
The Standard Model ◽  
The Impact

This paper describes the work pursued in the years 2008–2013 on improving the Standard Model prediction of selected flavor-physics observables. The latter includes: (1) [Formula: see text], that quantifies indirect CP violation in the [Formula: see text] system and (2) the very rare decay [Formula: see text], recently measured at the LHC. Concerning point (1), the paper describes our reappraisal of the long-distance contributions to [Formula: see text],[Formula: see text] that have permitted to unveil a potential tension between CP violation in the [Formula: see text]- and [Formula: see text]-system. Concerning point (2), the paper gives a detailed account of various systematic effects pointed out in Ref. 4 and affecting the Standard Model [Formula: see text] decay rate at the level of 10% — hence large enough to be potentially misinterpreted as nonstandard physics, if not properly included. The paper further describes the multifaceted importance of the [Formula: see text] decays as new physics probes, for instance how they compare with [Formula: see text]-peak observables at LEP, following the effective-theory approach of Ref. 5. Both cases (1) and (2) offer clear examples in which the pursuit of precision in Standard Model predictions offered potential avenues to discovery. Finally, this paper describes the impact of the above results on the literature, and what is the further progress to be expected on these and related observables.

scholarly journals Testing lepton flavour universality with (semi)-leptonic $$\varvec{D_{(s)}}$$ decays

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
Robert Fleischer ◽  
Ruben Jaarsma ◽  
Gabriël Koole
Keyword(s):  
Standard Model ◽  
Branching Ratios ◽  
Current Data ◽  
Leptonic Decays ◽  
Independent Analysis ◽  
The Standard Model ◽  
Model Independent ◽  
Pseudo Scalar ◽  
The Impact ◽  
Lepton Flavour

Abstract Data in B-meson decays indicate violations of lepton flavour universality, thereby raising the question about such phenomena in the charm sector. We perform a model-independent analysis of NP contributions in (semi)-leptonic decays of $$D_{(s)}$$D(s) mesons which originate from $$c \rightarrow d \bar{{\ell }} \nu _l$$c→dℓ¯νl and $$c \rightarrow s \bar{{\ell }} \nu _{\ell }$$c→sℓ¯νℓ charged-current interactions. Starting from the most general low-energy effective Hamiltonian containing four-fermion operators and the corresponding short-distance coefficients, we explore the impact of new (pseudo)-scalar, vector and tensor operators and constrain their effects through the interplay with current data. We pay special attention to the elements $$|V_{cd}|$$|Vcd| and $$|V_{cs}|$$|Vcs| of the Cabibbo–Kobayashi–Maskawa matrix and extract them from the $$D_{(s)}$$D(s) decays in the presence of possible NP decay contributions, comparing them with determinations utilizing unitarity. We find a picture in agreement with the Standard Model within the current uncertainties. Using the results from our analysis, we make also predictions for leptonic $$D_{(s)}^+ \rightarrow e^+ \nu _e$$D(s)+→e+νe modes which could be hugely enhanced with respect to their tiny Standard Model branching ratios. It will be interesting to apply our strategy at the future high-precision frontier.

scholarly journals THE EFFECT OF ELECTROMAGNETIC PROPERTIES OF NEUTRINOS ON THE PHOTON–NEUTRINO DECOUPLING TEMPERATURE

2012 ◽  
Vol 27 (32) ◽  
pp. 1250187
Author(s):  
S. C. İNAN ◽  
M. KÖKSAL
Keyword(s):  
Lagrangian Model ◽  
Electromagnetic Properties ◽  
Beyond The Standard Model ◽  
Ultrahigh Energy ◽  
Qcd Phase Transition ◽  
Effective Lagrangian ◽  
Independent Analysis ◽  
The Standard Model ◽  
Model Independent ◽  
The Impact

We examine the impact of electromagnetic properties of neutrinos on the annihilation of relic neutrinos with ultrahigh energy cosmic neutrinos for the [Formula: see text] process. For this process, photon–neutrino decoupling temperature is calculated via effective Lagrangian model beyond the standard model. We find that photon–neutrino decoupling temperature can be importantly reduced below the QCD phase transition with the model independent analysis defining electromagnetic properties of neutrinos.

SEARCHING FOR AXIONS AND OTHER EXOTICS WITH DARK MATTER DETECTORS

2010 ◽  
Vol 25 (02n03) ◽  
pp. 564-572
Author(s):  
MAXIM POSPELOV
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Cold Dark Matter ◽  
Direct Detection ◽  
Annual Modulation ◽  
The Standard Model ◽  
Detection Capabilities ◽  
The Impact ◽  
Particle Decays ◽  
O 10

I consider models of light super-weakly interacting cold dark matter, with [Formula: see text] mass, focusing on bosonic candidates such as pseudoscalars and vectors. I analyze the cosmological abundance, the γ-background created by particle decays, the impact on stellar processes due to cooling, and the direct detection capabilities in order to identify classes of models that pass all the constraints. In certain models, variants of photoelectric (or axioelectric) absorption of dark matter in direct-detection experiments can provide a sensitivity to the superweak couplings to the Standard Model which is superior to all existing indirect constraints. In all models studied, the annual modulation of the direct-detection signal is at the currently unobservable level of O(10-5).

scholarly journals Precision Electroweak Data: Present Status and Future Prospects

1997 ◽  
Vol 12 (23) ◽  
pp. 4109-4154 ◽  
Author(s):  
Peter B. Renton
Keyword(s):  
Standard Model ◽  
Present Status ◽  
Model Parameters ◽  
Second Phase ◽  
Independent Variables ◽  
The Standard Model ◽  
Model Independent ◽  
The Impact ◽  
Precision Electroweak Data

The present status of precision electroweak data is reviewed. These data include LEP measurements of the mass and width of the Z, together with various measurements on the Z-fermion couplings. These data are compared to, and combined with, data from the SLC on the left–right polarized asymmetry, A LR , and the left–right forward–backward asymmetries for b and c quarks. These measurements are combined with hadron collider measurements from the Tevatron and CERN on the mass of the W boson, mW, as well as other electroweak data, in global electroweak fits in which various Standard Model parameters are determined. A comparison is made between the results of direct measurements of mW and the top-quark mass, mt, as determined from the Tevatron, with the indirect results coming from electroweak radiative corrections. Using all precision electroweak data, fits are also made to determine limits on the mass of the Higgs boson, mH. The influence on these limits of specific measurements, particularly those which are somewhat inconsistent with the Standard Model, is explored. The data are also analyzed in terms of the quasi model independent ∊ variables. Improvements in the determination of all of these quantities are expected when the Z data at LEP are fully analyzed, and further measurements on A LR and related asymmetries performed at the SLC. In addition, substantial improvements in the determination of mW are expected from measurements at the Tevatron and in the second phase of LEP. An estimate is made of the likely precision of these data, and the implications of the impact of these data on precision electroweak tests are discussed. This discussion is made both in terms of the Standard Model and also in the context of the quasi model independent ∊ variables.

scholarly journals Modelling the effect of denitrification on polar ozone depletion for Arctic winter/spring 2004/05

2011 ◽  
Vol 11 (2) ◽  
pp. 3857-3884 ◽  
Author(s):  
W. Feng ◽  
M. P. Chipperfield ◽  
S. Davies ◽  
G. W. Mann ◽  
K. S. Carslaw ◽  
...  
Keyword(s):  
Standard Model ◽  
Ozone Depletion ◽  
Transport Model ◽  
The Arctic ◽  
Chemical Transport Model ◽  
Particle Sedimentation ◽  
Ozone Loss ◽  
The Standard Model ◽  
The Impact ◽  
Polar Ozone

Abstract. A three-dimensional (3-D) chemical transport model (CTM), SLIMCAT, has been used to quantify the effect of denitrification on ozone loss for the Arctic winter/spring 2004/05. The simulated HNO3 is found to be highly sensitive to the polar stratospheric cloud (PSC) scheme used in the model. Here the standard SLIMCAT full chemistry model, which uses a thermodynamic equilibrium PSC scheme, overpredicts the Arctic ozone loss for Arctic winter/spring 2004/05 due to the overestimation of denitrification and stronger chlorine activation than observed. A model run with a detailed microphysical denitrification scheme, DLAPSE (Denitrification by Lagrangian Particle Sedimentation), is less denitrified than the standard model run and better reproduces the observed HNO3 as measured by Airborne SUbmillimeter Radiometer (ASUR) and Aura Microwave Limb Sounder (MLS) instruments. The overestimated denitrification causes a small overestimation of Arctic polar ozone loss (~5–10% at ~17 km) by the standard model. Use of the DLAPSE scheme improves the simulation of Arctic ozone depletion compared with the inferred partial column ozone loss from ozonesondes and satellite data. Overall, denitrification is responsible for a ~30% enhancement in O3 depletion for Arctic winter/spring 2004/05, suggesting that the successful simulation of the impact of denitrification on Arctic ozone depletion also requires the use of a detailed microphysical PSC scheme in the model.

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