scholarly journals Spiral Galaxies rotation curves with renormalization group effects to gravity

2013 ◽  
Author(s):  
PAULO LOUZADA CASTRO DE OLIVEIRA
Keyword(s):  
Renormalization Group ◽  
Spiral Galaxies ◽  
Rotation Curves ◽  
Group Effects

scholarly journals Another SMEFT story: Z′ facing new results on ε′/ε, ∆MK and K → $$ \pi \nu \overline{\nu} $$

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Jason Aebischer ◽  
Andrzej J. Buras ◽  
Jacky Kumar
Keyword(s):  
Renormalization Group ◽  
Mass Difference ◽  
Branching Ratios ◽  
New Physics ◽  
Matrix Elements ◽  
Isospin Breaking ◽  
Left Handed ◽  
The Standard Model ◽  
First Time ◽  
Group Effects

Abstract Recently the RBC-UKQCD lattice QCD collaboration presented new results for the hadronic matrix elements relevant for the ratio ε′/ε in the Standard Model (SM) albeit with significant uncertainties. With the present knowledge of the Wilson coefficients and isospin breaking effects there is still a sizable room left for new physics (NP) contributions to ε′/ε which could both enhance or suppress this ratio to agree with the data. The new SM value for the K0 − $$ {\overline{K}}^0 $$ K ¯ 0 mass difference ∆MK from RBC-UKQCD is on the other hand by 2σ above the data hinting for NP required to suppress ∆MK. Simultaneously the most recent results for K+ → $$ {\pi}^{+}\nu \overline{\nu} $$ π + ν ν ¯ from NA62 and for KL → $$ {\pi}^0\nu \overline{\nu} $$ π 0 ν ν ¯ from KOTO still allow for significant NP contributions. We point out that the suppression of ∆MK by NP requires the presence of new CP-violating phases with interesting implications for K → $$ \pi \nu \overline{\nu} $$ πν ν ¯ , KS → μ+μ− and KL → π0ℓ+ℓ− decays. Considering a Z′-scenario within the SMEFT we analyze the dependence of all these observables on the size of NP still allowed by the data on ε′/ε. The hinted ∆MK anomaly together with the εK constraint implies in the presence of only left-handed (LH) or right-handed (RH) flavour-violating Z′ couplings strict correlation between K+ → $$ {\pi}^{+}\nu \overline{\nu} $$ π + ν ν ¯ and KL → $$ {\pi}^0\nu \overline{\nu} $$ π 0 ν ν ¯ branching ratios so that they are either simultaneously enhanced or suppressed relative to SM predictions. An anticorrelation can only be obtained in the presence of both LH and RH couplings. Interestingly, the NP QCD penguin scenario for ε′/ε is excluded by SMEFT renormalization group effects in εK so that NP effects in ε′/ε are governed by electroweak penguins. We also investigate for the first time whether the presence of a heavy Z′ with flavour violating couplings could generate through top Yukawa renormalization group effects FCNCs mediated by the SM Z-boson. The outcome turns out to be very interesting.

scholarly journals Rotation Curves in the Outer Parts of Galaxies from HI Observations

1978 ◽  
Vol 77 ◽  
pp. 23-31 ◽  
Author(s):  
Edwin E. Salpeter
Keyword(s):  
Spiral Galaxies ◽  
Rotation Curves ◽  
Flat Rotation Curves ◽  
Arecibo Observatory

21cm observations at the Arecibo Observatory for 9 edge-on spiral galaxies are described. Flat rotation curves are found in most cases.

scholarly journals The Massive Dark Corona Of Our Galaxy

1996 ◽  
Vol 173 ◽  
pp. 175-176
Author(s):  
K.C. Freeman
Keyword(s):  
Rotation Curve ◽  
Spiral Galaxies ◽  
Galactic Center ◽  
Galactic Disk ◽  
Galactic Rotation ◽  
Rotation Curves ◽  
Stellar Component ◽  
The Galaxy ◽  
Galactic Rotation Curve

From their rotation curves, most spiral galaxies appear to have massive dark coronas. The inferred masses of these dark coronas are typically 5 to 10 times the mass of the underlying stellar component. I will review the evidence that our Galaxy also has a dark corona. Our position in the galactic disk makes it difficult to measure the galactic rotation curve beyond about 20 kpc from the galactic center. However it does allow several other indicators of the total galactic mass out to very large distances. It seems clear that the Galaxy does indeed have a massive dark corona. The data indicate that the enclosed mass within radius R increases like M(R) ≈ R(kpc) × 1010M⊙, out to a radius of more than 100 kpc. The total galactic mass is at least 12 × 1011M⊙.

scholarly journals Comparison between two scalar field models using rotation curves of spiral galaxies

2018 ◽  
Vol 1010 ◽  
pp. 012005 ◽  
Author(s):  
Lizbeth M. Fernández-Hernández ◽  
Mario A. Rodríguez-Meza ◽  
Tonatiuh Matos
Keyword(s):  
Scalar Field ◽  
Spiral Galaxies ◽  
Rotation Curves ◽  
Scalar Field Models

Magnetic fields as an alternative explanation for the rotation curves of spiral galaxies

Nature ◽  
1992 ◽  
Vol 360 (6405) ◽  
pp. 652-653 ◽  
Author(s):  
E. Battaner ◽  
J. L. Garrido ◽  
M. Membrado ◽  
E. Florido
Keyword(s):  
Magnetic Fields ◽  
Alternative Explanation ◽  
Spiral Galaxies ◽  
Rotation Curves

Extended rotation curves of high-luminosity spiral galaxies. III - The spiral galaxy NGC 7217

1978 ◽  
Vol 226 ◽  
pp. 770 ◽  
Author(s):  
C. J. Peterson ◽  
M. S. Roberts ◽  
V. C. Rubin ◽  
W. K., Jr. Ford
Keyword(s):  
Spiral Galaxy ◽  
Spiral Galaxies ◽  
High Luminosity ◽  
Rotation Curves
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