| 1. |
- Ahmady, M R, et al.
(författare)
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ESTIMATING THE ANNIHILATION DECAY B-s -> rho gamma WITH FACTORIZATION
- 2009
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Ingår i: Modern Physics Letters A. - 0217-7323 .- 1793-6632. ; 24:39, s. 3173-3181
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Tidskriftsartikel (refereegranskat)abstract
- The branching ratio for the rare two-body B-s -> rho gamma decay is calculated using the factorization assumption. This transition is dominated by the annihilation diagrams and, in principle, prone to receiving substantial contributions from new physics. We estimate Br(B-s -> rho gamma) approximate to 1.6 x 10(-9) within the Standard Model and investigate the sensitivity of this decay mode to the effects of two new physics scenarios: vector quark model and supersymmetry. Our results indicate that the shift in branching ratio is at most around 10% with the addition of vector quarks and is negligibly small in the constrained minimal supersymmetric extension of the Standard Model.
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| 2. |
- Alfaro, J, et al.
(författare)
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BRST formulation of partition function constraints
- 1997
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Ingår i: MODERN PHYSICS LETTERS A. - : WORLD SCIENTIFIC PUBL CO PTE LTD. - 0217-7323. ; 12:15, s. 1119-1126
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We show that the constraints on the generating functional have direct BRST-extensions in terms of nilpotent operators Delta that annihilate this generating functional, and which may be of arbitrarily high order. The free energy F in the presence of extern
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| 3. |
- Assie, M., et al.
(författare)
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Neutron correlations in 6He viewed through nuclear break-up
- 2010
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Ingår i: Modern Physics Letters A. - 0217-7323 .- 1793-6632. ; 25:21-23, s. 1846-1849
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Tidskriftsartikel (refereegranskat)abstract
- Nuclear break-up as a tool to study neutron correlations is investigated both theoretically and experimentally. First a time dependent theory going beyond mean field has been developed and shows that correlations between nucleons can be probed through nuclear break-up. Secondly, nuclear break-up of He-6 on Pb-208 target was studied at 20 A.MeV using a secondary beam of He-6 produced by the SPIRAL facility at GANIL. From the correlation function, a strong contribution of the di-neutron configuration of He-6 is found.
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| 4. |
- Aydemir, Ufuk, et al.
(författare)
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The 750 GeV diphoton excess in unified SU(2)(L) x SU(2)(R) x SU(4) models from noncommutative geometry
- 2016
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Ingår i: Modern Physics Letters A. - 0217-7323 .- 1793-6632. ; 31:18
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Tidskriftsartikel (refereegranskat)abstract
- We discuss a possible interpretation of the 750 GeV diphoton resonance, recently reported at the large hadron collider (LHC), within a class of SU(2)(L) x SU(2)(R) x SU(4) models with gauge coupling unification. The unification is imposed by the underlying noncommutative geometry (NCG), which in these models is extended to a left-right symmetric completion of the Standard Model (SM). Within such unified SU(2)(L) x SU(2)(R) x SU(4) models the Higgs content is restrictively determined from the underlying NCG, instead of being arbitrarily selected. We show that the observed cross-sections involving the 750 GeV diphoton resonance could be realized through a SM singlet scalar field accompanied by colored scalars, present in these unified models. In view of this result, we discuss the underlying rigidity of these models in the NCG framework and the wider implications of the NCG approach for physics beyond the SM.
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| 5. |
- Bengtsson, Ingemar, et al.
(författare)
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Black holes : Their large interiors
- 2015
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Ingår i: Modern Physics Letters A. - 0217-7323 .- 1793-6632. ; 30:21
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Tidskriftsartikel (refereegranskat)abstract
- Christodoulou and Rovelli (CR) have remarked on the large interiors possessed by static black holes. We amplify their remarks, and extend them to the spinning case.
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| 6. |
- Bijnens, Johan, et al.
(författare)
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The Hadronic Light-by-Light Contribution to the Muon Anomalous Magnetic Moment: Where do we stand?
- 2007
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Ingår i: Modern Physics Letters A. - 0217-7323. ; 22, s. 767-782
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Forskningsöversikt (refereegranskat)abstract
- We review the status of the hadronic light-by-light contribution to the muon anomalous magnetic moment and critically compare recent calculations. We also study in detail which momentum regions the pi0 exchange main contribution originates. We also argue that amu{light-by-light} = (11 pm 4) times 10-10 encompasses the present understanding of this contribution and comment on some directions to improve on that.
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| 7. |
- Brink, Lars, 1943
(författare)
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Maximal supersymmetry and exceptional groups
- 2010
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Ingår i: Modern Physics Letters A. - 0217-7323. ; 25:32, s. 2715-2725, s. 262-272
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Tidskriftsartikel (refereegranskat)abstract
- The article is a tribute to my old mentor, collaborator and friend Murray Gell-Mann. In it I describe work by P. Ramond, S.-S. Kim and myself where we describe the N = 8 supergravity in the light-cone formalism. We show how the Cremmer-Julia E-7(7) nonlinear symmetry is implemented and how the full supermultiplet is a representation of the E-7(7) symmetry. I also show how the E-7(7) symmetry is a key to understand the higher order couplings in the theory and is very useful when we discuss possible counterterms for this theory.
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| 8. |
- Cederwall, Martin, 1961
(författare)
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D=11 supergravity with manifest supersymmetry
- 2010
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Ingår i: Modern Physics Letters A. - 0217-7323. ; 25:38, s. 3201-3212
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Tidskriftsartikel (refereegranskat)abstract
- The complete supersymmetric action for eleven-dimensional supergravity is presented. The action is polynomial in the scalar fermionic pure spinor superfield, and contains only a minor modification to the recently proposed three-point coupling.
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| 9. |
- DALARSSON, N
(författare)
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PHASE-INTEGRAL APPROACH TO THE WAVE-EQUATION OF THE UNIVERSE
- 1995
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Ingår i: MODERN PHYSICS LETTERS A. - : WORLD SCIENTIFIC PUBL CO PTE LTD. - 0217-7323. ; 10:33, s. 2495-2500
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We apply the phase-integral method to the Wheeler-DeWitt equation in a closed Friedmann-Robertson-Walker (FRW) model for the simple minisuperspace, where the only degree of freedom is that of the scale factor R of the closed homogeneous and isotropic univ
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| 10. |
- Deser, S., et al.
(författare)
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Problems of massive gravities
- 2015
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Ingår i: Modern Physics Letters A. - 0217-7323 .- 1793-6632. ; 30:3-4
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Tidskriftsartikel (refereegranskat)abstract
- The method of characteristics is a key tool for studying consistency of equations of motion; it allows issues such as predictability, maximal propagation speed, superluminality, unitarity and acausality to be addressed without requiring explicit solutions. We review this method and its application to massive gravity (mGR) theories to show the limitations of these models' physical viability: Among their problems are loss of unique evolution, superluminal signals, matter coupling inconsistencies and micro-acausality (propagation of signals around local closed time-like curves (CTCs)/closed causal curves (CCCs)). We extend previous no-go results to the entire three-parameter range of mGR theories. It is also argued that bimetric models suffer a similar fate.
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