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Related papers: Supersymmetric Models with Approximate CP

200 papers

We investigate the possible sizes of all the CP-violating asymmetries offered by the angular distribution of rare decay $\Lambda_b\rightarrow \Lambda(\to p \pi^-) \ell^+\ell^-$ in the Standard Model and new physics scenarios motivated by…

High Energy Physics - Phenomenology · Physics 2023-07-21 Diganta Das , Jaydeb Das , Girish Kumar , Niladribihari Sahoo

We consider spontaneous CP violation in the Next to Minimal Supersymmetric Standard Model (NMSSM), without the usual $Z_3$ discrete symmetry. CP violation can occur at tree level, raising a potential conflict with the experimental bounds on…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. T. Davies , C. D. Froggatt , A. Usai

In this talk I discuss CP violation in hyperon decays in Left-Right symmetric models. I show that the asymmetry in polarization in $\Lambda \to p\pi^-$ can be as large as $6\times 10^{-4}$ in these models, which is an order of magnitude…

High Energy Physics - Phenomenology · Physics 2016-09-01 Xiao-Gang He

We review the present status of CP violating problem in supersymmetric extensions of the standard model. We analyze the constraints imposed by the experimental limits of the electron, neutron, and mercury electric dipole moments on the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Shaaban Khalil

Simply based on CP arguments, we argue against a Standard Model explanation of the baryon asymmetry of the universe in the presence of a first order phase transition. A CP-asymmetry is found in the reflection coefficients of quarks hitting…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. B. Gavela , P. Hernández , J. Orloff , O. Pène

Recent improvements to the limit of Delta M_{B_s} imply that pure superweak theories, while not excluded, no longer provide a good fit to the data. A class of general superweak theories is introduced in which all flavor changing…

High Energy Physics - Phenomenology · Physics 2009-10-30 Riccardo Barbieri , Lawrence Hall , Achille Stocchi , Neal Weiner

Supersymmetric models with nonuniversal down type squark masses can enrich the chiral structure and CP violating phenomena in $b\to s\gamma$ decays. Direct CP violation in $b\to s \gamma$, mixing induced CP violation in radiative $B_{d,s}$…

High Energy Physics - Phenomenology · Physics 2016-08-25 Chun-Khiang Chua , Xiao-Gang He , Wei-Shu Hou

We have studied new CP violating effects in $\Lambda_b \to p \pi$ decay mode, that can arise in Minimal Supersymmetric Standard Model with R-parity violation. We have estimated how much R-parity violation modifies the Standard Model…

High Energy Physics - Phenomenology · Physics 2011-03-23 R. Mohanta

One common way to define spontaneous symmetry breaking involves explicit symmetry breaking. This definition can be used in any approach to Effective Field Theory, from perturbation theory to lattice simulations. It allows us to study the…

High Energy Physics - Phenomenology · Physics 2017-10-23 Leonardo Pedro

A spontaneously-broken CP provides an alternative to the KM mechanism for CP violation with the advantage that the strong CP problem is solved. We consider, for such a model with a new gauged U(1), the incorporation of low-energy…

High Energy Physics - Phenomenology · Physics 2009-10-30 Paul H. Frampton , Otto C. W. Kong

Solutions of the Strong CP Problem based on the spontaneous breaking of CP must feature a non-generic structure and simultaneously explain a coincidence between a priori unrelated CP-even and CP-odd mass scales. We show that these…

High Energy Physics - Phenomenology · Physics 2021-08-04 Alessandro Valenti , Luca Vecchi

The origin of CP violation is a major mystery, especially in relation to the strong CP problem. CP being a spontaneously broken symmetry could provide an elegant solution. However, such models have difficulty making themselves compatible…

High Energy Physics - Phenomenology · Physics 2007-05-23 Otto C. W. Kong

The observation of a sizable CP asymmetry in the inclusive decays B -> Xs gamma would be a clean signal of New Physics. In the Standard Model, this asymmetry is below 1 % in magnitude. In extensions of the Standard Model with new…

High Energy Physics - Phenomenology · Physics 2009-10-31 Matthias Neubert

CP violation in K and B decays is reviewed in the Standard Model (SM) and beyond the SM. In K decays, one is seeking first evidence for CP violation in direct $K\to \pi\pi$ decays. This would not give a precise quantitative test for the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Michael Gronau

We argue that the observation of a sizable direct CP asymmetry A_{CP} in the inclusive decays B -> X_s gamma would be a clean signal of New Physics. In the Standard Model, A_{CP} can be calculated reliably and is found to be below 1% in…

High Energy Physics - Phenomenology · Physics 2016-08-25 A. L. Kagan , M. Neubert

We find in theories with spontaneous P and CP violation that symmetries needed to set the tree level strong CP phase to zero can also set all non-zero tree level CP violating phases to the maximal value \pi / 2 in the symmetry basis…

High Energy Physics - Phenomenology · Physics 2012-09-27 Ravi Kuchimanchi

In the standard model, CP asymmetries in the $B^\pm \to \pi^\pm K$ channels are about 2% based on perturbative calculation. Rescattering effects might enhance it to at most (20-25)%. We show that lepton-number-violating $\lambda'$ couplings…

High Energy Physics - Phenomenology · Physics 2007-05-23 Gautam Bhattacharyya

The Supersymmetric Standard Model is a benchmark theoretical framework for particle physics, yet it suffers from a number of deficiencies, chief among which is the strong CP problem. Solving this with an axion in the context of selected new…

High Energy Physics - Phenomenology · Physics 2015-05-13 Ernest Ma

New CP violating physics in $b\to s$ transitions will modify the CP asymmetries in B decays into final CP eigenstates ($\phi K_S$, $\eta^\prime K_S$, $\pi^0 K_S$, $\omega K_S$, $\rho^0 K_S$ and $\eta K_S$) from their Standard Model values.…

High Energy Physics - Phenomenology · Physics 2009-11-11 Gerhard Buchalla , Gudrun Hiller , Yosef Nir , Guy Raz

We briefly comment on the question of spontaneous CP violation for several models of weak interactions. We focus on one of the minimal extensions of the Standard Model where spontaneous CP violation is viable,the next-to-minimal…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ana M. Teixeira