Search results for "VIOLATION"
showing 10 items of 540 documents
Unitarity Triangle from CP invariant quantities
2006
We construct the CKM unitarity triangle from CP invariant quantities, using the coupling constant of weak decays with flavor change from b to u, and the particle - antiparticle mixing probability in the B_s and B_d systems. Also included are new measurements of the coupling V_us in Kaon decays. Of the two solutions, one agrees perfectly with the triangle constructed from CP violating processes in the K and B meson systems. The common solution yields a triangle with an area of J/2 = (1.51 +/- 0.09) x 10^{-5} and a CP violating phase gamma = 63.1^o +/- 4.0^o.
Radiative Kaon decays and CP violation in chiral perturbation theory
1988
38 páginas, 11 figuras, 2 tablas.-- CERN-TH-4853-87 ; UWTHPH-1987-31.
Top quark anomalous tensor couplings in the two-Higgs-doublet models
2013
We compute the one loop right and left anomalous tensor couplings (g(R) and g(L), respectively) for the top quark, in the aligned two-Higgs-doublet model. They are the magnetic-like couplings in the most general parameterization of the tbW vertex. We find that the aligned two-Higgs doublet model, that includes as particular cases some of the most studied extensions of the Higgs sector, introduces new electroweak contribution's and provides theoretical predictions that are very sensitive to both new scalar masses and the neutral scalar mixing angle. For a largo area in the parameters space we obtain significant deviations in both the real and the imaginary parts of the couplings gR and gL, c…
Translational dynamics effects on the non-local correlations between two atoms
2005
A pair of atoms interacting successively with the field of the same cavity and exchanging a single photon, leave the cavity in an entangled state of Einstein-Podolsky-Rosen (EPR) type (see, for example, [S.J.D. Phoenix, and S.M. Barnett, J. Mod. Opt. \textbf{40} (1993) 979]). By implementing the model with the translational degrees of freedom, we show in this letter that the entanglement with the translational atomic variables can lead, under appropriate conditions, towards the separability of the internal variables of the two atoms. This implies that the translational dynamics can lead, in some cases, to difficulties in observing the Bell's inequality violation for massive particles.
Delta M_K and epsilon_K in SUSY at the Next-to-Leading order
1998
We perform a Next-to-Leading order analysis of Delta S=2 processes beyond the Standard Model. Combining the recently computed NLO anomalous dimensions and the B parameters of the most general Delta S=2 effective Hamiltonian, we give an analytic formula for Delta M_K and epsilon_K in terms of the Wilson coefficients at the high energy scale. This expression can be used for any extension of the Standard Model with new heavy particles. Using this result, we consider gluino-mediated contributions to Delta S=2 transitions in general SUSY models and provide an improved analysis of the constraints on off-diagonal mass terms between the first two generations of down-type squarks. Finally, we improv…
Testing for new physics with low-energy anti-neutrino sources: LAMA as a case study
1998
Some electroweak models with extended neutral currents, such as those based on the $E_6$ group, lead to an increase of the $\bar{\nu}-e$ scattering cross section at energies below 100 keV. We propose to search for the heavy Z' boson contribution in an experiment with a high-activity artificial neutrino source and with a large-mass detector. We present the case for the LAMA experiment with a large NaI(Tl) detector located at the Gran Sasso underground laboratory. The neutrino flux is known to within a one percent accuracy, in contrast to the reactor case and one can reach lower neutrino energies. Both features make our proposed experiment more sensitive to extended gauge models, such as the …
Sensitivity of the Cherenkov Telescope Array for probing cosmology and fundamental physics with gamma-ray propagation
2021
Full list of authors: Abdalla, H.; Abe, H.; Acero, F.; Acharyya, A.; Adam, R.; Agudo, I; Aguirre-Santaella, A.; Alfaro, R.; Alfaro, J.; Alispach, C.; Aloisio, R.; Batista, R. Alves; Amati, L.; Amato, E.; Ambrosi, G.; Anguner, E. O.; Araudo, A.; Armstrong, T.; Arqueros, F.; Arrabito, L.; Asano, K.; Ascasibar, Y.; Ashley, M.; Backes, M.; Balazs, C.; Balbo, M.; Balmaverde, B.; Baquero Larriva, A.; Martins, V. Barbosa; Barkov, M.; Baroncelli, L.; de Almeida, U. Barres; Barrio, J. A.; Batista, P-, I; Becerra Gonzalez, J.; Becherini, Y.; Beck, G.; Tjus, J. Becker; Belmont, R.; Benbow, W.; Bernardini, E.; Berti, A.; Berton, M.; Bertucci, B.; Beshley, V; Bi, B.; Biasuzzi, B.; Biland, A.; Bissaldi, …
Violation of the equivalence principle from light scalar dark matter
2018
In this paper, we study the local observational consequences of a violation of the Einstein Equivalence Principle induced by models of light scalar Dark Matter (DM). We focus on two different models where the scalar field couples linearly or quadratically to the standard model of matter fields. For both these cases, we derive the solutions of the scalar field. We also derive from first principles the expressions for two types of observables: (i) the local comparison of two atomic sensors that are differently sensitive to the constants of Nature and (ii) the local differential acceleration between two test-masses with different compositions. For the linear coupling, we recover that the signa…
Tau neutrinos in the next decade: from GeV to EeV
2022
Tau neutrinos are the least studied particle in the standard model. This whitepaper discusses the current and expected upcoming status of tau neutrino physics with attention to the broad experimental and theoretical landscape spanning long-baseline, beam-dump, collider, and astrophysical experiments. This whitepaper was prepared as a part of the NuTau2021 Workshop.
Physics beyond colliders at CERN: beyond the Standard Model working group report
2019
The Physics Beyond Colliders initiative is an exploratory study aimed at exploiting the full scientific potential of the CERN's accelerator complex and scientific infrastructures through projects complementary to the LHC and other possible future colliders. These projects will target fundamental physics questions in modern particle physics. This document presents the status of the proposals presented in the framework of the Beyond Standard Model physics working group, and explore their physics reach and the impact that CERN could have in the next 10–20 years on the international landscape.