Why care about (θ13,δ)(\theta_{13},\delta) degeneracy at future neutrino experiments

The presence of several clone solutions in the simultaneous measurement of ($\theta_{13},\delta$) has been widely discussed in literature. Here, after a pedagogical introduction on why these clones arise, we discuss how the clones location in the ($\theta_{13},\delta$) plane change as a function of the physical input pair ($\bar\theta_{13},\bar\delta$). We compare the clone flow of a set of possible future neutrino experiments: the CERN SuperBeam, BetaBeam and Neutrino Factory proposals. We show that the combination of these specific BetaBeam and SuperBeam could not help in solving the degeneracies. The combination of one of them with the Neutrino Factory Golden and Silver channel can, instead, be used to solve completely the eightfold degeneracy.Comment: 7 pages, 12 figures. Talk given at the XXXIXth Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Italy, 21-28 Mar 200

Revisiting the production of ALPs at B-factories

In this paper, the production of Axion-Like Particles (ALPs) at B-factories via the process e+e− → γa is revisited. To this purpose, the relevant cross-section is computed via an effective Lagrangian with simultaneous ALP couplings to b-quarks and photons. The interplay between resonant and non-resonant contributions is shown to be relevant for experiments operating at s=mϒ(nS), with n = 1, 2, 3, while the non-resonant one dominates at ϒ(4S). These effects imply that the experimental searches performed at different quarkonia resonances are sensitive to complementary combinations of ALP couplings. To illustrate these results, constraints from existing BaBar and Belle data on ALPs decaying into invisible final states are derived, and the prospects for the Belle-II experiment are discussedThe authors acknowledge F. Anulli, D. Becirevic, S. Fajfer, A. Guerrera, C. Hearty, S.J.D. King, T. Ferben, S. Lacaprara, M. Margoni, F. Mescia, M. Passera and P. Paradisi for very useful exchanges. This project has received support by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement N◦ 674896 (ITN Elusives) and 690575 (RISE InvisiblePlus) and by the exchange of researchers project “The flavor of the invisible universe” funded by the Italian Ministry of Foreign Affairs and International Cooperation (MAECI). L.M. acknowledges partial financial support by the Spanish MINECO through the “Ram´on y Cajal” programme (RYC-2015-17173), by the Spanish “Agencia Estatal de Investigaci´on” (AEI) and the EU “Fondo Europeo de Desarrollo Regional” (FEDER) through the project FPA2016-78645-P, and through the Centro de excelencia Severo Ochoa Program under grant SEV-2016-0597. L.M. thanks the Physics and Astronomy Department ‘G.Galilei’ of the Universit`a degli Studi di Padova for hospitality during the development of this projec

Weak Electric Dipole Moments of Heavy Fermions in the MSSM

A minimal supersymmetric version of the Standard Model with complex parameters allows contributions to the weak-electric dipole moments of fermions at the one-loop level. Assuming generation-diagonal trilinear soft-susy-breaking terms and the usual GUT constraint, a set of CP-violating physical phases can be introduced. In this paper the general expressions for the one-loop contribution to the WEDM in a generic renormalizable theory are given and the size of the WEDM of the tau lepton and the b quark in such a supersymmetric model is discussed.Comment: 12 pages, 1 ps + 4 eps figures, LaTeX using epsf.sty. Some comments and references added. Accepted in Phys. Lett. B. The complete ps-file is also available via WWW at http://www-itp.physik.uni-karlsruhe.de/prep/prep.htm

νμ\nu_\mu disappearance at the SPL, T2K-I and the Neutrino Factory

We study the $\nu_\mu$ disappearance channel at T2K-phase I and the SPL and analyse the achievable reduction of present uncertainties in $\theta_{23}$ and $\Delta m^2_{23}$. We analyse the impact of discrete ambiguities in sign($\Delta m^2{23}$) and sign($2 \tan \theta_{23}$). We show how the disappearance channel at the Neutrino Factory is complementary to the ``golden'' and ``silver'' appearance channels and can be used to reduce the eightfold-ambiguity problem in ($\theta_{13}-\delta$).Comment: 2 pages, 3 epsfig; NUFACT'05, 21-26 June 2005, Frascat