arXiv subjects

Orlando Panella

Publications and source records attributed to Orlando Panella.

24 records · Page 2Linked to original sources

arXiv2009

Gamma gamma \to mu tau b bbar in Susy Higgs mediated lepton flavor violation

The process gamma gamma \to mu tau b bbar is studied in the minimal supersymmetric standard model within a large tan_beta scenario imposing on the parameter space present direct and indirect constraints from B physics and rare LFV tau-decays. At a photon collider based on an e+e- linear collider with a center of mass energy of 800 GeV with the parameters of the TESLA proposal (expected integrated gamma-gamma luminosity L=200-500 inverse fb) the LFV signal can be probed for masses of the heavy neutral Higgs bosons A,H from 300 GeV up to the kinematical limit ~ 600 GeV for tan_beta in the range 30,60.

hep-ph↗

arXiv2007

Acquisition of Information is Achieved by the Measurement Process in Classical and Quantum Physics

No consensus seems to exist as to what constitutes a measurement which is still considered somewhat mysterious in many respects in quantum mechanics. At successive stages mathematical theory of measure, metrology and measurement theory tried to systematize this field but significant questions remain open about the nature of measurement, about the characterization of the observer, about the reliability of measurement processes etc. The present paper attempts to talk about these questions through the information science. We start from the idea, rather common and intuitive, that the measurement process basically acquires information. Next we expand this idea through four formal definitions and infer some corollaries regarding the measurement process from those definitions. Relativity emerges as the basic property of measurement from the present logical framework and this rather surprising result collides with the feeling of physicists who take measurement as a myth. In the closing this paper shows how the measurement relativity wholly consists with some effects calculated in QM and in Einstein's theory.

quant-ph↗

arXiv2005

Sleptonium at the linear collider and the slepton co-next-to-lightest supersymmetric particle scenario in gauge mediated symmetry breaking models

We discuss the possibility of formation and subsequent detection of a supersymmetric bound state composed of a slepton--antislepton pair at the next linear collider. The Green function method is used within a non-relativistic approximation to estimate the threshold production cross-section of the $2P$ bound state. The parameter space of Gauge Mediated Symmetry Breaking (GMSB) models allow a particular scenario in which a charged slepton ($\widetilde{e}_R, \widetildeμ_R$ or $\widetildeτ_1$) is the NLSP. Within this scenario the produced $2P$ bound-state decays, through a dipole transition, into the $1S$ ground-state with branching ratio $\approx 100% $ emitting a very soft ($\approx 1 $ MeV) photon which goes undetected. The spectroscopy of the $1S$-state shows that it decays into two photons with $Br \approx 0.5$ up to $m_{NLSP} \approx 1$ TeV. Thus NLSP sleptonium threshold production gives rise to the signal $e^+e^- \to 2P \to 1S + "soft γ" \to γγ$ which when compared with the standard model two-photon process ($ e^+e^- \to γγ$) has a statistical significance ($SS$=signal/noise) which, at an energy offset from threshold of E=20 GeV, goes from $SS=11$ to $SS=2$ when the mass of the NLSP ranges in the interval $[100,200]$ GeV.

hep-ph↗

arXiv2004

Loop level lepton flavor violation at linear colliders

We present a study of loop-level lepton flavor vioalting signals in models with heavy Majorana neutrinos and in the supersymmetric extension of the standard model. The attention is focused to the $e^- e^-$ option of the next generation of linear colliders and its potential of discovering new physics is emphasized.

hep-ph↗

arXiv1995

Constraints on Composite-Models Effective Lagrangians from Neutrinoless Double Beta Decay

We give a brief review of the existing bounds on effective couplings for excited states ($e^*, ν^*, u^*, d^* $) of the ordinary quarks and leptons arising from a composite model scenario. We then explore the phenomenological implications of the hypothesis that the excited neutrino $ν^*$ might be of Majorana type. Recent bounds on the half-life of the $ΔL =2 $ neutrinoless double beta decay ($0νββ$) are used to constraint the compositeness effective couplings. We show that the bounds so obtained are roughly of the same order of magnitude as those available from high energy experiments.

hep-ph↗

arXiv1994

Bounds on Compositeness from Neutrinoless Double Beta Decay

Assuming the existence of a heavy Majorana neutral particle arising from a composite model scenario we discuss the constraints imposed by present experimental limits of half-life neutrinoless double beta decay $(0νββ) $ measurements on the coupling of the heavy composite neutrinos to the gauge bosons. For neutrino masses $M_N = 1 $ TeV we obtain a rather weak lower bound on the compositeness scale: $Λ\ge 0.23 $ TeV.

hep-ph↗