arXiv subjects

C. G. S. Costa

Publications and source records attributed to C. G. S. Costa.

6 recordsLinked to original sources

arXiv2004

The concept of Existence and the derivation of a Quantum Force

We define a new dynamical variable, the relative existence e, in terms of space and time. Taking it as a generalized positional coordinate, we show that for conservative systems the canonically conjugated momentum is identified as the classical force. Applying Wilson-Sommerfeld-Bohr's quantum conditions for a conditionally periodic motion, we derive an expression for the quantum force, F = hbar k f_e, where k is the wave number and f_e is the characteristic frequency of the system. Applying Dirac's method to the Poisson Brackets involving existence and force, we obtain the uncertainty relation Delta e Delta F >= hbar/2. The force quantization may have already been observed in stimulated bichromatic optical force experiments, used to deflect, decelerate and manipulate laser-cooled atomic beams.

quant-ph↗

arXiv2001

Prompt Atmospheric Neutrinos: Phenomenology and Implications

We present an overview of the phenomenology of prompt neutrinos produced in the atmosphere by the decay of charmed particles. In face of the great activity involving operational and proposed large scale neutrino telescopes, we discuss the implications of different scenarios in calculating the prompt flux, upon the detectable signals in these experiments.

hep-ph↗

arXiv2001

The prompt TeV-PeV atmospheric neutrino window

We discuss the possible existence of an observational window, in the TeV-PeV energy range, for the detection of prompt neutrinos from the decay of charmed particles produced in cosmic ray interactions with the atmosphere. We calculate the event rates for muon and tau neutrinos of heavy quark, mostly charm, origin. We argue that their prompt fluxes are observable in a kilometer-scale neutrino telescope, even though the calculations are subjected to large uncertainties, which we quantify. We raise the possibility that a small component of prompt neutrinos may already be present in the observed samples of current experiments. We also discuss the interplay of the predicted fluxes with those produced by the flavor oscillation of conventional atmospheric neutrinos, and by anticipated cosmic sources.

hep-ph↗

arXiv2001

The prompt lepton cookbook

We review the calculation of the prompt lepton flux, produced in the atmosphere by the semileptonic decay of charmed particles. We describe side by side the intermediary ingredients used by different authors, which include not only the charm production model, but also other atmospheric particle showering parameters. After evaluating separately the relevance of each single ingredient, we analyze the effect of different combinations over the final result. We highlight the impact of the prompt lepton flux calculation upon high-energy neutrino telescopes.

hep-ph↗

arXiv1996

Composition of Primary Cosmic Rays Beyond the ``Knee''from Emulsion Chamber Observations

We show that the simplest assumptions for the dynamics of particle production allow us to understand the fluxes of hadrons and photons at mountain altitudes as well as the structure of individual events. The analysis requires a heavy nuclear component of primary cosmic rays above the ``knee" in the spectrum with average mass number $ = 7.3 \pm 0.9$.

astro-ph↗

arXiv1995

Particle Production in Very High-Energy Cosmic-Ray Emulsion Chamber Events: Usual and Unusual Events

We show that a simple scaling model of very forward particle production, consistent with accelerator and air shower data, can describe all features of the very high-energy interactions recorded with emulsion chambers. This is somewhat surprising after numerous claims that the same data implied large scaling violations or new dynamics. Interestingly, we cannot describe some of the Centauro events, suggesting that these events are anomalous independently of their well-advertised unusual features such as the absence of neutral secondaries.

hep-ph↗