Search results for "Proper time"
showing 3 items of 13 documents
Measurement of the and B− meson lifetimes
1993
Abstract The lifetimes of the B 0 and B − mesons have been measured with the ALEPH detector at LEP. Semileptonic decays of B 0 and B − mesons were partially reconstructed by identifying events containing a lepton with an associated D ∗+ or D 0 meson. The proper time of the B meson was estimated from the measured decay length and the momentum and mass of the D -lepton system. A fit to the proper time of 77 D ∗+ l − and 77 D 0 l − candidates, combined with a constraint on the lifetime ratio ( τ − τ 0 ) arising from the relative rates of observed D ∗+ l − and D 0 l − events, yielded the following lifetimes: τ 0 =1.52 −0.18 +0.20 ( stat. ) −0.13 +0.07 ( syst. ) ps , τ − = 1.47 −0.19 +0.22 ( sta…
A quantum model of Schwarzschild black hole evaporation
1996
We construct a one-loop effective metric describing the evaporation phase of a Schwarzschild black hole in a spherically symmetric null-dust model. This is achieved by quantising the Vaidya solution and by chosing a time dependent quantum state. This state describes a black hole which is initially in thermal equilibrium and then the equilibrium is switched off, so that the black hole starts to evaporate, shrinking to a zero radius in a finite proper time. The naked singularity appears, and the Hawking flux diverges at the end-point. However, a static metric can be imposed in the future of the end-point. Although this end-state metric cannot be determined within our construction, we show tha…
A Numbers-Based Approach to a Free Particle's Spacetime
2020
A possibility is proposed to define the proper spacetime of a free nonzerorest- mass m_0 particle based on the connection of its lasting proper time to an open sequence of natural numbers counting de Broglie time periods (h/c^2)(m^(-1)_ 0 ) [see R. Ferber, A Missing Link: What is Behind de Broglie's" Periodic Phenomenon"?, Foundations of Physics Letters 9, 575 (1996)]. It is suggested to define a set of twodirectional intervals of the particle's proper space (proper distances) following the construction of positive and negative integers from the ordered pairs of the natural numbers, which belong to the sequence 1, 2, ..., n defining the elapsed interval of de Broglie time t_n. Corresponding…