Quantum Theory of Neutrino Oscillations for Pedestrians - Simple Answers to Confusing Questions

Why are different mass states coherent? What is the correct formula for the oscillation phase? How can textbook formulas for oscillations in time describe experiments which never measure time? How can we treat the different velocities and different transit times of different mass eigenstates and avoid incorrect factors of two? How can textbook forumulas which describe coherence between energy states be justified when Stodolsky's theorem states there is no coherence between different energies? Is covariant relativistic quantum field theory necessary to describe neutrino oscillations? How important is the detector, which is at rest in the laboratory and cannot be Lorentz tranformed to other frames? These questions are answered by a simple rigorous calculation which includes the quantum fluctuations in the position of the detector and in the transit time between source and detector. The commonly used standard formula for neutrino oscillation phases is confirmed. An "ideal" detector which measures precisely the energy and momentum of the neutrino destroys all phases in the initial wave packet and cannot observe oscillations. A realistic detector preserves the phase differences between neutrinos having the same energy and different momenta and confirms the standard formula. Whether phase differences between neutrinos with different energies are observable or destroyed by the detector is irrelevant.Comment: 10 pages, Introduction expanded to explain sources of confusion in detai

Physics of vacuum at ITEP and around

Recollections about a few episodes from the history of physics of vacuum, connected with the names of Pomeranchuk, Landau, Zeldovich, Sakharov and Kirzhnits. The text of the talk will be published in the Proceedings of the International Conference ``From the Smallest to the Largest Distances'', Tribute to Jean Tran-Thanh-Van, May 24-26, 2001 (``Surveys in High Energy Physics'', Taylor and Francis, 2002, v.16, No.3).Comment: 10 page

How strong can the coupling of leptonic photons be?

Consequences of possible existence of leptonic photon are considered for a range of values of leptonic charge. In the case of a strong Coulomb-like leptonic repulsion between electrons the existence of ordinary condensed matter is impossible: antineutrinos cannot neutralize this destructive repulsion. The upper limit of leptonic charge is inferred from the E\"{o}tv\"os type experiments. If however there exist light stable scalar bosons with leptonic charge (e.g. singlet antisneutrinos) they may neutralize the electron repulsion. Possible experimental manifestations of such leptonic bosons in gases and condensed matter are briefly discussed.Comment: 13 pages in standard LaTe

A thought experiment with clocks in static gravity

In order to directly demonstrate that in static gravitational field the rate of clocks increases with their distance from the source a simple thought experiment is proposed.Comment: 4 pages, LaTeX, no figure

Quirks in supersymmetry with gauge coupling unification

I investigate the phenomenology of supersymmetric models with extra vector-like supermultiplets that couple to the Standard Model gauge fields and transform as the fundamental representation of a new confining non-Abelian gauge interaction. If perturbative gauge coupling unification is to be maintained, the new group can be SU(2), SU(3), or SO(3). The impact on the sparticle mass spectrum is explored, with particular attention to the gaugino mass dominated limit in which the supersymmetric flavor problem is naturally solved. The new confinement length scale is astronomical for SO(3), so the new particles are essentially free. For the SU(2) and SU(3) cases, the new vector-like fermions are quirks; pair production at colliders yields quirk-antiquirk states bound by stable flux tubes that are microscopic but long compared to the new confinement scale. I study the reach of the Tevatron and LHC for the optimistic case that in a significant fraction of events the quirk-antiquirk bound state will lose most of its energy before annihilating as quirkonium.Comment: 28 page

The Einstein formula: E_0=mc^2 "Isn't the Lord laughing?"

The article traces the way Einstein formulated the relation between energy and mass in his work from 1905 to 1955. Einstein emphasized quite often that the mass $m$ of a body is equivalent to its rest energy $E_0$. At the same time he frequently resorted to the less clear-cut statement of equivalence of energy and mass. As a result, Einstein's formula $E_0=mc^2$ still remains much less known than its popular form, $E=mc^2$, in which $E$ is the total energy equal to the sum of the rest energy and the kinetic energy of a freely moving body. One of the consequences of this is the widespread fallacy that the mass of a body increases when its velocity increases and even that this is an experimental fact. As wrote the playwright A N Ostrovsky "Something must exist for people, something so austere, so lofty, so sacrosanct that it would make profaning it unthinkable."Comment: 20 page

Leptonic Photon and Light Element Abundancies

In the framework of a model, in which a single leptonic photon $\gamma_l$ has the same coupling to the doublets $\mu\nu_{\mu}$ and $\bar{\tau}\bar{\nu}_{\tau}$, there is no cosmological bound on the strength of this coupling.Comment: 3 pages, plain LaTe

The Life and Legacy of Pomeranchuk

The life of Isaak Yakovlevich Pomeranchuk was short (20.05.1913 -- 14.12.1966). But the impact of his personality and his works on physics and physicists is remarkable. The talk describes the biography of I.Ya. Pomeranchuk, his major contibutions to condenced matter physics, nuclear and elementary particle physics. The talk is appended by a complete bibliography of I.Ya. Pomeranchuk's publications.Comment: Introductory talk given at the conference "I. Ya. Pomeranchuk and physics at the turn of centuries". To be published by "World Scientific