arXiv subjects

Yutaka Tobita

Publications and source records attributed to Yutaka Tobita.

17 recordsLinked to original sources

arXiv2024

Topological interaction of neutrino with photon in the magnetic field -- Electroweak Hall effect

The effective interaction of a neutrino with a photon in magnetized plasma is obtained from a strong field expansion in the electroweak standard model. The interaction is expressed by a Chern-Simons form of the neutrino current and the electromagnetic vector potential of the coupling strength proportional to $\frac{n_e}{B} \times e G_F$. The derivation of the interaction Lagrangian and its properties are presented.

hep-ph↗

arXiv2020

Finite-size corrections to Fermi's Golden rule II: Quasi-stationary composite states

Many-body states described by a Schrödinger equation include states of overlapping waves of non-vanishing interaction energies. These peculiar states formed in many-body transitions remain in asymptotic regions, and lead a new component to the transition probability. The probability is computed rigorously following the von Neumann's fundamental principle of quantum mechanics with an S-matrix that is defined with normalized functions, instead of plane waves. That includes the intriguing correction term to the Fermi's golden rule, in which a visible energy is smaller than the initial energy, and reveals macroscopic quantum phenomena for light particles. Processes in Quantum Electrodynamics are analyzed and the sizable corrections are found in the dilute systems. The results suggest that these states play important roles in natural phenomena, and the verification in laboratory would be possible with recent advanced technology.

hep-ph↗

arXiv2017

Interaction of the SN1987A Neutrino with the Galaxy

In previous publications we have shown that long-ignored approximations in standard model calculations could have significant implications for very low mass particles such as neutrinos and photons. In particular we showed that, in a dilute plasma such as that in the solar corona, a significant decay probability of $ν' \rightarrow ν+ γ$ will be possible as a consequence of the terms ignored in making the approximations. Here the $ν'$ and $ν$ are high and low mass eigenstates of the neutrino. In this paper, we investigate the effect in the vicinity of an expanding supernovae remnant such as SN1987A. We show that, in the dilute plasma external to the remnant, such decays are possible and significant. We describe a calculation of effects of such decays on the anti-neutrinos from SN1987A. The calculated anti-neutrino energy against arrival time agrees reasonably well with that observed, assuming that the expansion velocity of the remnant is $\approx 0.2 c$ and that the plasma density is high within the expanding remnant.

hep-ph↗

arXiv2017

Finite-Size Corrections to the Excitation Energy Transfer in a Massless Scalar Interaction Model

We study the excitation energy transfer (EET) for a simple model in which a massless scalar particle is exchanged between two molecules. We show that a finite-size effect appears in EET by the interaction energy due to overlapping of the quantum waves in a short time interval. The effect generates finite-size corrections to Fermi's golden rule and modifies EET probability from the standard formula in the Forster mechanism. The correction terms come from transition modes outside the resonance energy region and enhance EET probability substantially.

physics.chem-ph↗

arXiv2017

Transition Probability for the Neutrino Wave in Muon Decay and Oscillation Experiments

This paper elucidates the anomalous decay of the muon ascribed to extended waves. Due to a large overlap of the parent and daughters, the transition amplitude and probability for the neutrinos are modified from the standard formula. A rigorous probability from the von Neumann's fundamental principle of the quantum mechanics at a large time interval $T$ is, $P=TΓ+ P^{(d)}$, where $Γ$ is derived from the Fermi's golden rule, and $P^{(d)}$ is a correction term. A new term $P^{(d)}$ has origins in the overlapping waves, and influences the determinations of physical parameters. By including $P^{(d)}$, short-baseline neutrino experiments with LSND, KARMEN, and MiniBooNE become consistent each other and with the solar, long-baseline, and reactor experiments within the three neutrinos. Byproduct is that the absolute neutrino mass of the neutrinos can be measured.

hep-ph↗

arXiv2015

Electroweak Hall Effect of Neutrino and Coronal Heating

The inversion of temperature at the solar corona is hard to understand from classical physics, and the coronal heating mechanism remains unclear. The heating in the quiet region seems contradicting with the thermodynamics and is a keen problem for physicists. A new mechanism for the coronal heating based on the neutrino radiative transition unique in the corona region is studied. The probability is enormously amplified by an electroweak Chern-Simons form and overlapping waves, and the sufficient energy is transfered. Thus the coronal heating is understood from the quantum effects of the solar neutrino.

hep-ph↗

arXiv2014

Anomalous radiative transitions

Anomalous transitions involving photons derived by many-body interaction of the form, $\partial_μ G^μ$, in the standard model are studied. This does not affect the equation of motion in the bulk, but makes wave functions modified, and causes the unusual transition characterized by the time-independent probability. In the transition probability at a time-interval $T$ expressed generally in the form $P=T Γ_0 +P^{(d)}$, now with $ P^{(d)} \neq 0 $. The diffractive term $P^{(d)}$ has the origin in the overlap of waves of the initial and final states, and reveals the characteristics of waves. In particular, the processes of the neutrino-photon interaction ordinarily forbidden by Landau-Yang's theorem ($Γ_0=0$) manifests itself through the boundary interaction. The new term leads to physical processes over a wide energy range to have finite probabilities. New methods of detecting neutrinos using laser are proposed that are based on this difractive term, which enhance the detectability of neutrinos by many orders of magnitude.

hep-ph↗

arXiv2014

Matter-enhanced transition probabilities in quantum field theory

The relativistic quantum field theory is the unique theory that combines the relativity and quantum theory and is invariant under the Poincaré transformation. The ground state, vacuum, is singlet and one particle states are transformed as elements of irreducible representation of the group. The covariant one particles are momentum eigenstates expressed by plane waves and extended in space. Although the S-matrix defined with initial and final states of these states hold the symmetries and are applied to isolated states, out-going states for the amplitude of the event that they are detected at a finite-time interval T in experiments are expressed by microscopic states that they interact with, and are surrounded by matters in detectors and are not plane waves. These matter-induced effects modify the probabilities observed in realistic situations. The transition amplitudes and probabilities of the events are studied with the S-matrix, $S[\text T]$, that satisfies the boundary condition at T. Using $S[\text T]$, the finite-size corrections of the form of ${1/\text T}$ are found. The corrections to the Fermi's golden rule become larger than the original values in some situations for light particles. They break Lorentz invariance even in high energy region of short de Broglie wave lengths.

hep-ph↗

arXiv2014

Finite-size corrections to Fermi's golden rule: I. Decay rates

A quantum mechanical wave of a finite size moves like a classical particle and shows a unique decay probability. Because the wave function evolves according to the Schrödinger equation, it preserves the total energy but not the kinetic energy in the intermediate-time region of a decay process where those of the parent and daughters overlap. The decay rate computed with Fermi's golden rule requires corrections that vary with the distance between the initial and final states, and the energy distribution of the daughter is distorted from that of plane waves. The corrections have universal properties in relativistically invariant systems and reveal macroscopic quantum phenomena for light particles. The implications for precision experiments in beta decays and various radiative transitions are presented.

hep-ph↗

arXiv2013

A new method for measuring the absolute neutrino mass

The probability of the event that a neutrino produced in pion decay is detected in the intermediate $T$ shorter than the life-time $τ_π$, $T \leq τ_π$, is sensitive to the absolute mass of the neutrino. With a newly formulated S-matrix $S[T]$ that satisfies the boundary conditions of the experiments at a finite $T$, the rate of the event is computed as $Γ_0+\tilde{g}(ω_ν, {T};τ_π) \tilde Γ_{1} $, where $\tilde{g}(ω_ν,{T};τ_π)$ depends weakly on $τ_π$ and $ω_ν={m_ν^2c^4}/{(2E_ν\hbar)}$, $c$ is the speed of light. $Γ_0$ is the standard one and the correction, $\tilde{g}(ω_ν, {T};τ_π) \tilde Γ_{1} $, reflects relativistic invariance and is rigorously computed via the light-cone singularity of the system and reveals the diffraction pattern of a single quantum. The formula explains unsolved anomalies of neutrino experiments and indicates the heavy neutrino mass, $0.098 \pm 0.022$ or $0.083 \pm 0.026$ {eV}/ $c^2$ for normal or inverted mass hierarchies, respectively.

hep-ph↗

arXiv2013

On transition of non-stationary waves

The probability of the events that the final states are detected with or interact with the nucleus in a finite time interval T was found to be, $P=\text T Γ_0 +P^{(d)}$. $Γ_0$ is computed with Fermi's golden rule, and does not depend on the nuclear wave functions. $P^{(d)}$ is not given by Fermi's golden rule, and depends on the nuclear wave functions. In the electron mode of pion decays, $Γ_0$ is proportional to $m_e^2$ but $P^{(d)}$ for the event that the neutrino is detected is proportional to $m_ν^{-2}$. $P^{(d)}$ does not hold the helicity suppression satisfied in $Γ_0$ and is inevitable in non-stationary quantum phenomena.

hep-ph↗

arXiv2012

Neutrino diffraction induced by many body interaction

The neutrino produced in the pion decay reveals a new diffraction phenomenon due to many-body interactions in an intermediate time region when wave functions of the parent and daughters overlap. Because of diffraction, the probability to detect the neutrino involves a large finite-size correction that depends on the neutrino mass, $m_ν$ and energy, $E_ν$, the speed of light, $c$, and the distance $L$ between the positions of the initial pion and final neutrino, ${m_ν^2c^4 L}/{(2E_ν\hbar)}$. The correction vanishes for the charged leptons and is finite for the neutrino at a macroscopic distance, $L$, of near-detector regions in ground experiments. A new method for determining the absolute neutrino mass is proposed.

hep-ph↗

arXiv2012

Long-range correlations of neutrinos in hadron reactions and neutrino diffraction II: neutrino

In this II, a probability to detect the neutrino produced in a high-energy pion decay is shown to receive the large finite-size correction. The neutrino interacts extremely weakly with matters and is described with a many-body wave function together with the pion and charged lepton. This wave function slowly approaches to an asymptotic form, which is probed by the neutrino. The whole process is described by an S-matrix of a finite-time interval, which couples with states of non-conserving kinetic energy, and the final states of a broad spectrum specific to a relativistic invariant system contribute to the positive semi-definite correction similar to diffraction of waves through a hole. This diffraction component for the neutrino becomes long range and stable under changes of the pion's energy. Moreover, it has a universal form that depends on the absolute neutrino mass. Thus a new method of measuring the absolute neutrino mass is suggested.

hep-ph↗

arXiv2012

Resolving LSND anomaly by neutrino diffraction

In the charged pion decay, a neutrino is produced in pair with a charged lepton and they have the same production rate. In this paper we show that neutrinos have their own space-time correlations in a wide area and are detected in a different manner from charged leptons, owing to extremely small mass. The neutrino flux reveals a unique interference effect in the form of diffraction of non-stationary waves. The diffraction component of the flux shows a slow position-dependence and leads to an electron neutrino at short base-line regions. The electron neutrino flux at short distances is attributed to the neutrino diffraction and the one at long distances is to the normal flavor oscillation. The former depends upon the average mass-squared $\bar m^2_ν$ and the latter depends upon the mass-squared difference $δm^2_ν$. The LSND and the two neutrino experiment (TWN) measure $\bar m^2_ν$ and the other experiments measure $δm^2_ν$. Hence they are consistent with each other. The neutrino diffraction would supply valuable information on the absolute neutrino mass.

hep-ph↗

arXiv2012

Diffraction-corrected neutrino flux and $νN$ total cross section

A neutrino produced in a particle decay maintains an unusual wave nature that reveals a diffraction phenomenon in a large spatial region. Diffraction gives a new component to a neutrino flux in this region and modifies determinations of physical quantities in neutrino experiments. A total cross section of neutrino nucleon scattering at high energies is studied in this paper. A cross section is proportional to an energy in the quark-parton model and is modified with the energy-dependent neutrino flux induced by the diffraction component. A total number of events divided by the energy is not constant but has a slight energy dependence. Theoretical values agree well with the recent experiments.

hep-ph↗

arXiv2010

Coherence length of cosmic background radiation enlarges the attenuation length of the ultra-high energy proton

It is pointed out that an agreement of the one particle energy spectrum of the cosmic background radiation (CMBR) with Plank distribution of 2.725 [K] does not give a strong constraint on the coherence length of CMBR if the mean free path of CMBR is very long. The coherence length in this situation is estimated as a few times of $k_BT$. Due to this finite coherence length, the attenuation length of ultra-high energy cosmic rays (UHECR) is reduced in the $Δ$ resonance region,i.e., around $10^{20}$ [eV]. The small attenuation length makes the suppression of the flux of cosmic rays in this energy region less prominent than the naive estimation

hep-ph↗

arXiv2009

On coherence lengths of wave packets

Coherence lengths of one particle states described by quantum wave functions are studied. We show that one particle states in various situations are not described by simple plane waves but are described by wave packets that are superpositions of plane waves. Wave packet is an approximate eigenstate of the free Hamiltonian and has a finite spatial size which we call the coherence length. The coherence lengths in the coordinate space and in the momentum space are studied in the present paper. We investigate several mechanisms of forming wave packets, stabilities of wave packets, and transformations of wave packets.

quant-ph↗