Non-unitarity of Minkowskian non-local quantum field theories

We show that Minkowskian non-local quantum field theories are not unitary. We consider a simple one loop diagram for a scalar non-local field and show that the imaginary part of the corresponding complex amplitude is not given by Cutkosky rules, indeed this diagram violates the unitarity condition. We compare this result with the case of an Euclidean non-local scalar field, that has been shown to satisfy the Cutkosky rules, and we clearly identify the reason of the breaking of unitarity of the Minkowskian theory.

Scattering of charged fermion to two-dimensional wormhole with constant axial magnetic flux

Scattering of charged fermion with $$(1+2)$$ ( 1 + 2 ) -dimensional wormhole in the presence of constant axial magnetic flux is explored. By extending the class of fermionic solutions of the Dirac equation in the curved space of wormhole surface to include normal modes with real energy and momentum, we found a quantum selection rule for the scattering of fermion waves to the wormhole. The newly found momentum–angular momentum relation implies that only fermion with the quantized momentum $$k=m'/a\sqrt{q}$$ k = m ′ / a q can be transmitted through the hole. The allowed momentum is proportional to an effective angular momentum quantum number $$m'$$ m ′ and inversely proportional to the radius of the throat of the wormhole a. Flux dependence of the effective angular momentum quantum number permits us to select fermions that can pass through according to their momenta. A conservation law is also naturally enforced in terms of the unitarity condition among the incident, reflected, and transmitted waves. The scattering involving quasinormal modes (QNMs) of fermionic states in the wormhole is subsequently explored. It is found that the transmitted waves through the wormhole for all scenarios involving QNMs are mostly suppressed and decaying in time. In the case of QNMs scattering, the unitarity condition is violated but a more generic relation of the scattering coefficients is established. When the magnetic flux $$\phi =mhc/e$$ ϕ = m h c / e , i.e., quantized in units of the magnetic flux quantum hc/e, the fermion will tunnel through the wormhole with zero reflection.

Jarlskog determinant and data on flavor matrices

The essences of the weak [Formula: see text] violation, the quark and lepton Jarlskog invariants, are determined toward future model buildings beyond the Standard Model (SM). The equivalence of two calculations of Jarlskog invariants gives a bound on the [Formula: see text] phase in some parametrization. Satisfying the unitarity condition, we obtain the CKM and PMNS matrices from the experimental data, and present the results in matrix forms. The Jarlskog determinant [Formula: see text] in the quark sector is found to be [Formula: see text] while [Formula: see text] in the leptonic sector is [Formula: see text] in the normal hierarchy parametrization.

Cul-De-Sac of the Spatial Image of Proton Interactions

The unitarity condition in the impact parameter space is used to obtain some information about the shape of the interaction region of colliding protons. It is shown that, strictly speaking, a reliable conclusion can be gained only if the behavior of the elastic scattering amplitude (especially, its imaginary part) at all transferred momenta is known. This information is currently impossible to obtain from experimentation. In practice, several assumptions and models are used. They lead to different results as shown below.

Some Recent Results on High-Energy Proton Interactions

Recent experimental results about the energy behavior of the total cross sections, the share of elastic and inelastic contributions to them, the peculiar shape of the differential cross section and our guesses about the behavior of real and imaginary parts of the elastic scattering amplitude are discussed. The unitarity condition relates elastic and inelastic processes. Therefore it is used in the impact-parameter space to get some information about the shape of the interaction region of colliding protons by exploiting new experimental data. The obtained results are described.

Methods of parameterization of amplitudes and extraction of resonances, D-decay amplitudes

Amplitudes used for analyses of two-body interactions very often are not unitary therefore can not guarantee correct results. It is, however, quite easy to construct unitary amplitude or check whether given amplitude fulfills unitarity condition. Only few conditions must be fulfilled to guarantee unitarity. Presently, when in many data analyses very small, overlapping or broad signals are studied, non-unitary effects can significantly influence results and lead to nonphysical interpretation of obtained parameters.

Unified quaternionic description of charge and spin transport and intrinsic nonlinearity of spin currents

We present a unified theory of charge and spin transport using quaternionic formalism. It is shown that both charge and spin currents can be combined together to form a quaternionic current. The scalar and vector part of quaternionic currents correspond to charge and spin currents, respectively. We formulate a unitarity condition on the scattering matrix for quaternionic current conservation. It is shown that in the presence of spin flip interactions, a weaker quaternionic unitarity condition implying charge flux conservation but spin flux nonconservation is valid. Using this unified theory, we find that spin currents are intrinsically nonlinear. Its implication for recent experimental observation of spin generation far away from the boundaries are discussed.

Is There a Hollow Inside the Proton?

We discuss a recently proposed interpretation of some model descriptions of the proton-proton elastic scattering data as a manifestation of alleged relative transparency of the central part of the interaction region in the impact parameter space. We argue that the presence of nonzero real part of the elastic scattering amplitude in the unitarity condition enables to conserve the traditional interpretation.

Critical behavior of cross sections at LHC

Recent experimental data on elastic scattering of high energy protons show that the critical regime has been reached at LHC energies. The approach to criticality is demonstrated by increase of the ratio of elastic to total cross sections from ISR to LHC energies. At LHC it reaches the value which can result in principal change of the character of proton interactions. The treatment of new physics of hollowed toroid-like hadrons requires usage of another branch of the unitarity condition. Its further fate is speculated and interpreted with the help of the unitarity condition in combination with present experimental data. The gedanken experiments to distinguish between different possibilities are proposed.