Searcharxiv⌕ Search

arXiv subjects

Harald Fritzsch

Publications and source records attributed to Harald Fritzsch.

At least 37 records · Page 2Linked to original sources
arXiv2012

Neutrino Mixing Angles from Texture Zeros of the Lepton Mass Matrices

Taking into account the latest neutrino oscillation data, we study texture zeros of the lepton mass matrices. Assuming the Dirac neutrino mass matrix M_D, the charged-lepton mass matrix M_l and the mass matrix of heavy right-handed Majorana neutrinos M_R to have three texture zeros, we show that the observed neutrino mixing angles can naturally be obtained. The phenomenological implications for the neutrino mass spectrum, the CP-violating phases, the tritium beta decay and the neutrinoless double-beta decay are explored.

hep-ph↗
arXiv2012

Matter Non-conservation in the Universe and Dynamical Dark Energy

In an expanding universe the vacuum energy density ρ_Λ is expected to be a dynamical quantity. In quantum field theory in curved space-time ρ_Λ should exhibit a slow evolution, determined by the expansion rate of the universe H. Recent measurements on the time variation of the fine structure constant and of the proton-electron mass ratio suggest that basic quantities of the Standard Model, such as the QCD scale parameter Λ_{QCD}, may not be conserved in the course of the cosmological evolution. The masses of the nucleons m_N and of the atomic nuclei would also be affected. Matter is not conserved in such a universe. These measurements can be interpreted as a leakage of matter into vacuum or vice versa. We point out that the amount of leakage necessary to explain the measured value of \dot{m}_N/m_N could be of the same order of magnitude as the observationally allowed value of \dotρ_Λ/ρ_Λ, with a possible contribution from the dark matter particles. The dark energy in our universe could be the dynamical vacuum energy in interaction with ordinary baryonic matter as well as with dark matter.

hep-ph↗
arXiv2012

Composite Weak Bosons at the LHC

In a composite model of the weak bosons the p-wave bosons are studied. The state with the lowest mass is identified with the boson, which might have been detected recently at the LHC. Specific properties of these excited bosons are studied, in particular their decays into weak bosons, into photons and into leptons or quarks.

hep-ph↗
arXiv2012

Lepton Mixing and the Neutrino Mixing Angle theta_13

We discuss the neutrino oscillations, using texture zero mass matrices for the leptons, including radiative correction. The neutrino mixing angle theta_13 is calculated and agrees with the result of the new Daya Bay experiment.

hep-ph↗
arXiv2012

The Size of the Weak Bosons

We study the hypothesis that weak bosons are composite systems, which have a size of the order of 10^{-17} cm. The electromagnetic selfenergies of the weak bosons lead to specific departures from the standard electroweak model, in agreement with observation. Above the energy of 1 TeV the standard electroweak model breaks down completely.

hep-ph↗
arXiv2011

Composite Weak Bosons, Leptons and Quarks

The weak bosons consist of two fermions, bound by a new confining gauge force. The mass scale of this new interaction is determined. At energies below 0.5 TeV the standard electroweak theory is valid. A neutral isoscalar weak boson X must exist - its mass is less than 1 TeV. It will decay mainly into quark and lepton pairs and into two or three weak bosons. Above the mass of 1 TeV one finds excitations of the weak bosons, which mainly decay into pairs of weak bosons. Leptons and quarks consist of a fermion and a scalar. Pairs of leptons and pairs of quarks form resonances at very high energy.

hep-ph↗
arXiv2011

Two-zero Textures of the Majorana Neutrino Mass Matrix and Current Experimental Tests

In view of the latest T2K and MINOS neutrino oscillation data which hint at a relatively large theta_13, we perform a systematic study of the Majorana neutrino mass matrix M_nu with two independent texture zeros. We show that three neutrino masses (m_1, m_2, m_3) and three CP-violating phases (delta, rho, sigma) can fully be determined from two neutrino mass-squared differences (delta m^2, Delta m^2) and three flavor mixing angles (theta_12, theta_23, theta_13). We find that seven patterns of M_nu (i.e., A_{1,2}, B_{1,2,3,4} and C) are compatible with current experimental data at the 3-sigma level, but the parameter space of each pattern is more strictly constrained than before. We demonstrate that the texture zeros of M_nu are stable against the one-loop quantum corrections, and there exists a permutation symmetry between Patterns A_1 and A_2, B_1 and B_2 or B_3 and B_4. Phenomenological implications of M_nu on the neutrinoless double-beta decay and leptonic CP violation are discussed, and a realization of those texture zeros by means of the Z_n flavor symmetries is illustrated.

hep-ph↗
arXiv2011

Flavor Mixing of Quarks and Neutrinos

The "texture zero mass matrices" for the quarks and leptons describe very well the flavor mixing of the quarks and leptons. We can calculate the angles of the unitarity triangle. We expect the angle alpha of the unitarity triangle to be 90 degrees. The masses of the neutrinos can be calculated - they are very small, the largest neutrino mass is 0.05 eV. We calculated the matrix element of the mixing matrix, relevant for the reactor mixing angle. It can be measured in the near future in the DAYA BAY experiment.

hep-ph↗
arXiv2011

Non-Hermitian Perturbations to the Fritzsch Textures of Lepton and Quark Mass Matrices

We show that non-Hermitian and nearest-neighbor-interacting perturbations to the Fritzsch textures of lepton and quark mass matrices can make both of them fit current experimental data very well. In particular, we obtain θ_{23} \simeq 45^\circ for the atmospheric neutrino mixing angle and predict θ_{13} \simeq 3^\circ to 6^\circ for the smallest neutrino mixing angle when the perturbations in the lepton sector are at the 20% level. The same level of perturbations is required in the quark sector, where the Jarlskog invariant of CP violation is about 3.7 \times 10^{-5}. In comparison, the strength of leptonic CP violation is possible to reach about 1.5 \times 10^{-2} in neutrino oscillations.

hep-ph↗
arXiv2010

Composite Weak Bosons

The weak bosons, leptons and quarks are considered as composite particles. The interaction of the constituents is a confining gauge interaction. The standard electroweak model is a low energy approximation. The mixing of the neutral weak boson with the photon is a dynamical mechanism, similar to the mixing between the photon and the rho-meson in QCD. This mixing provides information about the energy scale of the confining gauge force. It must be less than 1 TeV. At and above this energy many narrow resonances should exist, which decay into weak bosons and into lepton and quark pairs. Above 1 TeV excited leptons should exist, which decay into leptons under emission of a weak boson or a photon. These new states can be observed with the detectors at the Large Hadron Collider in CERN.

hep-ph↗
arXiv2009

Relating the neutrino mixing angles to a lepton mass hierarchy

We propose two phenomenological scenarios of lepton mass matrices and show that either of them can exactly give rise to \tan^2θ_{13} = m_e/(m_e + 2m_μ), \tan^2θ_{23} = m_μ/(m_e + m_μ) and \tan^2θ_{12} = (m_e m_2 + 2m_μm_1)/(m_e m_1 + 2m_μm_2) in the standard parametrization of lepton flavor mixing. The third relation, together with current experimental data, predicts a normal but weak hierarchy for the neutrino mass spectrum. We also obtain θ_{13} \approx 2.8^\circ for the smallest neutrino mixing angle and J \approx 1.1% for the Jarlskog invariant of leptonic CP violation, which will soon be tested in the long-baseline reactor and accelerator neutrino oscillation experiments. A seesaw realization of both scenarios is briefly discussed.

hep-ph↗
arXiv2008

Isospin Mass Differences of Heavy Baryons

We discuss the mass differences for isospin multiplets of the charmed and b-flavored baryons. The mass of the neutral b-flavored sigma baryon, which is not measured, is calculated. We point out, that the measurements of the mass differences between the charmed sigma and chi baryons might be wrong.

hep-ph↗
arXiv2007

Deviations from Tri-bimaximal Neutrino Mixing in Type-II Seesaw and Leptogenesis

Current experimental data allow the zero value for one neutrino mass, either m_1 = 0 or m_3 = 0. This observation implies that a realistic neutrino mass texture can be established by starting from the limit (a) m_1 = m_2 = 0 and m_3 \neq 0 or (b) m_1 = m_2 \neq 0 and m_3 = 0. In both cases, we may introduce a particular perturbation which ensures the resultant neutrino mixing matrix to be the tri-bimaximal mixing pattern or its viable variations with all entries being formed from small integers and their square roots. We find that it is natural to incorporate this kind of neutrino mass matrix in the minimal Type-II seesaw model with only one heavy right-handed Majorana neutrino N in addition to the SU(2)_L Higgs triplet Δ_L. We show that it is possible to account for the cosmological baryon number asymmetry in the m_3 =0 case via thermal leptogenesis, in which the one-loop vertex correction to N decays is mediated by Δ_L and the CP-violating asymmetry of N decays is attributed to the electron flavor.

hep-ph↗
arXiv2006

A Time Variation of Proton-Electron Mass Ratio and Grand Unification

Astrophysical observations indicate a time variation of the proton-electron mass ratio and of the fine-structure constant. We discuss this phenomenon in models of Grand Unification. In these models a time variation of the fine-structure constant and of the proton mass are expected, if either the unified coupling constant or the scale of unification changes, or both change. We discuss in particular the change of the proton mass. Experiments in Quantum Optics could be done to check these ideas.

astro-ph↗
arXiv2006

Grand Unification in the SO(10) Model

Extrapolating the coupling strengths to very high energies, one finds that they do not converge to a single coupling constant, as expected in the simplest gauge theory of Grand Unification, the SU(5) theory. We find that the coupling constants do converge, provided that two new intermediate energy scales are introduced, the energies where the group SU(4), containing the color group, and the right-isospin gauge group are spontaneously broken down.

hep-ph↗
arXiv2006

Lepton Mass Hierarchy and Neutrino Mixing

We speculate that the mass spectrum of three neutrinos might have a normal hierarchy as that of three charged leptons or that of three up-type (or down-type) quarks. In this spirit, we propose a novel parametrization of the $3\times 3$ lepton flavor mixing matrix. Its mixing angles $θ_l$ and $θ_ν$ can be related to the mass ratios $m_e/m_μ$ and $m_1/m_2$ in a specific texture of lepton mass matrices with vanishing (1,1) elements: $\tanθ_l = \sqrt{m_e/m_μ}$ and $\tanθ_ν= \sqrt{m_1/m_2}$. The latter relation, together with solar and atmospheric neutrino oscillation data, predicts 0.0030 eV $\lesssim m_1 \lesssim$ 0.0073 eV, 0.009 eV $\lesssim m_2 \lesssim $ 0.012 eV and 0.042 eV $\lesssim m_3 \lesssim$ 0.058 eV. The smallest neutrino mixing angle is found to be $θ_{13} \approx θ_l/\sqrt{2} \approx 3^\circ$, which is experimentally accessible in the near future.

hep-ph↗
arXiv2004

A Time Dependence of QCD

From astrophysics there are indications that the finestructure constant $α$ has changed during the past 10 billion years. Within grand unification one can deduce that also the QCD scale has changed. Tests for a time variation of this scale are described. The result of the new experiment in Munich is discussed.

hep-ph↗