Limits on neutrino-antineutrino transitions from a study of high-energy neutrino interactions

We distinguish electron and positron tracks from ν_e and $\text{ν}{}_{\mathrm{<mtext>e</mtext>}}$ charged-current interactions in a large bubble chamber f ed with a neon-hydrogen mixture. No evidence is seen for an excess of $\text{ν}{}_{\mathrm{<mtext>e</mtext>}}$ interactions from primary $\text{ν}{}_{\mathrm{<mtext>e</mtext>}}$ sources secondary $\text{ν}{}_{\mathrm{\mu }}\text{→}\text{ν}{}_{\mathrm{<mtext>e</mtext>}}\text{or}$$\text{ν}{}_{\mathrm{<mtext>e</mtext>}}\text{→}\text{ν}{}_{\mathrm{<mtext>e</mtext>}}$ oscillations. Upper limits on oscillation parameters, majoron sion and lepton-number violating π and K decays are presented.     

Possible heavy lepton signals at pp colliders

If a new sequential heavy lepton L exists with mass below that of the W boson, it will give rise to the following decay chains: W → Lν_Lwith $\text{L}\text{→}\text{e}\text{ν}{}_{\mathrm{<mtext>e</mtext>}}\text{ν}{}_{\mathrm{<mtext>L</mtext>}}$ or $\text{L}\text{→}\text{Q}\text{qν}{}_{\mathrm{<mtext>L</mtext>}}$. We critically study, and quantify, the possibility of identifying this heavy lepton signal against the various backgrounds in high energy p?p collision. We find that the leptonic decay signal is plagued by serious b?b, W → eν, and W → τν backgrounds, whereas the hadronic decay mode leads to a distinctive signature, after selected cuts are applied. We discuss how the mass of such a lepton may be determined.     

Corrections to νe−νμ universality in neutral current interactions

We examine the effects of higher-order corrections on the universality between ν_μ and ν_e in the Weinberg-Salam model. The leading correction to neutral current amplitudes is an apparent difference in the values of sin²θ as measured by ν_μ and ν_e beams. The difference is .     

Spectroscopic information on ground-state Ar2, Kr2, and Xe2 from interatomic potentials

Calculations of vibrational and rotational level spacings of homonuclear inert gas diatomic molecules by numerical integration of the radial Schrödinger equation are presented. The potentials which were used for the ground states of Ar₂, Kr₂, and Xe₂ were obtained from accurate fits to the molecular beam scattering data. From the calculated $\text{Δ}\text{G}{}_{\mathrm{<mtext>v+</mtext><mtext>1</mtext><mtext>2</mtext>}}\text{'}\text{s}$ and B_v's, the following spectroscopic constants (in cm^?1) were fitted: for Ar₂ω_e = 31.92, ω_ex_e = 3.31, ω_ey_e = 0.11, B_e = 0.060, α_e = 0.004; for $\text{Kr}{}_2\text{ω}{}_{\mathrm{e}}\text{? 23.99}$, $\text{ω}{}_{\mathrm{e}}\text{x}{}_{\mathrm{e}}\text{? 1.30}$, $\text{ω}{}_{\mathrm{e}}\text{y}{}_{\mathrm{e}}\text{? 0.021}$, $\text{B}{}_{\mathrm{e}}\text{? 0.024}$, $\text{α}{}_{\mathrm{e}}\text{? 0.001}$; for $\text{Xe}{}_2\text{ω}{}_{\mathrm{e}}\text{? 21.26}$, $\text{ω}{}_{\mathrm{e}}\text{x}{}_{\mathrm{e}}\text{? 0.75}$, $\text{ω}{}_{\mathrm{e}}\text{y}{}_{\mathrm{e}}\text{? 0.008}$, $\text{B}{}_{\mathrm{e}}\text{? 0.013}$, $\text{α}{}_{\mathrm{e}}\text{? 0.0004}$.     

Neutral currents and stellar cooling

If weak neutral currents couple with the strengths suggested by recent experiments, then stellar cooling via neutrino pair emission from thermally excited nuclear states may be significant in white dwarfs with central temperature ?10^8° K. At higher temperatures, other neutrino cooling processes are more important. In the sun, the decay of thermally excited ⁵⁷Fe nuclei may produce a moderately large, but probably unobservable, low-energy flux of ν_μ, $\text{g}\text{?}\text{n}{}_{\mathrm{\mu }}$, ν_e, and $\text{g}\text{?}\text{n}{}_{\mathrm{e}}$ neutrinos.     

A gauge theory of weak and electromagnetic interactions with spontaneous parity breaking

We present a unified gauge theory of weak and electromagnetic interactions in which parity is spontaneously broken together with gauge invariance, by the Higgs mechanism. The gauge group is SU(2) × U(1), and a heavy neutrino is associated with every charged lepton. After the breaking of the original parity-conserving theory, both a purely vector electromagnetic current and the usual V-A charged currents are obtained. Z is coupled to a vector electron current, and the model predicts equal $\text{ν}{}_{\mathrm{\mu }}\text{e}\text{and}\text{ν}{}_{\mathrm{\mu }}\text{e}$ cross sections. Extension to hadrons is made by introducing three charmed quarks p′, n′ and λ′ of the same charges as p, n and λ. All the experimental results $\text{(ν}{}_{\mathrm{\mu }}\text{e}\text{,}\text{ν}{}_{\mathrm{\mu }}\text{e}\text{,}\text{ν}{}_{\mathrm{<mtext>e</mtext>}}\text{e}$, ν_μ and $\text{ν}{}_{\mathrm{\mu }}$ hadron scatterings) are compatible with a value of sin²θ_W of order 0.4.     

Microwave spectrum of sulfur difluoride in the first excited vibrational states vibrational potential function and equilibrium structure

Microwave spectra of SF₂ in the first excited states of the three normal modes were observed and analyzed. A comparison of the observed inertia defects in the ν₁ and ν₃ states with those calculated by omitting the contributions of the Coriolis interaction between the two modes led to a $\text{ν}\text{?}{}_1\text{-}\text{ν}\text{?}{}_3$ vibrational frequency differences of 25.72 ± 0.33 cm^?1, with ν₁ being definitely higher. The inertia defect in the ground state and our measured values for the inertia defect in the ν₂ state and for the $\text{ν}\text{?}{}_1\text{-}\text{ν}\text{?}{}_3$ difference were combined with the centrifugal distortion constants of Kirchhoff et al. [J. Mol. Spectrosc.48, 157–164 (1973)] to improve the harmonic force field. The interaction constant between the two SF stretching coordinates was determined precisely. The third-order and the cubic anharmonic potential constants were calculated from the observed vibration-rotation constants. The equilibrium structure was determined to be $\text{r}{}_{\mathrm{e}}\text{(}\text{SF}\text{) = 1.58745 ± 0.00012}\text{A}\text{?}$ and θ_e(FSF) = 98.048 ± 0.013°.     

Experimental limits on the mass and decay lifetime of νμ

The nonobservation of photon-induced e⁺e^? pairs pointing in the neutrino beam direction in large bubble chambers would allow one to set an upper limit on the product m_νμλ^CM for muon-type neutrinos, where m_νμ is the mass and λ^CM is the intrinsic partial decay width in sec^?1 for ν_μ→γ+X. In the theory of Eliezer and Ross where , this implies an upper limit on m_νμ considerably smaller than the present upper limit, and a large lower limit on the lifetime τ_νμ.     

The intermediate weak boson and weak interactions at high energy

The high-energy pire-leptonic weak interaction is investigated based on the assumption of the existence of a charged vector boson which mediates the weak processes. With the aid of the fixed-t dispersion relation the following relation is obtained: The weak boson mass m_W should satisfy $\text{m}{}_{\mathrm{<mtext>W</mtext>}}\text{? G}{}^{\mathrm{<mtext>?</mtext><mtext>1</mtext><mtext>2</mtext>}}$, with G the Fermi coupling constant, if the asymptotic value of the cross section becomes of the order of the strong interaction in the energy region observable in cosmic rays, etc.The scattering processes $\text{e}\text{+ν→}\text{e}\text{+ν}\text{and}\text{e}\text{+}\text{ν}\text{→}\text{e}\text{+}\text{ν}$ are examined by the aid of the N/D method. For a large vector-boson mass $\text{m}{}_{\mathrm{<mtext>W</mtext>}}\text{?100}\text{GeV}$, an S-wave resonance should exist for the process e+ν→e+ν while for $\text{e}\text{+}\text{ν}\text{→}\text{e}\text{+}\text{ν}$ there should exist a P-wave resonance which corresponds to the intermediate weak boson. The neutral current is then estimated. It is shown that the neutral current produced as a higher-order effect is not inconsistent with the present experiments on the pure-leptonic weak interaction if m_W?1 TeV.     

Limitation on scalar neutrino masses from Tau decay

The apparent absence of the decay $\text{τ →}\text{ν}{}_{\mathrm{\tau }}\text{ν}{}_{\mathrm{?}}{}^1\text{?,}\text{where}\text{? =}\text{e or}\text{μ}\text{and}\text{ν}{}_{\mathrm{i}}$ is the spin-zero supersymmetric partner of ν_i, implies that the $\text{ν}{}_{\mathrm{i}}$ masses are sufficiently large that the decay is suppressed (assuming the supersymmetric partners exist). We give the resulting limits, which depend on the mass of the W? (the supersymmetric partner of the W) which mediates the decay, and on whether one or both $\text{ν}$ is massive. These are the only experimental limits on $\text{ν}$ masses.     

Problems of interpreting energy loss data for non-zero emergent angles

The energy-angle distribution has been measured for heavy projectiles (9 ? Z₁ ? 92) incident on thin carbon foils in the velocity region $\text{0.4 ? ν/ν}{}_0\text{? 1 (ν}{}_0\text{= e}{}^2\text{/}\text{h}\text{?}\text{)}$. Using ²⁰Ne data as an example, we report results that demonstrate that the thickness dependence of the specific energy loss depends strongly on the emergent angle of the ions. This observation resolves apparent discrepancies in the literature.     

A search at high energies for antineutrino-electron elastic scattering

We have searched for candidates for the weak neutral leptonic current reaction $\text{ν}{}_{\mathrm{\mu }}\text{+}\text{e}{}^{\mathrm{?}}\text{→}\text{ν}{}_{\mathrm{\mu }}\text{+}\text{e}{}^{\mathrm{?}}$ in the Fermilab 15 ft bubble chamber filled with a heavy neon-hydrogen mix. Based on zero observed events of this type we find the 90% confidence level upper limit for the rate for this reaction relative to the total antineutrino charged current rate to be 3.9 × 10^?4 and, in the Weinberg-Salam model, sin²θ_W ? 0.37.     

Radiative corrections to neutrino-lepton scattering in the SU(2)L ⊗ U(1) theory

The radiative corrections of O(α) to the final electron spectrum and the total cross sections for the processes $\text{ν}{}_{\mathrm{\mu }}\text{+}\text{e}\text{→ ν}{}_{\mathrm{\mu }}\text{+}\text{e}\text{,}\text{ν}{}_{\mathrm{\mu }}\text{+}\text{e}\text{→ ν}{}_{\mathrm{<mtext>e</mtext>}}\text{+}\text{e}\text{, ν}{}_{\mathrm{<mtext>e</mtext>}}\text{+}\text{e}\text{→ ν}\text{e}\text{+}\text{e and}\text{ν}{}_{\mathrm{<mtext>e</mtext>}}\text{+}\text{e}$ are studied in the framework of the SU(2)_L ? U(1) theory. The electroweak corrections to the fisrt two processes are presented in two equivalent schemes in terms of (G_μ, sin²θ_w) and $\text{(G}{}_{\mathrm{\mu }}\text{,}\text{sin}{}^2\text{θ}\text{?}{}_{\mathrm{<mtext>w</mtext>}}\text{(m}{}_{\mathrm{<mtext>w</mtext>}}\text{))}$. As a byproduct, the relationship to O(α) between the basic parameters $\text{sin}{}^2\text{θ}{}_{\mathrm{<mtext>W</mtext>}}\text{≡ 1 ? m}{}_{\mathrm{<mtext>W</mtext>}}{}^2\text{/m}{}_{\mathrm{<mtext>Z</mtext>}}{}^2\text{and sin}{}^2\text{θ}\text{?}{}_{\mathrm{<mtext>W</mtext>}}\text{(m}{}_{\mathrm{<mtext>W</mtext>}}\text{)}$ (defined by modified minimal subtraction) is explicitly given. The QED corrections are evaluated in the extreme relativistic (ER) regime of the final electron (E′_e ? m_e) for the situation in which the bremsstrahlung photons are unobserved and unrestricted. The ER approximation allows us to obtain simple analytic expressions for the differential electron spectrum and the total cross sections. The relationship to O(G_Fα) between the spin-averaged differential cross sections for the above processes in the ER regime is derived.     

An experimental investigation of the radiative structure decay K+ → e+υγ

The decay K⁺ → e⁺υγ has been investigated. For the structure-dependent part with positive γ-helicity (SD₊) the branching ratio $\text{Γ(}\text{SD}{}_{\mathrm{+}}\text{)}\text{Γ(}\text{K}{}_{\mathrm{\mu 2}}\text{) = (2.33 ± 0.42) × 10}{}^{\mathrm{?5}}$ is obtained from 51 ± 3 events observed in the kinematical region E_e ? 235 MeV, E_γ > 48 MeV and θ_eγ > 140°. For the corresponding part with negative γ-helicity we obtain an upper limit Γ(SD_?)/Γ(SD₊) < 11 (90% CL) from the sample of electrons with energies 220 MeV ? E_e < 230 MeV and with no γ in the backward direction. This upper limit implies that the ratio of structure-dependent axial vector amplitudes lies outside the region $\text{?1.8 < a}{}_{\mathrm{<mtext>K</mtext>}}\text{υ}{}_{\mathrm{<mtext>K</mtext>}}\text{< ?0.54}$.For the decay $\text{K}{}^{\mathrm{+}}\text{→}\text{e}{}^{\mathrm{+}}\text{νν}\text{ν}$ the limit $\text{Γ(}\text{K}{}^{\mathrm{+}}\text{→}\text{e}{}^{\mathrm{+}}\text{νν}\text{ν}\text{)/Γ(}\text{K}{}_{\mathrm{e2}}\text{) < 3.8}$ 90% confidence level) was found.     

Cosmological bounds on a left-right symmetric model

The right-handed neutrino cross sections of the processes ν_L + ? → ν_R + ? and ν_R + ? → ν_R + ?, where ? is a relativistic lepton, are calculated in the SU(2)_L × SU(2)_R × U(1) model. According to a cosmological criterion the parameters of the model are bounded. In particular we obtain the bound $\text{M}{}_{\mathrm{<mtext>W</mtext>}}{}_{\mathrm{<mtext>R</mtext>}}\text{? 30 M}{}_{\mathrm{<mtext>W</mtext>}}{}_{\mathrm{<mtext>L</mtext>}}$, assuming the neutrinos are Dirac four-component particles.     

Infrared spectrum of acetonitrile: Analysis of Coriolis resonance

The Coriolis resonance between ν₄ and ν₇ in CH₃CN and between ν₁ and ν₅, ν₃ and ν₆, and ν₄ and ν₇ in CD₃CN has been analyzed, applying the technique developed by DiLauro and Mills, to obtain the signs of [$\text{ζ}{}_{\mathrm{r,sa}}{}^{\mathrm{y}}\text{(}\text{?p}\text{?Q}{}_{\mathrm{r}}\text{)(}\text{?p}\text{?Q}{}_{\mathrm{sa}}\text{)}$] and the ratio of $\text{?μ}\text{?Q}{}_{\mathrm{r}}$ to $\text{?μ}\text{?Q}{}_{\mathrm{s}}$ for the interacting pairs in CD₃CN. For (ν₄, ν₇) in both CH₃CN and CD₃CN, the sign of [$\text{ζ}{}_{\mathrm{r,sa}}{}^{\mathrm{y}}\text{(}\text{?p}\text{?Q}{}_{\mathrm{r}}\text{)(}\text{?p}\text{?Q}{}_{\mathrm{sa}}\text{)}$] is found to be negative as it is also for (ν₁, ν₅) in CD₃CN. For (ν₃, ν₆) the sign of this interaction term is found to be positive. For a given definition of normal coordinates the signs of these interaction terms give the relative signs of $\text{?p}\text{?Q}{}_{\mathrm{r}}$ and $\text{?p}\text{?Q}{}_{\mathrm{sa}}$; our study also gives approximate values for the corresponding ratio [$\text{(}\text{?p}\text{?Q}{}_{\mathrm{r}}\text{)}\text{(}\text{?p}\text{?Q}{}_{\mathrm{sa}}\text{)}$]     

Search for neutrino oscillations in “Gargamelle” at SPS

The ν events collected in “Gargamelle” exposed at the CERN SPS wide band beam are reanalyzed to search for possible ν_μ → ν_e oscillations. No effect is found and an upper limit of 1.2 eV at 68% c.l. is determined for the mass parameters $\text{Δm = (m}{}_1{}^2\text{? m}{}_2{}^2\text{)}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ in the case of maximum neutrino mixing. A limit on the ν_μ → ν_τ transition probability is also quoted, but the sensitivity is smaller.     

Rotation-vibration analysis of the Coriolis-coupled ν5g, ν6g, ν8g and ν9 bands of H2CCO

Medium resolution infrared grating spectra of gaseous ketene, H₂CCO were recorded between 1000 and 400 cm^?1, both at instrument temperature (40°C) and with cooling (?40°C). Interferometric Fourier spectra were also measured at ?70°C with resolution 0.22 cm^?1 between 450 and 330 cm^?1. The K structure of the fundamentals ν₅, ν₆, ν₈, and ν₉ was assigned. These fundamentals are coupled by a-axis Coriolis interactions. These couplings were analysed on the symmetric top basis for setting up the perturbation matrix and by utilizing the K-dependent Coriolis shifts of levels. A preliminary analysis of the Coriolis intensity anomalies was also undertaken.Band center values from combination differences are $\text{ν}{}_5{}^0\text{= 587.30 (27)}$ and $\text{ν}{}_6{}^0\text{= 528.36 (39)}\text{cm}{}^{\mathrm{?1}}$. Synthetic spectra indicate the band origins of ν₈ and ν₉ to be close to 977.8 and 439.0 cm^?1, respectively. Estimates of Coriolis coupling constants obtained from synthetic spectra are $\text{ζ}{}_{58}{}^{\mathrm{a}}\text{= + 0.33 (5)}$, $\text{ζ}{}_{68}{}^{\mathrm{a}}\text{= + 0.714 (20)}$, $\text{ζ}{}_{59}{}^{\mathrm{a}}\text{= ? 0.774 (20)}$, and $\text{ζ}{}_{69}{}^{\mathrm{a}}\text{= ? 0.30 (2)}$. Approximate ratios of unperturbed vibrational transition moments obtained from spectral simulations are $\text{M}{}_8{}^0\text{:±iM}{}_5{}^0\text{:±iM}{}_6{}^0\text{:M}{}_9{}^0\text{≈ +2:?9:+10:+0.5}$.     

Leptonic nonet in SUL (3) × SUR (3)

A left-right symmetric SU_L(3) × SU_R(3) gauge model with leptons in the ($\text{3}\text{, 3) + (3,}\text{3}$) representation is presented. The SU^I_L(2)×U(1) subgroup is practically the WS + GIM model for $\text{sin}{}^2\text{?}{}_{\mathrm{<mtext>W</mtext>}}\text{≈}\text{3}\text{8}$, with additional currents involving heavy leptons. μ→eγ is naturally suppressed and a new kind of $\text{ν}{}_{\mathrm{<mtext>e</mtext>}}\text{?}\text{ν}{}_{\mathrm{\mu }}$ oscillations is possible. τ and 3_μ events can be related to one leptonic triplet. The model is naturally imbedded in exceptional groups.