Phenomenology of colored radiative neutrino mass model and its implications on cosmic-ray observations

We extend the colored Zee–Babu model with a gauged U(1)B-L symmetry, and a scalar singlet dark matter(DM) candidate S. The spontaneous breaking of U(1)B-L leaves a residual Z_2 symmetry that stabilizes the DM, and generates a tiny neutrino mass at the two-loop level with the color seesaw mechanism. After investigating the DM and flavor phenomenology of this model systematically, we further focus on its imprint on two cosmic-ray anomalies: The Fermi-LAT gamma-ray excess at the Galactic Center(GCE), and the Pe V ultra-high energy(UHE)neutrino events at the IceCube. We found that the Fermi-LAT GCE spectrum can be well-fitted by DM annihilation into a pair of on-shell singlet Higgs mediators while being compatible with the constraints from the relic density,direct detections, and dwarf spheroidal galaxies, in the Milky Way. Although the UHE neutrino events at the IceCube could be accounted for by the resonance production of a Te V-scale leptoquark, the relevant Yukawa couplings have been severely limited by the current low-energy flavor experiments. We subsequently derive the IceCube limits on the Yukawa couplings by employing its latest six-year data.     

Nuclear responses for neutrinos and neutrino studies by double beta decays and inverse beta decays

This is a brief report on recent studies of nuclear responses for neutrinos (v) by charge exchange reactions, v masses by double beta (ββ) decays and of solar and supernova v’s by inverse β decays. Subjects discussed include (1) v studies in nuclear micro-laboratories, (2) v masses studied by ββ decays of ¹⁰⁰Mo and nuclear responses for ββ — v, (3) solar and supernova v’s by inverse β decays and v responses for ⁷¹Ga and ¹⁰⁰Mo, and (4) MOON (molybdenum observatory of neutrinos) for spectroscopic studies of Majorana v masses with sensitivity of m _v ∼ 0.03 eV by ββ decays of ¹⁰⁰Mo and real-time studies of low energy solar and supernova v’s by inverse β decays of ¹⁰⁰Mo.     

Mean square number fluctuation for a fermion source and its dependence on neutrino mass for the universal cosmic neutrino background

Using the general formulation for obtaining chemical potentialμ of an ideal Fermi gas of particles at temperature T, with particle rest mass m₀ and average density 〈N〉/V, the dependence of the mean square number fluctuation 〈ΔN ²〉/V on the particle mass m₀ has been calculated explicitly. The numerical calculations are exact in all cases whether rest mass energym ₀c² is very large (non-relativistic case), very small (ultra-relativistic case) or of the same order as the thermal energy k_BT. Application of our results to the detection of the universal very low energy cosmic neutrino background (CNB), from any of the three species of neutrinos, shows that it is possible to estimate the neutrino mass of these species if from approximate experimental measurements of their momentum distribution one can extract, someday, not only the density 〈N _v〉/V but also the mean square fluctuation 〈Δ _v ² 〉/V. If at the present epoch, the universe is expanding much faster than thermalization rate for CNB, it is shown that our analysis leads to a scaled neutrino massm _v instead of the actual massm _0v .     

Estimate of the background of a gravitational-wave detector due to cosmic rays

Summary The authors examine once more the effect of cosmic rays on a resonating gravitational-wave antenna in view of the very high sensitivities that are required for detecting the supernovae of the Virgo Cluster. They show that, at sea-level, the secondaries generated in the bar by the electromagnetic interaction of high-energy muons produce signals with rates much larger than that expected from supernovae. This inconvenience is eliminated in an underground laboratory.

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Riassunto Gli autori esaminano nuovamente l'effetto dei raggi cosmici su di una antenna gravitazionale risonante, in considerazione della elevata sensibilità che è necessario raggiungere per rivelare le supernovae del Virgo Cluster. Essi mostrano che al livello del mare i secondari generati nella sbarra dalla interazione electtromagnetica dei muoni di alta energia producono segnali con frequenza statistica maggiore di quella prevista per le supernovae. Questo inconveniente è eliminato in un laboratorio sotterraneo.

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Резюме В работе исследуется влияние космических лучей на резонансную антенну гравитационнын волн, в виду высокой чувствиельности, необходимой для детектирования сверхновых в созвездии Девы. Доказывается, что на уровне моря вторичные частицы, образованные в результате электромагнитного взаимодействия высокоэнергетических мюонов произодят сигналы с интенсивностями, много большими, чем ожидаемые интенсивности сигналов от сверхновых. Это противоречие устраняется в подземной лабоатории.

     

极大口径光学望远镜凸非球面副镜的补偿检测法研究

提出了一种检测大口径、快焦比凸双曲面反射镜的补偿检验方法,补偿系统由一组小透镜和一块大口径反射标准镜组成,标准镜的口径约为被检验镜的1.8倍,该方法为极大口径光学望远镜凸非球面副镜的检验提供了一种有效的解决方案。以美国30 m望远镜（TMT）3.1 m,F/1的凸双曲面副镜为例,进行了补偿光路的设计优化。设计结果表明,该方法可以直接检测到直径达3.1 m的大口径、快焦比凸双曲面副镜的整个表面质量,补偿系统像差被校正得很好,PV值约为/100,弥散斑直径在衍射极限范围内。     

Measurement of separate cosmic-ray electron and positron spectra with the fermi large area telescope

We measured separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope. Because the instrument does not have an onboard magnet, we distinguish the two species by exploiting Earth's shadow, which is offset in opposite directions for opposite charges due to Earth's magnetic field. We estimate and subtract the cosmic-ray proton background using two different methods that produce consistent results. We report the electron-only spectrum, the positron-only spectrum, and the positron fraction between 20 and 200?GeV. We confirm that the fraction rises with energy in the 20-100?GeV range. The three new spectral points between 100 and 200?GeV are consistent with a fraction that is continuing to rise with energy.     

Linear seesaw model with T7 symmetry for neutrino mass and mixing

We propose a low-scale Standard Model extension with begin{document}$T_7times Z_4 times Z_3times Z_2$end{document} symmetry that can successfully explain observed neutrino oscillation results within the begin{document}$3 sigma$end{document} range. Small neutrino masses are obtained via the linear seesaw mechanism. Normal and inverted neutrino mass orderings are considered with three lepton mixing angles in their experimentally allowed begin{document}$3sigma$end{document} ranges. The model provides a suitable correlation between the solar and reactor neutrino mixing angles, which is consistent with the begin{document}${rm{TM}}_2$end{document} pattern. The prediction for the Dirac phase is begin{document}$delta_{rm CP}in (295.80, 330.0)^circ$end{document} for both normal and inverted orderings, including its experimentally maximum value, while those for the two Majorana phases are begin{document}$eta_1in (349.60, 356.60)^circ,, eta_2=0$end{document} for normal ordering and begin{document}$eta_1in (3.44, 10.37)^circ, , eta_2=0$end{document} for inverted ordering. In addition, the predictions for the effective neutrino masses are consistent with the present experimental bounds.     

Dark matter,neutrino mass,cutoff for cosmic-ray neutrino,and the Higgs boson invisible decay from a neutrino portal interaction

We study an effective theory beyond the standard model(SM) where either of the two additional gauge singlets, a Majorana fermion and a real scalar, constitutes all or some fraction of dark matter. In particular, we focus on the masses of the two singlets in the range of O(10) MeV-O(10) GeV with a neutrino portal interaction, which plays an important role not only in particle physics but also in cosmology and astronomy. We point out that the thermal dark matter abundance can be explained by(co-)annihilation, where the dark matter with a mass greater than 2 GeV can be tested in future lepton colliders, CEPC, ILC, FCC-ee and CLIC, in the light of the Higgs boson invisible decay. When the gauge singlets are lighter than O(100) MeV, the interaction can affect the neutrino propagation in the universe due to its annihilation with cosmic background neutrino into the gauge singlets. Although in this case it can not be the dominant dark matter, the singlets are produced by the invisible decay of the Higgs boson at such a rate which is fully within reach of future lepton colliders. In particular, a high energy cutoff of cosmic-ray neutrino,which may account for the non-detection of Greisen-Zatsepin-Kuzmin(GZK) neutrino or the non-observation of the Glashow resonance, can be set. Interestingly, given the cutoff and the mass(range) of WIMPs, a neutrino mass can be"measured" kinematically.     

High-energy cosmic rays: Puzzles,models, and giga-ton neutrino telescopes

The existence of cosmic rays of energies exceeding 10²⁰ eV is one of the mysteries of high-energy astrophysics. The spectrum and the high energy to which it extends rule out almost all suggested source models. The challenges posed by observations to models for the origin of high-energy cosmic rays are reviewed, and the implications of recent new experimental results are discussed. Large area high-energy cosmic ray detectors and large volume high-energy neutrino detectors currently under construction may resolve the high-energy cosmic ray puzzle, and shed light on the identity and physics of the most powerful accelerators in the Universe.     

Baikal neutrino telescope: Status, results, and prospects of development

The main physical results obtained with the Baikal neutrino telescope NT200 during the period 1998–2003 are reviewed: the limits for the diffuse flux of high-energy neutrinos, high-energy muons, and magnetic monopoles and the results of search for neutrinos from the center of the Earth due to annihilation of weakly interacting massive particles and from local neutrino sources. In April, 2005, the neutrino telescope NT200 was extended by introduction of three new strings, located at a distance of 100 m from the NT200 center. The new deep-water complex NT200+ has an effective volume for detecting cascades from high-energy neutrinos larger than that of NT200 by a factor of 4. At a cascade energy of 10 PeV, the effective volume of the new complex is 10⁷ m³. Further development of the Baikal neutrino experiment is related to the design and fabrication of a detector with a volume of about 1 km³. Original Russian Text ? K.V.Antipin, V.M. Ainutdinov, V.A. Balkanov, I.A. Belolaptikov, D.A. Borshchev, N.M. Budnev, R.V. Vasil’ev, R. Vishnevskii, I.A. Danil’chenko, G.V. Domogatskii, A.A. Doroshenko, A.P. D’yachok, Zh.-A.M. Dzhilkibaev, O.N. Gaponenko, K.V. Golubkov, O.A. Gress, T.I. Gress, O.I. Grishin, V.A. Zhukov, A.M. Klabukov, A.I. Klimov, A.A. Kochanov, K.V. Konishchev, A.P. Koshechkin, L.A. Kuz’michev, V.F. Kulepov, E. Middel, T. Mikokaiskii, M.B. Milenin, R.R. Mirgazov, S.P. Mikheev, E.A. Osipova, G.L. Pan’kov, L.V. Pan’kov, A.I. Panfilov, D.P. Petukhov, E.N. Pliskovskii, P.G. Pokhil, V.A. Poleshchuk, E.G. Popova, V.V. Prosin, M.I. Rozanov, V.Yu. Rubtsov, Yu.A. Semenei, B.A. Tarashchanskii, S.V. Fialkovskii, B.K. Shaibonov, A.A. Sheifler, A.V. Shirokov, K. Spiring, I.V. Yashin, 2007, published in Izvestiya Rossiiskoi Akademii Nauk. Seriya Fizicheskaya, 2007, Vol. 71, No. 4, pp. 597–601.     

Optical background measurement in a potential site for the NEMO KM undersea neutrino telescope

We describe the measurement of the deep sea optical background in some sites south of Capo Passero, Sicily. A continuous flux of about 440 photons cm ^-2 s ^-1 in the wavelength interval 440-550 nm is estimated due to the decays of the ⁴⁰K contained in the sea water. Bioluminescence light bursts are also observed and an example of time evolution is reported. All the measurements were accomplished using a deep sea module also described in this article. Received: 20 April 2002 / Published online: 26 July 2002     

低轨微小卫星及小碎片搜索/跟踪机动式大视场光电望远镜

有效反射面积小,运动速度快的空间低轨卫星和小碎片的日益增多对现有地基探测跟踪技术提出了挑战。本文分析了国外现有低轨小目标光电探测技术的发展现状,结合低轨小目标的探测需求,提出了一种用于低轨微小卫星及小碎片搜索/跟踪探测的机动式车载大视场光电望远镜设计方案。介绍了该望远镜的光学系统、跟踪架及载车,描述了它的工作模式和图像处理,讨论了系统的搜索和探测能力。结果表明,该望远镜对300 km轨道高度的目标搜索能力达到13.5星等（相当于直径5 cm目标）,可以满足搜索和跟踪低轨微小卫星及小碎片探测的实际需求。     

Cosmogenic neutrinos and gamma rays

We describe the photoproduction interactions of ultrahigh energy protons on the universal photon backgrounds and the production of very high-energy neutrinos and γ-rays in such interactions. We compare the production in propagation in the microwave background to that in the extragalactic background light. The propagation of heavy nuclei is discussed only briefly. We show the extreme models for cosmogenic neutrino production and the limits set on them by different experiments.     

HARP: a hadron production experiment for the neutrino factory and for the atmospheric neutrino flux

The HARP experiment will carry out, at the CERN PS, a large programme of measurements of secondary hadron production, over the full solid angle, produced on thin and thick nuclear targets by beams of protons and pions with momenta in the range 2 to 15 GeV/c. The first aim of the experiment is to acquire adequate knowledge of pion yields for an optimal design of the recently proposed neutrino factory. The second aim is to reduce substantially the existing 30% uncertainty in the calculation of absolute atmospheric neutrino fluxes and the 7% uncertainty in the ratio of neutrino flavours.     

STAR CLUSTER: a tracking array for gamma-ray astronomy

Summary A new type of extensive air shower array-telescope is being constructed, close to the GREX scintillator array at Haverah Park. The design of the new instrument is based on identification and measurement of individual shower particles by means of pattern recognition techniques applied to data from LST chambers above and below a thin sheet of high-Z material. Air showers will be detected in the range from 10¹⁴ eV to 10¹⁸ eV. The directions of the shower primaries will be reconstructed with an accuracy of a few tenths of a degree using triangulation between tracks of detected shower particles: >1 GeV electrons, photons and muons. Particle densities measured at the detector locations will be used to calculate shower sizes and core locations. Information about the height of production of the high-energy secondaries will be obtained for each shower. This information will be taken into account in calculating the primary energies. It will be used together with the observed muon content (ratio of muons to all particles), to draw conclusions about the nature of the primary particles. Paper presented at the V Cosmic Physics National Conference, S. Miniato, November 27–30, 1990.     

Pseudo-dirac neutrinos: a challenge for neutrino telescopes

Neutrinos may be pseudo-Dirac states, such that each generation is actually composed of two maximally mixed Majorana neutrinos separated by a tiny mass difference. The usual active neutrino oscillation phenomenology would be unaltered if the pseudo-Dirac splittings are deltam(2) less, similar 10(-12) eV(2); in addition, neutrinoless double beta decay would be highly suppressed. However, it may be possible to distinguish pseudo-Dirac from Dirac neutrinos using high-energy astrophysical neutrinos. By measuring flavor ratios as a function of L/E, mass-squared differences down to deltam(2) approximately 10(-18) eV(2) can be reached. We comment on the possibility of probing cosmological parameters with neutrinos.     

Neutrino masses and mixings: a theoretical perspective

We briefly review the recent activity on neutrino masses and mixings which was prompted by the confirmation of neutrino oscillations by the Superkamiokande experiment.