A variety of new physics models allows for neutrinos to up-scatter into heavier states. If the incident neutrino is energetic enough, the heavy neutrino may travel some distance before decaying. In this work, we consider the atmospheric neutrino flux as a source of such events. At IceCube, this would lead to a "double-bang" (DB) event topology, similar to what is predicted to occur for tau neutrinos at ultra-high energies. The DB event topology has an extremely low background rate from coincident atmospheric cascades, making this a distinctive signature of new physics. Our results indicate that IceCube should already be able to derive new competitive constraints on models with GeV-scale sterile neutrinos using existing data.
High Energy Neutrino Astronomy has been revealed by a sudden change in the flavor composition around maximal energies since three years of recording in ice km detector. However these discover didn' t led to any clear promised Neutrino Astronomy land yet. No correlation with hard gamma sources was found. Moreover the astrophysical spectra expected at Fermi value, seem to converge to a softer value, also required to avoid any Glashow resonant neutrino signal. We suggest a main solution within a composite flux ruled by prompt atmospheric neutrinos. Nevertheless the recent discover of twentyone cr…
In light of the exciting campaign of cosmogenic neutrino detection, we investigate the double and multiple tau bangs detectable at future tau neutrino telescopes. Such events are expected from the Standard Model (SM) higher-order processes, which can be easily identified with broad techniques anticipated at future tau neutrino telescopes. We find that SM perturbative processes can already contribute observable double-bang events to telescopes with a sensitivity of collecting $\mathcal{O}(100)$ cosmogenic neutrino events. The detectable but suppressed rate in fact makes the double and multiple …
IceCube Neutrino Astronomy is considered. The tau neutrino flavor paucity and the asymmetry for the tracks suggest a dominant atmospheric charm noise. The correlated cascades and tracks asymmetry with relevant statistics enforce the charm noise dominance in the data. The charm signal may explain at once the absence of correlation for the tracks data with the galactic plane and with known brightest gamma sources.
While the low-energy excess observed at MiniBooNE remains unchallenged, it has become increasingly difficult to reconcile it with the results from other sterile neutrino searches and cosmology. Recently, it has been shown that non-minimal models with new particles in a hidden sector could provide a better fit to the data. As their main ingredients they require a GeV-scale $Z'$, kinetically mixed with the photon, and an unstable heavy neutrino with a mass in the 150 MeV range that mixes with the light neutrinos. In this letter we point out that atmospheric neutrino experiments (and, in particul…
Dark matter (DM) scattering and its subsequent capture in the Sun can boost the local relic density, leading to an enhanced neutrino flux from DM annihilations that is in principle detectable at neutrino telescopes. We calculate the event rates expected for a radiative seesaw model containing both scalar triplet and singlet-doublet fermion DM candidates. In the case of scalar DM, the absence of a spin dependent scattering on nuclei results in a low capture rate in the Sun, which is reflected in an event rate of less than one per year in the current IceCube configuration with 86 strings. For si…
We consider long-lived relic particles as the source of the PeV-scale neutrinos detected at the IceCube observatory over the last six years. We derive the present day neutrino flux, including primary neutrinos from direct decays, secondary neutrinos from electroweak showering, and tertiary neutrinos from re-scatters off the relic neutrino background. We compare the high-energy neutrino flux prediction to the most recently available datasets and find qualitative differences to expected spectra from other astrophysical processes. We utilize electroweak corrections to constrain heavy decaying rel…
A variety of new physics scenarios allow for neutrinos to up-scatter into a heavy neutral lepton state. For a range of couplings and neutrino energies, the heavy neutrino may travel some distance before decaying to visible final states. When both the up-scattering and decay occur within the detector volume, these "double bang" events produce distinctive phenomenology with very low background. In this work, we first consider the current sensitivity at Super-Kamiokande via the atmospheric neutrino flux, and find current data may already provide new constraints. We then examine projected future s…
Very recently, the IceCube Collaboration reported a flux of neutrinos in the energy range 50 TeV < E_ν< 2 PeV, which departs from expectations from atmospheric background at the 5.7σlevel. This flux is in remarkable agreement with the expected diffuse flux of neutrinos from starburst galaxies, and the 3 highest energy events have uncertainty contours encompassing some of such systems. These events, all of which have well-measured energies above 1 PeV, exhibit shower topologies, for which the angular resolution is about 15^\circ. Due to this angular uncertainty and the a posteriori nature of cu…
We propose a new way to probe non-standard interactions (NSI) of neutrinos with matter using the ultra-high energy (UHE) neutrino data at current and future neutrino telescopes. We consider the Zee model of radiative neutrino mass generation as a prototype, which allows two charged scalars -- one $SU(2)_L$-doublet and one singlet, both being leptophilic, to be as light as 100 GeV, thereby inducing potentially observable NSI with electrons. We show that these light charged Zee-scalars could give rise to a Glashow-like resonance feature in the UHE neutrino event spectrum at the IceCube neutrino …
The last few years, 2013-2016, the high energy neutrino events in ICECUBE and the last rich UHECR maps by AUGER and TA were hopefully opening a new High Energy astronomy age. Unfortunately the foreseen correlation between neutrino with best gamma X sources has not (yet) been found. The most celebrated GRB gamma sources do not correlate to any neutrino events. The expected Local Group anisotropy in UHECR within the nuleon GZK cut off, has just fade away. UHECR events from Virgo are almost absent. Above two hundred TeV energy tau neutrino might shine by double bang in detectable way in ICECUBE. …
Two of the key unresolved issues facing Standard Model physics are (i) the appearance of a small but non-zero neutrino mass, and, (ii) the missing mass problem in the Universe. The focus of this paper is a previously proposed low energy effective theory that couples a dark scalar to Standard Model neutrinos. This provides a stable dark matter candidate as well as radiatively generating a neutrino mass. Within this framework we will then construct an entirely new bound from the IceCube-170922A event which takes into account (i) the possible neutrino mass hierarchies, (ii) the effect of cosmolog…
The announcement by the IceCube Collaboration of the observation of 53 astrophysical neutrino candidates in the energy range 0.03 \alt E_ν/PeV \alt 2 has been greeted with a great deal of justified excitement. Herein we provide fits of single and a broken power-law energy-spectra to these high-energy starting events (HESEs). By comparing our statistical results from fits to (background-free) shower HESE data with the spectral shape of muon neutrinos recently reported by the IceCube Collaboration, we show that there is (3 σ) evidence for a break in the spectrum of astrophysical neutrinos. After…
The energy spectrum of high-energy neutrinos reported by the IceCube collaboration shows a dip between 400 TeV and 1 PeV. One intriguing explanation is that high-energy neutrinos scatter with the cosmic neutrino background through a $\sim$ MeV mediator. Taking the density matrix approach, we develop a formalism to study the propagation of PeV neutrinos in the presence of the new neutrino interaction. If the interaction is flavored such as the gauged $L_μ-L_τ$ model we consider, the resonant collision may not suppress the PeV neutrino flux completely. The new force mediator may also contribute …
According to recent conjectures on the existence of large extra dimensions in our universe, black holes may be produced during the interaction of Ultra High Energy Cosmic Rays with the atmosphere. However, and so far, the proposed signatures are based on statistical effects, not allowing identification on an event by event basis, and may lead to large uncertainties. In this note, events with a double bang topology, where the production and instantaneous decay of a microscopic black hole (first bang) is followed, at a measurable distance, by the decay of an energetic tau lepton (second bang) ar…
Despite not have been yet identified by the IceCube detector, events generated from $ν_τ$ deep inelastic neutrino scattering in ice with varied topologies, such as double cascades (often called \textit{double bangs}), \textit{lollipops} and \textit{sugardaddies}, constitute a potential laboratory for low-x parton studies. Here we investigate these events, analyzing the effect of next-to-next-to-leading order (NNLO) Parton Distribution Function (PDFs) in the total neutrino--nucleon cross section, as compared with the color dipole formalism, where saturation effects play a major role. Energy dep…
We use CORSIKA+Herwig simulation code to produce ultra-high energy neutrino interactions in the atmosphere. Our aim is to reproduce extensive air showers originated by extragalactic tau-neutrinos. For charged current tau-neutrino interactions in the atmosphere, beside the air shower originated from the neutrino interaction, it is expected that a tau is created and may decay before reaching the ground. That phenomenon makes possible the generation of two related extensive air showers, the so called Double-Bang event. We make an analysis of the main characteristics of Double-Bang events in the a…
A bilinear R-Parity breaking SUSY model for neutrino mass and mixing predicts the lightest superparticle to decay mainly into a pair of tau leptons or b quarks along with a neutrino for relatively light SUSY spectra. This leads to a distinctive triple bang signature of SUSY events at ultrahigh energy neutrino telescopes like IceCube or Antares. While the expected signal size is only marginal at IceCube, it will be promising for a future multi-km^3 size neutrino telescope.
Rome University（罗马大学）；INFN Rome（意大利国家核物理研究所罗马分部）；MIFP（马利诺国际前沿物理中心）；APC laboratory（粒子与宇宙学实验室）；National Research Nuclear University ”MEPHI” (Moscow State Engineering Physics Institute)（国立研究核子大学莫斯科工程物理学院）；Niccolò Cusano University（尼古拉·库萨诺大学）；University Roma Tre（罗马三大）；Gubkin Russian State University (National Research University)（古比雪夫俄罗斯国立大学）；Institute of Physics, Southern Federal University（南联邦大学物理研究所）
Leptoquarks have been suggested to solve a variety of discrepancies between the expected and observed phenomenon. In this paper, we show that the scalar doublet Leptoquark with Hypercharge 7/6 can simultaneously explain the recent measurement of $R_{K}$, $R_{K^*}$, the excess in anomalous magnetic moment of muon, and the observed excess in IceCube HESE data. For appropriate choice of couplings, the flavor anomalies are generated at one-loop level and IceCube data is explained via resonant production of the Leptoquark. Several constraints from LHC searches are imposed on the model parameter spa…
Highest energy neutrino events (contained) in cubic km ICECUBE detector resulted in last three years to be as many as $37-2=35$ signals (two of those having been recently discharged); these tens-hundred TeV (32 energetic events) up to rarest (only 3) PeV cascade showers, proved to have an extraterrestrial origin. The UHE neutrino flavor transition from a $ν_μ$ atmospheric dominance (over $ν_{e}$ showers at TeV energy), toward a higher energy shower cascade ($ν_{e}$, $ν_τ$) events at few tens TeV up to PeV energy is a hint of such a fast extraterrestrial injection. The majority (28 out of 35) o…
A tentative excess in the electron spectrum at 1.4 TeV was recently reported by the DArk Matter Particle Explorer (DAMPE). A non-astrophysical scenario in which dark matter particles annihilate or decay in a local clump has been invoked to explain the excess. If $e^\pm$ annihilation channels in the final states are mediated by left-handed leptons as a component in the $SU(2)_L$ doublet, neutrinos with similar energies should have been simultaneously produced. We demonstrate that generic dark matter models can be decisively tested by the existing IceCube data. In case of a non-detection, such m…
A single power law flux spectrum of high energy neutrinos does not adequately explain the entire 60 TeV to 10 PeV event spectrum observed at IceCube, specially the excess of PeV events and the lack of Glashow resonance events expected at 6.3 PeV cannot be simultaneously explained by a single power law source neutrino flux. Here we consider a model of neutrino splitting $ν\rightarrow 3 ν$ over cosmological distances. Starting from a single power-law spectrum expected from the astrophysical sources, we show that by adjusting the decay length and spectral index one can give a better fit to the ob…
We discuss a simple non-supersymmetric model based on the electroweak gauge group $SU(2)_L\times SU(2)^\prime\times U(1)_{B-L}$ where the lightest of the right-handed neutrinos, which are part of the leptonic doublet of $SU(2)^\prime$, play the role of a long-lived unstable dark matter with mass in the multi-PeV range. We use a resonant $s$-channel annihilation to obtain the correct thermal relic density and relax the unitarity bound on dark matter mass. In this model, there exists a 3-body dark matter decay mode producing tau leptons and neutrinos, which could be the source for the PeV cascad…
The flavor of cosmic neutrinos may help unveil their sources and could reveal the presence of new physics in the neutrino sector. We consider the impacts of next-generation neutrino detectors, including the planned upgrade to neutrino detector--IceCube-Gen2, which is well-positioned to make dramatic improvements in both flavor and spectral measurements. We show that various models in neutrino physics beyond the Standard Model, such as neutrino decay, pseudo-Dirac states, and neutrino self-scattering, may be found or strongly constrained at IceCube-Gen2 and KM3NeT. We find that the additional f…
Extensions of the Standard Model with charged Higgs, having a non-negligible coupling with neutrinos, can have interesting implications vis-à-vis neutrino experiments. Such models can leave their footprints in the ultra-high energy neutrino detectors like IceCube in the form of neutrino non-standard interactions (NSIs) which can also be probed in lower energy neutrino experiments. We consider a model based on the neutrinophilic two-Higgs doublets and study its imprints in the recently reported excess neutrino events in the PeV energy bins at the IceCube. An additional signature of the model is…
The origin of ultra-high energy cosmic rays (UHECR) has been widely regarded as one of the major questions in the frontiers of particle astrophysics. Gamma ray bursts (GRB), the most violent explosions in the universe second only to the Big Bang, have been a popular candidate site for UHECR productions. The recent IceCube report on the non-observation of GRB induced neutrinos therefore attracts wide attention. This dilemma requires a resolution: either the assumption of GRB as UHECR accelerator is to be abandoned or the expected GRB induced neutrino yield was wrong. It has been pointed out tha…
While the first kilometer-scale neutrino telescope, IceCube, is under construction, alternative plans exist to build even larger detectors that will, however, b e limited by a much higher neutrino energy threshold of 10 PeV or higher rather than 10 to 100 GeV. These future projects detect radio and acoustic pulses as w ell as air showers initiated by ultra-high energy neutrinos. As an alternative, we here propose an expansion of IceCube, using the same strings, placed on a gri d with a spacing of order 500 m. Unlike other proposals, the expanded detector uses methods that are understood and ca…
Big Bang Nucleosynthesis and the Neutrino-Extended Standard Model Effective Field Theory
University of Amsterdam（阿姆斯特丹大学）；Nikhef, Theory Group（尼赫夫理论组）；Bethe Center for Theoretical Physics & Physikalisches Institut der Universität Bonn（波恩大学贝特理论物理中心及物理研究所）；Department of Physics, Faculty of Science, University of Zagreb（萨格勒布大学理学院物理系）
Cosmogenic neutrinos reach the Earth with energies around 10^9 GeV, and their interactions with matter will be measured in upcoming experiments (Auger, IceCube). Models with extra dimensions and the fundamental scale at the TeV could imply signals in these experiments. In particular, the production of microscopic black holes by cosmogenic neutrinos has been extensively studied in the literature. Here we make a complete analysis of gravity-mediated interactions at larger distances, where they can be calculated in the eikonal approximation. In these processes a neutrino of energy E_νinteracts el…
We investigate the possibility of detecting cosmic ultra-high energy tau-neutrinos by means of a process involving a double extensive air shower, the so-called Double-Bang Phenomenon. In this process a primary tau-neutrino interacts with an atmospheric quark creating a first hadronic shower and a tau-lepton, which subsequently decays creating a second cascade. The number of these events strongly depends on the flux of tau-neutrinos arriving at the Earth's atmosphere and can be used to test some theoretical models related to the production of ultra-high energy tau-neutrinos. We estimate the pot…
We consider an extension of the Standard Model by two right-handed neutrinos, especially with masses lighter than charged $K$ meson. This simple model can realize the seesaw mechanism for neutrino masses and also the baryogenesis by flavor oscillations of right-handed neutrinos. We summarize the constraints on right-handed neutrinos from direct searches as well as the big bang nucleosynthesis. It is then found that the possible range for the quasi-degenerate mass of right-handed neutrinos is $M_N \geq 163 \MeV$ for normal hierarchy of neutrino masses, while $M_N = 188 \text{--} 269 \MeV$ and $…
We examine whether observable majoron emission in double beta decay can be compatible with the big-bang nucleosynthesis (NS) and the observed neutrino flux from SN1987A. It is found that the NS upper bound on $^4$He abundance implies that the majoron-neutrino Yukawa coupling constant $g\leq 9\times 10^{-6}$ and its maximal value is allowed only when the scalar quartic coupling constant $λ$ is extremely small, $λ\leq 100g^2$. It is also observed that, although quite less restrictive, SN1987A also provides independent constraints on coupling constants.
We investigate the possibility of detecting ultra-high energy cosmic tau-neutrinos by means of a process involving a double extensive air shower, the so-called Double-Bang Phenomenon. In this process a primary tau-neutrino interacts with an atmospheric quark creating a hadronic extensive air shower that contains a tau which subsequently decays creating a second extensive air shower. The number of these events strongly depends on the cross section and on the flux of ultra-high energy tau-neutrinos arriving at the Earth's atmosphere. We estimate the potential of optical detectors to observe Doub…
Considering the scheme with mixing of three neutrinos and a mass hierarchy that can accommodate the results of solar and atmospheric neutrino experiments, it is shown that the results of solar neutrino experiments imply a lower bound for the effective Majorana mass in neutrinoless double-beta decay, under the natural assumptions that massive neutrinos are Majorana particles and there are no unlikely fine-tuned cancellations among the contributions of the different neutrino masses. Considering the four-neutrino schemes that can accommodate also the results of the LSND experiment, it is shown th…
We study the phenomenology of two leptoquarks, the Standard Model $SU(2)$ singlets $S_1$ and $U_1$, with regard to the latest experimental data from the low-energy flavor physics measurements, LHC, and the IceCube neutrino experiment. We consider a scenario when scalar (vector) leptoquark $S_1$ ($U_1$) couples exclusively to the down quark and the neutrinos (charged leptons) of all flavors, where the leptoquark in question couples to the SM lepton doublets. The couplings of $S_1$ ($U_1$) to the up-type quarks and the charged leptons (neutrinos) are in turn uniquely determined via $SU(2)$ symme…
Dimuon events induced by charm-quark productions from neutrino deep inelastic scattering (DIS) processes have been studied in traditional DIS experiments for decades. The recent progress in neutrino telescopes makes it possible to search such dimuon events at energies far beyond laboratory scale. In this paper, we construct a simulation framework to calculate yields and distributions of dimuon signals in an IceCube-like km3 scale neutrino telescope. Due to experimental limitation in the resolution of double-track lateral distance, only dimuon produced outside the detector volume are considered…
Large neutrino event numbers in future experiments measuring coherent elastic neutrino nucleus scattering allow precision measurements of standard and new physics. We analyze the current and prospective limits of a light scalar particle coupling to neutrinos and quarks, using COHERENT and CONUS as examples. Both lepton number conserving and violating interactions are considered. It is shown that current (future) experiments can probe for scalar masses of a few MeV couplings down to the level of $10^{-4}$ $(10^{-6})$. Scalars with masses around the neutrino energy allow to determine their mass …
We propose that the state of the universe does {\it not} spontaneously violate CPT. Instead, the universe after the big bang is the CPT image of the universe before it, both classically and quantum mechanically. The pre- and post-bang epochs comprise a universe/anti-universe pair, emerging from nothing directly into a hot, radiation-dominated era. CPT symmetry selects a unique QFT vacuum state on such a spacetime, providing a new interpretation of the cosmological baryon asymmetry, as well as a remarkably economical explanation for the cosmological dark matter. Requiring only the standard thre…
The importance and signatures of cosmic tau--(anti)neutrinos have been studied for upward-- and downward--going $μ^-+μ^+$ and hadronic shower event rates relevant for present and future underground water or ice detectors, utilizing the unique and reliable ultrasmall--$x$ predictions of the dynamical (radiative) parton model. The upward--going $μ^- +μ^+$ event rates calculated just from cosmic $ν_μ+\barν_μ$ fluxes are sizeably enhanced by taking into account cosmic $ν_τ+ \barν_τ$ fluxes and their associated $τ^- +τ^+$ fluxes as well. The coupled transport equations for the upward--going $\stack…
