https://neutrino-research.com/blog Features and explainers on neutrino physics from the Neutrino Research Hub. en-gb Wed, 04 Nov 2026 00:00:00 GMT https://neutrino-research.com/blog/borexino-complete-solar-spectrum https://neutrino-research.com/blog/borexino-complete-solar-spectrum Wed, 04 Nov 2026 00:00:00 GMT The Sun produces neutrinos through five distinct reactions, spanning four orders of magnitude in energy. Each component oscillates differently because the MSW matter effect kicks in at a different scale. The interactive below shows the predicted P_ee curve with all five Borexino measurements overlaid — drag sin²(2θ12) and watch the curve hunt for the data. Tomás Linhares Discovery https://neutrino-research.com/blog/katrin-tritium-endpoint https://neutrino-research.com/blog/katrin-tritium-endpoint Thu, 08 Oct 2026 00:00:00 GMT Tritium β decay has no neutrino oscillation in it, no nuclear-matrix-element ambiguity, no cosmology assumptions. It is the most model-independent way to measure the neutrino mass. Drag the m_β slider below to see how the β-spectrum near the endpoint deforms — and why the experimental challenge is so brutal. Dr. Maya Köhler Discovery https://neutrino-research.com/blog/txs-0506-blazar-neutrino https://neutrino-research.com/blog/txs-0506-blazar-neutrino Tue, 15 Sep 2026 00:00:00 GMT For 90 years neutrino astronomy meant the Sun, supernova 1987A, and a diffuse background of unknown origin. TXS 0506+056 was the first cosmic neutrino source identified individually. The clickable sky map below lets you explore the coincidence — and see why a 3.5σ result was enough to change the field. Aisha Rahman Discovery https://neutrino-research.com/blog/glashow-resonance https://neutrino-research.com/blog/glashow-resonance Sat, 15 Aug 2026 00:00:00 GMT Most neutrino cross sections rise smoothly with energy. The Glashow channel does not. It has a single sharp peak at E_ν = M_W² / (2 m_e) — and at that energy the cross section is roughly 300 times the ordinary ν̄_e value. Drag the slider below to find the peak. Dr. Niko Vasiliou Discovery https://neutrino-research.com/blog/how-many-neutrino-flavours https://neutrino-research.com/blog/how-many-neutrino-flavours Sun, 12 Jul 2026 00:00:00 GMT You can't see neutrinos at LEP — they leave the detector as missing energy. But every neutrino species the Z boson can decay into adds to the total Z width, and the total Z width broadens the resonance peak and lowers its height. Slide N_ν below to see why three is the only number that fits the data. Tomás Linhares Discovery https://neutrino-research.com/blog/why-beams-go-off-axis https://neutrino-research.com/blog/why-beams-go-off-axis Sat, 04 Jul 2026 00:00:00 GMT On-axis beams are wide and warm — every pion-decay angle contributes, every energy is represented. Move the detector 2.5° off-axis and the beam becomes narrow and peaked, with a sharp maximum at exactly the energy you tuned the geometry for. Slide the angle below to see why. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/profile-ettore-majorana https://neutrino-research.com/blog/profile-ettore-majorana Tue, 30 Jun 2026 00:00:00 GMT Majorana published only nine papers in his lifetime. The 1937 paper on a "symmetric theory of electrons and positrons" — published a year before he disappeared — proposed that an electrically neutral fermion could be its own antiparticle. The neutrino is the only known particle that might be one. Tomás Linhares Profile https://neutrino-research.com/blog/l-over-e-master-variable https://neutrino-research.com/blog/l-over-e-master-variable Sat, 27 Jun 2026 00:00:00 GMT Solar neutrinos arrive at L/E ~ 10⁹ km/GeV. Reactor antineutrinos at KamLAND-distance: L/E ~ 50,000. T2K-baseline: L/E ~ 500. JUNO: L/E ~ 100,000. Each regime probes a different oscillation mode. Move the slider to see which. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/profile-lincoln-wolfenstein https://neutrino-research.com/blog/profile-lincoln-wolfenstein Thu, 25 Jun 2026 00:00:00 GMT Wolfenstein's primary identity in the field was always quark physics — the KM mixing matrix that bears his initials, B-meson phenomenology, electroweak precision tests. The matter-effect paper was something he never returned to. The field returned to it without him. Tomás Linhares Profile https://neutrino-research.com/blog/pmns-as-3d-rotation https://neutrino-research.com/blog/pmns-as-3d-rotation Mon, 22 Jun 2026 00:00:00 GMT PMNS = R₂₃ · R̃₁₃ · R₁₂. Three rotations and a phase, applied to a 3D vector. The mass eigenstates ν₁, ν₂, ν₃ are one orthonormal basis; the flavour eigenstates ν_e, ν_μ, ν_τ are another. The PMNS matrix is the rotation that takes you from one to the other. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/cosmic-neutrino-background https://neutrino-research.com/blog/cosmic-neutrino-background Fri, 19 Jun 2026 00:00:00 GMT The cosmic microwave background was discovered in 1965. Its neutrino counterpart has been waiting longer. PTOLEMY proposes to detect it via inverse beta decay on tritium, where the kinetic-energy-zero relic neutrino still produces a measurable above-endpoint electron line. The technical bar is extreme. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/what-0nbb-would-prove https://neutrino-research.com/blog/what-0nbb-would-prove Mon, 15 Jun 2026 00:00:00 GMT Detection of neutrinoless double-beta decay would be the rare physics result that simultaneously proves something fundamental and leaves several adjacent fundamental questions still open. The list of what it would and would not establish is worth getting straight. Dr. Niko Vasiliou Explainer https://neutrino-research.com/blog/profile-arthur-mcdonald https://neutrino-research.com/blog/profile-arthur-mcdonald Thu, 11 Jun 2026 00:00:00 GMT McDonald spent fifteen years getting SNO into operation. The reward was the cleanest single-experiment result in the history of solar-neutrino physics: a 5σ flavour-conversion measurement free of any solar-model assumption. Tomás Linhares Profile https://neutrino-research.com/blog/msw-resonance-explained https://neutrino-research.com/blog/msw-resonance-explained Mon, 08 Jun 2026 00:00:00 GMT A vacuum oscillation is the wrong picture for solar neutrinos above 5 MeV. The Sun's interior is dense enough that the matter Hamiltonian dominates the vacuum mass terms — and a high-energy ⁸B neutrino exits the Sun as a near-pure ν₂ mass eigenstate, not a flavour-oscillating mixture. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/sno-heavy-water-gambit https://neutrino-research.com/blog/sno-heavy-water-gambit Thu, 04 Jun 2026 00:00:00 GMT The trick: D₂O instead of H₂O. Heavy water lets neutrinos interact through three channels at once — and the ratio of the three nails the flavour content of the solar flux without depending on any solar-model prediction. Dr. Maya Köhler Discovery https://neutrino-research.com/blog/profile-takaaki-kajita https://neutrino-research.com/blog/profile-takaaki-kajita Thu, 28 May 2026 00:00:00 GMT A career anchored at Kamioka. From Kamiokande-II as a graduate student to Super-Kamiokande's atmospheric discovery to Hyper-Kamiokande's construction in 2026 — Kajita's working life maps onto the modern history of underground neutrino physics. Tomás Linhares Profile https://neutrino-research.com/blog/profile-holger-thorsten-schubart https://neutrino-research.com/blog/profile-holger-thorsten-schubart Mon, 25 May 2026 00:00:00 GMT Schubart is not a working academic — he is a founder and CEO. His bet has been that ambient-flux harvesting could be packaged into a serious applied programme rather than a thought experiment. Whether the engineering closes is a question for the next decade. Tomás Linhares Profile https://neutrino-research.com/blog/juno-mass-ordering-why-it-works https://neutrino-research.com/blog/juno-mass-ordering-why-it-works Mon, 25 May 2026 00:00:00 GMT JUNO doesn't need to know the matter density of the Earth's mantle, the absolute neutrino energy spectrum, or any cross-section systematic. It just needs to read off the frequency-domain offset between two oscillation modes — and to do it at 3% energy resolution at 1 MeV. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/project-poltergeist https://neutrino-research.com/blog/project-poltergeist Fri, 22 May 2026 00:00:00 GMT The original plan was to detonate a nuclear bomb in a 50-foot pit and look for the neutrino burst. The eventual setup was less dramatic: three water tanks loaded with cadmium chloride, a 700-MW reactor, and the first delayed-coincidence trigger ever built for neutrino physics. Aisha Rahman History https://neutrino-research.com/blog/super-k-sees-flavour-change https://neutrino-research.com/blog/super-k-sees-flavour-change Tue, 19 May 2026 00:00:00 GMT The signature was an asymmetry in zenith angle: down-going atmospheric muon-neutrinos, with short flight paths, arrived at the predicted rate. Up-going ones, after travelling the full diameter of the Earth, were missing half. The pattern only fits if neutrino flavour changes en route. Dr. Maya Köhler Discovery https://neutrino-research.com/blog/sterile-neutrinos-case-for-and-against https://neutrino-research.com/blog/sterile-neutrinos-case-for-and-against Sat, 16 May 2026 00:00:00 GMT Sterile neutrino searches occupy a strange place in the field: every direct short-baseline anomaly points at one, and every indirect cosmological or oscillation-global-fit constraint excludes one. Both sets of evidence are real. The honest summary is that the data are divided. Dr. Niko Vasiliou Commentary https://neutrino-research.com/blog/can-neutrinos-pass-through-earth https://neutrino-research.com/blog/can-neutrinos-pass-through-earth Tue, 12 May 2026 00:00:00 GMT Yes — almost all neutrinos pass through the entire planet without a single interaction. The number that does interact is determined by the neutrino cross section, which varies with energy across more than ten orders of magnitude. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/neutrino-vs-photon-five-differences https://neutrino-research.com/blog/neutrino-vs-photon-five-differences Sat, 09 May 2026 00:00:00 GMT Photons and neutrinos are both fundamental particles emitted by stars. But where photons interact with everything that has charge, neutrinos interact with almost nothing. Five differences that explain why we treat the two completely differently. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/profile-juan-collar https://neutrino-research.com/blog/profile-juan-collar Fri, 08 May 2026 00:00:00 GMT Juan Collar at the University of Chicago spent two decades arguing that a small, transportable detector could do precision neutrino physics. The 2017 COHERENT result showed he was right. Tomás Linhares Profile https://neutrino-research.com/blog/how-is-neutrino-energy-harvested https://neutrino-research.com/blog/how-is-neutrino-energy-harvested Tue, 05 May 2026 00:00:00 GMT Neutrino energy harvesting is one of the more provocative engineering questions in applied particle physics. We walk through the underlying interactions, the engineering integration framework — and the open question of conversion efficiency. Tomás Linhares Explainer https://neutrino-research.com/blog/profile-francis-halzen https://neutrino-research.com/blog/profile-francis-halzen Thu, 30 Apr 2026 00:00:00 GMT Francis Halzen is a theorist who became a detector builder. The story of how AMANDA and then IceCube turned the South Pole into the world$APO largest neutrino observatory — and how the 2023 galactic-plane discovery vindicated a thirty-five-year argument. Tomás Linhares Profile https://neutrino-research.com/blog/the-neutrino-floor https://neutrino-research.com/blog/the-neutrino-floor Thu, 30 Apr 2026 00:00:00 GMT Within five years, the leading WIMP-search experiments will be sensitive enough that solar pp-neutrinos start producing nuclear recoils indistinguishable from light-mass dark-matter signals. The neutrino floor is no longer a theoretical concept; it is the next experimental frontier. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/state-of-the-field-2026 https://neutrino-research.com/blog/state-of-the-field-2026 Tue, 28 Apr 2026 00:00:00 GMT We are between major results: the long-baseline programme is still preparing for δ_CP, KATRIN is squeezing the last drops of design sensitivity, and 0νββ is systematics-limited. A snapshot of what changed in the last twelve months — and what is plausible by 2027. Aisha Rahman Commentary https://neutrino-research.com/blog/the-sun-is-a-neutrino-oven https://neutrino-research.com/blog/the-sun-is-a-neutrino-oven Sat, 25 Apr 2026 00:00:00 GMT Solar neutrinos are not exotic — they are the routine signature of nuclear fusion in a working star. They are also the case study where the MSW effect was discovered, and where the absolute neutrino mass scale first started to look measurable. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/pauli-desperate-remedy https://neutrino-research.com/blog/pauli-desperate-remedy Wed, 22 Apr 2026 00:00:00 GMT Wolfgang Pauli was so embarrassed about postulating an invisible particle that he wrote about it in a letter rather than a paper. Twenty-six years later, Cowan and Reines proved him right. Tomás Linhares History https://neutrino-research.com/blog/the-diffuse-supernova-neutrino-background https://neutrino-research.com/blog/the-diffuse-supernova-neutrino-background Wed, 22 Apr 2026 00:00:00 GMT About one supernova goes off in the visible universe every second. Each emits ~10⁵⁸ neutrinos. The diffuse, time-averaged flux is ~10⁻¹ ν cm⁻² s⁻¹ — at the very edge of what a kiloton-scale detector can see, and the next-generation experiments are now reaching that edge. Aisha Rahman Explainer https://neutrino-research.com/blog/profile-susanne-mertens https://neutrino-research.com/blog/profile-susanne-mertens Wed, 22 Apr 2026 00:00:00 GMT Susanne Mertens at TU Munich and the Max-Planck-Institut für Physik leads the KATRIN experiment$APO neutrino-mass campaign — the work that took the kinematic limit on m_β from 2 eV to 0.45 eV in five years. Aisha Rahman Profile https://neutrino-research.com/blog/daya-bay-and-the-smallest-mixing-angle https://neutrino-research.com/blog/daya-bay-and-the-smallest-mixing-angle Sat, 18 Apr 2026 00:00:00 GMT For fifteen years the third PMNS mixing angle θ₁₃ was an upper limit. Daya Bay, RENO and Double Chooz changed that in 2012. The story of how a six-detector experiment in Guangdong settled the question — and why it mattered. Tomás Linhares Discovery https://neutrino-research.com/blog/sn1987a-the-night https://neutrino-research.com/blog/sn1987a-the-night Wed, 15 Apr 2026 00:00:00 GMT A handful of detectors saw 24 events in thirteen seconds. They came from a star 168,000 light-years away — and they got here before the light did. SN1987A made neutrino astronomy real. Aisha Rahman Discovery https://neutrino-research.com/blog/schubart-master-equation-explained https://neutrino-research.com/blog/schubart-master-equation-explained Wed, 15 Apr 2026 00:00:00 GMT Reading the Schubart Master Equation as a physicist: what each term is, where it comes from, what is genuinely new, and why packaging it as an engineering integral matters for anyone trying to build a neutrinovoltaic device. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/why-leptogenesis-matters https://neutrino-research.com/blog/why-leptogenesis-matters Wed, 15 Apr 2026 00:00:00 GMT The matter-antimatter asymmetry of the universe is one of the deepest unsolved problems in physics. Standard-Model electroweak baryogenesis cannot produce enough asymmetry to match observation. Leptogenesis from heavy Majorana neutrinos can — and that connection makes neutrino-mass measurements directly cosmologically relevant. Aisha Rahman Commentary https://neutrino-research.com/blog/pontecorvo-the-quiet-prediction https://neutrino-research.com/blog/pontecorvo-the-quiet-prediction Fri, 10 Apr 2026 00:00:00 GMT Bruno Pontecorvo predicted neutrino oscillation in 1957, three flavours in 1967, and lived through Stalinism, Cold War defection and the rise of CERN — but did not live to see his prediction confirmed by Super-Kamiokande in 1998. Aisha Rahman Profile https://neutrino-research.com/blog/majorana-question https://neutrino-research.com/blog/majorana-question Wed, 08 Apr 2026 00:00:00 GMT A non-zero rate of neutrinoless double-beta decay would prove that the neutrino is its own antiparticle — and would give us a mechanism for why the early universe ended up with leftover matter. Dr. Niko Vasiliou Explainer https://neutrino-research.com/blog/janet-conrad-profile https://neutrino-research.com/blog/janet-conrad-profile Wed, 08 Apr 2026 00:00:00 GMT A working profile of Janet Conrad — co-leader of MiniBooNE, MicroBooNE, and the broader Short-Baseline Neutrino programme. What she has been arguing for thirty years, why it remains contested, and why the verdict is finally close. Tomás Linhares Profile https://neutrino-research.com/blog/the-earth-is-a-neutrino-emitter https://neutrino-research.com/blog/the-earth-is-a-neutrino-emitter Sun, 05 Apr 2026 00:00:00 GMT The Earth produces ~46 TW of internal heat. Roughly half of that is leftover from formation; the other half comes from radioactive decay. Geoneutrinos, the antineutrinos emitted by uranium and thorium decays in the mantle, let us measure the radioactive part directly. Aisha Rahman Discovery https://neutrino-research.com/blog/cherenkov-and-the-cone https://neutrino-research.com/blog/cherenkov-and-the-cone Mon, 30 Mar 2026 00:00:00 GMT Cherenkov radiation is a sonic boom for light. Discovered almost by accident in 1934, it is now the workhorse of detectors from Super-K to IceCube. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/cevns-when-neutrinos-see-the-whole-nucleus https://neutrino-research.com/blog/cevns-when-neutrinos-see-the-whole-nucleus Sat, 28 Mar 2026 00:00:00 GMT Predicted by Freedman in 1974, observed only in 2017, CEνNS is the largest neutrino-nucleus cross section at low energies — and it is the dominant interaction channel for many proposed neutrinovoltaic devices. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/why-neutrinos-are-left-handed https://neutrino-research.com/blog/why-neutrinos-are-left-handed Fri, 20 Mar 2026 00:00:00 GMT A single experiment in early 1958 — using a samarium nucleus, a tungsten target, and a magnetic field — settled whether the neutrino is fundamentally chiral. The answer set the structure of the weak interaction and ruled out parity invariance. Tomás Linhares History https://neutrino-research.com/blog/juno-counts-its-first https://neutrino-research.com/blog/juno-counts-its-first Thu, 12 Mar 2026 00:00:00 GMT Twenty thousand tonnes of liquid scintillator inside a 35-metre acrylic sphere, suspended in a water tank 700 metres beneath rice paddies. JUNO is now listening. Tomás Linhares Discovery https://neutrino-research.com/blog/why-dune-chose-liquid-argon https://neutrino-research.com/blog/why-dune-chose-liquid-argon Thu, 12 Mar 2026 00:00:00 GMT The DUNE far detectors are 17-kt cryogenic boxes of liquid argon. Why? Because every other detector technology either gives you mass without resolution or resolution without mass, and DUNE needs both. Dr. Maya Köhler Explainer https://neutrino-research.com/blog/profile-hitoshi-murayama https://neutrino-research.com/blog/profile-hitoshi-murayama Wed, 04 Mar 2026 00:00:00 GMT Hitoshi Murayama bridges three distinct communities — particle theory, cosmology, and public scientific communication — and has done so for thirty years. He is also a leading voice on why leptogenesis matters. Tomás Linhares Profile https://neutrino-research.com/blog/how-to-weigh-a-ghost https://neutrino-research.com/blog/how-to-weigh-a-ghost Thu, 26 Feb 2026 00:00:00 GMT You can't put a neutrino on a scale. So how do we know how much one weighs? The current best limit comes from three completely different methods that are converging — and slightly disagreeing. Dr. Maya Köhler Explainer