The OPERA experiment measures the velocity of neutrinos produced at CERN and detected 730 km away at the Gran Sasso laboratory to high precision. To do so it must accurately measure the time of flight of neutrinos between the two sites by precisely synchronizing clocks at CERN and Gran Sasso, determining the baseline distance through geodesy, and calibrating the timing of the proton beam and neutrino detection. This allows OPERA to search for small deviations from the speed of light in the measurement of the neutrino velocity.
The Large Hadron Collider at CERN is the world's most largest machine, having stored magnet energy in excess of 5 Giga-Joules, and energy stored in each circulating beam in excess of 360 Mega-Joules.
A machine protection system has been implemented to protect LHC against the risks related to stored energies, whilst allowing the machine to operate close to the physical limits.
The Large Hadron Collider at CERN is the world's most largest machine, having stored magnet energy in excess of 5 Giga-Joules, and energy stored in each circulating beam in excess of 360 Mega-Joules.
A machine protection system has been implemented to protect LHC against the risks related to stored energies, whilst allowing the machine to operate close to the physical limits.
Signal decompositions using trans-dimensional Bayesian methods: Alireza Rooda...Alireza_Roodaki
These are the slides I have used during the defense of my thesis (see https://sites.google.com/site/alireza4702/publications/phd-thesis for more information).
First results from the full-scale prototype for the Fluorescence detector Arr...Toshihiro FUJII
The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a design concept for the next generation of ultrahigh-energy cosmic ray (UHECR) observatories, addressing the requirements for a large-area, low-cost detector suitable for measuring the properties of the highest energy cosmic rays. In the FAST design, a large field of view is covered by a few pixels at the focal plane of a mirror or Fresnel lens. Motivated by the successful detection of UHECRs using a prototype comprised of a single 200 mm photomultiplier-tube and a 1 m2 Fresnel lens system [Astropart.Phys. 74 (2016) 64-72], we have developed a new full-scale prototype consisting of four 200 mm photomultiplier-tubes at the focus of a segmented mirror of 1.6 m in diameter. In October 2016 we installed the full-scale prototype at the Telescope Array site in central Utah, USA, and began steady data taking. We report on first results of the full-scale FAST prototype, including measurements of artificial light sources, distant ultraviolet lasers, and UHECRs.
35th International Cosmic Ray Conference — ICRC2017 18th July, 2017
Bexco, Busan, Korea
Robot navigation in unknown environment with obstacle recognition using laser...IJECEIAES
Robot navigation in unknown and dynamic environments may result in aimless wandering, corner traps and repetitive path loops. To address these issues, this paper presents the solution by comparing the standard deviation of the distance ranges of the obstacles appeared in the robot navigation path. For the similar obstacles, The standard deviations of distance range vectors, obtained from the laser range finder sensor of the robot at similar pose, are very close to each other. Therefore, the measurements of odometer sensor are also combined with the standard deviation to recognize the location of the obstacles. A novel algorithm, with obstacle detection feature, is presented for robot navigation in unknown and dynamic environments. The algorithm checks the similarity of the distance range vectors of the obstacles in the path and uses this information in combination with the odometer measurements to identify the obstacles and their locations. The experimental work is carried out using Gazebo simulator.
Measurement of the neutrino velocity with the OPERA detector in the CNGS beamSebastien Bianchin
The OPERA neutrino experiment at the underground Gran Sasso Laboratory has measured the velocity of neutrinos from the CERN CNGS beam over a baseline of about 730 km with much higher accuracy than previous studies conducted with accelerator neutrinos. The measurement is based on high-statistics data taken by OPERA in the years 2009, 2010 and 2011. Dedicated upgrades of the CNGS timing system and of the OPERA detector, as well as a high precision geodesy campaign for the measurement of the neutrino baseline, allowed reaching comparable systematic and statistical accuracies. An early arrival time of CNGS muon neutrinos with respect to the one computed assuming the speed of light in vacuum of (60.7 \pm 6.9 (stat.) \pm 7.4 (sys.)) ns was measured. This anomaly corresponds to a relative difference of the muon neutrino velocity with respect to the speed of light (v-c)/c = (2.48 \pm 0.28 (stat.) \pm 0.30 (sys.)) \times 10-5.
Signal decompositions using trans-dimensional Bayesian methods: Alireza Rooda...Alireza_Roodaki
These are the slides I have used during the defense of my thesis (see https://sites.google.com/site/alireza4702/publications/phd-thesis for more information).
First results from the full-scale prototype for the Fluorescence detector Arr...Toshihiro FUJII
The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a design concept for the next generation of ultrahigh-energy cosmic ray (UHECR) observatories, addressing the requirements for a large-area, low-cost detector suitable for measuring the properties of the highest energy cosmic rays. In the FAST design, a large field of view is covered by a few pixels at the focal plane of a mirror or Fresnel lens. Motivated by the successful detection of UHECRs using a prototype comprised of a single 200 mm photomultiplier-tube and a 1 m2 Fresnel lens system [Astropart.Phys. 74 (2016) 64-72], we have developed a new full-scale prototype consisting of four 200 mm photomultiplier-tubes at the focus of a segmented mirror of 1.6 m in diameter. In October 2016 we installed the full-scale prototype at the Telescope Array site in central Utah, USA, and began steady data taking. We report on first results of the full-scale FAST prototype, including measurements of artificial light sources, distant ultraviolet lasers, and UHECRs.
35th International Cosmic Ray Conference — ICRC2017 18th July, 2017
Bexco, Busan, Korea
Robot navigation in unknown environment with obstacle recognition using laser...IJECEIAES
Robot navigation in unknown and dynamic environments may result in aimless wandering, corner traps and repetitive path loops. To address these issues, this paper presents the solution by comparing the standard deviation of the distance ranges of the obstacles appeared in the robot navigation path. For the similar obstacles, The standard deviations of distance range vectors, obtained from the laser range finder sensor of the robot at similar pose, are very close to each other. Therefore, the measurements of odometer sensor are also combined with the standard deviation to recognize the location of the obstacles. A novel algorithm, with obstacle detection feature, is presented for robot navigation in unknown and dynamic environments. The algorithm checks the similarity of the distance range vectors of the obstacles in the path and uses this information in combination with the odometer measurements to identify the obstacles and their locations. The experimental work is carried out using Gazebo simulator.
Measurement of the neutrino velocity with the OPERA detector in the CNGS beamSebastien Bianchin
The OPERA neutrino experiment at the underground Gran Sasso Laboratory has measured the velocity of neutrinos from the CERN CNGS beam over a baseline of about 730 km with much higher accuracy than previous studies conducted with accelerator neutrinos. The measurement is based on high-statistics data taken by OPERA in the years 2009, 2010 and 2011. Dedicated upgrades of the CNGS timing system and of the OPERA detector, as well as a high precision geodesy campaign for the measurement of the neutrino baseline, allowed reaching comparable systematic and statistical accuracies. An early arrival time of CNGS muon neutrinos with respect to the one computed assuming the speed of light in vacuum of (60.7 \pm 6.9 (stat.) \pm 7.4 (sys.)) ns was measured. This anomaly corresponds to a relative difference of the muon neutrino velocity with respect to the speed of light (v-c)/c = (2.48 \pm 0.28 (stat.) \pm 0.30 (sys.)) \times 10-5.
Tra Trieste e Nova Gorica per lo studio dei fenomeni ultraveloci / Between Trieste and Nova Gorica for the study of ultra-fast phenomena - by Cesare Grazioli
Rob Meagley and Andrew Bleloch at Health Extension Salon #5Health_Extension
Dr. Rob Meagley and Dr. Andrew Bleloch present their focused summary of the recent 2012 Foresight Nanotechnology Conference, answering the question: which will be powerfull enough to intervene in aging processes first: biotechnology or nanotechnology?
Sensors are becoming ubiquitous in our lives and possible applications are countless. Micro and nanotechnologies are the natural choice for enabling complex sensor nodes, as they are small (thus unobtrusive), cheap and low power. Carbon nanotubes (CNTs) are a perfect example of how nanosystems offer features unachievable with microsystems: their outstanding structural, mechanical and electronic properties have immediately resulted in numerous device demonstrators from transistors, to physical and chemical sensors, and actuators. A key idea of the project is to combine elements from the fundamental knowledge base on the physics of carbon nanotubes, gathered in the past several years, and the fundamental engineering sciences in the area of micro/nano-electromechanical systems, to develop novel devices and processes based on CNTs.
Specificaly, it seeks to demonstrate concepts and devices for ultra-low power, highly miniaturized functional blocks for sensing and electronics. Due to their small mass and high stiffness, doubly clamped CNTs can exhibit huge resonant frequencies. These are carbon nanotube resonators which, as recently demonstrated or predicted theoretically, can reach the multi-GHz range, can be tuned via straining over a wide range of frequency, offer an unprecedented sensitivity to strain or mass loading, exhibit high quality factors, and all these with a very low power consumption.
Dr. Gernot S. Pomrenke presents an overview of his program, Photonics and Optoelectronics, at the AFOSR 2013 Spring Review. At this review, Program Officers from AFOSR Technical Divisions will present briefings that highlight basic research programs beneficial to the Air Force.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Tr...Sérgio Sacani
Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the
atmospheres of terrestrial planets via follow-up spectroscopic observations. However, the number of such planets
receiving low insolation is still small, limiting our ability to understand the diversity of the atmospheric
composition and climates of temperate terrestrial planets. We report the discovery of an Earth-sized planet
transiting the nearby (12 pc) inactive M3.0 dwarf Gliese 12 (TOI-6251) with an orbital period (Porb) of 12.76 days.
The planet, Gliese 12 b, was initially identified as a candidate with an ambiguous Porb from TESS data. We
confirmed the transit signal and Porb using ground-based photometry with MuSCAT2 and MuSCAT3, and
validated the planetary nature of the signal using high-resolution images from Gemini/NIRI and Keck/NIRC2 as
well as radial velocity (RV) measurements from the InfraRed Doppler instrument on the Subaru 8.2 m telescope
and from CARMENES on the CAHA 3.5 m telescope. X-ray observations with XMM-Newton showed the host
star is inactive, with an X-ray-to-bolometric luminosity ratio of log 5.7 L L X bol » - . Joint analysis of the light
curves and RV measurements revealed that Gliese 12 b has a radius of 0.96 ± 0.05 R⊕,a3σ mass upper limit of
3.9 M⊕, and an equilibrium temperature of 315 ± 6 K assuming zero albedo. The transmission spectroscopy metric
(TSM) value of Gliese 12 b is close to the TSM values of the TRAPPIST-1 planets, adding Gliese 12 b to the small
list of potentially terrestrial, temperate planets amenable to atmospheric characterization with JWST.
Gliese 12 b, a temperate Earth-sized planet at 12 parsecs discovered with TES...Sérgio Sacani
We report on the discovery of Gliese 12 b, the nearest transiting temperate, Earth-sized planet found to date. Gliese 12 is a
bright (V = 12.6 mag, K = 7.8 mag) metal-poor M4V star only 12.162 ± 0.005 pc away from the Solar system with one of the
lowest stellar activity levels known for M-dwarfs. A planet candidate was detected by TESS based on only 3 transits in sectors
42, 43, and 57, with an ambiguity in the orbital period due to observational gaps. We performed follow-up transit observations
with CHEOPS and ground-based photometry with MINERVA-Australis, SPECULOOS, and Purple Mountain Observatory,
as well as further TESS observations in sector 70. We statistically validate Gliese 12 b as a planet with an orbital period of
12.76144 ± 0.00006 d and a radius of 1.0 ± 0.1 R⊕, resulting in an equilibrium temperature of ∼315 K. Gliese 12 b has excellent
future prospects for precise mass measurement, which may inform how planetary internal structure is affected by the stellar
compositional environment. Gliese 12 b also represents one of the best targets to study whether Earth-like planets orbiting cool
stars can retain their atmospheres, a crucial step to advance our understanding of habitability on Earth and across the galaxy.
The importance of continents, oceans and plate tectonics for the evolution of...Sérgio Sacani
Within the uncertainties of involved astronomical and biological parameters, the Drake Equation
typically predicts that there should be many exoplanets in our galaxy hosting active, communicative
civilizations (ACCs). These optimistic calculations are however not supported by evidence, which is
often referred to as the Fermi Paradox. Here, we elaborate on this long-standing enigma by showing
the importance of planetary tectonic style for biological evolution. We summarize growing evidence
that a prolonged transition from Mesoproterozoic active single lid tectonics (1.6 to 1.0 Ga) to modern
plate tectonics occurred in the Neoproterozoic Era (1.0 to 0.541 Ga), which dramatically accelerated
emergence and evolution of complex species. We further suggest that both continents and oceans
are required for ACCs because early evolution of simple life must happen in water but late evolution
of advanced life capable of creating technology must happen on land. We resolve the Fermi Paradox
(1) by adding two additional terms to the Drake Equation: foc
(the fraction of habitable exoplanets
with significant continents and oceans) and fpt
(the fraction of habitable exoplanets with significant
continents and oceans that have had plate tectonics operating for at least 0.5 Ga); and (2) by
demonstrating that the product of foc
and fpt
is very small (< 0.00003–0.002). We propose that the lack
of evidence for ACCs reflects the scarcity of long-lived plate tectonics and/or continents and oceans on
exoplanets with primitive life.
A Giant Impact Origin for the First Subduction on EarthSérgio Sacani
Hadean zircons provide a potential record of Earth's earliest subduction 4.3 billion years ago. Itremains enigmatic how subduction could be initiated so soon after the presumably Moon‐forming giant impact(MGI). Earlier studies found an increase in Earth's core‐mantle boundary (CMB) temperature due to theaccumulation of the impactor's core, and our recent work shows Earth's lower mantle remains largely solid, withsome of the impactor's mantle potentially surviving as the large low‐shear velocity provinces (LLSVPs). Here,we show that a hot post‐impact CMB drives the initiation of strong mantle plumes that can induce subductioninitiation ∼200 Myr after the MGI. 2D and 3D thermomechanical computations show that a high CMBtemperature is the primary factor triggering early subduction, with enrichment of heat‐producing elements inLLSVPs as another potential factor. The models link the earliest subduction to the MGI with implications forunderstanding the diverse tectonic regimes of rocky planets.
Climate extremes likely to drive land mammal extinction during next supercont...Sérgio Sacani
Mammals have dominated Earth for approximately 55 Myr thanks to their
adaptations and resilience to warming and cooling during the Cenozoic. All
life will eventually perish in a runaway greenhouse once absorbed solar
radiation exceeds the emission of thermal radiation in several billions of
years. However, conditions rendering the Earth naturally inhospitable to
mammals may develop sooner because of long-term processes linked to
plate tectonics (short-term perturbations are not considered here). In
~250 Myr, all continents will converge to form Earth’s next supercontinent,
Pangea Ultima. A natural consequence of the creation and decay of Pangea
Ultima will be extremes in pCO2 due to changes in volcanic rifting and
outgassing. Here we show that increased pCO2, solar energy (F⨀;
approximately +2.5% W m−2 greater than today) and continentality (larger
range in temperatures away from the ocean) lead to increasing warming
hostile to mammalian life. We assess their impact on mammalian
physiological limits (dry bulb, wet bulb and Humidex heat stress indicators)
as well as a planetary habitability index. Given mammals’ continued survival,
predicted background pCO2 levels of 410–816 ppm combined with increased
F⨀ will probably lead to a climate tipping point and their mass extinction.
The results also highlight how global landmass configuration, pCO2 and F⨀
play a critical role in planetary habitability.
Constraints on Neutrino Natal Kicks from Black-Hole Binary VFTS 243Sérgio Sacani
The recently reported observation of VFTS 243 is the first example of a massive black-hole binary
system with negligible binary interaction following black-hole formation. The black-hole mass (≈10M⊙)
and near-circular orbit (e ≈ 0.02) of VFTS 243 suggest that the progenitor star experienced complete
collapse, with energy-momentum being lost predominantly through neutrinos. VFTS 243 enables us to
constrain the natal kick and neutrino-emission asymmetry during black-hole formation. At 68% confidence
level, the natal kick velocity (mass decrement) is ≲10 km=s (≲1.0M⊙), with a full probability distribution
that peaks when ≈0.3M⊙ were ejected, presumably in neutrinos, and the black hole experienced a natal
kick of 4 km=s. The neutrino-emission asymmetry is ≲4%, with best fit values of ∼0–0.2%. Such a small
neutrino natal kick accompanying black-hole formation is in agreement with theoretical predictions.
Detectability of Solar Panels as a TechnosignatureSérgio Sacani
In this work, we assess the potential detectability of solar panels made of silicon on an Earth-like
exoplanet as a potential technosignature. Silicon-based photovoltaic cells have high reflectance in the
UV-VIS and in the near-IR, within the wavelength range of a space-based flagship mission concept
like the Habitable Worlds Observatory (HWO). Assuming that only solar energy is used to provide
the 2022 human energy needs with a land cover of ∼ 2.4%, and projecting the future energy demand
assuming various growth-rate scenarios, we assess the detectability with an 8 m HWO-like telescope.
Assuming the most favorable viewing orientation, and focusing on the strong absorption edge in the
ultraviolet-to-visible (0.34 − 0.52 µm), we find that several 100s of hours of observation time is needed
to reach a SNR of 5 for an Earth-like planet around a Sun-like star at 10pc, even with a solar panel
coverage of ∼ 23% land coverage of a future Earth. We discuss the necessity of concepts like Kardeshev
Type I/II civilizations and Dyson spheres, which would aim to harness vast amounts of energy. Even
with much larger populations than today, the total energy use of human civilization would be orders of
magnitude below the threshold for causing direct thermal heating or reaching the scale of a Kardashev
Type I civilization. Any extraterrrestrial civilization that likewise achieves sustainable population
levels may also find a limit on its need to expand, which suggests that a galaxy-spanning civilization
as imagined in the Fermi paradox may not exist.
Jet reorientation in central galaxies of clusters and groups: insights from V...Sérgio Sacani
Recent observations of galaxy clusters and groups with misalignments between their central AGN jets
and X-ray cavities, or with multiple misaligned cavities, have raised concerns about the jet – bubble
connection in cooling cores, and the processes responsible for jet realignment. To investigate the
frequency and causes of such misalignments, we construct a sample of 16 cool core galaxy clusters and
groups. Using VLBA radio data we measure the parsec-scale position angle of the jets, and compare
it with the position angle of the X-ray cavities detected in Chandra data. Using the overall sample
and selected subsets, we consistently find that there is a 30% – 38% chance to find a misalignment
larger than ∆Ψ = 45◦ when observing a cluster/group with a detected jet and at least one cavity. We
determine that projection may account for an apparently large ∆Ψ only in a fraction of objects (∼35%),
and given that gas dynamical disturbances (as sloshing) are found in both aligned and misaligned
systems, we exclude environmental perturbation as the main driver of cavity – jet misalignment.
Moreover, we find that large misalignments (up to ∼ 90◦
) are favored over smaller ones (45◦ ≤ ∆Ψ ≤
70◦
), and that the change in jet direction can occur on timescales between one and a few tens of Myr.
We conclude that misalignments are more likely related to actual reorientation of the jet axis, and we
discuss several engine-based mechanisms that may cause these dramatic changes.
The solar dynamo begins near the surfaceSérgio Sacani
The magnetic dynamo cycle of the Sun features a distinct pattern: a propagating
region of sunspot emergence appears around 30° latitude and vanishes near the
equator every 11 years (ref. 1). Moreover, longitudinal flows called torsional oscillations
closely shadow sunspot migration, undoubtedly sharing a common cause2. Contrary
to theories suggesting deep origins of these phenomena, helioseismology pinpoints
low-latitude torsional oscillations to the outer 5–10% of the Sun, the near-surface
shear layer3,4. Within this zone, inwardly increasing differential rotation coupled with
a poloidal magnetic field strongly implicates the magneto-rotational instability5,6,
prominent in accretion-disk theory and observed in laboratory experiments7.
Together, these two facts prompt the general question: whether the solar dynamo is
possibly a near-surface instability. Here we report strong affirmative evidence in stark
contrast to traditional models8 focusing on the deeper tachocline. Simple analytic
estimates show that the near-surface magneto-rotational instability better explains
the spatiotemporal scales of the torsional oscillations and inferred subsurface
magnetic field amplitudes9. State-of-the-art numerical simulations corroborate these
estimates and reproduce hemispherical magnetic current helicity laws10. The dynamo
resulting from a well-understood near-surface phenomenon improves prospects
for accurate predictions of full magnetic cycles and space weather, affecting the
electromagnetic infrastructure of Earth.
Extensive Pollution of Uranus and Neptune’s Atmospheres by Upsweep of Icy Mat...Sérgio Sacani
In the Nice model of solar system formation, Uranus and Neptune undergo an orbital upheaval,
sweeping through a planetesimal disk. The region of the disk from which material is accreted by
the ice giants during this phase of their evolution has not previously been identified. We perform
direct N-body orbital simulations of the four giant planets to determine the amount and origin of solid
accretion during this orbital upheaval. We find that the ice giants undergo an extreme bombardment
event, with collision rates as much as ∼3 per hour assuming km-sized planetesimals, increasing the
total planet mass by up to ∼0.35%. In all cases, the initially outermost ice giant experiences the
largest total enhancement. We determine that for some plausible planetesimal properties, the resulting
atmospheric enrichment could potentially produce sufficient latent heat to alter the planetary cooling
timescale according to existing models. Our findings suggest that substantial accretion during this
phase of planetary evolution may have been sufficient to impact the atmospheric composition and
thermal evolution of the ice giants, motivating future work on the fate of deposited solid material.
Exomoons & Exorings with the Habitable Worlds Observatory I: On the Detection...Sérgio Sacani
The highest priority recommendation of the Astro2020 Decadal Survey for space-based astronomy
was the construction of an observatory capable of characterizing habitable worlds. In this paper series
we explore the detectability of and interference from exomoons and exorings serendipitously observed
with the proposed Habitable Worlds Observatory (HWO) as it seeks to characterize exoplanets, starting
in this manuscript with Earth-Moon analog mutual events. Unlike transits, which only occur in systems
viewed near edge-on, shadow (i.e., solar eclipse) and lunar eclipse mutual events occur in almost every
star-planet-moon system. The cadence of these events can vary widely from ∼yearly to multiple events
per day, as was the case in our younger Earth-Moon system. Leveraging previous space-based (EPOXI)
lightcurves of a Moon transit and performance predictions from the LUVOIR-B concept, we derive
the detectability of Moon analogs with HWO. We determine that Earth-Moon analogs are detectable
with observation of ∼2-20 mutual events for systems within 10 pc, and larger moons should remain
detectable out to 20 pc. We explore the extent to which exomoon mutual events can mimic planet
features and weather. We find that HWO wavelength coverage in the near-IR, specifically in the 1.4 µm
water band where large moons can outshine their host planet, will aid in differentiating exomoon signals
from exoplanet variability. Finally, we predict that exomoons formed through collision processes akin
to our Moon are more likely to be detected in younger systems, where shorter orbital periods and
favorable geometry enhance the probability and frequency of mutual events.
Emergent ribozyme behaviors in oxychlorine brines indicate a unique niche for...Sérgio Sacani
Mars is a particularly attractive candidate among known astronomical objects
to potentially host life. Results from space exploration missions have provided
insights into Martian geochemistry that indicate oxychlorine species, particularly perchlorate, are ubiquitous features of the Martian geochemical landscape. Perchlorate presents potential obstacles for known forms of life due to
its toxicity. However, it can also provide potential benefits, such as producing
brines by deliquescence, like those thought to exist on present-day Mars. Here
we show perchlorate brines support folding and catalysis of functional RNAs,
while inactivating representative protein enzymes. Additionally, we show
perchlorate and other oxychlorine species enable ribozyme functions,
including homeostasis-like regulatory behavior and ribozyme-catalyzed
chlorination of organic molecules. We suggest nucleic acids are uniquely wellsuited to hypersaline Martian environments. Furthermore, Martian near- or
subsurface oxychlorine brines, and brines found in potential lifeforms, could
provide a unique niche for biomolecular evolution.
Continuum emission from within the plunging region of black hole discsSérgio Sacani
The thermal continuum emission observed from accreting black holes across X-ray bands has the potential to be leveraged as a
powerful probe of the mass and spin of the central black hole. The vast majority of existing ‘continuum fitting’ models neglect
emission sourced at and within the innermost stable circular orbit (ISCO) of the black hole. Numerical simulations, however,
find non-zero emission sourced from these regions. In this work, we extend existing techniques by including the emission
sourced from within the plunging region, utilizing new analytical models that reproduce the properties of numerical accretion
simulations. We show that in general the neglected intra-ISCO emission produces a hot-and-small quasi-blackbody component,
but can also produce a weak power-law tail for more extreme parameter regions. A similar hot-and-small blackbody component
has been added in by hand in an ad hoc manner to previous analyses of X-ray binary spectra. We show that the X-ray spectrum
of MAXI J1820+070 in a soft-state outburst is extremely well described by a full Kerr black hole disc, while conventional
models that neglect intra-ISCO emission are unable to reproduce the data. We believe this represents the first robust detection of
intra-ISCO emission in the literature, and allows additional constraints to be placed on the MAXI J1820 + 070 black hole spin
which must be low a• < 0.5 to allow a detectable intra-ISCO region. Emission from within the ISCO is the dominant emission
component in the MAXI J1820 + 070 spectrum between 6 and 10 keV, highlighting the necessity of including this region. Our
continuum fitting model is made publicly available.
WASP-69b’s Escaping Envelope Is Confined to a Tail Extending at Least 7 RpSérgio Sacani
Studying the escaping atmospheres of highly irradiated exoplanets is critical for understanding the physical
mechanisms that shape the demographics of close-in planets. A number of planetary outflows have been observed
as excess H/He absorption during/after transit. Such an outflow has been observed for WASP-69b by multiple
groups that disagree on the geometry and velocity structure of the outflow. Here, we report the detection of this
planet’s outflow using Keck/NIRSPEC for the first time. We observed the outflow 1.28 hr after egress until the
target set, demonstrating the outflow extends at least 5.8 × 105 km or 7.5 Rp This detection is significantly longer
than previous observations, which report an outflow extending ∼2.2 planet radii just 1 yr prior. The outflow is
blueshifted by −23 km s−1 in the planetary rest frame. We estimate a current mass-loss rate of 1 M⊕ Gyr−1
. Our
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and oriented orthogonal to the Galactic plane, centered at coordinates l = 0.08◦
, b = −1.42◦
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have been produced by a plasma outflow channel extending from the Galactic center. Our fits of the
feature’s spectra favor a complex two-component model consisting of thermal and recombining plasma
components, possibly a sign of shock compression or heating of the interstellar medium by outflowing
material. Assuming a recombining plasma scenario, we further estimate the cooling timescale of this
plasma to be on the order of a few hundred to thousands of years, leading us to speculate that a
sequence of accretion events onto the Galactic Black Hole may be a plausible quasi-continuous energy
source to sustain the observed morphology
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
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Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
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Neha Bajwa, Vice President of Product Marketing, Neo4j
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Sudheer Mechineni, Head of Application Frameworks, Standard Chartered Bank
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Sectoral targets and attacks as well as the cost of ransom
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Major cyber events in 2024
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Cyber risk predictions
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https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
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1. Measurement of the neutrino velocity with
the OPERA detector in the CNGS beam
Dario Autiero
IPN Lyon
On behalf of the OPERA Collaboration
D. Autiero - CERN - 23 September 2011 1
2. The OPERA Collaboration
160 physicists, 30 institutions, 11 countries
Italy Korea
Belgium Jinju
IIHE-ULB Brussels LNGS Assergi
Bari
Bologna Russia
Croatia
IRB Zagreb LNF Frascati INR RAS Moscow
L’Aquila LPI RAS Moscow
Naples ITEP Moscow
France Padova SINP MSU Moscow
LAPP Annecy Rome JINR Dubna
IPNL Lyon
Salerno
IPHC Strasbourg
Switzerland
Japan Bern
Germany Aichi ETH Zurich
Hamburg Toho
Kobe
Israel Nagoya Turkey
Technion Haifa Utsunomiya METU Ankara
http://operaweb.lngs.infn.it/scientists/?lang=en
D. Autiero - CERN - 23 September 2011 2
3. We profited from the collaboration of individuals and groups that worked
with us for the various metrology measurements reported here:
CERN: CNGS, Survey, Timing and PS groups
The geodesy group of the Università Sapienza of Rome
The Swiss Institute of Metrology (METAS)
The German Institute of Metrology (PTB)
D. Autiero - CERN - 23 September 2011 3
4. Principle of the neutrino velocity measurement
Definition of neutrino velocity:
Definition of neutrino velocity:
ratio of precisely measured baseline and time of flight
ratio of precisely measured baseline and time of flight
Time of flight measurement:
tagging of neutrino production time
tagging of neutrino interaction time by a far detector
accurate determination of the baseline (geodesy)
expected small effects: long baseline required
blind analysis: “box” opened after adequate level of systematic
errors was reached
D. Autiero - CERN - 23 September 2011 4
5. Past experimental results
FNAL experiment (Phys. Rev. Lett. 43 (1979) 1361)
high energy (Eν > 30 GeV) short baseline experiment. Tested deviations down
to |v-c|/c ≤ 4×10-5 (comparison of muon-neutrino and muon velocities).
SN1987A (see e.g. Phys. Lett. B 201 (1988) 353)
electron (anti) neutrinos, 10 MeV range, 168’000 light years baseline.
|v-c|/c ≤ 2×10-9.
Performed with observation of neutrino and light arrival time.
MINOS (Phys. Rev. D 76 072005 2007)
muon neutrinos, 730 km baseline, Eν peaking at ~3 GeV with a tail extending
above 100 GeV.
(v-c)/c = 5.1 ± 2.9×10-5 (1.8 σ).
D. Autiero - CERN - 23 September 2011 5
6. THE DESIGN OF THE OPERA EXPERIMENT
ECC BRICKS + ELECTRONIC DETECTORS FOR νµ ντ OSCILLATION STUDIES
νµ beam
ECC brick
1 mm
electronics
trackers
τ
ντ
Pb
emulsion layers
interface films (CS)
D. Autiero - CERN - 23 September 2011 6
7. THE IMPLEMENTATION OF THE PRINCIPLE
SM1 SM2
Target area Muon spectrometer
D. Autiero - CERN - 23 September 2011 7
8. The Target Tracker (TT)
pre-location of neutrino interactions and event timing
- Extruded plastic scintillator strips (2.6 cm width)
- Light collections with WLS fibres
- Fibres read out at either side with multi-anode 64 pixels PMTs (H7546)
1.7 m 64 strips
TT module 6.9m
Wave length shifting fibers
H7546
Read out by 1 Front-End DAQ board per side
D. Autiero - CERN - 23 September 2011 8
9. OPERA readout scheme
General Server ORACLE D.B. Server & replicant
Internet GPS
antenna
firewall
CISCO 3750
DHCP
DNS
External Manager
lab Optical link
Undergound
lab
TT RPC PT TT RPC PT GPS
DAQ 1 DAQ 1 DAQ 1 DAQ 2 DAQ 2 DAQ 2 clock
PC
CISCO 3750
CISCO 2950
CISCO 2950
×31 ×22 ×2 ×6 ×31 ×22 ×2 ×6
Veto
trigger ×3 ×3
2 16 2 8 16 2 8
PT PT
RPC XPC RPC XPC
trigger trigger
trigger trigger trigger trigger
E/O E/O
Veto T.T. RPC XPC PT T.T. RPC XPC PT
Trigger-less, asynchronous Front-End nodes (1200); Gigabit Ethernet network
D. Autiero - CERN - 23 September 2011 9
10. Clock distribution system (10 ns UTC event time-stamp granularity)
Front-end Target Tracker
board 31 planes (SM1)
Plane i
Master board
OPERA
master clock
OPERA master clock
1 PPms local oscillator VECTRON
OC-050 (stability 10-12/s)
Mezzanine DAQ card common to all sub-detectors Front End nodes:
CPU (embedded LINUX), Memory, FPGA, clock receiver and ethernet
D. Autiero - CERN - 23 September 2011 10
11. “INTERNAL” and “EXTERNAL” OPERA EVENTS
νµ CC
µ from external interaction
NC
D. Autiero - CERN - 23 September 2011 11
12. The LNGS underground physics laboratory
CERN
73
0k
m
LNGS
1400 m
CNGS
OPERA
D. Autiero - CERN - 23 September 2011 12
13. THE CNGS neutrino beam
• SPS protons: 400 GeV/c
• Cycle length: 6 s
• Two 10.5 µs extractions (by kicker magnet) separated by 50 ms
• Beam intensity: 2.4 1013 proton/extraction
• ~ pure muon neutrino beam (<E> = 17 GeV) travelling through
the Earth’s crust
D. Autiero - CERN - 23 September 2011 13
14. CNGS events selection
GPS
TSPS TOPERA
Offline coincidence of SPS proton extractions (kicker time-tag) and OPERA events
|TOPERA – (TKicker + TOFc)| < 20 µs
Synchronisation with standard GPS systems ~100 ns (inadequate for our purposes)
Real time detection of neutrino interactions in target and in the rock surrounding OPERA
D. Autiero - CERN - 23 September 2011 14
15. CNGS events selection
cosmics
D. Autiero - CERN - 23 September 2011
OPERA data: narrow peaks of the order of the spill width (10.5 µs)
Negligible cosmic-ray background: O(10-4)
Selection procedure kept unchanged since first events in 2006
D. Autiero - CERN - 23 September 2011 15
16. From CNGS event selection to neutrino velocity measurement
Extraction 1
ns
Extraction 2
ns
Typical neutrino event time distributions in 2008 w.r.t kicker magnet trigger pulse:
1) Not flat
2) Different timing for first and second extraction
Need to precisely measure the protons spills
Need to precisely measure the protons spills
D. Autiero - CERN - 23 September 2011 16
17. Clock 1
GPS clocks at LNGS w.r.t.
60 ns Cs clock:
(ns)
1) Large oscillations
hours 2) Uncertainties on CERN-OPERA
Clock 2 synchronisation
hours
Need accurate time synchronisation system
Collaboration with CERN timing team since 2003
Collaboration with CERN timing team since 2003
Major upgrade in 2008
Major upgrade in 2008
D. Autiero - CERN - 23 September 2011 17
18. OPERA sensitivity
• High neutrino energy - high statistics ~16000 events
• Sophisticated timing system: ~1 ns CNGS-OPERA synchronisation
• Accurate calibrations of CNGS and OPERA timing chains: ~ 1 ns level
• Precise measurement of neutrino time distribution at CERN through proton
waveforms
• Measurement of baseline by global geodesy: 20 cm accuracy over 730 km
Result: ~10 ns overall accuracy on TOF with similar stat. and sys. errors
D. Autiero - CERN - 23 September 2011 18
19. CNGS-OPERA synchronization
Time-transfer Time-transfer
equipment equipment
D. Autiero - CERN - 23 September 2011 19
20. Standard GPS receivers ~100 ns accuracy:
CERN Symmetricom XLi (source of General Machine Timing)
LNGS: ESAT 2000
2008: installation of a twin high accuracy system calibrated by METAS (Swiss metrology
institute) Septentrio GPS PolaRx2e + Symmetricom Cs-4000
PolaRx2e:
• frequency reference from Cs clock
• internal time tagging of 1PPS with respect to individual satellite observations
• offline common-view analysis in CGGTTS format
• use ionosphere free P3 code
Standard technique for high accuracy time transfer
Permanent time link (~1 ns) between reference points at CERN and OPERA
D. Autiero - CERN - 23 September 2011 20
22. GPS common-view mode
Standard GPS operation:
resolves x, y, z, t with ≥ 4 satellite observations
Common-view mode (the same satellite for the two
sites, for each comparison):
x, y, z known from former dedicated measurements:
determine time differences of local clocks (both
sites) w.r.t. the satellite, by offline data exchange
730 km << 20000 km (satellite height) similar
paths in ionosphere
D. Autiero - CERN - 23 September 2011 22
23. Result: TOF time-link correction (event by event)
D. Autiero - CERN - 23 September 2011 23
24. CERN-OPERA inter-calibration cross-check
Independent twin-system calibration by the Physikalisch-Technische Bundesanstalt
High accuracy/stability portable time-
transfer setup @ CERN and LNGS
GTR50 GPS receiver, thermalised, external
Cs frequency source, embedded Time
Interval Counter
Correction to the time-link:
tCERN - tOPERA= (2.3 ± 0.9) ns
D. Autiero - CERN - 23 September 2011 24
25. Proton timing by
Beam Current
SPS Transformer
Fast BCT 400344
(~ 400 MHz)
CNGS
Proton pulse digitization:
• Acqiris DP110 1GS/s waveform digitizer (WFD)
• WFD triggered by a replica of the kicker signal
• Waveforms UTC-stamped and stored in CNGS
database for offline analysis
2010 calibration with Cs clock
D. Autiero - CERN - 23 September 2011 25
26. Proton spill shape
Reminiscence of the Continuous Turn extraction from PS (5 turns)
SPS circumference = 11 x PS circumference: SPS ring filled at 10/11
Shapes varying with time and both extractions
Precise accounting with WFD waveforms:
more accurate than: e.g. average neutrino distribution in a near detector
26
D. Autiero - CERN - 23 September 2011
28. Neutrino event-time distribution PDF
• Each event is associated to its proton spill waveform
• The “parent” proton is unknown within the 10.5 µs extraction time
normalized waveform sum: PDF of predicted time distribution of neutrino events
compare to OPERA detected neutrino events
Extraction 1 Extraction 2
2009- 2011 2009- 2011
PDF PDF
(ns) (ns)
different timing w.r.t. kicker magnet signal
D. Autiero - CERN - 23 September 2011 28
29. Neutrino production point
Unknown neutrino production point:
1)accurate UTC time-stamp of protons
2)relativistic parent mesons (full FLUKA simulation)
TOFc = assuming c from BCT to OPERA (2439280.9 ns)
TOFtrue = accounting for speed of mesons down to decay point
∆t = TOFtrue -TOFc
〈∆t〉 = 1.4 x 10-2 ns
D. Autiero - CERN - 23 September 2011 29
30. Summary of the principle for the TOF measurement
y x
z
Measure δt =TOFc - TOFν
D. Autiero - CERN - 23 September 2011 30
31. Geodesy at LNGS
Dedicated measurements
at LNGS: July-Sept. 2010
(Rome Sapienza
Geodesy group)
2 new GPS benchmarks
on each side of the 10 km
GPS highway tunnel
GPS measurements
ported underground to
OPERA
GPS
D. Autiero - CERN - 23 September 2011 31
32. Combination with CERN geodesy
CERN –LNGS measurements (different periods) combined in the
ETRF2000 European Global system, accounting for earth dynamics
(collaboration with CERN survey group)
LNGS benchmarks
In ETRF2000
Cross-check: simultaneous CERN-LNGS measurement of GPS
benchmarks, June 2011
Resulting distance (BCT – OPERA reference frame)
(731278.0 ± 0.2) m
D. Autiero - CERN - 23 September 2011 32
33. LNGS position monitoring
Monitor continent drift and important geological events (e.g. 2009 earthquake)
D. Autiero - CERN - 23 September 2011 33
34. Time calibration techniques
Delay TA ?
Start End
• Portable Cs-4000:
Comparison: time-tags vs 1PPS signal (Cs clock)
at the start- and end-point of a timing chain
Start End
CS 1PPS CS 1PPS
• Double path fibers measurement:
by swapping Tx and Rx component of the opto-chain
TA ?
Start End
Optical fiber
TB ? Measure TA-TB
Measure TA+TB TA,TB
TA ?
Start End
Optical fiber
TB ?
D. Autiero - CERN - 23 September 2011 34
35. BCT calibration (1)
Dedicated beam experiment:
BCT plus two pick-ups (~1 ns) with LHC beam (12 bunches, 50 ns spacing)
∆tBCT = t4 - t3 = (580 ± 5) ns
t4
WFD
t1 t2 t3
BPK1 BPK2 BCT
t3 : derived by t1 - t2 measurement and survey
D. Autiero - CERN - 23 September 2011 35
36. BCT calibration (2)
ZOOM
LHC beam
result: signals comparison after
∆BCT compensation
D. Autiero - CERN - 23 September 2011 36
38. (+) delays increasing δt
(-) delays decreasing δt
D. Autiero - CERN - 23 September 2011 38
39. TT time response measurement
FPGA
PMT
Scintillator, WLS fibers, PMT, analog FE chip (ROC)
up to FPGA trigger input
UV laser excitation:
delay from photo-cathode to FPGA input: 50.2 ± 2.3 ns
Average event time response: 59.6 ± 3.8 ns (sys)
(including position and p.h. dependence, ROC time-walk,
DAQ quantization effects accounted by simulations)
D. Autiero - CERN - 23 September 2011 39
40. Delay calibrations summary
Item Result Method
CERN UTC distribution (GMT) 10085 ± 2 ns • Portable Cs
• Two-ways
WFD trigger 30 ± 1 ns Scope
BTC delay 580 ± 5 ns • Portable Cs
• Dedicated beam experiment
LNGS UTC distribution (fibers) 40996 ± 1 ns • Two-ways
• Portable Cs
OPERA master clock distribution 4262.9 ± 1 ns • Two-ways
• Portable Cs
FPGA latency, quantization curve 24.5 ± 1 ns Scope vs DAQ delay scan
(0.5 ns steps)
Target Tracker delay 50.2 ± 2.3 ns UV picosecond laser
(Photocathode to FPGA)
Target Tracker response 9.4 ± 3 ns UV laser, time walk and photon
(Scintillator-Photocathode, arrival time parametrizations, full
trigger time-walk, quantisation) detector simulation
CERN-LNGS intercalibration 2.3 ± 1.7 ns • METAS PolaRx calibration
• PTB direct measurement
D. Autiero - CERN - 23 September 2011 40
41. Continuous two-way measurement of UTC delay at CERN
(variations w.r.t. nominal)
± 0.4 ns
July 2011
Technical stop
(no data)
D. Autiero - CERN - 23 September 2011 41
42. Event selection (earliest TT hit of the event as “stop”)
Statistics: 2009-2010-2011 CNGS runs (~1020 pot)
Internal events:
Same selection procedure as for oscillation searches: 7586 events
External events:
Rock interaction require muon 3D track: 8525 events
(Timing checked with full simulation, 2 ns systematic uncertainty by adding external
events)
Data/MC agree for 1st hit timing (within systematics)
D. Autiero - CERN - 23 September 2011 42
43. Event time corrections
Time-link correction (blue points)
origin
14 m
Correction due to the earliest
hit position
average correction: 140 cm
(4.7 ns)
D. Autiero - CERN - 23 September 2011 43
44. Analysis method
For each neutrino event in OPERA proton extraction waveform
Sum up and normalise: PDF w(t) separate likelihood for each extraction
Maximised versus δt:
δt= TOFc- TOFν
Positive (negative) δt neutrinos
arrive earlier (later) than light
statistical error evaluated from log
likelihood curves
D. Autiero - CERN - 23 September 2011 44
45. Blind analysis
Analysis deliberately conducted by referring to the obsolete timing of
2006:
1) Wrong baseline, referred to an upstream BCT in the SPS, ignoring accurate
geodesy
2) Ignoring TT and DAQ time response in OPERA
3) Using old GPS inter-calibration prior to the time-link
4) Ignoring the BCT and WFD delays
5) Ignoring UTC calibrations at CERN
Resulting δt by construction much larger than individual
Resulting δt by construction much larger than individual
calibration contributions ~ 1000 ns
calibration contributions ~ 1000 ns
“Box” opened once all correction contributions reached
“Box” opened once all correction contributions reached
satisfactory accuracy
satisfactory accuracy
D. Autiero - CERN - 23 September 2011 45
46. Data vs PDF: before and after likelihood result
First extraction Second extraction
δt = 0 ns δt = 0 ns
(BLIND) δt = TOFc-TOFν =
(1048.5 ± 6.9) ns (stat)
First extraction Second extraction
δt = 1048.5 ns δt = 1048.5 ns χ2 / ndof :
first extraction: 1.06
second extraction: 1.12
D. Autiero - CERN - 23 September 2011 46
47. Zoom on the extractions leading and trailing edges
D. Autiero - CERN - 23 September 2011 47
48. Analysis cross-checks
1) Coherence among
CNGS
runs/extractions
2) No hint for e.g. day-
night or seasonal effects:
|d-n|: (17.1 ± 15.5) ns
|(spring+fall) – summer|:
(11.3 ± 14.3) ns
3) Internal vs external events:
All events: δt (blind) = TOFc -TOFν = (1048.5 ± 6.9 (stat.)) ns
Internal events only: (1047.4 ± 11.2 (stat.)) ns
D. Autiero - CERN - 23 September 2011 48
49. Opening the box
timing and baseline corrections systematic uncertainties
Systematic uncertainties ns
Baseline (20 cm) 0.67
Decay point 0.2
Interaction point 2
UTC delay 2
LNGS fibres 1
DAQ clock transmission 1
FPGA calibration 1
FWD trigger delay 1
CNGS-OPERA GPS synchronization 1.7
MC simulation (TT timing) 3
TT time response 2.3
BCT calibration 5
Total uncertainty (in quadrature) 7.4
D. Autiero - CERN - 23 September 2011 49
50. Results
For CNGS νµ beam, <E> = 17 GeV:
δt = TOFc-TOFν=
(1048.5 ± 6.9 (stat.)) ns – 987.8 ns = (60.7 ± 6.9 (stat.) ± 7.4 (sys.)) ns
relative difference of neutrino velocity w.r.t. c:
(v-c)/c = δt /(TOFc - δt) = (2.49 ± 0.28 (stat.) ± 0.30 (sys.)) ×10-5
(730085 m used as neutrino baseline from parent mesons average decay point)
6.0 σ significance
D. Autiero - CERN - 23 September 2011 50
51. Study of the energy dependence
<E>=28.1 GeV
• Only internal muon-neutrino CC events used for energy measurement (5489
events)
(E = Eµ + Ehad)
• Full MC simulation: no energy bias in detector time response (<1 ns)
systematic errors cancel out
δt = TOFc-TOFν= (60.3 ± 13.1 (stat.) ± 7.4 (sys.)) ns for <Eν> = 28.1 GeV
(result limited to events with measured energy)
D. Autiero - CERN - 23 September 2011 51
52. No clues for energy dependence within the present sensitivity in
the energy domain explored by the measurement
D. Autiero - CERN - 23 September 2011 52
53. Conclusions (1)
• The OPERA detector at LNGS in the CERN CNGS muon neutrino beam has allowed the
most sensitive terrestrial measurement of the neutrino velocity over a baseline of about 730
km.
• The measurement profited of the large statistics accumulated by OPERA (~16000 events), of
a dedicated upgrade of the CNGS and OPERA timing systems, of an accurate geodesy
campaign and of a series of calibration measurements conducted with different and
complementary techniques.
• The analysis of data from the 2009, 2010 and 2011 CNGS runs was carried out to measure
the neutrino time of flight. For CNGS muon neutrinos travelling through the Earth’s crust with
an average energy of 17 GeV the results of the analysis indicate an early neutrino arrival time
with respect to the one computed by assuming the speed of light:
δt = TOFc-TOFν= (60.7 ± 6.9 (stat.) ± 7.4 (sys.)) ns
• We cannot explain the observed effect in terms of known systematic uncertainties. Therefore,
the measurement indicates a neutrino velocity higher than the speed of light:
(v-c)/c = δt /(TOFc - δt) = (2.48 ± 0.28 (stat.) ± 0.30 (sys.)) ×10-5
with an overall significance of 6.0 σ.
D. Autiero - CERN - 23 September 2011 53
54. Conclusions (2)
• A possible δt energy dependence was also investigated. In the energy domain
covered by the CNGS beam and within the statistical accuracy of the measurement
we do not observe any significant effect.
• Despite the large significance of the measurement reported here and the stability of
the analysis, the potentially great impact of the result motivates the continuation of
our studies in order to identify any still unknown systematic effect.
• We do not attempt any theoretical or phenomenological interpretation of the results.
D. Autiero - CERN - 23 September 2011 54
55. Thank you for your attention
Thank you for your attention
D. Autiero - CERN - 23 September 2011 55