# A Galactic Neutrino Network?

by on May 22, 2008

SETI quite naturally started with the assumption that we should look in the realm of photons for signals from other stars. After all, radio or optical wavelengths were things we understood, and the interest in radio and attendant theorizing about ‘waterhole’ frequencies and interstellar beacons continues to be worth examining. But a truly advanced civilization might be using methods we haven’t yet managed to exploit. Of these, a singularly interesting choice is communication by neutrino.

John Learned (University of Hawaii) and colleagues take on this issue in a new paper just posted to the arXiv site, looking at the advantages of the notoriously elusive neutrino. A major plus is that the signal to noise problem is tricky for radio and optical methods, especially in the galactic plane, whereas neutrinos, depending on their energy levels, can offer an essentially noise-free band. We also run into severe problems with photons as we look at line of sight communications anywhere near the galactic center, intervening materials causing signals to be attenuated.

But neutrinos show up with little attenuation from almost any direction, and are free of photon scattering that introduces jitter in arrival time and direction. The paper looks at the neutrino energies best suited for galactic communication, noting that low energy neutrinos are a problem because natural sources (like supernovae) produce emissions that can obscure a signal. The paper runs through the factors considered in choosing a high energy level near 6.3 PeV “…such that it would be clear at once that it is an artifical source such as ETI and not some random background.”

Given the distances and times involved, the question of when an extraterrestrial civilization might choose to send a message becomes intricate. Although it’s a digression from the neutrino beam technology considered in the rest of the paper, the discussion is provocative:

We presume that the ETIs, though in our galaxy, are remote. Even if an ETI has been observing us, it may be a long while (timescale of thousands of years) before they would send us an introductory message. So if they want to send a message in advance, saying hello and welcome to the galactic network, they are going to have to speculate about when to bother to transmit. From the jittering of advances in speciation, with the great die offs, it seems clear that evolution is a stochastic process, with ﬂuctuations on a timescale of many millions of years. The evolution of technology may ﬂuctuate over a timescale of thousands of years, as exempliﬁed by the long periods of lack of technological progress in post-Roman Europe, China and India. One must reason that no useful prediction could be made as to when the industrial revolution would take off and high technology would arise. Thus the ETI would have to be transmitting speculatively over a long period.

The possibility of two stages of communication arises, the first stage being an ‘attention-getter’ signal, the second the sending of information. Artifacts could be more efficient than transmitting data, and could be sent to promising star systems with the assumption of later discovery by the inhabitants there. So a message from the stars might simply be short and to the point, a set of instructions telling us where to find the alien object.

Producing the needed neutrino beam goes beyond our current technology, but making neutrino beams in this energy range may well be feasible for a sufficiently advanced culture:

…we do not know the methods that may be available to advanced civilizations to make a neutrino (or any other) beam. We have direct evidence in the 1020 eV cosmic rays, the gamma ray bursts (GRBs), the micro-Quasars, and the amazingly collimated jets from active galactic nuclei (AGN), so that we might suspect that we do not yet understand some fundamental issues on particle acceleration. For example, how does one get an earth mass accelerated to a gamma of 1000 in a distance of a few light seconds, as has been inferred for gamma ray burst jets or “cannonballs”? So, for present purposes, we shall assume that an ETI would ﬁnd it affordable and worthwhile to expend such resources to communicate with our TES [Technically Emergent Society].

The beauty of directed beams of neutrinos at the energy levels considered here is that their signal would clearly signal the presence of an extraterrestrial civilization, there being no known natural mechanism for making neutrinos in only this energy range. The authors estimate that properly encoded data could accumulate at a rate of roughly 1000 pages per year. If any civilizations have taken this course and are actively transmitting to us, we can sit back and wait for the result, for the neutrino detectors coming online should soon discover their signatures.

The paper is Learned, Pakvasa and Zee, “Galactic Neutrino Communication,” available online.

tacitus May 22, 2008 at 12:18

Actually, there’s a case to be made for three, maybe even four stages of communication:

1) The “We Are Here” signal. The attention grabber. Something big, massive even, and omnidirectional. For example, modifying the behavior of a star in a clearly artificial way–e.g. modulating the timing of a pulsar or Cepheid variable all the way to exploding a ring of supernovae simultaneously (useful across intergalactic distances!).

2) The “This is How You Hear Us” signal. A powerful radio beacon for us to steer our radio telescopes towards, with a very simple message with basic instructions on how to access their higher bandwidth communications channel. Its use of basic technology increases the chances that ETIs will be able to tune in.

3) The “This Is How You Talk To Us” message. Now this might be as far as it goes — higher bandwidth communication at light speed via neutrinos (as per the article). But what if an ETI has discovered a means of communicating faster than the speed of light as in Star Trek’s subspace, or wormholes, etc.? If they wanted to talk to others they would obviously have to disseminate the information somehow, and bootstrapping other ETIs through a four stage communication process would be the way to do it.

Who knows, that last part is the stuff of science fiction for now, but it’s a tantalizing thought. That’s why SETI, even though it’s a long shot in the short term, is so important. You never know what kind of knowledge and information may be out there for us to tune in to.

dad2059 May 22, 2008 at 13:17

Novel concept and one that makes good sense. If we speculate that there are real K-Type II civilizations, they would be the ones who would use such a communication technology given the energy requirements.

Unless it could be proven that quantum gravitons exist, then all bets are off.

Mark Phelps May 22, 2008 at 18:03

Very interesting article,’Macroscope by Piers Anthony looks at the issue from a unique perspective and in some detail.

Administrator May 22, 2008 at 18:10

Ah, Macroscope! I’ve got my battered old paperback around here some place (rummaging)… Will be fun to revisit that one, and thanks for the tip.

Zeroth May 22, 2008 at 21:03

I’ve argued for years that SETI (if it demonstrates anything) demonstrates scientific myopias. At considerable risk of paraphrasing Rumsfeld… but we don’t know what we don’t know. There seems to be this in-built assumption that the current horizons are the limit, rather than the racing certainty that a new horizons exist from the perspective of the old… and likely ad infinitum. We use EM to communicate so ET must also, what else is there? SETI should be recast as SETN… the search for like-minded, extra-terrestrial Neanderthals.

ljk May 22, 2008 at 21:27

Looking for ET’s neutrino beam

Might extraterrestrials be communicating via neutrinos?

http://physicsworld.com/cws/article/news/34283

forrest noble May 22, 2008 at 21:40

Looks like potentially very useful technology to me.

ljk May 23, 2008 at 11:57

While I see your point, Zeroth, I also have to ask: Unless
you have a fleet of starships handy, how else do you propose
we search for ETI? Waiting around for them to show up is
not very productive in m view.

SETI scientists are using the parameters given to us by
current real physics and technology. They may not be the
right ones in the end, but not trying is essentially useless.
And even knowing what doesn’t work will help narrow down
what is or is not out there.

george scaglione May 23, 2008 at 20:02

forrest this is a very good tack we have taken here that maybe we will go further into in days to come.thank you :) george

Zeroth May 23, 2008 at 20:26

ljk, I don’t discourage listening using the knowledge and technology at our disposal… merely the forming of hard conclusions based on the historically absurd assumption that our present state-of-the-art, viz the carrier, is the zenith.

James M. Essig May 23, 2008 at 21:50

Hi Folks;

It occurred to me that the production of a toriodal rotating beam of neutrinos, super symmetric hot dark matter, super symmetric cold dark matter etc., might be fabricated wherein the self gravitation of the neutrinos or other weakly interacting particles would keep the particles rotating around a common center of mass.

Energy could be bleed off the circulating beam as needed and harnessed by media based on strongly interacting weak nuclear force reacting materials or energy fields.

Perhaps such self contained toriods could be set up in hyperspace, the Bulk of P-brane theory, or other higher dimensional space where they could be safely maintained in near black hole volumetrically enclosed mass/energy density.

Obviously, for neutrinos, the velocity of revolution of the ring about its center of mass would be almost C and therefore a rotationally bound state of such a beam of neutrinos would necessarily approach neutron density.

Another idea involves the notion of beaming ultra high energy neutrinos to the vicinity of a very massive star, a white dwarf, neutron star, stellar massed black hole, or super massive black hole such that the body surface skimming neutrinos in the inbound beam would get a gravity assist velocity boost. My only concern here is that since neutrinos travel so close to C, they might obtain a gravitational wavelength increase just as photons do as a result of general relativistic frequency reduction.

Thanks;

Jim

Enzo May 23, 2008 at 22:53

Old article on New Scientist on some research conducted by Pirelli in Italy to use neutrinos for communications. This would means no laying of cables and no satellites, just beam them through Earth :
http://www.newscientist.com/article/mg18224436.000-from-tyres-to-neutrinos.html

http://www.pirellilabs.com/web/material_innovation/challenging_science/unconventional_neutrino_detection/default.page

Needless to say, neutrino detection and generation is challenging to say the least……

andy May 24, 2008 at 8:38

Colour me sceptical about neutrino transmissions: the kind of superaccelerators required to send such signals seem highly impracticable for the end result… unless your civilisation is spread out over a vast region of the galaxy over which attenuation becomes a problem and for some reason you don’t want to route your signals through intermediate nodes, using electromagnetic transmission seems far cheaper and easier to control.

ljk May 24, 2008 at 20:57

The ANTARES Neutrino Telescope: first results

Authors: Thierry Pradier, for the ANTARES Collaboration

(Submitted on 16 May 2008)

Abstract: The ANTARES Collaboration is completing the deployment of a 12 lines underwater detector, 2500m deep in the Mediterranean Sea, dedicated to high energy neutrino astronomy. Starting with the first line in 2006, 10 lines were continuously recording data by the end of 2007, which allow us to reconstruct downward-going cosmic muons, and search for the first upward-going neutrino-induced muons. Calibration topics will be described and preliminary results presented.

Comments: 8 pages, 7 figures; contribution to the Proceedings of the 43rd “Rencontres de Moriond ElectroWeak”, La Thuile (Val d’Aosta, Italy) March 1 – 8, 2008

Subjects: Astrophysics (astro-ph)

Cite as: arXiv:0805.2545v1 [astro-ph]

Submission history

[v1] Fri, 16 May 2008 14:47:22 GMT (1935kb,D)

http://arxiv.org/abs/0805.2545

george scaglione May 25, 2008 at 12:20

jim,everybody,the last few postings above once again remind me of how lucky i am to be a part of such a cool group that brings forward sooo many good ideas! now,lol, the implementation…there now is another matter! :( have a great week end all ! your friend george

James M. Essig May 25, 2008 at 22:50

Hi Enzo;

It was about 2 1/2 to 3 decades ago when conjectures were made about the possibility of, I believe, the U.S. and/or Soviet Navies having neutrino beam communication systems wherein top secret orders would be relayed through the Earth to submarines at prearranged locations such as for missile launch orders or patrol itineraries. The idea was that one or more accelerators could generate a narrow beam of neutrinos which could not be effectively intercepted.

Neutrino beams would seem to me to be an excellent means by which ETI civilizations could send coded messages.

If we could learn how to selectively alter the interaction of a ship with the interstellar environment so that the ship and its contents would interact with the interstellar medium as weakly as neutrinos do, then incredibly high gamma factors might be achieved without the risk of drag, collisions etc., except collisions with neutron stars, black holes, and any existent quark nuggets and the like.

Thanks;

Jim

ljk May 26, 2008 at 15:05

The IceCube Cosmological Connection: Status and prospects of the polar neutrino observatory

Authors: M. Ribordy, for the IceCube Collaboration

(Submitted on 22 May 2008)

Abstract: We report on the current construction status of the IceCube high energy neutrino observatory and possible future construction plans. With the completion of the fourth construction season in Feb. 2008, the observatory is now instrumenting half a cubic kilometer of ice, greatly increasing the horizon for high energy neutrino detection. We briefly describe physics topics related to cosmology, such as indirect searches for supersymmetric cold dark matter, for slow and relativistic magnetic monopoles, GZK neutrinos and violation of Lorentz invariance or Equivalence Principle. It is anticipated that upon completion the new detector will vastly increase the sensitivity and extend the reach of AMANDA to higher energies.

Comments: 4p. 5fig., Rencontres de Moriond 2008, cosmology session, proceeding

Subjects: Astrophysics (astro-ph)

Cite as: arXiv:0805.3546v1 [astro-ph]

Submission history

From: Mathieu Ribordy [view email]

[v1] Thu, 22 May 2008 21:46:53 GMT (229kb,D)

http://arxiv.org/abs/0805.3546

ljk May 28, 2008 at 14:21

High Energy Neutrinos from the Cold: Status and Prospects of the Icecube Experiment

Authors: Cecile Portello-Roucelle, for the IceCube collaboration

(Submitted on 23 May 2008)

Abstract: The primary motivation for building neutrino telescopes is to open the road for neutrino astronomy, and to offer another observational window for the study of cosmic ray origins. Other physics topics, such as the search for WIMPs, can also be developed with neutrino telescope.

As of March 2008, the IceCube detector, with half of its strings deployed, is the world largest neutrino telescope taking data to date and it will reach its completion in 2011. Data taken with the growing detector are being analyzed.

The results of some of these works are summarized here. AMANDA has been successfully integrated into IceCube data acquisition system and continues to accumulate data. Results obtained using only AMANDA data taken between the years 2000 and 2006 are also presented. The future of IceCube and the extensions in both low and high energy regions will finally be discussed in the last section.

Comments: 8 pages, Moriond EW 2008 conference proceedings

Subjects: Astrophysics (astro-ph)

Cite as: arXiv:0805.3948v1 [astro-ph]

Submission history

From: Cecile Roucelle [view email]

[v1] Fri, 23 May 2008 19:43:14 GMT (1932kb)

http://arxiv.org/abs/0805.3948

Tony June 4, 2008 at 0:39

Walking to work the other day, I was thinking about the “recent” supernova that was calculated to have exploded 150-odd years ago (from our perspective) when a car alarm a few blocks over went off. Of course, many ignored it, but enough turned toward it to suggest an idea.

Aside from all the technical possibilities for alerting ETIs to our presence, what if we used a natural cosmic phenomenon as an attention getter. Imagine a few dozen radio and optical telescopes across the Earth casually turning toward a new supernova or similarly rare phenomenon to gather the details, and a few days later, also capturing a “Hey, you’re looking in this direction anyway… just wanted to say hello” signal.

(Of course, the civilization broadcasting would be aiming their “..hello” 180 degrees away from the phenomenon for this to work!)

I have no idea if this idea is simply ridiculous as I’m no expert, just a casual space and SETI buff, but I thought I’d share and I would welcome your thoughts.

Tony

ljk June 4, 2008 at 10:24

Tony, that is an idea that has been considered to SETI which
makes a lot of sense.

What else in a galaxy would get the attention of anyone with
an understanding of astronomy and a level of technology that
does not need to be too advanced besides a supernova? That
would be a perfect time to aim transmissions in the direction
of any potential SN observers.

The one problem I see with this at least on this planet is that
most astronomers who observe SN are not looking or listening
for ETI messages, nor do they seem particularly interested in
doing so. Add in the fact that most “mainstream” astronomers
would be shooting themselves in the foot at this time if they
said they found an alien signal while examining a SN and you
can see the issue here.

The other issue is I don’t know how many or if any SETI
researchers at all are examining the skies in the region of
the numerous supernovae that are reported nearly every
day from some part of the Cosmos.

The same pluses and minuses apply to gamma ray bursts
as well.

Ever read James Gunn’s The Listeners? The plot involves
an alien society that beams all its knowledge to Earth when
it know that its main sun is going to go nova. This is another
good reason to observe SN in a SETI context. It also gives
an alien society a reason to transmit to us and others: Since
their culture is doomed anyway, it makes little sense to worry
plus it gives that society a chance to continue on into the
future by preserving its history as a gift to others.

I wonder what can be done to get SETI folks to start
observing SN more?

Ron S June 4, 2008 at 12:51

Tony, there’s no particular reason it wouldn’t work, though there are still some technical problems. However as a first step we could assume there is a somewhat more extroverted civilization between us and the phenomenon, and they would naturally transmit in our direction. So we could listen, with the techniques already available to us. I don’t know if anyone has ever implemented a search algorithm on this basis. For example, when a nova first appears the interest of (exo-)astronomers would be high.

george scaglione June 4, 2008 at 14:45

tony,just read your idea above about how a natural phenomena could be used to signal others.smartest idea i’ve seen all day! thank you. respectfully, george

Tony June 4, 2008 at 23:39

Thanks for the feedback, ljk, Ron and george. If anyone wants to talk this out further, drop me a note at email tonyfleming org. I would particularly interested in catching and really examing some of the problems we might run into as ljk has pointed out, it would be a worthy thought experiment if not something that could actually be moved forward with the right people.

Thanks,
Tony

Tony June 4, 2008 at 23:39

that’s email at tonyfleming dot org

george scaglione June 5, 2008 at 9:10

tony,thank you very much i won’t hesitate to e mail when something comes up! i can be reached at udt109@ aol.com your friend george oooh that invitation is open to pretty much anyone in our group as well that may wish to say something.again everybody,your friend george

ljk June 5, 2008 at 16:36

Tony, two SETI places to start to contact them about their
plans to search supernovae for artificial signals are The SETI
Institute at http://www.seti.org and The SETI League at
http://www.setileague.org

As for operational Optical SETI groups, go to this list for
contact information:

http://www.setileague.org/otherweb/optical.htm

Good luck and let us know what they have to say about it.

James M. Essig June 6, 2008 at 23:00

Hi Folks;

This discussion is turning out to be a good one with about 8 postings in just the last two days.

Tony, I too have to agree with George and the rest of the above commenters that your idea is a good one. Since we have not had any confirmed SETI transmissions, we might as well consider as many novel ideas and ways as we can for which ETI may broadcast signals.

I think the SETI program is a great one and it is my opinion that Uncle Sam should reinstate government sponsorship of this program. I can imagine that using computers such as the one’s used in the U.S. by the National Security Agency or NSA (which are rumored to be among the most powerful, if not the most powerful computers on Earth) to sift through data to flag and anomalies of interest could be one of the best uses for such computers that I can imagine.

Thanks;

Jim

ljk June 12, 2008 at 0:00

Neutrino Physics with the IceCube Detector

Authors: J. Kiryluk, for the IceCube Collaboration

(Submitted on 10 Jun 2008)

Abstract: IceCube is a cubic kilometer neutrino telescope under construction at the South Pole. The primary goal is to discover astrophysical sources of high energy neutrinos. We describe the detector and present results on atmospheric muon neutrinos from 2006 data collected with nine detector strings.

Comments: 5 pages, 4 figures. To appear in the ‘Lake Louise Winter Institute 2008′ conference proceedings, February 18-23 2008, Alberta, Canada

Subjects: Astrophysics (astro-ph)

Cite as: arXiv:0806.1717v1 [astro-ph]

Submission history

From: Joanna Kiryluk [view email]

[v1] Tue, 10 Jun 2008 19:04:27 GMT (227kb)

http://arxiv.org/abs/0806.1717

ljk July 3, 2008 at 16:51

IceCube: A Cubic Kilometer Radiation Detector

Authors: Spencer R. Klein, for the IceCube Collaboration

(Submitted on 30 Jun 2008)

Abstract: IceCube is a 1 km^3 neutrino detector now being built at the Amundsen-Scott South Pole Station. It consists of 4800 Digital Optical Modules (DOMs) which detect Cherenkov radiation from the charged particles produced in neutrino interactions. IceCube will observe astrophysical neutrinos with energies above about 100 GeV. IceCube will be able to separate \nu_\mu, \nu_e and \nu_\tau interactions because of their different topologies. IceCube construction is currently 50% complete.

Comments: 7 pages, presented at SORMA West 2008 (Symposium on Radiation Measurement and Applications)

Subjects: Instrumentation and Detectors (physics.ins-det); Astrophysics (astro-ph); Nuclear Experiment (nucl-ex)

Cite as: arXiv:0807.0034v1 [physics.ins-det]

Submission history

From: Spencer Klein [view email]

[v1] Mon, 30 Jun 2008 22:26:27 GMT (926kb)

http://arxiv.org/abs/0807.0034

James M. Essig July 4, 2008 at 15:12

Hi ljk;

Thanks for posting the above link on the IceCube.

I applaud the effort to study high energy neutrinos with the IceCube detector. This project to study neutrinos offers the potential for the discovery of fundamental physics principles which can only benefit humanity.

Neutrinos, those ephemeral particles that interact via the weak nuclear force and then very weakly with baryonic matter, have some peculiar properties that make them fascinating research objects for both theoretical and experimental high energy physicists.

Because, these particles which are always observed to travel at the speed of light, or just below the speed of light or C with an as yet un-measurable velocity difference, they offer insight into the transition boundary for particles that travel less than C and particles that travel at C. The possible discovery of any new physics in this, for lack of a better phrase, transition zone, may result from the break down of the physics defined by the basic special relativistic Lorenz transformation factor, gamma.

Another peculiar property of neutrinos is that they have been experimentally determined to possess a tiny rest mass whereas according to the venerable Standard Model of Particles and Interactions, they should have zero rest mass and travel at exactly C. Thus, the study of neutrinos can lead to the refinement of the standard model or to validation of newer models such as string theory, P-brane theory, M-theory and the like.

Even though the rest mass of neutrinos have been inferred to be roughly on the order of 1 eV/(C EXP 2) or less, they have been observed to possess energies at least as high as 1 TeV in cosmic rays or cosmic ray decay chains.

It seems odd that particles with such a tiny rest mass but so high of a kinetic energy should interact so weakly with ordinary matter. Heck, but that’s the weak force.

I throw a party, if per chance, another neutrino species is discovered.

Thanks;

Jim

ljk July 30, 2008 at 0:11

Feasibility of acoustic neutrino detection in ice: Design and performance of the South Pole Acoustic Test Setup (SPATS)

Authors: S. Boeser, C. Bohm, F. Descamps, J. Fischer, A. Hallgren, R. Heller, S. Hundertmark, K. Krieger, R. Nahnhauer, M. Pohl, P. B. Price, K.-H. Sulanke, D. Tosi, J. Vandenbroucke

(Submitted on 29 Jul 2008)

Abstract: The South Pole Acoustic Test Setup (SPATS) has been built to evaluate the acoustic characteristics of the South Pole ice in the 10 to 100 kHz frequency range so that the feasibility and specific design of an acoustic neutrino detection array at South Pole can be evaluated.

SPATS consists of three vertical strings that were deployed in the upper 400 meters of the South Pole ice cap in January 2007, using the upper part of IceCube holes. The strings form a triangular array with the longest baseline 421 meters. Each of them has 7 stages with one transmitter and one sensor module. Both are equipped with piezoelectric ceramic elements in order to produce or detect sound. Analog signals are brought to the surface on electric cables where they are digitized by a PC-based data acquisition system.

The data from all three strings are collected on a master-PC in a central facility, from which they are sent to the northern hemisphere via a satellite link or locally stored on tape. A technical overview of the SPATS detector and its performance is presented.

Comments: To appear in the Proceedings of the International Cosmic Ray Conference, 2007

Subjects: Astrophysics (astro-ph)

Cite as: arXiv:0807.4676v1 [astro-ph]

Submission history

From: Freija Descamps [view email]

[v1] Tue, 29 Jul 2008 14:46:49 GMT (135kb,D)

http://arxiv.org/abs/0807.4676

ljk August 6, 2008 at 23:55

Neutrino Astrophysics

Authors: W. C. Haxton

(Submitted on 5 Aug 2008)

Abstract: I review the current status of neutrino astrophysics, including solar neutrinos; atmospheric neutrinos; neutrino mass and oscillations; supernova neutrinos; neutrino nucleosynthesis (Big Bang nucleosynthesis, the neutrino process, the r-process); neutrino cooling and red giants; and high energy neutrino astronomy.

Comments: 37 pages, 15 figures; presentation at an introductory level

Subjects: Nuclear Theory (nucl-th); Astrophysics (astro-ph)

Report number: INT PUB 08-26

Cite as: arXiv:0808.0735v1 [nucl-th]

Submission history

From: Wick Haxton [view email]

[v1] Tue, 5 Aug 2008 22:30:46 GMT (1117kb,D)

http://arxiv.org/abs/0808.0735

ljk April 7, 2009 at 13:10

Sensitivity on Earth Core and Mantle densities using Atmospheric Neutrinos

Authors: E. Borriello, G. Mangano, A. Marotta, G. Miele, P. Migliozzi, C.A. Moura, S. Pastor, O. Pisanti, P. Strolin

(Submitted on 6 Apr 2009)

Abstract: Neutrino radiography may provide an alternative tool to study the very deep structures of the Earth. Though these measurements are unable to resolve the fine density layer features, nevertheless the information which can be obtained are independent and complementary to the more conventional seismic studies.

The aim of this paper is to assess how well the core and mantle averaged densities can be reconstructed through atmospheric neutrino radiography. We find that an order 2% sensitivity could be achieved for a ten year data taking at an underwater km$^3$ Neutrino Telescope. This result do not take into account systematics related to the details of the experimental apparatus.

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); High Energy Physics – Phenomenology (hep-ph)

Report number: DSF/30/2008, IFIC/08-67

Cite as: arXiv:0904.0796v1 [astro-ph.EP]

Submission history

From: Ofelia Pisanti [view email]

[v1] Mon, 6 Apr 2009 12:46:11 GMT (431kb)

http://arxiv.org/abs/0904.0796

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