5 Observations consistent with being a m 2 = - 0.11 eV 2 Tachyon

1. 5 Observations consistent with being a m2 = - 0.11 eV2 Tachyon 6 Robert Ehrlich George Mason University mason.gmu.edu/~rehrlich Youtube:“Einstein on faster-than-light speeds?” ABSTRACT ABSTRACT: Despite the apparent conflict with relativity, some physicists have continued to seek evidence for the existence of  hypothetical faster-than-light particles dubbed tachyons.  In the past all claims of tachyons have, however, later been shown to be incorrect, or at least not reproducible.  Nevertheless, the speaker believes that the tachyon is not some mythical beast, and that we may be on the verge of proving its existence.  Specifically, he believes that the ever-surprising neutrino, or its electron flavor, is actually a tachyon.   It might be useful to check out the speaker’s youtube video or a press release describing his latest research on the subject, both of which can be found on his web site: http://mason.gmu.edu/~rehrlich/

2. Consistency of the six values of

3. The OPERA experiment (2011) “The phantom of the OPERA” Sent “bunches” of neutrinos from CERN to a detector 730 km away Compared their time of flight to that of light, c Measured neutrino speed higher than c by 0.0000237 % NOT the way experiment was done! photon photon Experiment has been redone by OPERA and others, and all now show a departure from c within the experimental uncertainty -- just the latest of a number of false sightings. This is not the greatest time to make the case for superluminal (FTL) neutrinos!

4. Nothing can go faster than light … if it travels in in vacuum … if it carries energy or information … if it is measured locally within the space … if it started out slower than light

5. Why were tachyons first proposed? (1962) How can you define the rest mass of tachyons which can never be at rest? m is imaginary! Bilaniuk, O.-M. P.; Deshpande, V. K.; Sudarshan, E. C. G. "'Meta' Relativity". American Journal of Physics30 718 (1962).

6. The only known candidates for being tachyons are one of the 3 types of neutrinos. Why? ANSWER: Only neutrinos have masses so close to zero that within the experimental uncertainty we do not know if m2 > 0 or m2 <0, but we do know that m2 is non-zero.

7. What we now know about neutrinos Wolfgang Pauli (1929), “I’ve done something terrible. I have predicted an undetectable particle“ They come in 2.98 +/- 0.008 “flavors” – electron, muon, and a tau neutrinos Each of the 3 flavor states is a quantum mechanical mixture of 3 states having specific masses. The flavor states can oscillate from one to another as a beam of neutrinos propagates. Originally, they were thought to be massless, but existence of oscillations means they are not Super-K detector

8. More on mass and flavor states Flavor eigenstates: Neutrinos emitted and absorbed in these states Flavor states have an “effective” mass Currently only have mass limits on individual flavors or their sum Mass eigenstates: From oscillation experiments we have good values for Absolute scale of masses is unknown Each mass propagates with an energy-dependent speed: Normal Hierarchy Inverted Hierarchy

9. If you want to learn if neutrinos have v > c, do not bother to measure their speed! Measuring their mass is a much more sensitive test

10. Tritium Beta Decay Can only set an upper limit so far

11. How I became a “tachyon hunter?” Chodos et al. (1985): Electron neutrinos as tachyon candidates For tachyons

12. High energy cosmic rays

13. A Radical proposal: Missing protons?

14. Missing protons interpreted as being due to the onset of proton beta decay at an energy E = Eknee Proton beta decay (normally energetically forbidden) why? Inverse beta decay (allowed if proton has enough E & neutrino is a tachyon) Two 1999 Phys Rev articles: From energy of knee deduce neutrino is a tachyon with: m2 = -- 0.25 + 0.12 eV2 Proton decay above knee leads to “pile-up” of neutrons just above knee  a small peak at ~ 4.5 PeV. Peak seen using Cygnus X-3 data)

15. 2nd 1999 paper in which peak claimed Counts above background vs energy Signal based on counts in 2.5% wide interval of phase, background based on the other 97.5% -- factor of 40 background suppression 1 PeV 10 PeV 100 PeV 5 PeV Reception to the two 1999 papers?

16. Some brand new results(Could not have been done in 1999)

17. Variety of cosmological parameters & data …plus more derived quantities

18. The “effective” number of neutrinos, During the radiation epoch (T > 10,000 K) the energy density of radiation controls the rate of expansion Radiation includes both photons, neutrinos & any “neutrino-like” particles: Photon energy density: Neutrino energy density: = the “effective” number of neutrino species -- need not be an integer & can vary with cosmological time -- cosmological data can be used to deduce & hence -- standard model says: -- deviation from standard model: -- Actual value is much less well-known that other cosmological parameters

19. Tachyonic neutrino mass based on dark energy (Davies & Moss) 1 Using a more up-to-date value: We obtain an actual value & not an upper limit:

20. CMB & Lensing data fit: 3 + 0 case 2 3 neutrinos must be nearly degenerate But suppose electron neutrino is a tachyon Gravitational mass is negative Let the magnitudes of the 3 masses be equal

21. Chodos model (2012) 3 Problems with theories of tachyons Chodos suggests new discrete symmetry: Light cone reflection (LCR) & develops a theory of neutrinos that is VSR & LCR invariant Theory requires that neutrinos come in + m2 (tachyon-tardyon) pairs Requires at least one sterile neutrino: Can have any odd number of sterile nu’s (do need another + m2pair, i.e., 3 +3) With 3 sterile neutrinos many solutions exist with these pairings: Based on 3 + 1 fit to CMB fluctuations & lensing data:

22. “Fine structure” in CR spectrum above knee 4 Published data from Tunka Collaboration Excess counts after subtracting two straight lines shown

23. 2nd Knee in CR spectrum 5 Interpret 2nd knee as threshold for alpha decay

24. 6 Controversial

25. The six observations 1 2 3 4 5 6

26. Summary so far Introduction to tachyons & why neutrinos are the only candidates Cosmic ray analysis in 1999 based on an idea by Chodos et al led to the hypothesis the electron neutrino is a – 0.25 + 0.13 eV2 tachyon A 2nd 1999 Phys Rev paper gave further supporting cosmic ray evidence New paper: 5 observations from data involving particle physics, cosmology & cosmic rays are all consistent with the electron neutrino being a tachyon & value consistent with original hypothesis & yields a much more precise mass There are no phenomena that should be observed and are not, assuming the hypothesis is true, as was the case with OPERA The two best ways to get definitive proof: (a) the KATRIN experiment, (b) another core-collapse supernova in our galaxy

27. The Katrin Experiment: find m 2 from tritium beta decay: -- should permit a hundred-fold improvement in precision Main spectrometer for Katrin Experiment being transported through the village of Leopold shafen en route to Karlsrube in 2006. Katrin should start taking data in 2016 & expects to achieve a 1 sigma uncertainty of Could see at the level of

28. ms-fine structure in SN (Ellis et al.) Two possibilities: If ms-fine structure seen  must have |m| < 0.02 eV & could easily disprove If fine structure not seen, can deduce neutrino mass by “unsmearing” data (finding time distribution at SN) by subtracting from the measured arrival time the neutrino travel time : If the neutrino masses have a very non-standard hierarchy may even see each mass state separately

29. Could neutrino mass states arrive separately?R. Cowsik (1988)Neutrino travel time Neutrino arrival time

30. A bit of philosophy on different ways to make big discoveries

31. Pack hunters (6,000 Higgsians) Lone wolves or crackpots Two types of physicists seeking to make fundamental discoveries Massive $10 Billion apparatus & many years spent in preparation Analyze existing data in a novel way & takes little time to complete Lone wolves may be stronger, more aggressive and far more dangerous than the average wolf that is a member of a pack. However, lone wolves have difficulty hunting, as wolves’ favorite prey, large ungulates, are nearly impossible for a single wolf to bring down alone. Instead, lone wolves will generally hunt smaller animals and scavenge carrion. Wikipedia entry Problems: getting funding & you won’t get the Nobel prize Problems: getting access to someone else’s raw data & most of the time you will be wrong Advantage of getting advice from many highly knowledgeableexperts Advantage of not getting advice from many experts “It’s better to be lucky than smart.”

32. Tardy- centrism mason.gmu.edu/~rehrlich