CERN team claims measurement of neutrino speed >c

[LaurieAG]

They ran the experiment with far shorter neutrino pulses and came up with results consistent with the earlier data.

All the new test does is exclude elements that were retested, it does not prove that there is no error.

The bits that don't change much are the most interesting though.

In order to achieve an accurate determination of the delay between the BCT and the BPK signals, a measurement was performed in the particularly clean experimental condition of the SPS proton injection to the Large Hadron Collider (LHC) machine of 12 bunches with a width of about 1 ns and with 50 ns spacing, passing through the BCT and the two pick-up detectors. This measurement was performed simultaneously for the 12 bunches and yielded ΔtBCT = (580 ± 5 (sys.)) ns.

The systematic error also accounts for uncertainties on the modelling of the time response of the BCT, including cables and electronics, which results in a broadening of the digitised signal with respect to the proton current pulse.

In order to achieve an accurate determination of the delay between the BCT and the BPK signals, a measurement was performed in the particularly clean experimental condition of the SPS proton injection to the Large Hadron Collider (LHC) machine of 12 bunches with 50 ns spacing, passing through the BCT and the two pick-up detectors. This measurement was performed simultaneously for the 12 bunches and yielded ΔtBCT = (580 ± 5 (sys.)) ns.

So how big was the width of each bunch in the original paper? Why is the calibration of the bunches the same in both experiments?

The cumulative error can still hide a cycle miscount type error like that in post #300 (#800 before cull).

 

[LaurieAG]

Twelve times fifty ns spacers plus twelve times one ns pulse equals six hundred and twelve ns. How big were the pulses in the original calibration -27/12 ns each?

The result is 580 ± 32 ns i.e a range of 64 ns.

 

[BertMorrien]

In http://arxiv.org/abs/1109.4897v2 an alternative analysis of the previous data is mentioned. Quote from page 23:
"
An alternative method to extract the value of delta-t consists in building the likelihood function by associating each neutrino interaction to its waveform instead of using the global PDF. This method can in principle lead to smaller statistical errors given the direct comparison of each event with its related waveform.
"
Now there are 3 results:
The original: σt = (57.8 ± 7.8 (stat.) +8.3/-5.9 (sys.)) ns.
The alternative analysis: σt = (54.5 ± 5.0 (stat.) +9.6/ -7.2 (sys.)) ns.
The short pulse experiment: σt = (62.1 ± 3.7(stat) + 8.3/-5.9 (sys.)) ns
In the latter, I included the systematic error mentioned at page 29:
"
At first order, systematic uncertainties related to the bunched beam operation are equal or smaller than those affecting the result obtained with the nominal CNGS beam.
"

My conclusion is, that the three results are compatible, but I would like to see a more elaborate explanation of the systematic errors, especially for the alternative analysis and the short pulse experiment.

In fact, the alternative method suggests that it relies on the PEW amplitude at the event time minus the TOF.
Note that in this way all events are treated as if they occur at the same time and so it rules out any effect of uneven event spreading, something that cannot be said from the original analysis.
This also greatly reduces the effect of PEW parts not corresponding to the event time minus the TOF, in fact these PEW parts cannot contain any information about the start time of the proton/neutrino that caused the event, so these parts must be considered as noise.
Summing the PEWs around the event time minus the TOF, gives a Gaussian curve, its top indicating the TOF, with a resolution that is intrinsically equal to the 1 ns resolution of the digitizer.
Due to the large time uncertainties, the PDF is expected to be wider than the 5 ns period of the 200 MHz SPS radio frequency. Hence the Gaussian curve will show smaller adjacent Gausian curves, each at a distance of 5 ns,
as a result of the coloured noise due to the mentioned 200 MHz radio frequency.
However, with many events, the curve at TOF should still have the highest value. This leaves little room for greater statistical errors than 1 ns with respect to the PEW timing.

Now, this is all speculation, because the report does not indicate more details of the alternative analysis.
Can anybody tell more about the alternative analysis and the systematic errors of this analysis and the short pulse experiment?

Bert

 

[StevieTNZ]

If a confirmation comes that neutrions travel faster than light, would the other particles that have been confirmed not to go faster than light be tested again to see if they go faster than light? Or is the FTL phenomena applicable only to neutrions?

 

[miguel_barros]

I'm afraid someone had made a blunder on the CERN OPERA NEUTRINO paper.

They are using the GRAND CIRCLE DISTANCE, not the CHORD that goes trough earth.

After checking the papers i found where.

The mistake was made on the BASELINE they are using.

2439260,9 nanoseconds is the surface distance 731,27 km from CERN to OPERA
the 730+ km CHORD (traversing the Earth and correctly established in the CNGS global geodesy at 730,535 or the value stated in their own paper of 730,085) would give a baseline of 2,4368 or 2,4353 milliseconds.

2,439 milliseconds CANNOT be found with C=299792458 m/s and
the stated distance.

With the corrected values the TOF for the neutrinos yields a speed below C (but within a thousandth of it's speed)

Please do check yourself and forward this information to those concerned.

Best regards

Miguel Barros


p.s. often when looking for flees we miss the elephant roaming the room. I debugged enough data and human errors to know better than to check the details before checking the "can't be true" huge ones.

 

[jtbell]

Please do check yourself and forward this information to those concerned.

How about you forward this information to them?

I doubt any of the OPERA collaboration read this forum; it's not part of our mission to be part of research.

 

[miguel_barros]

doing my best to do so

btw, check pages 49-50 of their work

http://docs.google.com/viewer?a=v&q=cache:G7ohgcN9BCMJ:indico.cern.ch/materialDisplay.py%3FmaterialId%3Dslides%26confId%3D155620+cern+opera+neutrino+average+time+of+flight&hl=en&pid=bl&srcid=ADGEEShoN8VhCM3x5F_Ekgr3ZMVtMgUEjWfvqkjFaWreQdt34UQQpPqvSAzrww4x9WRm9KFrtaSPNG7O03VSq03xA5kDEHtDz9kqscfN-9gUuKeGEedz0QKrYKGJnOPKMe287uNN7-ls&sig=AHIEtbQLwCKfHRvdV4tCk1n1rE1da11O3w

I'm sure you can see the number on baseline @page 49 and the distance on page 50

try dividing them and tell me that's the C you know and love

 

[kloptok]

miguel_barros: If you read the OPERA paper again, you will find the following quote:

"The baseline considered for the measurement of the neutrino velocity is then the sum of (730534.61 ± 0.20) m between the CNGS target focal point and the origin of the OPERA detector reference frame, and (743.391 ± 0.002) m between the BCT and the focal point, i.e. (731278.0 ± 0.2) m."

It appears that there is an additional distance of about 740 m between this BCT (Beam Current Transformer) that has to be added, except for the chord distance of 730 km or so between CERN and Gran Sasso. If the above sum (731287.0 +- 0.2) m is used when calculating the baseline in ns, the number at the top of p.49 in the ppt presentation you linked to is obtained.

 

[zaybu]

In Ramakrishna's paper, http://arxiv.org/ftp/arxiv/papers/1111/1111.1922.pdf , it very much nails the error in the Opera`s findings.

QUESTION: The author derived equation (9), page 5. It is a difference of two square-roots using an approximation method. Can anyone help in how this is done?

Thanks

 

[miguel_barros]

EXACTLY they had a precise
the distance was established BETWEEN SOURCE and TARGET AT 730.534

http://docs.google.com/viewer?a=v&q=cache:td6R9tT-ZWcJperaweb.lngs.infn.it/Opera/publicnotes/note132.pdf+DETRMINATION+OF+CNGS+GEODOSY&hl=en&pid=bl&srcid=ADGEESi4fhQbojkl7CX4Hzz3WKCi0SwELICoz_PEUmWTREQsWZ79kpETPexVmWUevXnorAQOZoJFdR2AFMdzciVuF2hGwEILwl9T9eHvxIuF1BlZe4c3dSUDuK2lQA6Hd5qccGq45sx8&sig=AHIEtbTyci-nfj5SZEgAAKm4kShf_3_G8w

but they had 731.278 km as a precise distance (on the surface) and added back a FOCAL POINT distance to CBT when the calculation was already SOURCE TO TARGET

IT WOULD HAVE TO BE A WEIRD UNIVERSE where the correction added up to the exact surface distance. And the Geodesy would be made incorrectly to start with.

I repeat, they re-added the ARCH TO CHORD DISTANCE period.

they can't add a "focal point" for pions and kaons , neutrino TOF is recorded from CERN-CBT to OPERA and that's 730,543 km

I assume you are using

http://docs.google.com/viewer?a=v&q=cache:reYU9-LclQ0J:www.nithep.ac.za/3nr.file+%22%22The+ba%22The+baseline+considered+for+the+measurement+of+the+neutrino+velocity+is+then+the+sum+of+%22seline+considered+for+the+measurement+of+the+neutrino+velocity+is+then+the+sum+of&hl=en&pid=bl&srcid=ADGEESihVgRilHUi1p_6p-Vq-8MRohO9zeqAKk7fuHPFX77-do_W98xRI6vGPlxfFtjwPeqgYhliQZYaqT8WkC11vBBVjKIfLcmS3gufEFVH1fu1H_IKMDftMTUdTgExLN8DZO0pGewb&sig=AHIEtbSy1milgBxhewJi57N4-w3QfUtJPQ

 

[miguel_barros]

miguel_barros: If you read the OPERA paper again, you will find the following quote:

"The baseline considered for the measurement of the neutrino velocity is then the sum of (730534.61 ± 0.20) m between the CNGS target focal point and the origin of the OPERA detector reference frame, and (743.391 ± 0.002) m between the BCT and the focal point, i.e. (731278.0 ± 0.2) m."

It appears that there is an additional distance of about 740 m between this BCT (Beam Current Transformer) that has to be added, except for the chord distance of 730 km or so between CERN and Gran Sasso. If the above sum (731287.0 +- 0.2) m is used when calculating the baseline in ns, the number at the top of p.49 in the ppt presentation you linked to is obtained.

Do check my answer above, you might have missed it, I didn't quote you and the GPS/time issue got in the way

 

[miguel_barros]

FURTHERMORE (in their own words)

"730085 m used as neutrino baseline from parent mesons average decay point"

even the 730534 m was too far, some decay took place further away from the SOURCE (target t40-s, source point for the geodesy study)decay point = source of the neutrinos, no neutrinos before that, just us Muons

average decay point = center signal to compare with OPERA

they had already shortened the distance from 730534 to 730085 because TT41 proton beam hitting the T40 target would not be enough to yeld the neutrinos, they had a decay tunnel for that but it was WITHIN the 730534 mwith C=299792458

the baseline should be: 0,002435301 s for central signal

they used 0,002439261

there is no physical room to place a magical 700 odd meters in before t40-s, not with neutrinos in it, not with timed time
check page 4

http://docs.google.com/viewer?a=v&q=cache:reYU9-LclQ0J:www.nithep.ac.za/3nr.file+%22%22The+ba%22The+baseline+considered+for+the+measurement+of+the+neutrino+velocity+is+then+the+sum+of+%22seline+considered+for+the+measurement+of+the+neutrino+velocity+is+then+the+sum+of&hl=en&pid=bl&srcid=ADGEESihVgRilHUi1p_6p-Vq-8MRohO9zeqAKk7fuHPFX77-do_W98xRI6vGPlxfFtjwPeqgYhliQZYaqT8WkC11vBBVjKIfLcmS3gufEFVH1fu1H_IKMDftMTUdTgExLN8DZO0pGewb&sig=AHIEtbSy1milgBxhewJi57N4-w3QfUtJPQ

and there is no distance available between TS40 and OPERA beyond 730534 m

Q.E.D.

EDIT where i mention TS40 it should read T40S

p.s. unless they thought the geodesy study was for THEIR detector and failed to notice (read) that 730 was for T40s, that would be an hubris worth of a greek tragedy

 

[FlexGunship]

I Google Maps'd it and found out that the distance they're using is actually the distance you'd have to drive if you only take major highways but avoid tolls.

So.

Yeah.

 

[DevilsAvocado]

Someone MUST CALL the OPREA team NOW!

 

[FlexGunship]

If a confirmation comes that neutrions travel faster than light, would the other particles that have been confirmed not to go faster than light be tested again to see if they go faster than light? Or is the FTL phenomena applicable only to neutrions?

Someone MUST CALL the OPREA team NOW!

OPREA must know about their neutrions!

 

[DevilsAvocado]

Yeah!

 

[Jorrie]

In Ramakrishna's paper, http://arxiv.org/ftp/arxiv/papers/1111/1111.1922.pdf , it very much nails the error in the Opera`s findings.

Given your question, how sure are you about your statement?

I think that (like van Elburg) Ramakrishna is barking up the wrong tree. He seems to be calculating a relativistic Sagnac effect in the frame of the orbiting common-view satellite. AFAIK, that frame of reference does not feature in any GPS calculations (apart from the initial offsetting of the satellite clock rates).

 

[miguel_barros]

I was preparing a private answer to someone who had a very constructive input, but I might as well leave it here as it seems more likely than the arch/chord.

Anyway, it's a simpler and prideful error that happened to mimic the arch-chord values

they used 730,534 km as distance from OPERA to THEIR CBT

the GEODESY study was from T40 S (target for proton beam, first muons and way upstream from their CBT)



no distance beyond 730,534 between T40s and OPERA

so no neutrinos before 0,002436801 s from OPERA (target 40) just protons

and they're using a 0,002439261 baseline because in a T40->CBT---->OPERA line they mis-read 730,534 as CBT---> OPERA and added the average T40->CBT where decay took place to an already too big CBT to Opera

best regards

Miguel Barros

p.s. if anyone CAN ask the CERN team if they took their detector or the target as the CERN point for the Geodesy value I think that would be worth doing...

 

[FlexGunship]

p.s. if anyone CAN ask the CERN team if they took their detector or the target as the CERN point for the Geodesy value I think that would be worth doing...

You have precisely the same abilities as the rest of us. Write it up, submit it for peer review, and get your paper published.

Also, your posts are getting progressively more difficult to read. As a courtesy to those of us reading, please concentrate on capitalization and punctuation; my eyes just glaze over after a sentence or two.

 

[miguel_barros]

I did not wish to bother.

Maybe one image can explain better than words.

Find 700 meters of error and I'll drop this right now.

Remember this is an Arch, not a Chord.

http://www.gpsvisualizer.com/map?lat1=46.246885&lon1=6.069517&lat2=42.44463405572&lon2=13.56281609083&convert_format=&gc_segments=&gc_altitude=&tickmark_interval=&show_wpt=3&add_elevation=&trk_colorize=&google_wpt_sym=circle&bearing_coords1=46.246885%2C+6.069517&distance=731.278&bearing=122.69&bearing_coords2=42.44463405572%2C+13.56281609083&format=google

 

[FlexGunship]

Find 700 meters of error and I'll drop this right now.

That's the thing... I don't think anyone is actually arguing your point, we just can't figure out why you keep pressing us. We're not CERN. This is www.physicsforums.com. We are a website. You should write your paper, get it peer-reviewed, get it published, get lavished with praised, and then get rich. Not a single one of us will stop you!

 

[The Lobster]

I have doubts about the validity of this experiment.

 

[Drakkith]

That's the thing... I don't think anyone is actually arguing your point, we just can't figure out why you keep pressing us. We're not CERN. This is www.physicsforums.com. We are a website. You should write your paper, get it peer-reviewed, get it published, get lavished with praised, and then get rich. Not a single one of us will stop you!

Does this really require a paper to be published and all that? I figured an e-mail or phone call or something to CERN would work. But I have no idea really.
Plus it seems like something really simple to be missed by so many people for so long.

 

[FlexGunship]

Plus it seems like something really simple to be missed by so many people for so long.

...

 

[StevieTNZ]

Perhaps email one of the authors?

 

[danR]

I mentioned earlier that the most rigorous test would be a foot-race between neutrino and light-pulses down an evacuated tube.

But if the phenomenon is real, that may not test for what someone cited earlier in this post: negative refractive index for neutrinos in (dense) matter:

http://arxiv.org/pdf/1109.5445v7

This elegant solution, they explain, would explain consistency between the CERN result(s), and SN1987a; neutrino velocities in vacuo do not exceed c, but they do exceed c in vacuo traversing matter.

In fact, we could generalize the notion; perhaps many particles suffer negative refractive effects, but the difference would be so tiny, that only the long distances that neutrinos can traverse through matter make a test practical.

 

[lalbatros]

I mentioned earlier that the most rigorous test would be a foot-race between neutrino and light-pulses down an evacuated tube.

But if the phenomenon is real, that may not test for what someone cited earlier in this post: negative refractive index for neutrinos in (dense) matter:

http://arxiv.org/pdf/1109.5445v7

This elegant solution, they explain, would explain consistency between the CERN result(s), and SN1987a; neutrino velocities in vacuo do not exceed c, but they do exceed c in vacuo traversing matter.

In fact, we could generalize the notion; perhaps many particles suffer negative refractive effects, but the difference would be so tiny, that only the long distances that neutrinos can traverse through matter make a test practical.

This would only be a reformulation of the problem.
Such an interaction between neutrino and rocks would defeat causality and would allow FTL communication. It would also imply some collective FTL process in the rocks which would also be contradictory with anything we know. In addition, neutrinos do not interact mcuh with matter, and therefore the "index of refraction" should be quite close to 1.

 

[danR]

This would only be a reformulation of the problem.
Such an interaction between neutrino and rocks would defeat causality and would allow FTL communication. It would also imply some collective FTL process in the rocks which would also be contradictory with anything we know. In addition, neutrinos do not interact mcuh with matter, and therefore the "index of refraction" should be quite close to 1.

I think you have missed key elements of the paper:

In this experiment, neutrinos seem to behave, during the 735 km travel, either as tachyons or as they had a pseudo-tachyonic behavior when transversing a material, like photons in meta-materials [9, 10] with negative refractive index or less than unity, that allows an apparent superluminal propagation without violating causality.​

[emph added]

and with reference to phase velocity:

As vg > vp, the medium would cause the speed of only certain Fourier components of neutrino wavefunction in it to be larger than the speed of light in vacuum for a band of neutrino oscillation frequencies obeying the Majorana condition p ≥ kc, but seems to be forbidden by CG effect for a standard neutrino.​

Mere phase-velocity would not allow FTL communication, and the implications of the paper is that Einstein was, again, correct: nothing communicative can travel faster than c in vacuo.

 

[miguel_barros]

Last reflection that I had as I slowly find that I might have erred on the distance error...

could the anomaly be due to an additional laggard decay on the hadron stopper?

18 meters (3 graphite 15 iron) =60 ns

It wouldn't be as nice as a vacuum but those that survived, survived.

Specially with the additional extraction made by the first 3 meters of graphite of the Hadron stopper

It might be visible on the neutrino detection form:

- two normal functions instead of one,
- even, one might dream, neutrino interference patterns

And the effect could be different on different sized beams.

- larger sized beams could give bigger signals

It might explain the difference between higher and lower energy neutrinos anomaly

- kaons still decaying in the stopper
- freshly made kaons, graphite stopper, decaying fast in the stopper and beyond

As the TOF is compared on a form fitted PDF, with an additional 60ns of true extraction, assuming that the last to arrive were the last protons, we'd assume the first had arrived 60 seconds earlier.

Any comments?

Best regards

 

[Centri-Fagin]

'Faster than light neutrinos' accelerate?

Does anybody know if the neutrinos sent from CERN to Gran Sasso have their speed measured beofre the leave the CERN facility?
CERN shoot their hadrons around at 99.9% the speed of light?
If the neutrinos are also 'built up' to this speed then for the readings that they are getting at Gran Sasso (faster than speed of light), the neutrinos would not only travel faster than light but also be accelerating without additional energy?