LHCb results show generation non-Universality (non-SM)

[ChrisVer]

This article suggests something was found and that today we will be able to find the paper online.
http://www.eurekalert.org/pub_releases/2015-08/uom-ess082615.php

I am eager to see what the found and at what significance...asking for extra experiments means that the significance they got was not high enough to consist an actual discovery(?). So nevertheless if someone sees the publication before I do, post it here please?

Nevertheless it would be cool... either for SUSYs (non-minimal coupling) or GUTs (like a NUGIM I guess)... although it's getting quiet tiring with the news they let to reach out the world (with a significance of >2std we are told that something new was discovered...I guess that's marketing)

 

[websterling]

Hey, Chris,
This is probably the arXiv version of the paper-
http://arxiv.org/abs/1506.08614
http://arxiv.org/abs/1506.08614
Still not online at PRL

Measurement of the ratio of branching fractions B(B¯¯¯0→D∗+τ−ν¯τ))/B(B¯¯¯0→D∗+μ−ν¯μ)

Abstract-
The branching fraction ratio R(D∗)≡B(B¯¯¯0→D∗+τ−ν¯τ)/B(B¯¯¯0→D∗+μ−ν¯μ) is measured using a sample of proton-proton collision data corresponding to 3.0\invfb of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ−→μ−ν¯μντ. The semitauonic decay is sensitive to contributions from non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate B¯¯¯0 decays gives R(D∗)=0.336±0.027(stat)±0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the Standard Model.

 

[ChrisVer]

I also checked that but I was told (and later figured out by myself) that it was old (late June and not ends of August).

 

[mfb]

Looks like a false alarm.

LHCb publishes important results on their public page before random news websites get them. Nothing there. Also, CERN would make a press release.

eurekalert.org refers to Brian Hamilton as one of the leading analyzers, which matches the arXiv preprint websterling found, and the description fits as well. It is also in agreement with a different recent news directly linking this (and mentioning the same publication date).
2.1 sigma significance is nothing. There are multiple 2-sigma-deviations, but those measurements are not independent.

 

[dukwon]

The result is right there on the LHCb public page, under "25 May 2015: An intriguing anomaly."

http://lhcb-public.web.cern.ch/lhcb-public/#RDst

2.1 sigma on its own is nothing, but the HFAG combination of R(D) and R(D*) from LHCb, BaBar and Belle comes out to 3.9 sigma.

http://www.slac.stanford.edu/xorg/hfag/semi/eps15/eps15_dtaunu.html

Something to watch for Run 2 of the LHC, along with R_K, P´₅ and B⁰→ϕμμ

 

[mfb]

The result is right there on the LHCb public page, under "25 May 2015: An intriguing anomaly."

http://lhcb-public.web.cern.ch/lhcb-public/#RDst

Right, but 2.1 sigma is not a significant result. Although some "scientific" disciplines believe it would be.[/size]
The 3.9 sigma combination is mainly driven by BaBar analyses 2012 and 2013.

Something to watch for Run 2 of the LHC, along with R_K, P´₅ and B⁰→ϕμμ

For sure.
Add $H \to \mu \tau$ to the list, although it is hard (but not impossible) to get that without violating muon decay constraints.

 

[Rainbowend]

It's hard to say anything right now with 2.1 sigma, I would suggest let's just wait and see when more data come out.

 

[ChrisVer]

The 3.9 sigma combination is mainly driven by BaBar analyses 2012 and 2013.

And is that good or bad?

 

[mfb]

It means the LHCb result is not contributing very much to the average.
2016 data should help, and by 2018 LHCb might be much more precise than the other experiments if the systematics can be reduced sufficiently.

 

[RGevo]

Don't forget about the R_k measurement too.

http://arxiv.org/abs/1406.6482

 

[mfb]

And multiple other measurements with a ~2 sigma tension all in the same direction, but those have correlated systematics so they could have a common source.
Run 2 of the LHC will certainly be interesting.