added a warning box at the top of the entry

]]>added pointer to today’s

- Marco Ciuchini, Marco Fedele, Enrico Franco, Ayan Paul, Luca Silvestrini, Mauro Valli,
*Constraints on Lepton Universality Violation from Rare B Decays*[arXiv:2212.10516]

who accordingly conclude:

that current data no longer provide strong hints for NP.

I have linked to this from a new subsection *Fixing the backgrounds*.

But it looks like it’s time to close this thread. Sorry for all the noise.

(I was prepared to eventually be disappointed. But the way this ends up being disappointing is itself disappointing.)

]]>This here is more explicit:

- Davide Castelvecchi,
*Hint of crack in standard model vanishes in LHC data*, Nature News (20 Dec 2022)

added pointer to the recent:

- LHCb collaboration,
*Measurement of lepton universality parameters in $B^+ \to K^+ \ell^+ \ell^-$ and $B^0 \to K^{\ast 0} \ell^+ \ell^-$ decays*[arXiv:2212.09153]

which claims that re-analysis of hadronic backgrounds in kaonic decays makes the decay rate in the electron channel go down, so that the ratio $R_K$, $R_{K^\ast}$ over the corresponding muon channel is accurately described by the standard model (cf. A. Maas, 20 Dec 2022).

]]>added pointer to today’s

- Ashutosh Kotwal, Joaquim Matias, Andrea Mauri, Tom Tong, Lukas Varnhorst,
*Round table on Standard Model Anomalies*[arXiv:2211.13030]

added pointer to today’s

- Amarjit Soni,
*Precision tau physics: Challenge for Theory, on and off the lattice*[arXiv:2211.05839]

together with a quote of the first couple of paragraphs

]]>also added pointer to:

- Jason Aebischer, Gino Isidori, Marko Pesut, Ben A. Stefanek, Felix Wilsch,
*Confronting the vector leptoquark hypothesis with new low- and high-energy data*[arXiv:2210.13422]

added pointer to:

- Syuhei Iguro, Teppei Kitahara, Ryoutaro Watanabe,
*Global fit to $b \to c \tau \nu$ anomalies 2022 mid-autumn*[arXiv:2210.10751]

together with quotes (here) of the new $\sigma$s they state in their conclusions:

]]>present data deviates from the SM predictions at 4.3σ

added pointer to today’s

- W. G. Parrott, C. Bouchard, C. T. H. Davies,
*The search for new physics in $B \to K \ell^+ \ell^-$ and $B \to K \nu^+ \nu^-$ using precise lattice QCD form factors*[arXiv:2210.10898]

together with this quote from their conclusion:

]]>We present the first fully relativistic determination of the scalar, vector and tensor form factors for $B \to K$ decays. […] Using these form factors, we can calculate the SM branching fraction for $B \to K e(\mu)+ e(\mu)^-$ […] We find tensions above $3\sigma$ in the ratio of our result with LHCb, and above $5\sigma$ in one instance for the low $q^2$ bin.

added pointer to yesterday’s new measurement announcement by LHCb:

- Gregory Max Ciezarek on behalf of the LHCb collaboration:
*First joint measurement of $R(D^\ast)$ and $R(D^0)$ at LHCb*, LHC seminar (2022) [indico:1187939, slides: pdf]

(upshot: previous analyses of the flavour anomaly in the $R(D)$-channel confirmed)

]]>added pointer to today’s

- Mario Fernández Navarro, Stephen F. King,
*$B$-anomalies in a twin Pati-Salam theory of flavour*[arXiv:2209.00276]

added pointer to today’s

- F. Mahmoudi,
*Theoretical Review of Rare B Decays*[arXiv:2208.05755]

together with this quote:

]]>The updated NP fits to rare B decays […] follow the same trend as with the previous set of results favouring in particular new physics contributions in the Wilson coefficient $C^\mu_9$, with an increased significance. […] The projections for clean observables, show that if the current tensions remain, $R_K$ can establish NP with 5σ significance already with less than 20 $fb^{-1}$ of data. The main source of theory uncertainty in global fits is due to non-local hadronic contributions. However, different fits with different setups, inputs and statistical frameworks show a remarkable agreement so that the experimental observation of the discrepancy in these observables would be a clear sign of physics beyond the SM.

almost missed this announcement when being on vacation:

- W. G. Parrott, C. Bouchard, C. T. H. Davies,
*Standard Model predictions for $B \to K \ell^+ \ell^-$, $B \to K \ell^-_1 \ell^+_2$ and $B \to K \nu \bar\nu$ using form factors from Nf=2+1+1 lattice QCD*[arXiv:2207.13371]

have added the pointer now, together with this quote:

We have used our improved scalar, vector and tensor form factors calculated in $N_f = 2+1+1$ lattice QCD […] Our improved form factors significantly sharpen the tension, which becomes particularly strong in the region below the charmonium resonances. For $1.1 \lt q^2 \lt 6 GeV^2$ we find a tension of 4.7σ for $B^+ \to K^+ \mu^+ \mu^-$ and 3.6σ for $B^0 \to K^+ \mu^+ \mu^-$ with LHCb ’14A and 3.3σ for $B^+ \to K^+ e^+ e^-$ with LHCb ’21

So that’s now $4.7 \sigma$ in a single channel.

]]>also added (under “Relation to other anomalies” here) the following remark:

]]>In ACMM22 it is argued (see footnote 3) that also the huge anomaly reported by CDF collaboration 2022 in the mass of the W-boson is compatible with (in fact predicted by) the $B$-meson decay anomalies.

have re-organized the entry slightly: Moved the references/quotes on statistical signifcance across all channels out of the section “Status and Outlook” and into the section “Statistical significance”.

]]>added pointer to

- Marcel Algueró, Andreas Crivellin, Claudio Andrea Manzari, Joaquim Matias,
*Unified Explanation of the Anomalies in Semi-Leptonic $B$ decays and the $W$ Mass*, Physical Review D (2022) [arXiv:2201.08170]

(which was updated on the arXiv today) and added (under “Updates in 2022”, here) this quote:

]]>when combining all tests of LFUV (like $R_{K^+}$ ) with $B$ decays involving muon pairs […], one finds a preference for new physics (NP) hypotheses of more than 7σ compared to the SM. Note that such a high significance is only possible since all measurements are compatible with each other, i.e. they form a coherent picture

added pointer to today’s review:

- Monika Blanke,
*Theory Perspective on Heavy Flavour Physics*, talk at 10th Edition of the Large Hadron Collider Physics Conference (2022) [arXiv:2207.07354, talk slides and recording: indico.cern:4686945]

(no real news, except that the picture remains – reference to experimental hint for GUTs now commonplace)

]]>added pointer to today’s review:

- Diego Guadagnoli, Patrick Koppenburg,
*Lepton-flavor violation and lepton-flavor-universality violation in b and c decays*[arXiv:2207.01851]

together with this quote (from the abstract):

]]>The main final message is that all the instruments necessary to fully establish the putative new effects are at hand, thanks to running experiments and their upgrades. Therefore this subject stands concrete chances to usher genuinely unexpected discoveries.

added pointer to this new textbook:

- Marina Artuso, Gino Isidori, Sheldon Stone,
*New Physics in $b$ Decays*, World Scientific (2020) $[$doi:10.1142/9789811251306$]$

(though it doesn’t seem really published/available yet)

]]>Luckily today

- Alessandra D’Alise et al.,
*Standard model anomalies: Lepton flavour non-universality, g-2 and W-mass*$[$arXiv:2204.03686$]$

was updated, which reminded me to include it. Added the following quote (here)

]]>We critically analyze the body of results that hints to the existence of New Physics from possible violations of lepton universality observed by the LHCb experiment. $[\cdots]$ the deviations from the Standard Model are at the 4.7σ level when including only the hadronic insensitive observables while it increases to 6.1σ when including also the hadronic sensitive ones.

$[...]$ Scalar leptoquarks, either a singlet or a doublet of weak interactions, can explain all the anomalies.

For when the editing functionality is back, to add these pointers:

Some days ago, Isidori et al. further strengthened their claim that the flavour anomalies point to a Randall-Sundrum model with 3-branes:

- Javier Fuentes-Martin, Gino Isidori, Javier M. Lizana, Nudzeim Selimovic, Ben A. Stefanek,
*Flavor hierarchies, flavor anomalies, and Higgs mass from a warped extra dimension*(arXiv:2203.01952)

highlighted again today in the review:

- Javier M. Lizana,
*B-physics anomalies: UV models*, talk at*32nd Rencontres de Blois on “Particle Physics and Cosmology”*(arXiv:2203.05544)

(Noteworthy that these authors are not string theorists but pure HEP phenomenologists. They just went for the best fit of the data seen in the flavour anomalies.)

]]>added pointer to today’s

- David London, Joaquim Matias,
*$B$ Flavour Anomalies: 2021 Theoretical Status Report*(arXiv:2110.13270)

added to the Introduction (here) a paragraph on the branching ratios being “clean observables”

]]>added pointer to today’s new measurement result:

- LHCb collaboration
*Tests of lepton universality using $B^0 \to K^0_S l^+ l^-$− and $B^+ \to K^\ast \ell^+ \ell^-$ decays*(arXiv:2110.09501)

(Apparently it’s another but small addition to the emerging pattern, see here. Though from this graphics it looks rather convincing.)

]]>