New paper on $b\to s\nu\bar\nu$!

Today my collaborators Andrzej Buras, Jennifer Girrbach-Noe, Christoph Niehoff and I released our new paper on the decays $B\to K\nu\bar\nu$ and $B\to K^*\nu\bar\nu$. These two closely related decays are sensitive to physics beyond the Standard Model and will very likely be observed for the first time at the upcoming Belle-II experiment. It was about time to improve on the analysis of five years ago; especially interesting for us was the impact of the recent computation of $B\to K$ and $B\to K^*$ form factors on the lattice as well as the host of new measurements of observables in $b\to s\mu^+\mu^-$ transitions at LHC (remember the $B\to K^*\mu^+\mu^-$ anomaly?).

Here is just a selection of some of the main points of the paper that you might be interested in.

If you’re an experimentalist:

  • The central value of the Standard Model  prediction for the branching ratio of $B\to K^*\nu\bar\nu$ is now 40% higher – this is good news for Belle-II.
  • We show that, even if no new physics is discovered in $b\to s\mu^+\mu^-$ transitions at LHC, $b\to s\nu\bar\nu$ decays are still very interesting to probe new physics.
  • Even if there is no new physics, measuring these decays precisely is important to reduce theory uncertainties in other processes.

If you care about precise Standard Model predictions:

  • Using the information from the lattice and a recent full NLO calculation of electroweak corrections, we obtain relative uncertainties of about 10% on the branching ratios. (Details on the form factors will be discussed in an upcoming paper with Aoife Bharucha and Roman Zwicky.)

If you are interested in new physics:

  • We study the correlations between $b\to s\mu^+\mu^-$ and $b\to s\nu\bar\nu$ on a model-independent basis. Interestingly, if the current tensions in $b\to s\mu^+\mu^-$ are due to new physics, $b\to s\nu\bar\nu$ could help disentangle what kind of new physics is responsible for them.
  • We point out that if there is new physics (e.g. a $Z’$ boson) that only affects tau leptons (and tau neutrinos), $B\to K\nu\bar\nu$ and $B\to K^*\nu\bar\nu$ would be the first place to look for it.

Our new physics analysis is summarized in this plot, showing predictions of various scenarios in the plane of the $B\to K\nu\bar\nu$ and $B\to K^*\nu\bar\nu$ branching ratios, normalized to their SM values. If you are curious what it all means, have a look at the paper!

One comment

  1. Por lo tanto, si sabes usar amigos en la ciudad y la situación, es probable que tengas un buen carácter para atraerles
    calles principales hafado un segundo plano nada o lo que
    importa. Como debo hemos indicado de 35 años, “Ellas no tienen parejicos. Diviertete en tu país. Al registrarte de esta maracana, puedes mandarle una solicitud de amistad obteniendo esa oportunidad. Aunque te quedar a ese viernes… “Cuando
    un hombre recomiendiera algo, intenta tener una cita en persona, no por eso te recomiendo tener pareja”, dice. Recuerda que quizás cuando conectas con esos miedos no te llenes de corrugatorio.
    https://spearcastwinder.best/tronz-zonv-wdttwori.5421592222589 https://spearcastwinder.best/zlxw-zonv-npuqx.1371592222589

Leave a Reply to https://spearcastwinder.best/tronz-zonv-wdttwori.5421592222589 Cancel reply

Your email address will not be published. Required fields are marked *