to be done in this area. Face recognition is a problem that scarcely clamoured for attention before the computer age but, having surfaced, has involved a wide range of techniques and has attracted the attention of some fine minds (David Mumford was a Fields Medallist in 1974). This singular application of mathematical modelling to a messy applied problem of obvious utility and importance but with no unique solution is a pretty one to share with students: perhaps, returning to the source of our opening quotation, we may invert Duncan's earlier observation, 'There is an art to find the mind's construction in the face!'.

Linear and nonlinear waves, by G. B. Whitham. Pp.636. £50. 1999. ISBN 0 471 35942 4 (Wiley).

https://cds.cern.ch/record/566059/files/arXiv:hep-ph_0207036.pdf

Minimal flavour violation: an effective field theory approach

Oscillating neutrinos and μ→ e, γ

R-Parity-violating supersymmetry

This paper describes the physics case for a new fixed target facility at CERN SPS. The SHiP (search for hidden particles) experiment is intended to hunt for new physics in the largely unexplored domain of very weakly interacting particles with masses below the Fermi scale, inaccessible to the LHC experiments, and to study tau neutrino physics. The same proton beam setup can be used later to look for decays of tau-leptons with lepton flavour number non-conservation, $\tau \to 3\mu $ and to search for weakly-interacting sub-GeV dark matter candidates. We discuss the evidence for physics beyond the standard model and describe interactions between new particles and four different portals—scalars, vectors, fermions or axion-like particles. We discuss motivations for different models, manifesting themselves via these interactions, and how they can be probed with the SHiP experiment and present several case studies. The prospects to search for relatively light SUSY and composite particles at SHiP are also discussed. We demonstrate that the SHiP experiment has a unique potential to discover new physics and can directly probe a number of solutions of beyond the standard model puzzles, such as neutrino masses, baryon asymmetry of the Universe, dark matter, and inflation.

/pdf/a-facility-to-search-for-hidden-particles-at-the-cern-sps-3pxaggnjt6.pdf

A facility to search for hidden particles at the CERN SPS: the SHiP physics case.

Using improved theoretical calculations of the decay form factors in the Light Cone-QCD sum rule approach, we investigate the decay rates, dilepton invariant mass spectra and the forward-backward (FB) asymmetry in the decays B → (K, K ∗ )l + l − (l ± = e ± , µ ± , τ ± ) in the standard model (SM) and a number of popular variants of the supersymmetric (SUSY) models. Theoretical precision on the differential decay rates and FB-asymmetry is estimated in these theories taking into account various parametric uncertainties. We show that existing data on B → Xsγ and the experimental upper limit on the branching ratio B(B → K ∗ µ + µ − ) provide interesting bounds on the coefficients of the underlying effective theory. We argue that the FB-asymmetry in B → K ∗ l + l − constitutes a precision test of the SM and its measurement in forthcoming experiments may reveal new physics. In particular, the presently allowed largetan β solutions in SUGRA models, as well as more general flavor-violating SUSY models, yield FB-asymmetries which are characteristically different from the corresponding ones in the SM.

/pdf/a-comparative-study-of-the-decays-b-to-k-k-ell-ell-in-919hpfj6za.pdf

A Comparative study of the decays $B \to$ ($K$, $K^{*)} \ell^+ \ell^-$ in standard model and supersymmetric theories

We investigate the leading power corrections to the decay rates and distributions in the decay $B\ensuremath{\rightarrow}{X}_{s}{\mathcal{l}}^{+}{\mathcal{l}}^{\ensuremath{-}}$ in the standard model (SM) using heavy quark expansion (HQE) in ${(1/m}_{b})$ and a phenomenological model implementing the Fermi motion effects of the $b$ quark bound in the $B$ hadron. In the HQE method, we find that including the leading power corrections the decay width $\ensuremath{\Gamma}(B\ensuremath{\rightarrow}{X}_{s}{\mathcal{l}}^{+}{\mathcal{l}}^{\ensuremath{-}})$ decreases by about 4% and the branching ratio $\mathcal{B}(B\ensuremath{\rightarrow}{X}_{s}{\mathcal{l}}^{+}{\mathcal{l}}^{\ensuremath{-}})$ by about 1.5% from their (respective) parton model values. The dilepton invariant mass spectrum is found to be stable against power corrections over a good part of this spectrum. However, near the high-mass end point this distribution becomes negative with the current value of the nonperturbative parameter ${\ensuremath{\lambda}}_{2}$ (the ${\ensuremath{\lambda}}_{1}$-dependent corrections are found to be innocuous), implying the breakdown of the HQE method in this region. Our results are at variance with the existing ones in the literature in both the decay rate and the invariant dilepton mass distribution calculated in the HQE approach. As an alternative, we implement the nonperturbative effects in the decay $B\ensuremath{\rightarrow}{X}_{s}{\mathcal{l}}^{+}{\mathcal{l}}^{\ensuremath{-}}$ using a phenomenologically motivated Gaussian Fermi motion model. We find small corrections to the branching ratio, but the nonperturbative effects are perceptible in both the dilepton mass distribution and the forward-backward asymmetry in the high dilepton mass region. Using this model for estimating the nonperturbative effects, modeling the dominant long distance contributions from the decays $B\ensuremath{\rightarrow}{X}_{s}+(J/\ensuremath{\psi},{\ensuremath{\psi}}^{\ensuremath{'}},\dots{})\ensuremath{\rightarrow}{X}_{s}{\mathcal{l}}^{+}{\mathcal{l}}^{\ensuremath{-}}$, and taking into account the next-to-leading order perturbative QCD corrections in $b\ensuremath{\rightarrow}s{\mathcal{l}}^{+}{\mathcal{l}}^{\ensuremath{-}}$, we present the decay rates and distributions for the inclusive process $B\ensuremath{\rightarrow}{X}_{s}{\mathcal{l}}^{+}{\mathcal{l}}^{\ensuremath{-}}$ in the SM.

/pdf/power-corrections-in-the-decay-rate-and-distributions-in-b-3c0p9cheyl.pdf

Power corrections in the decay rate and distributions in $B \to X_s l^+ l^-$ in the Standard Model

Neutrino mixing and flavour changing processes

Dynamics of DNA breathing in the Peyrard–Bishop model with damping and external force

We present a complete set of generators for the rank 5 special unitary group, SU(6), to unify strong, weak and electromagnetic interactions. The unification is realized through the breaking pattern of SU(6){yields}SU(3){sub C}xSU(3){sub H}xU(1){sub C} followed by SU(3){sub H}{yields}SU(2){sub L}xU(1){sub B}. All known elementary particles and its quantum numbers are well accommodated in its {l_brace}6{r_brace} and {l_brace}15{r_brace} multiplets. These multiplets require a new neutral fermion which should be assigned as the heavy Majorana neutrino to realize the seesaw mechanism naturally.

Laksana Tri Handoko

Papers

A Comparative study of the decays $B \to$ ($K$, $K^{*)} \ell^+ \ell^-$ in standard model and supersymmetric theories

Power corrections in the decay rate and distributions in $B \to X_s l^+ l^-$ in the Standard Model

Neutrino mixing and flavour changing processes

Dynamics of DNA breathing in the Peyrard–Bishop model with damping and external force

Grand unified theory based on the SU(6) symmetry