Related papers: Kaon decay constraints on vector bosons coupled to…
Leptonic decay widths and leptonic decay constants of light vector mesons and weak leptonic decay widths and weak decay constants of light and heavy pseudoscalar mesons have been studied in a field- theoretic framework based on the…
We analyze the three-body decays of the long-lived neutral kaon $K_L \to \pi\pi a$, where $a$ is an axion-like particle (ALP), and compare them to the two-body decay $K_L \to \pi^0 a$. While the latter requires both flavor violation (FV)…
We study the decays of the $J^{PC}=1^{-+}$ hybrid nonet using a Lagrangian invariant under the flavor symmetry, parity reversal, and charge conjugation. We use the available experimental data, the lattice predictions, and the flavor…
The vector and axial vector current mixing phenomena at low temperature pion gas by Dey, Eletsky and Ioffe, leads to the low temperature correction of the photon-vector meson coupling ($g_\rho$) at order $\epsilon=T^2/6f_\pi^2$ and the…
The improved results on a direct search for a new X(16.7 MeV) boson which could explain the anomalous excess of $e^+e^-$ pairs observed in the excited 8Be nucleus decays ("Berillium anomaly") are reported. Due to its coupling to electrons,…
A decade long search for the rare kaon decay to pi^+nunu-bar has been pursued by E787. Two signal events are observed, giving a measurement of the branching ratio Br(K^+ -> PI^+NUNU-BAR)=1.57^+1.75_-0.82 x 10^-10 and a constraint on the…
The NA48/2 experiment at CERN collected a large sample of charged kaon decays into final states with multiple charged particles in 2003--2004. A new upper limit on the rate of the lepton number violating decay…
A search is presented for narrow heavy resonances decaying to a top quark and a bottom quark using data collected by the CMS experiment at sqrt(s) = 13 TeV in 2016. The data set analyzed corresponds to an integrated luminosity of 35.9…
Simple dynamics, few available decay channels, and extremely well controlled radiative and loop corrections, make pion and muon decays a sensitive means for testing the underlying symmetries, the universality of weak fermion couplings, as…
We explore constraints on gauge bosons of a weakly coupled $U(1)_{B-L}$, $U(1)_{L_\mu-L_e}$, $U(1)_{L_e-L_\tau}$ and $U(1)_{L_\mu-L_\tau}$. To do so we apply the full constraining power of experimental bounds derived for a hidden photon of…
A search is presented for a narrow resonance decaying to a pair of oppositely charged muons using $\sqrt{s} =$ 13 TeV proton-proton collision data recorded at the LHC. In the 45-75 and 110-200 GeV resonance mass ranges, the search is based…
A search for a narrow-width resonance decaying into two Higgs bosons, each decaying into a bottom quark-antiquark pair, is presented. The search is performed using proton-proton collision data corresponding to an integrated luminosity of…
A search for W' bosons decaying to a top and a bottom quark in final states including an electron or a muon is performed with the CMS detector at the LHC. The analyzed data correspond to an integrated luminosity of 138 fb$^{-1}$ of…
A search for pseudoscalar or scalar bosons decaying to a top quark pair ($\mathrm{t\bar{t}}$) in final states with one or two charged leptons is presented. The analyzed proton-proton collision data was recorded at $\sqrt{s}$ = 13 TeV by the…
These lecture notes concern recent developments in our understanding of the low energy properties of QCD. Significant progress has been made on the lattice and the beautiful experimental results on the Ke4 and K->3pi decays, as well as…
We discuss collider signatures of (1,1)-th Kaluza-Klein (KK) mode vector bosons in the framework of two universal extra dimension model, at a future electron-positron collider. Production of the (1,1)-th KK mode of electro-weak vector…
Motivated by the LHCb measurement, we analyze the $B_s\to \pi^+\pi^-\ell^+\ell^-$ decay in the kinematics region where the pion pairs have invariant mass in the range $0.5$-$1.3$ GeV and muon pairs do not originate from a resonance. The…
In this document we present the latest result on rare/forbidden decays for D mesons at the BESIII experiment. Based on 2.92/fb data taken at the center-of-mass energy 3.773 GeV with the BESIII detector, the flavor-changing neutral current…
We present a new limit on the production of a light dark-force mediator with the KLOE detector at DAPHNE. This boson, called U, has been searched for in the decay phi --> eta U, U --> e+ e-, analyzing the decay eta --> pi0 pi0 pi0 in a data…
We analyze various aspects of pion and kaon condensation in the framework of chiral perturbation theory. Considering a system at vanishing temperature and varying the isospin chemical potential and the strange quark chemical potential we…