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Preliminary results obtained by studying K{sup −}π{sup −}, K{sup −}π{sup −}π{sup 0}, and K{sup −}π{sup −}η systems in the VES experiment are presented. No statistically significant signals from possible resonances were observed in two- and three-particle mass spectra of doubly charged (sub)systems.
Precise measurements on rare radiative B decays are performed with the LHCb experiment at LHC. The LHCb results regarding the ratio of branching fractions for two radiative decays, B{sup 0} → K{sup *0}γ and B{sub s} → ϕγ, the direct CP asymmetry in B{sup 0} → K{sup *0}γ decay channel and the observation of the photon polarization in the B{sup ±} → K{sup ±}π{sup ∓}π{sup ±}γ decay, are included. The first two measurements were performed in 1 fb{sup –1} of pp collisions data and the third one in 3 fb{sup –1} of data, respectively.
The energy dependence of the cross sections for the processes e{sup +}e{sup −} → π{sup +}π{sup −}π{sup 0}, K{sup +}K{sup −}, ηπ{sup +}π{sup −}, ωπ{sub 0}, and K{sup +}K{sup −}π{sup +}π{sup −} is studied near the production threshold for a nucleon–antinucleon pair. It is shown that, within the measurement errors, the cross sections in question behave smoothly in this energy region.
We demonstrate that the K{sup +} mesons are sensitive to nuclear matter properties, especially to the hadronic equation of state (EoS). Once one has understood how K{sup +} behave in hadronic matter we can use these mesons to study the hadronic EoS. Several observables point towards a rather soft EoS at densities around three times the normal nuclear matter density ρ{sub 0}.
The results of earlier calculations of τ → (π{sup 0}, η, η′, K{sup 0})K{sup –}ν{sub τ} processes in the extended Nambu-Jona-Lasinio model are compared. The full widths of these processes are given. The contributions of intermediate vector and scalar mesons both in the ground state and in the first radially excited one (K*(892), K*(1410), K0*(800), K0*(1430), ρ(770), and ρ(1450)) are taken into account. The results are in reasonable agreement with the experimental data.
A high precision measurement of the ultra-rare $K^+ \to \pi^+ \nu \bar{\nu}$ decay at Fermilab would be one of the most incisive probes of quark flavor physics this decade.
This is a memorandum of understanding between the Fermi National Accelerator Laboratory (Fermilab) and the experimenters of Nagoya University, Pacific Northwest National Laboratory, the University of Cincinnati, and the University of Hawaii who have committed to participate in beam tests to be carried out during the 2011 - 2012 Fermilab Test Beam Facility program.
The fundamental origin of flavor in the Standard Model (SM) remains a mystery. Despite the roughly eighty years since Rabi asked “Who ordered that?” upon learning of the discovery of the muon, we have not understood the reason that there are three generations or, more recently, why the quark and neutrino mixing matrices and masses are so different. The solution to the flavor problem would give profound insights into physics beyond the Standard Model (BSM) and tell us about the couplings and the mass scale at which the next level of insight can be found. The SM fails to explain all observed phenomena: new interactions and yet unseen particles must exist. They may manifest themselves by causing SM reactions to differ from often very precise predictions. The Intensity Frontier (1) explores these fundamental questions by searching for new physics in extremely rare processes or those forbidden in the SM. This often requires massive and/or extremely finely tuned detectors.
We explore two directions in beyond the standard model physics: dark matter model building and probing new sources of CP violation. In dark matter model building, we consider two scenarios where the stability of dark matter derives from the flavor symmetries of the standard model. The first model contains a flavor singlet dark matter candidate whose couplings to the visible sector are proportional to the flavor breaking parameters. This leads to a metastable dark matter with TeV scale mediators. In the second model, we consider a fully gauged SU(3) 3 flavor model with a flavor triplet dark matter. Consequently, the dark matter multiplet is charged while the standard model fields are neutral under a remnant Z 3 which ensures dark matter stability. We show that a Dirac fermion dark matter with radiative splitting in the multiplet must have a mass in the range [0:5; 5] TeV in order to satisfy all experimental constraints. We then turn our attention to Higgs portal dark matter and investigate the possibility of obtaining bounds on the up, down, and strange quark Yukawa couplings. If Higgs portal dark matter is discovered, we find that direct detection rates are insensitive to vanishing light quark Yukawa couplings. We then review flavor models and give the expected enhancement or suppression of the Yukawa couplings in those models. Finally, in the last two chapters, we develop techniques for probing CP violation in the Higgs coupling to photons and in rare radiative decays of B mesons. While theoretically clean, we find that these methods are not practical with current and planned detectors. However, these techniques can be useful with a dedicated detector (e.g., a gaseous TPC). In the case of radiative B meson decay B 0 → (K* → Kππ) γ, the techniques we develop also allow the extraction of the photon polarization fraction which is sensitive to new physics contributions since, in the standard model, the right(left) handed polarization fraction is of O( Λ QCD =m b ) for $\bar{B}^{0}$(B 0 ) meson decays.
The major goals of our work on Belle II were to complete our contributions, a 64-channel PIN diode-based radiation monitor, to the precursor detector called Beast II and the electronics for the endcap K-Long/Muon (E-KLM) detector. This was done by Professor Cinabro, Technician Gutierrez, and undergraduate labor supported by US-Japan funds. Professor Bonvicini through US-Japan funds led the development and installation of a beamstrahlung monitor system in the Belle II interaction region. Graduate students Farhat and DiCarlo worked on this. We also worked on charm physics analysis.
We are describing our effort on the Mu2e experiment at Fermilab and the conclusion our work on the E14 experiment at J-PARC, also known as the KOTO experiment
Normal scalar nonet, K1 meson-2 pion decay, K1-K2 mass difference and S-wave pi-pion scattering
We present herein the most recent BABAR results on direct CP asymmetry measurements in B → X s γ, on partial branching fraction and CP asymmetry measurements in B → X s ℓ + ℓ - , on a search for B → π/ηℓ + ℓ - decays, on a search for lepton number violation in B + → X - ℓ + ℓ' + modes and a study of B 0 →ωω and B 0 → ωφ decays.
We present an update on total and partial branching fractions and on CP asymmetries in the semi-inclusive decay B → X s ℓ⁺ℓ - . Further, we summarize our results on branching fractions and CP asymmetries for semi-inclusive and fully-inclusive B → X s γ decays. We present the first result on the CP asymmetry difference of charged and neutral B → X s γ decays yielding the first constraint on the ratio of Wilson coefficients Im(C 8 eff /C 7 eff ).
One of the most difficult things in learning particle physics for the first time is to understand all of the various names. There are dozens and dozens and sometimes many names can apply to one particle or a single name can apply to many particles. It’s all very confusing. Luckily, Fermilab’s Dr. Don Lincoln made this video to help you sort it all out.