Search results for "Strange quark"
showing 10 items of 66 documents
Tau-decay determination of the strange quark mass
2000
6 páginas, 3 tablas.-- Comunicación presentada al QCD 99 Euroconference celebrado en Julio de 1999 en Montpellier (Francia).-- arXiv:hep-ph/9909559v1
Flavor-changing Higgs boson decays into bottom and strange quarks in supersymmetric models
2015
In this work, we explore the flavor-changing decays ${H}_{i}\ensuremath{\rightarrow}bs$ in a general supersymmetric scenario. In these models the flavor-changing decays arise at loop level, but---because they originate from a dimension-four operator---they do not decouple and may provide a first sign of new physics for heavy masses beyond the reach of colliders. In the framework of the minimal supersymmetric extension of the Standard Model, we find that the largest branching ratio of the lightest Higgs (${H}_{1}$) is $\mathcal{O}(1{0}^{\ensuremath{-}6})$ after imposing present experimental constraints, while heavy Higgs states may still present branching ratios $\mathcal{O}(1{0}^{\ensuremat…
A study of strange particles produced in neutrino neutral current interactions in the NOMAD experiment
2004
Results of a detailed study of strange particle production in neutrino neutral current interactions are presented using the data from the NOMAD experiment. Integral yields of neutral strange particles (K0s, Lambda, Lambda-bar) have been measured. Decays of resonances and heavy hyperons with an identified K0s or Lambda in the final state have been analyzed. Clear signals corresponding to K* and Sigma(1385) have been observed. First results on the measurements of the Lambda polarization in neutral current interactions have been obtained.
Nucleon Vector Strangeness Form Factors: Multi-pion Continuum and the OZI Rule
1997
We estimate the 3 \pi continuum contribution to the nucleon strange quark vector current form factors, including the effect of a 3 \pi \rho \pi resonance. We find the magnitude of this OZI-violating contribution to be comparable to that of typical OZI-allowed contributions. We also study the isoscalar electromagnetic form factors, and find that the presence of a \rho \pi resonance in the multi-pion continuum may generate an appreciable contribution.
A study of strange particle production in nu(mu) charged current interactions in the NOMAD experiment
2001
A study of strange particle production in $\nu_\mu$ charged current interactions has been performed using the data from the NOMAD experiment. Yields of neutral strange particles ($K^0_s, \Lambda, \bar{\Lambda}$) have been measured. Mean multiplicities are reported as a function of the event kinematic variables $E_\nu$, $W^2$ and $Q^2$ as well as of the variables describing particle behaviour within a hadronic jet: $x_F$, $z$ and $p_T^2$. Decays of resonances and heavy hyperons with identified $K^0_s$ and $\Lambda$ in the final state have been analyzed. Clear signals corresponding to $\rm {K^\star}^\pm$ $\rm {\Sigma^\star}^\pm$, $\rm \Xi^-$ and $\rm \Sigma^0$ have been observed. A study of s…
Integrating out strange quarks in ChPT
2007
We study three flavour chiral perturbation theory in a limit where the strange quark mass is much larger than the external momenta and the up and down quark masses, and where the external fields are those of two-flavour chiral perturbation theory. In this case, the theory reduces to the one of SU(2)_L x SU(2)_R. Through this reduction, one can work out the strange quark mass dependence of the LECs in the two-flavour case. We present the pertinent relations at two-loop order for F,B and l_i.
Strange Quark Mass Determination from Cabibbo-Suppressed Tau Decays
1999
29 páginas, 10 tablas.-- arXiv:hep-ph/9909244v1
Strange nucleon form-factors
2017
Abstract A broad program measuring parity-violation in electron-nuclear scattering has now provided a large set of precision data on the weak-neutral-current form-factors of the proton. Under comparison with well-measured electromagnetic nucleon form-factors, these measurements reveal the role of the strange quark sea on the low-energy interactions of the proton through the strange-quark-flavor vector form-factors. This review will describe the experimental program and the implications of the global data for the strange-quark vector form-factors. We present here a new fit to the world data.
Parity Violating Electron Scattering at the MAMI Facility in Mainz
2005
We report here on a new measurement of the parity violating (PV) asymmetry in the scattering of polarized electrons on unpolarized protons performed with the setup of the A4-collaboration at the MAMI accelerator facility in Mainz. This experiment is the first to use counting techniques in a parity violation experiment. The kinematics of the experiment is complementary to the earlier measurements of the SAMPLE collaboration at the MIT Bates accelerator and the HAPPEX collaboration at Jefferson Lab. After discussing the experimental context of the experiments, the setup at MAMI and preliminary results are presented.
Parity-violating electron scattering at MAMI
2003
A measurement of the parity-violating asymmetry in elastic scattering of polarized electrons on protons is currently running within the A4 Collaboration at the MAMI facility in Mainz. The aim is to reveal the contribution of strange quarks to the form factors of the nucleon at a Q 2 = 0.23 GeV2. The expected asymmetry without strangeness is around 5.4 × 10−6. After 600 hours of asymmetry data taking, an accuracy of 1 × 10−6 has been achieved.