Download or read book Search for Charged Lepton Violation in Narrow Upsilon Decays written by and published by . This book was released on 2011 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Charged lepton flavor violating processes are unobservable in the standard model, but they are predicted to be enhanced in several extensions to the standard model, including supersymmetry and models with leptoquarks or compositeness. We present a search for such processes in a sample of 99 x 106 [Upsilon](2S) decays and 117 x 106 [Upsilon](3S) decays collected with the BABAR detector. We place upper limits on the branching fractions [Beta]([Upsilon](nS) → e{sup {+-}}[tau]{sup {-+}}) and [Beta]([Upsilon](nS) → [mu]{sup {+-}}[tau]{sup {-+}}) (n = 2, 3) at the 10−6 level and use these results to place lower limits of order 1 TeV on the mass scale of charged lepton flavor violating effective operators.
Download or read book Search for the Lepton Flavour Violating Decay in Upsilon 3S emu written by Nafisa Tasneem and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Charged lepton flavour violating processes are highly suppressed in the standard model, but they are predicted to be enhanced in several new physics extensions including supersymmetry and models with leptoquarks or compositeness. Data collected with the BaBar detector at the SLAC PEP-II e$^+$e$^-$ asymmetric collider at a centre-of-mass energy of 10.36~GeV were used to search for electron-muon flavor violation in $\Upsilon (3S)\rightarrow e^{\pm}\mu^{\pm}$ decays. The search was conducted using a data sample in which 118 million $\Upsilon (3S)$ mesons were produced, corresponding to an integrated luminosity of 27~$fb^{-1}$. There is no evidence of a signal in the $\Upsilon (3S)$ data and we report our results as upper limits on $\mathcal{B}(\Upsilon(3S)\rightarrow e^{\pm}\mu^{\mp})
Download or read book Search for Lepton Flavour Violating Decays of Heavy Resonances and Quantum Black Holes to an E Pair in Proton proton Collisions at u221A s written by and published by . This book was released on 2016 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for narrow resonances decaying to an electron and a muon is presented. The $mathrm {e}$ ${mu }$ mass spectrum is also investigated for non-resonant contributions from the production of quantum black holes (QBHs). The analysis is performed using data corresponding to an integrated luminosity of 19.7 $̃text {fb}̂text {-1}$ collected in proton-proton collisions at a centre-of-mass energy of 8 $̃text {TeV}$ with the CMS detector at the LHC. With no evidence for physics beyond the standard model in the invariant mass spectrum of selected $mathrm {e}mu $ pairs, upper limits are set at 95 $%$ confidence level on the product of cross section and branching fraction for signals arising in theories with charged lepton flavour violation. In the search for narrow resonances, the resonant production of a $mathrm { au }$ sneutrino in R-parity violating supersymmetry is considered. The $mathrm { au }$ sneutrino is excluded for masses below 1.28 $̃text {TeV}$ for couplings $lambda _=lambda _ç=lambda '_ķ=0.01$ , and below 2.30 $̃text {TeV}$ for $lambda _=lambda _ç=0.07$ and $lambda '_ķ=0.11$ . These are the most stringent limits to date from direct searches at high-energy colliders. In addition, the resonance searches are interpreted in terms of a model with heavy partners of the ${mathrm {Z}} $ boson and the photon. In a framework of TeV-scale quantum gravity based on a renormalization of Newton’s constant, the search for non-resonant contributions to the $mathrm {e}$ ${mu }$ mass spectrum excludes QBH production below a threshold mass $M_{mathrm {th}}$ of 1.99 $̃text {TeV}$ . In models that invoke extra dimensions, the bounds range from 2.36 $̃text {TeV}$ for one extra dimension to 3.63 $̃text {TeV}$ for six extra dimensions. Furthermore, this is the first search for QBHs decaying into the $mathrm {e}$ ${mu }$ final state.
Download or read book Search for Invisible Or Lepton Flavor Violating Upsilon Decays in BaBar written by and published by . This book was released on 2013 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Charged lepton flavour Violation in Z boson Decays with the ATLAS Detector written by ATLAS Collaboration CERN and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the XXIV DAE BRNS High Energy Physics Symposium Jatni India written by Bedangadas Mohanty and published by Springer Nature. This book was released on 2022-10-05 with total page 870 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents proceedings from the XXIV DAE-BRNS High Energy Physics (HEP) Symposium 2020, held at the National Institute of Science Education and Research, Jatni, Odisha, India. The contributions cover a variety of topics in particle physics, astroparticle physics, cosmology and related areas from both experimental and theoretical perspectives, namely (1) Standard Model Physics, (2) Beyond Standard Model Physics, (3) Relativistic Heavy-Ion Physics & QCD, (4) Neutrino Physics, (5) Particle Astrophysics & Cosmology, (6) Detector Development Future Facilities and Experiments, (7) Formal Theory, (8) Societal Applications: Medical Physics, Imaging, etc.
Download or read book Search For the Lepton Flavor Violating Decays Y 3S e Tau and Y 3S mu Tau written by and published by . This book was released on 2008 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Charged lepton-flavor violating processes are extremely rare in the Standard Model, but they are predicted to occur in several beyond-the-Standard Model theories, including Supersymmetry or models with leptoquarks or compositeness. We present a search for such processes in a sample of 117 x 106 [Upsilon](3S) decays recorded with the BABAR detector. We place upper limits on the branching fractions BF([Upsilon](3S) 2!e{sup {+-}}[tau]{sup {-+}})
Download or read book Search for Lepton Flavor Violation in the Decays Tau e Gamma and Tau mu Gamma written by and published by . This book was released on 2010 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Searches for lepton-flavor-violating decays of a [tau] lepton to a lighter mass lepton and a photon have been performed with the entire dataset of (963 ± 7) x 106 [tau] decays collected by the BABAR detector near the [Upsilon](4S), [Upsilon](3S) and [Upsilon](2S) resonances. The searches yield no evidence of signals and they set upper limits on the branching fractions of [Beta]([tau]{sup {+-}} 2!e{sup {+-}}[gamma])
Download or read book Search for Lepton Flavor Violation in the Decay L sup H sup h written by and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for the lepton-flavor-violating decay of the tau into one charged lepton and two charged hadrons has been performed using 221.4 fb−1 of data collected at an ee− center-of-mass energy around 10.58 GeV with the BABAR detector at the PEP-II storage ring. In all 14 decay modes considered, the numbers of events found in data are compatible with the background expectations. Upper limits on the branching fractions are set in the range (0.7-4.8) x 10−7 at 90% confidence level. All results are preliminary.
Download or read book Leptonic Decays of the Charged B Meson written by Luke Andrew Corwin and published by . This book was released on 2008 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: We present a search for the decay of the charged B meson into a charged lepton and a neutrino 458.9 million Upsilon(4S) decays recorded with the Babar detector at the SLAC PEP-II B-Factory. A sample of events with one reconstructed exclusive semileptonic B decay is selected, and in the recoil a search for the signal decay is performed. The tau lepton is identified in decays to an electron and two neutrinos; a muon and two neutrinos; a charged pion and a neutrino; or a charged pion, a neutral pion, and a neutrino. The analysis strategy and the statistical procedure is set up for branching fraction extraction or upper limit determination. We determine from the data set a preliminary measurement of the branching fraction a charged B decaying to a tau lepton and a neutrino = (1.8 " 0.8 " 0.1)E-4, which excludes zero at 2.4 standard deviations. We extract the B meson decay constant = 255 " 58 MeV. Combination with the hadronically tagged measurement yields (1.8 " 0.6)E-4. We also set preliminary limits on the branching fraction of charged B decaying to an electron and a neutrino at 7.7E-6 and the charged B decaying to a muon and a neutrino at 11E-6. The limits are at the 90% confidence level.
Download or read book A Search for Narrow States in Radiative Upsilon Decays written by Stephen T. Lowe and published by . This book was released on 1986 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Searches for Exotic Decays of the Upsilon 3S at BaBar written by and published by . This book was released on 2011 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper we present two searches for new physics in [Upsilon](3S) decays collected by the BABAR detector. We search for charged lepton-flavour violating decays of the [Upsilon](3S), which are unobservable in the Standard Model but are predicted to occur in several beyond-the-Standard Model scenarios. We also search for production of a light Higgs or Higgs-like state produced in radiative decays of the [Upsilon](3S) and decaying to muon pairs.
Download or read book Search for Lepton Flavor Violating Decay u2192 l l l l written by and published by . This book was released on 2010 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Standard Model (SM) is one of the most tested and verified physical theories of all time, present experimental observations are consistent with SM expectations. On the other hand SM can not explain many physical observations: the cosmological observations possibly infer the presence of dark matter which is clearly beyond the SM expectations; the SM Higgs model, while explaining the generation of fermion masses, can not explain the hierarchy problem and a non natural fine tuning of SM is needed to cancel out quadratic divergences in the Higgs boson mass. New physics (NP) beyond SM should hence be investigated: rising the energy above NP processes thresholds, and detecting new particles or new effects not predicted by the standard model directly, is one of the possible approaches; another approach is to make precision measurements of well known processes or looking for rare processes which involve higher order contribution from NP processes, this approach need higher luminosities with respect to the previous approach but lower beam energies. Search for Lepton Flavor Violation (LFV) in charged lepton decays is promising: neutrino physics provides indeed a clear and unambiguous evidence of LFV in the neutral lepton sector via mixing processes, which have been observed for the first time by the Homestake collaboration. We expect LFV in the charged sector as well, both in ? and ? sector, but current experimental searches for LFV processes did not find any evidence for those processes, and more results are expected to come from new experiments in the coming years.
Download or read book Search for Lepton Flavor Violating Decay tau to ell ell ell at BaBar written by and published by . This book was released on 2010 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Standard Model (SM) is one of the most tested and verified physical theories of all time, present experimental observations are consistent with SM expectations. On the other hand SM can not explain many physical observations: the cosmological observations possibly infer the presence of dark matter which is clearly beyond the SM expectations; the SM Higgs model, while explaining the generation of fermion masses, can not explain the hierarchy problem and a non natural fine tuning of SM is needed to cancel out quadratic divergences in the Higgs boson mass. New physics (NP) beyond SM should hence be investigated: rising the energy above NP processes thresholds, and detecting new particles or new effects not predicted by the standard model directly, is one of the possible approaches; another approach is to make precision measurements of well known processes or looking for rare processes which involve higher order contribution from NP processes, this approach need higher luminosities with respect to the previous approach but lower beam energies. Search for Lepton Flavor Violation (LFV) in charged lepton decays is promising: neutrino physics provides indeed a clear and unambiguous evidence of LFV in the neutral lepton sector via mixing processes, which have been observed for the first time by the Homestake collaboration. We expect LFV in the charged sector as well, both in [mu] and [tau] sector, but current experimental searches for LFV processes did not find any evidence for those processes, and more results are expected to come from new experiments in the coming years.
Download or read book Charakterisierung von Schleifscheibentopographien aus fertigungstechnischer Sicht written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Search for Lepton Flavour Violation in Z tau Mu Decays at Sqrt s written by Sara Svendsen and published by . This book was released on 2017 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Lepton Flavor and Lepton Number Violation in the Decay Tau to Lhh written by and published by . This book was released on 2005 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for lepton-flavor and lepton-number violation in the decay of the tau lepton into one charged lepton and two charged hadrons is performed using 221.4 fb−1 of data collected at an ee− center-of-mass energy of 10.58 GeV with the BABAR detector at the PEP-II storage ring. In all 14 decay modes considered, the observed data are compatible with background expectations, and upper limits are set in the range [Beta]([tau] 2!lhh')
