We report the results of a search for pair production of scalar bottom quarks ( ) and scalar third-generation leptoquarks ( LQ 3 ) in 5.2 fb −1 of collisions at the D0 experiment of the Fermilab ...Tevatron Collider. Scalar bottom quarks are assumed to decay to a neutralino ( ) and a b quark, and we set 95% C.L. lower limits on their production in the ( , ) mass plane such as for and for . The leptoquarks are assumed to decay to a tau neutrino and a b quark, and we set a 95% C.L. lower limit of 247 GeV on the mass of a charge-1/3 third-generation scalar leptoquark.
We report on a search for the pair production of second generation scalar leptoquarks (LQ(2)) in p (p) over bar collisions at the center-of-mass energy, root s = 1.96 TeV, using data corresponding to ...an integrated luminosity of 294 19 pb(-1) recorded with the DO detector. No evidence for a leptoquark signal in the LQ(2)LQ(2) -> mu q mu q channel has been observed, and upper bounds on the product of cross section times branching fraction were set. This yields lower mass limits of m(LQ2) > 247 GeV/c(2) for beta = B(LQ(2) -> mu q) = 1 and m(LQ2) > 182 GeV/c(2) for beta = 1/2. Combining these limits with previous DO results, the lower limits on the mass of a second generation scalar leptoquark are m(LQ2) > 251 GeV/c(2) and m(LQ2) > 204 GeV/c(2) for beta = I and beta = 1/2, respectively.
We report on a search for charge-1/3 third-generation leptoquarks (LQ) produced in p (p) over bar collisions at root s =1.96 TeV using the D0 detector at Fermilab. Third-generation leptoquarks are ...assumed to be produced in pairs and to decay to a tau neutrino and a b quark with branching fraction B. We place upper limits on sigma(p (p) over bar -> LQ (LQ) over bar )B-2 as a function of the leptoquark mass M-LQ. Assuming B=1, we exclude at the 95% confidence level third-generation scalar leptoquarks with M-LQ < 229 GeV.
We report on a search for the pair production of second generation scalar leptoquarks (LQ2) in pp¯ collisions at the center-of-mass energy s=1.96 TeV, using data corresponding to an integrated ...luminosity of 294±19 pb−1 recorded with the DØ detector. No evidence for a leptoquark signal in the LQ2LQ¯2→μqμq channel has been observed, and upper bounds on the product of cross section times branching fraction were set. This yields lower mass limits of mLQ2>247 GeV/c2 for β=B(LQ2→μq)=1 and mLQ2>182 GeV/c2 for β=1/2. Combining these limits with previous DØ results, the lower limits on the mass of a second generation scalar leptoquark are mLQ2>251 GeV/c2 and mLQ2>204 GeV/c2 for β=1 and β=1/2, respectively.
In this paper a review of the results on searches for pnysics beyond the standard model in pp collisions with the CMS experiment at √s = 7 and 8 TeV is presented. Aspects of the analyses and their ...achieved limits on Z′- and W′-bosons, heavy neutrino, 4^th generation, leptoquarks as well as extra dimensions will be covered.
New low-energy leptoquark interactions Hirsch, M.; Klapdor-Kleingrothaus, H.V.; Kovalenko, S.G.
Physics letters. B,
06/1996, Volume:
378, Issue:
1
Journal Article
Peer reviewed
Open access
We discuss an extension of the standard model (SM) with vector and scalar leptoquarks. The renormalizable leptoquark Lagrangian consistent with the SM gauge symmetry is presented including the ...leptoquark-Higgs interactions previously not considered in the literature. We discuss the importance of these new interactions for leptoquark phenomenology. After the electro-weak symmetry breaking they generate non-trivial leptoquark mass matrices. These lead to mixing between different
SU (2)
l
-multiplets of the leptoquarks and induce at low energies new effective 4-fermion lepton-quark vertices. The latter affect the standard leptoquark phenomenology. We discuss constraints on these interactions from the helicity-suppressed
π →
ν +
e decay.
In the last 20 years the disciplines of particle physics, astrophysics, nuclear physics and cosmology have grown together in an unprecedented way. A brilliant example is nuclear double beta decay, an ...extremely rare radioactive decay mode, which is one of the most exciting and important fields of research in particle physics at present and the flagship of non-accelerator particle physics.While already discussed in the 1930s, only in the 1980s was it understood that neutrinoless double beta decay can yield information on the Majorana mass of the neutrino, which has an impact on the structure of space-time. Today, double beta decay is indispensable for solving the problem of the neutrino mass spectrum and the structure of the neutrino mass matrix. The potential of double beta decay has also been extended such that it is now one of the most promising tools for probing beyond-the-standard-model particle physics, and gives access to energy scales beyond the potential of future accelerators.This book presents the breathtaking manner in which achievements in particle physics have been made from a nuclear physics process. Consisting of a 150-page highly factual overview of the field of double beta decay and a 1200-page collection of the most important original articles, the book outlines the development of double beta decay research - theoretical and experimental - from its humble beginnings until its most recent achievements, with its revolutionary consequences for the theory of particle physics. It further presents an outlook on the exciting future of the field.
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