Search results for "Large extra dimension"

Search for new phenomena with the monojet and missing transverse momentum signature using the ATLAS detector in s=7TeV proton–proton collisions

2011

A search for new phenomena in events featuring a high energy jet and large missing transverse momentum in proton-proton collisions at root s = 7 TeV is presented using a dataset corresponding to an integrated luminosity of 33 pb(-1) recorded with the ATLAS detector at the Large Hadron Collider. The number of observed events is consistent with the Standard Model prediction. This result is interpreted in terms of limits on a model of Large Extra Dimensions. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.

Physics at the Large Hadron Collider

2003

Abstract The experiments at the Large Hadron Collider LHC have a large discovery potential for physics beyond the Standard Model and in the investigation of the nature of electroweak symmetry breaking. The large event rates provided by the high luminosity LHC machine will, however, also allow to perform precision measurements of important Standard Model parameters. Both the discovery potential for new physics and the measurements of Standard Model parameters are summarized in the present paper.

A scheme with two large extra dimensions confronted with neutrino physics

2003

We investigate a particle physics model in a six-dimensional spacetime, where two extra dimensions form a torus. Particles with Standard Model charges are confined by interactions with a scalar field to four four-dimensional branes, two vortices accommodating ordinary type fermions and two antivortices accommodating mirror fermions. We investigate the phenomenological implications of this multibrane structure by confronting the model with neutrino physics data.

Search forB0Decays to Invisible Final States and toνν¯γ

2004

We establish upper limits on branching fractions for B0 decays to final states where the decay products are purely invisible (i.e., no observable final state particles) and for B0 decays to nunugamma. Within the standard model, these decays have branching fractions that are below current experimental sensitivity, but various models of physics beyond the standard model predict significant contributions from these channels. Using 88.5 x 10(6) BB pairs collected at the Upsilon(4S) resonance by the BABAR experiment at the PEP-II e(+)e- storage ring at the Stanford Linear Accelerator Center, we establish upper limits at the 90% confidence level of 22 x 10(-5) for the branching fraction of B0-->i…

Search for large extra dimensions via single photon plus missing energy final states at s=1.96TeV

2008

Made available in DSpace on 2022-04-28T20:42:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-06-30 We report on a search for large extra dimensions in a data sample of approximately 1fb-1 of pp̄ collisions at s=1.96TeV. We investigate Kaluza-Klein graviton production with a photon and missing transverse energy in the final state. At the 95% C.L. we set limits on the fundamental mass scale MD from 884to 778GeV for two to eight extra dimensions. © 2008 The American Physical Society. Universidad de Buenos Aires, Buenos Aires LAFEX Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro Universidade Do Estado Do Rio de Janeiro, Rio de Janeiro Universidade Federal Do ABC, Santo André In…

Search for Large Extra Dimensions in theMonojet+E̸TChannel with the DØ Detector

2003

We present a search for large extra dimensions (ED) in p (p) over bar collisions at a center-of-mass energy of 1.8 TeV using data collected by the DO detector at the Fermilab Tevatron in 1994-1996. Data corresponding to 78.8+/-3.9 pb(-1) are examined for events with large missing transverse energy, one high-p(T) jet, and no isolated muons. There is no excess observed beyond expectation from the standard model, and we place lower limits on the fundamental Planck scale of 1.0 and 0.6 TeV for 2 and 7 ED, respectively.

Search for Dark Matter Candidates and Large Extra Dimensions in Events with a Photon and Missing Transverse Momentum inppCollision Data ats=7  TeVwit…

2013

Constraining models with vector-like fermions from FCNC in K and B physics

2001

In this work, we update the constraints on tree level FCNC couplings in the framework of a theory with n isosinglet vector-like down quarks. In this context, we emphasize the sensitivity of the B -> J/psi K_S CP asymmetry to the presence of new vector-like down quarks. This CP asymmetry, together with the rare decays B -> X_{s,d} l bar{l} and K -> pi nu bar{nu} are the best options to further constrain the FCNC tree level couplings or even to point out, in the near future, the possible presence of vector-like quarks in the low energy spectrum, as suggested by GUT theories or models of large extra dimensions at the TeV scale.

Search for heavy resonances with the ATLAS detector

2014

The ATLAS detector at the Large Hadron Collider (LHC) is used to search for heavy resonances in various final states. Recent results from different analyses of the proton-proton (pp) collisions recorded in 2012 at a center-of-mass energy of √s =8 TeV corresponding to an integrated luminosity of Lint ≈ 20 fb−1 are presented. Various models are considered such as W′ and Z′ bosons, chiral bosons, excited quarks and technicolor, as well as a Randall-Sundrum graviton, the ADD large extra dimension scenario, (quantum) black holes and contact interactions.

Measurement of Dijet Angular Distributions ats=1.96  TeVand Searches for Quark Compositeness and Extra Spatial Dimensions

2009

We present the first measurement of dijet angular distributions in ppbar collisions at sqrt{s}=1.96TeV at the Fermilab Tevatron Collider. The measurement is based on a dataset corresponding to an integrated luminosity of up to 0.7fb-1 collected with the D0 detector. Dijet angular distributions have been measured over a range of dijet masses, from 0.25TeV to above 1.1TeV. The data are in good agreement with the predictions of perturbative QCD and are used to constrain new physics models including quark compositeness, large extra dimensions, and TeV-1 scale extra dimensions. For all models we set the most stringent direct limits to date.