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Title: Search for anomalous single top quark production in association with a photon in pp collisions at √(s) = 8 TeV

Abstract

We found the results of a search for flavor changing neutral currents (FCNC) through single top quark production in association with a photon is presented. The study is based on proton-proton collisions at a center-of-mass energy of 8 TeV using data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.8 fb-1. The search for tγ events where t → Wb andW → μn is conducted in final states with a muon, a photon, at least one hadronic jet with at most one being consistent with originating from a bottom quark, and missing transverse momentum. Furthermore, there was no evidence of single top quark production in association with a photon through a FCNC is observed. Upper limits at the 95% confidence level are set on the tug and tcg anomalous couplings and translated into upper limits on the branching fraction of the FCNC top quark decays: B(t → uγ) < 1.3 x 10-4 and B(t →cγ) < 1.7 x 10-3. Upper limits are also set on the cross section of associated tγ production in a restricted phase-space region. These are the most stringent limits currently available.

Authors:
 [1]
  1. Yerevan Physics Inst. (YerPhI) (Armenia). et al.
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP)
Contributing Org.:
CMS Collaboration
OSTI Identifier:
1230041
Report Number(s):
FERMILAB-PUB-15-513-CMS
Journal ID: ISSN 1029-8479; arXiv eprint number arXiv:1511.03951
Grant/Contract Number:  
AC02-07CH11359
Resource Type:
Accepted Manuscript
Journal Name:
Journal of High Energy Physics (Online)
Additional Journal Information:
Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2016; Journal Issue: 35; Journal ID: ISSN 1029-8479
Publisher:
Springer Berlin
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Khachatryan, Vardan. Search for anomalous single top quark production in association with a photon in pp collisions at √(s) = 8 TeV. United States: N. p., 2016. Web. https://doi.org/10.1007/JHEP04(2016)035.
Khachatryan, Vardan. Search for anomalous single top quark production in association with a photon in pp collisions at √(s) = 8 TeV. United States. https://doi.org/10.1007/JHEP04(2016)035
Khachatryan, Vardan. Wed . "Search for anomalous single top quark production in association with a photon in pp collisions at √(s) = 8 TeV". United States. https://doi.org/10.1007/JHEP04(2016)035. https://www.osti.gov/servlets/purl/1230041.
@article{osti_1230041,
title = {Search for anomalous single top quark production in association with a photon in pp collisions at √(s) = 8 TeV},
author = {Khachatryan, Vardan},
abstractNote = {We found the results of a search for flavor changing neutral currents (FCNC) through single top quark production in association with a photon is presented. The study is based on proton-proton collisions at a center-of-mass energy of 8 TeV using data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.8 fb-1. The search for tγ events where t → Wb andW → μn is conducted in final states with a muon, a photon, at least one hadronic jet with at most one being consistent with originating from a bottom quark, and missing transverse momentum. Furthermore, there was no evidence of single top quark production in association with a photon through a FCNC is observed. Upper limits at the 95% confidence level are set on the tug and tcg anomalous couplings and translated into upper limits on the branching fraction of the FCNC top quark decays: B(t → uγ) < 1.3 x 10-4 and B(t →cγ) < 1.7 x 10-3. Upper limits are also set on the cross section of associated tγ production in a restricted phase-space region. These are the most stringent limits currently available.},
doi = {10.1007/JHEP04(2016)035},
journal = {Journal of High Energy Physics (Online)},
number = 35,
volume = 2016,
place = {United States},
year = {2016},
month = {4}
}

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Works referenced in this record:

Measurement of the t -Channel Single Top Quark Production Cross Section in p p Collisions at s = 7 TeV
journal, August 2011


New Generation of Parton Distributions with Uncertainties from Global QCD Analysis
journal, July 2002


Zt, γt and t production at hadron colliders via strong flavour-changing neutral couplings
journal, September 2010


The anti- k t jet clustering algorithm
journal, April 2008


Search for flavor changing neutral currents in decays of top quarks
journal, July 2011


Supersymmetric QCD flavor-changing top quark decay
journal, October 1997


Search for Flavor-Changing Neutral Currents in Top-Quark Decays t Z q in p p Collisions at s = 8 TeV
journal, May 2014


Review of Particle Physics
journal, August 2014


Search for the Flavor-Changing Neutral-Current Decay t Z q in p p ¯ Collisions at s = 1.96 TeV
journal, November 2008


A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX
journal, June 2010

  • Alioli, Simone; Nason, Paolo; Oleari, Carlo
  • Journal of High Energy Physics, Vol. 2010, Issue 6
  • DOI: 10.1007/JHEP06(2010)043

A New Method for Combining NLO QCD with Shower Monte Carlo Algorithms
journal, November 2004


MCFM for the Tevatron and the LHC
journal, August 2010


PYTHIA 6.4 physics and manual
journal, May 2006


Rare top quark decays t cV in the top-color-assisted technicolor model
journal, July 2003


Search for single top quark production at HERA
journal, August 2009


Measurement of the inelastic proton–proton cross section at <mml:math altimg="si1.gif" overflow="scroll" xmlns:xocs="http://www.elsevier.com/xml/xocs/dtd" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.elsevier.com/xml/ja/dtd" xmlns:ja="http://www.elsevier.com/xml/ja/dtd" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:tb="http://www.elsevier.com/xml/common/table/dtd" xmlns:sb="http://www.elsevier.com/xml/common/struct-bib/dtd" xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:cals="http://www.elsevier.com/xml/common/cals/dtd" xmlns:sa="http://www.elsevier.com/xml/common/struct-aff/dtd"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>7</mml:mn><mml:mtext> TeV</mml:mtext></mml:math>
journal, May 2013


Parton distributions for the LHC
journal, July 2009


Confidence level computation for combining searches with small statistics
journal, September 1999

  • Junk, Thomas
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 434, Issue 2-3
  • DOI: 10.1016/S0168-9002(99)00498-2

Parton distributions with LHC data
journal, February 2013


TAUOLA - a library of Monte Carlo programs to simulate decays of polarized τ leptons
journal, May 1991


A minimal set of top anomalous couplings
journal, May 2009


Search for single top production at LEP
journal, December 2002


Pileup subtraction using jet areas
journal, January 2008


Geant4—a simulation toolkit
journal, July 2003

  • Agostinelli, S.; Allison, J.; Amako, K.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 506, Issue 3
  • DOI: 10.1016/S0168-9002(03)01368-8

Presentation of search results: the CL s technique
journal, September 2002


Top-pair production at hadron colliders with next-to-next-to-leading logarithmic soft-gluon resummation
journal, April 2012


Boosted decision trees as an alternative to artificial neural networks for particle identification
journal, May 2005

  • Roe, Byron P.; Yang, Hai-Jun; Zhu, Ji
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 543, Issue 2-3
  • DOI: 10.1016/j.nima.2004.12.018

Matching NLO QCD computations with parton shower simulations: the POWHEG method
journal, November 2007


Rare top decays t→cγ, t→cg and CKM unitarity
journal, February 2003


Search for Flavor-Changing Neutral Current Decays of the Top Quark in p p ¯ Collisions at s = 1.8 TeV
journal, March 1998


Search for single-top production in ep collisions at HERA
journal, February 2012


QCD corrections to hadronic W γ production with nonstandard WW γ couplings
journal, December 1993


Description and performance of track and primary-vertex reconstruction with the CMS tracker
journal, October 2014


Determination of jet energy calibration and transverse momentum resolution in CMS
journal, November 2011


Identification of b-quark jets with the CMS experiment
journal, April 2013


The performance of the CMS muon detector in proton-proton collisions at √ s = 7 TeV at the LHC
journal, November 2013


Search for single-top production in ep collisions at HERA
journal, May 2003


    Works referencing / citing this record:

    Top-quark physics at the Large Hadron Collider
    journal, May 2017


    What can we learn from triple top-quark production?
    journal, September 2019


    FCNC decays of standard model fermions into a dark photon
    journal, December 2016


    Constraining top quark flavor violation and dipole moments through three and four top quark productions at the LHC
    journal, November 2018

    • Malekhosseini, Malihe; Ghominejad, Mehrdad; Khanpour, Hamzeh
    • Physical Review D, Vol. 98, Issue 9
    • DOI: 10.1103/physrevd.98.095001