Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb−1 of pp collisions at √s = 13TeV with the ATLAS experiment

The ATLAS Collaboration

doi:10.1016/j.physletb.2019.135082

Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb⁻¹ of pp collisions at √s = 13TeV with the ATLAS experiment

The ATLAS Collaboration

Research output: Contribution to journal › Article › peer-review

36 Citations (Scopus)

3 Downloads (Pure)

Abstract

A search for flavour-changing neutral current (FCNC) events via the coupling of a top quark, a photon, and an up or charm quark is presented using 81 fb⁻¹ of proton–proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Events with a photon, an electron or muon, a b-tagged jet, and missing transverse momentum are selected. A neural network based on kinematic variables differentiates between events from signal and background processes. The data are consistent with the background-only hypothesis, and limits are set on the strength of the tqγ coupling in an effective field theory. These are also interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tuγ coupling of 36 fb (78 fb) and on the branching ratio for t → γu of 2.8 × 10⁻⁵ (6.1 × 10⁻⁵). In addition, they are interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tcγ coupling of 40 fb (33 fb) and on the branching ratio for t → γc of 22 × 10⁻⁵ (18 × 10⁻⁵).

Original language	English
Article number	135082
Pages (from-to)	1-21
Number of pages	21
Journal	Physics Letters B
Volume	800
DOIs	https://doi.org/10.1016/j.physletb.2019.135082
Publication status	Published - 10 Jan 2020
Externally published	Yes

Bibliographical note

Copyright the Author(s) 2019. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

Access to Document

10.1016/j.physletb.2019.135082Licence: CC BY

Publisher version (open access)Final published version, 1.41 MBLicence: CC BY

Cite this

@article{28df95a38b2949e7963a1477e9ca4d4b,

title = "Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb−1 of pp collisions at √s = 13TeV with the ATLAS experiment",

abstract = "A search for flavour-changing neutral current (FCNC) events via the coupling of a top quark, a photon, and an up or charm quark is presented using 81 fb−1 of proton–proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Events with a photon, an electron or muon, a b-tagged jet, and missing transverse momentum are selected. A neural network based on kinematic variables differentiates between events from signal and background processes. The data are consistent with the background-only hypothesis, and limits are set on the strength of the tqγ coupling in an effective field theory. These are also interpreted as 95\% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tuγ coupling of 36 fb (78 fb) and on the branching ratio for t → γu of 2.8 × 10−5 (6.1 × 10−5). In addition, they are interpreted as 95\% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tcγ coupling of 40 fb (33 fb) and on the branching ratio for t → γc of 22 × 10−5 (18 × 10−5).",

author = "\{The ATLAS Collaboration\} and G. Aad and B. Abbott and Abbott, \{D. C.\} and \{Abed Abud\}, A. and K. Abeling and Abhayasinghe, \{D. K.\} and Abidi, \{S. H.\} and Abouzeid, \{O. S.\} and Abraham, \{N. L.\} and H. Abramowicz and H. Abreu and Y. Abulaiti and Acharya, \{B. S.\} and B. Achkar and S. Adachi and L. Adam and \{Adam Bourdarios\}, C. and L. Adamczyk and L. Adamek and J. Adelman and M. Adersberger and A. Adiguzel and S. Adorni and T. Adye and Affolder, \{A. A.\} and Y. Afik and C. Agapopoulou and Agaras, \{M. N.\} and A. Aggarwal and C. Agheorghiesei and Aguilar-Saavedra, \{J. A.\} and F. Ahmadov and Ahmed, \{W. S.\} and X. Ai and G. Aielli and S. Akatsuka and {\AA}kesson, \{T. P.A.\} and E. Akilli and Akimov, \{A. V.\} and \{Al Khoury\}, K. and Alberghi, \{G. L.\} and J. Albert and \{Alconada Verzini\}, \{M. J.\} and S. Alderweireldt and M. Aleksa and Aleksandrov, \{I. N.\} and C. Alexa and D. Alexandre and T. Alexopoulos and A. Alfonsi and F. Alfonsi and M. Alhroob and B. Ali and G. Alimonti and J. Alison and Alkire, \{S. P.\} and C. Allaire and Allbrooke, \{B. M.M.\} and Allen, \{B. W.\} and Allport, \{P. P.\} and A. Aloisio and A. Alonso and F. Alonso and C. Alpigiani and Alshehri, \{A. A.\} and \{Alvarez Estevez\}, M. and \{{\'A}lvarez Piqueras\}, D. and Alviggi, \{M. G.\} and \{Amaral Coutinho\}, Y. and A. Ambler and L. Ambroz and C. Amelung and D. Amidei and \{Amor Dos Santos\}, \{S. P.\} and S. Amoroso and Amrouche, \{C. S.\} and F. An and C. Anastopoulos and N. Andari and T. Andeen and Anders, \{C. F.\} and Anders, \{J. K.\} and A. Andreazza and V. Andrei and Anelli, \{C. R.\} and S. Angelidakis and A. Angerami and Anisenkov, \{A. V.\} and A. Annovi and C. Antel and Anthony, \{M. T.\} and M. Antonelli and Antrim, \{D. J.A.\} and F. Anulli and M. Aoki and \{Aparisi Pozo\}, \{J. A.\} and \{Aperio Bella\}, L. and G. Arabidze and Araque, \{J. P.\} and \{Araujo Ferraz\}, V. and \{Araujo Pereira\}, R. and C. Arcangeletti and Arce, \{A. T.H.\} and Arduh, \{F. A.\} and Arguin, \{J. F.\} and S. Argyropoulos and Arling, \{J. H.\} and Armbruster, \{A. J.\} and A. Armstrong and O. Arnaez and H. Arnold and \{Arrubarrena Tame\}, \{Z. P.\} and A. Artamonov and G. Artoni and S. Artz and S. Asai and N. Asbah and Asimakopoulou, \{E. M.\} and L. Asquith and J. Assahsah and K. Assamagan and R. Astalos and Atkin, \{R. J.\} and M. Atkinson and Atlay, \{N. B.\} and H. Atmani and K. Augsten and G. Avolio and R. Avramidou and Ayoub, \{M. K.\} and Azoulay, \{A. M.\} and G. Azuelos and H. Bachacou and K. Bachas and M. Backes and F. Backman and P. Bagnaia and M. Bahmani and H. Bahrasemani and Bailey, \{A. J.\} and Bailey, \{V. R.\} and Baines, \{J. T.\} and M. Bajic and C. Bakalis and Baker, \{O. K.\} and Bakker, \{P. J.\} and \{Bakshi Gupta\}, D. and S. Balaji and Baldin, \{E. M.\} and P. Balek and F. Balli and Balunas, \{W. K.\} and J. Balz and E. Banas and A. Bandyopadhyay and Sw Banerjee and Bannoura, \{A. A.E.\} and L. Barak and Barbe, \{W. M.\} and Barberio, \{E. L.\} and D. Barberis and M. Barbero and G. Barbour and T. Barillari and Barisits, \{M. S.\} and J. Barkeloo and T. Barklow and R. Barnea and Barnes, \{S. L.\} and Barnett, \{B. M.\} and Barnett, \{R. M.\} and Z. Barnovska-Blenessy and A. Baroncelli and G. Barone and Barr, \{A. J.\} and \{Barranco Navarro\}, L. and F. Barreiro and \{Barreiro Guimar{\~a}es da Costa\}, J. and S. Barsov and R. Bartoldus and G. Bartolini and Barton, \{A. E.\} and P. Bartos and A. Basalaev and A. Bassalat and Basso, \{M. J.\} and Bates, \{R. L.\} and S. Batlamous and Batley, \{J. R.\} and B. Batool and M. Battaglia and M. Bauce and F. Bauer and Bauer, \{K. T.\} and Bawa, \{H. S.\} and Beacham, \{J. B.\} and T. Beau and Beauchemin, \{P. H.\} and F. Becherer and P. Bechtle and Beck, \{H. C.\} and Beck, \{H. P.\} and K. Becker and M. Becker and C. Becot and Beddall, \{A. J.\} and Beddall, \{A. J.\} and Bednyakov, \{V. A.\} and M. Bedognetti and Bee, \{C. P.\} and Beermann, \{T. A.\} and M. Begalli and M. Begel and A. Behera and Behr, \{J. K.\} and F. Beisiegel and Bell, \{A. S.\} and G. Bella and L. Bellagamba and A. Bellerive and P. Bellos and K. Beloborodov and K. Belotskiy and Belyaev, \{N. L.\} and D. Benchekroun and N. Benekos and Y. Benhammou and Benjamin, \{D. P.\} and M. Benoit and Bensinger, \{J. R.\} and S. Bentvelsen and L. Beresford and M. Beretta and D. Berge and \{Bergeaas Kuutmann\}, E. and N. Berger and B. Bergmann and Bergsten, \{L. J.\} and J. Beringer and S. Berlendis and Bernard, \{N. R.\} and G. Bernardi and C. Bernius and T. Berry and P. Berta and C. Bertella and Bertram, \{I. A.\} and \{Bessidskaia Bylund\}, O. and N. Besson and J. Shojaii",

note = "Copyright the Author(s) 2019. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.",

year = "2020",

month = jan,

day = "10",

doi = "10.1016/j.physletb.2019.135082",

language = "English",

volume = "800",

pages = "1--21",

journal = "Physics Letters B",

issn = "0370-2693",

publisher = "Elsevier",

}

TY - JOUR

T1 - Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb−1 of pp collisions at √s = 13TeV with the ATLAS experiment

AU - The ATLAS Collaboration

AU - Aad, G.

AU - Abbott, B.

AU - Abbott, D. C.

AU - Abed Abud, A.

AU - Abeling, K.

AU - Abhayasinghe, D. K.

AU - Abidi, S. H.

AU - Abouzeid, O. S.

AU - Abraham, N. L.

AU - Abramowicz, H.

AU - Abreu, H.

AU - Abulaiti, Y.

AU - Acharya, B. S.

AU - Achkar, B.

AU - Adachi, S.

AU - Adam, L.

AU - Adam Bourdarios, C.

AU - Adamczyk, L.

AU - Adamek, L.

AU - Adelman, J.

AU - Adersberger, M.

AU - Adiguzel, A.

AU - Adorni, S.

AU - Adye, T.

AU - Affolder, A. A.

AU - Afik, Y.

AU - Agapopoulou, C.

AU - Agaras, M. N.

AU - Aggarwal, A.

AU - Agheorghiesei, C.

AU - Aguilar-Saavedra, J. A.

AU - Ahmadov, F.

AU - Ahmed, W. S.

AU - Ai, X.

AU - Aielli, G.

AU - Akatsuka, S.

AU - Åkesson, T. P.A.

AU - Akilli, E.

AU - Akimov, A. V.

AU - Al Khoury, K.

AU - Alberghi, G. L.

AU - Albert, J.

AU - Alconada Verzini, M. J.

AU - Alderweireldt, S.

AU - Aleksa, M.

AU - Aleksandrov, I. N.

AU - Alexa, C.

AU - Alexandre, D.

AU - Alexopoulos, T.

AU - Alfonsi, A.

AU - Alfonsi, F.

AU - Alhroob, M.

AU - Ali, B.

AU - Alimonti, G.

AU - Alison, J.

AU - Alkire, S. P.

AU - Allaire, C.

AU - Allbrooke, B. M.M.

AU - Allen, B. W.

AU - Allport, P. P.

AU - Aloisio, A.

AU - Alonso, A.

AU - Alonso, F.

AU - Alpigiani, C.

AU - Alshehri, A. A.

AU - Alvarez Estevez, M.

AU - Álvarez Piqueras, D.

AU - Alviggi, M. G.

AU - Amaral Coutinho, Y.

AU - Ambler, A.

AU - Ambroz, L.

AU - Amelung, C.

AU - Amidei, D.

AU - Amor Dos Santos, S. P.

AU - Amoroso, S.

AU - Amrouche, C. S.

AU - An, F.

AU - Anastopoulos, C.

AU - Andari, N.

AU - Andeen, T.

AU - Anders, C. F.

AU - Anders, J. K.

AU - Andreazza, A.

AU - Andrei, V.

AU - Anelli, C. R.

AU - Angelidakis, S.

AU - Angerami, A.

AU - Anisenkov, A. V.

AU - Annovi, A.

AU - Antel, C.

AU - Anthony, M. T.

AU - Antonelli, M.

AU - Antrim, D. J.A.

AU - Anulli, F.

AU - Aoki, M.

AU - Aparisi Pozo, J. A.

AU - Aperio Bella, L.

AU - Arabidze, G.

AU - Araque, J. P.

AU - Araujo Ferraz, V.

AU - Araujo Pereira, R.

AU - Arcangeletti, C.

AU - Arce, A. T.H.

AU - Arduh, F. A.

AU - Arguin, J. F.

AU - Argyropoulos, S.

AU - Arling, J. H.

AU - Armbruster, A. J.

AU - Armstrong, A.

AU - Arnaez, O.

AU - Arnold, H.

AU - Arrubarrena Tame, Z. P.

AU - Artamonov, A.

AU - Artoni, G.

AU - Artz, S.

AU - Asai, S.

AU - Asbah, N.

AU - Asimakopoulou, E. M.

AU - Asquith, L.

AU - Assahsah, J.

AU - Assamagan, K.

AU - Astalos, R.

AU - Atkin, R. J.

AU - Atkinson, M.

AU - Atlay, N. B.

AU - Atmani, H.

AU - Augsten, K.

AU - Avolio, G.

AU - Avramidou, R.

AU - Ayoub, M. K.

AU - Azoulay, A. M.

AU - Azuelos, G.

AU - Bachacou, H.

AU - Bachas, K.

AU - Backes, M.

AU - Backman, F.

AU - Bagnaia, P.

AU - Bahmani, M.

AU - Bahrasemani, H.

AU - Bailey, A. J.

AU - Bailey, V. R.

AU - Baines, J. T.

AU - Bajic, M.

AU - Bakalis, C.

AU - Baker, O. K.

AU - Bakker, P. J.

AU - Bakshi Gupta, D.

AU - Balaji, S.

AU - Baldin, E. M.

AU - Balek, P.

AU - Balli, F.

AU - Balunas, W. K.

AU - Balz, J.

AU - Banas, E.

AU - Bandyopadhyay, A.

AU - Banerjee, Sw

AU - Bannoura, A. A.E.

AU - Barak, L.

AU - Barbe, W. M.

AU - Barberio, E. L.

AU - Barberis, D.

AU - Barbero, M.

AU - Barbour, G.

AU - Barillari, T.

AU - Barisits, M. S.

AU - Barkeloo, J.

AU - Barklow, T.

AU - Barnea, R.

AU - Barnes, S. L.

AU - Barnett, B. M.

AU - Barnett, R. M.

AU - Barnovska-Blenessy, Z.

AU - Baroncelli, A.

AU - Barone, G.

AU - Barr, A. J.

AU - Barranco Navarro, L.

AU - Barreiro, F.

AU - Barreiro Guimarães da Costa, J.

AU - Barsov, S.

AU - Bartoldus, R.

AU - Bartolini, G.

AU - Barton, A. E.

AU - Bartos, P.

AU - Basalaev, A.

AU - Bassalat, A.

AU - Basso, M. J.

AU - Bates, R. L.

AU - Batlamous, S.

AU - Batley, J. R.

AU - Batool, B.

AU - Battaglia, M.

AU - Bauce, M.

AU - Bauer, F.

AU - Bauer, K. T.

AU - Bawa, H. S.

AU - Beacham, J. B.

AU - Beau, T.

AU - Beauchemin, P. H.

AU - Becherer, F.

AU - Bechtle, P.

AU - Beck, H. C.

AU - Beck, H. P.

AU - Becker, K.

AU - Becker, M.

AU - Becot, C.

AU - Beddall, A. J.

AU - Bednyakov, V. A.

AU - Bedognetti, M.

AU - Bee, C. P.

AU - Beermann, T. A.

AU - Begalli, M.

AU - Begel, M.

AU - Behera, A.

AU - Behr, J. K.

AU - Beisiegel, F.

AU - Bell, A. S.

AU - Bella, G.

AU - Bellagamba, L.

AU - Bellerive, A.

AU - Bellos, P.

AU - Beloborodov, K.

AU - Belotskiy, K.

AU - Belyaev, N. L.

AU - Benchekroun, D.

AU - Benekos, N.

AU - Benhammou, Y.

AU - Benjamin, D. P.

AU - Benoit, M.

AU - Bensinger, J. R.

AU - Bentvelsen, S.

AU - Beresford, L.

AU - Beretta, M.

AU - Berge, D.

AU - Bergeaas Kuutmann, E.

AU - Berger, N.

AU - Bergmann, B.

AU - Bergsten, L. J.

AU - Beringer, J.

AU - Berlendis, S.

AU - Bernard, N. R.

AU - Bernardi, G.

AU - Bernius, C.

AU - Berry, T.

AU - Berta, P.

AU - Bertella, C.

AU - Bertram, I. A.

AU - Bessidskaia Bylund, O.

AU - Besson, N.

AU - Shojaii, J.

N1 - Copyright the Author(s) 2019. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

PY - 2020/1/10

Y1 - 2020/1/10

N2 - A search for flavour-changing neutral current (FCNC) events via the coupling of a top quark, a photon, and an up or charm quark is presented using 81 fb−1 of proton–proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Events with a photon, an electron or muon, a b-tagged jet, and missing transverse momentum are selected. A neural network based on kinematic variables differentiates between events from signal and background processes. The data are consistent with the background-only hypothesis, and limits are set on the strength of the tqγ coupling in an effective field theory. These are also interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tuγ coupling of 36 fb (78 fb) and on the branching ratio for t → γu of 2.8 × 10−5 (6.1 × 10−5). In addition, they are interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tcγ coupling of 40 fb (33 fb) and on the branching ratio for t → γc of 22 × 10−5 (18 × 10−5).

AB - A search for flavour-changing neutral current (FCNC) events via the coupling of a top quark, a photon, and an up or charm quark is presented using 81 fb−1 of proton–proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Events with a photon, an electron or muon, a b-tagged jet, and missing transverse momentum are selected. A neural network based on kinematic variables differentiates between events from signal and background processes. The data are consistent with the background-only hypothesis, and limits are set on the strength of the tqγ coupling in an effective field theory. These are also interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tuγ coupling of 36 fb (78 fb) and on the branching ratio for t → γu of 2.8 × 10−5 (6.1 × 10−5). In addition, they are interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tcγ coupling of 40 fb (33 fb) and on the branching ratio for t → γc of 22 × 10−5 (18 × 10−5).

UR - https://www.scopus.com/pages/publications/85075235650

U2 - 10.1016/j.physletb.2019.135082

DO - 10.1016/j.physletb.2019.135082

M3 - Article

AN - SCOPUS:85075235650

SN - 0370-2693

VL - 800

SP - 1

EP - 21

JO - Physics Letters B

JF - Physics Letters B

M1 - 135082

ER -

Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb⁻¹ of pp collisions at √s = 13TeV with the ATLAS experiment

Abstract

Bibliographical note

Access to Document

Other files and links

Fingerprint

Cite this