Física de partículas y campos
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A search for new resonances in multiple final states with a high transverse momentum Z boson in ?s=13 TeV pp collisions with the ATLAS detector
(SPRINGER, 2023/06/07) Aad G.; Abbott B.; Abbott D. C.; Abeling K.; Abidi S. H.; Aboulhorma A.; Abramowicz H.; Abreu H.; Abulaiti Y.; Abusleme Hoffman A. C.; Acharya B. S.; Achkar B.; Adam Bourdarios C.; Adamczyk L.; Adamek L.; Addepalli S. V.; Adelman J.; Adiguzel A.; Adorni S.; Adye T.; Affolder A. A.; Afik Y.; Agaras M. N.; Agarwala J.; Aggarwal A.; Agheorghiesei C.; Aguilar-Saavedra J. A.; Ahmad A.; Ahmadov F.; Ahmed W. S.; Ahuja S.; Ai X.; Aielli G.; Aizenberg I.; Akbiyik M.; Akesson T. P. A.; Akimov A. V.; Al Khoury K.; Alberghi G. L.; Albert J.
A generic search for resonances is performed with events containing a Z boson with transverse momentum greater than 100 GeV, decaying into e(+)e(-) or mu(+)mu(-). The analysed data collected with the ATLAS detector in proton-proton collisions at a centre-of-mass energy of 13TeV at the Large Hadron Collider correspond to an integrated luminosity of 139 fb(-1). Two invariant mass distributions are examined for a localised excess relative to the expected Standard Model background in six independent event categories (and their inclusive sum) to increase the sensitivity. No significant excess is observed. Exclusion limits at 95% confidence level are derived for two cases: a model-independent interpretation of Gaussian-shaped resonances with the mass width between 3% and 10% of the resonance mass, and a specific heavy vector triplet model with the decay mode W' -> ZW -> llqq.
Search for exclusive Higgs and Z boson decays to ?? and Higgs boson decays to K*? with the ATLAS detector
(ELSEVIER, 2023/12/10) Aad G.; Abbott B.; Abeling K.; Abidi S. H.; Aboulhorma A.; Abramowicz H.; Abreu H.; Abulaiti Y.; Hoffman A. C. Abusleme; Acharya B. S.; Bourdarios C. Adam; Adamczyk L.; Adamek L.; Addepalli S. V.; Adelman J.; Adiguzel A.; Adorni S.; Adye T.; Affolder A. A.; Afik Y.; Agaras M. N.; Agarwala J.; Aggarwal A.; Agheorghiesei C.; Aguilar-Saavedra J. A.; Ahmad A.; Ahmadov F.; Ahmed W. S.; Ahuja S.; Ai X.; Aielli G.; Tamlihat M. Ait; Aitbenchikh B.; Aizenberg I.; Akbiyik M.; Akesson T. P. A.; Akimov A. V.; Al Khoury K.; Alberghi G. L.; Albert J.
Searches for the exclusive decays of the Higgs boson to an omega meson and a photon or a K* meson and a photon can probe flavour-conserving and flavour-violating Higgs boson couplings to light quarks, respectively. Searches for these decays, along with the analogous Z boson decay to an omega meson and a photon, are performed with a pp collision data sample corresponding to integrated luminosities of up to 134 fb(-1) collected at root s = 13 TeV with the ATLAS detector at the CERN Large Hadron Collider. The obtained 95% confidence-level upper limits on the respective branching fractions are B(H -> omega gamma) < 5.5 x 10(-4), B(H -> K*gamma) < 2.2 x 10(-4) and B(Z -> omega gamma) < 3.9 x 10(-6). The limits for H -> omega gamma and Z -> omega gamma) are 370 times and 140 times the Standard Model expected values, respectively. The result for Z -> omega gamma corresponds to a two-orders-of-magnitude improvement over the limit obtained by the DELPHI experiment at LEP.