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Author (down) NA64 Collaboration (Andreev, Y.M. et al); Molina Bueno, L.
Title Search for a light Z' in the L-mu – L-tau scenario with the NA64-e experiment at CERN Type Journal Article
Year 2022 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 106 Issue 3 Pages 032015 - 12pp
Keywords
Abstract The extension of Standard Model made by inclusion of additional U(1) gauge L-mu – L-tau symmetry can explain the difference between the measured and the predicted value of the muon magnetic moment and solve the tension in B meson decays. This model predicts the existence of a new, light Z' vector boson, predominantly coupled to second and third generation leptons, whose interaction with electrons is due to a loop mechanism involving muons and taus. In this work, we present a rigorous evaluation of the upper limits in the Z' parameter space, obtained from the analysis of the data collected by the NA64-e experiment at CERN SPS, that performed a search for light dark matter with 2.84 x 10(11) electrons impinging with 100 GeV on an active thick target. The resulting limits touch the muon g – 2 preferred band for values of the Z' mass of order of 1 MeV, while the sensitivity projections for the future high-statistics NA64-e runs demonstrate the power of the electrons/positron beam approach in this theoretical scenario.
Address [Andreev, Yu M.; Dermenev, A., V; Gninenko, S. N.; Karneyeu, A. E.; Kirpichnikov, D., V; Kirsanov, M. M.; Kravchuk, L., V; Krasnikov, N., V; Tlisova, I; Toropin, A. N.] Inst Nucl Res, Moscow 117312, Russia, Email: luca.marsicano@ge.infn.it
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000862798400003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5376
Permanent link to this record
 
 
Author (down) NA64 Collaboration (Andreev, Y.M. et al); Molina Bueno, L.
Title Search for a New B-L Z' Gauge Boson with the NA64 Experiment at CERN Type Journal Article
Year 2022 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 129 Issue Pages 161801 - 6pp
Keywords
Abstract A search for a new Z′ gauge boson associated with (un)broken B−L symmetry in the keV–GeV mass range is carried out for the first time using the missing-energy technique in the NA64 experiment at the CERN SPS. From the analysis of the data with 3.22×10^11 electrons on target collected during 2016–2021 runs, no signal events were found. This allows us to derive new constraints on the Z′−e coupling strength, which, for the mass range 0.3≲ mZ′≲ 100  MeV, are more stringent compared to those obtained from the neutrino-electron scattering data.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5499
Permanent link to this record
 
 
Author (down) NA62 Collaboration (Cortina Gil, E. et al); Husek, T.
Title First search for K+ -> pi(+) nu(nu)over-bar using the decay-in-flight technique Type Journal Article
Year 2019 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 791 Issue Pages 156-166
Keywords
Abstract The NA62 experiment at the CERN SPS reports the first search for K+ -> pi(+) nu(nu) over bar using the decay-in-flight technique, based on a sample of 1.21 x10(11) K+ decays collected in 2016. The single event sensitivity is 3.15 x10(-10), corresponding to 0.267 Standard Model events. One signal candidate is observed while the expected background is 0.152 events. This leads to an upper limit of 14 x10(-10) on the K+ -> pi(+) nu(nu) over bar branching ratio at 95% CL.
Address [Gil, E. Cortina; Minucci, E.; Padolski, S.; Petrov, P.; Velghe, B.; Volpe, R.; Kleimenova, A.; Perrin-Terrin, M.] Catholic Univ Louvain, B-1348 Louvain La Neuve, Belgium, Email: radoslav.marchevski@cern.ch;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000462321800023 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3957
Permanent link to this record
 
 
Author (down) NA62 Collaboration (Cortina Gil, E. et al); Husek, T.
Title Search for production of an invisible dark photon in (0) decays Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 05 Issue 5 Pages 182 - 20pp
Keywords Beyond Standard Model; Exotics; Fixed target experiments; Rare decay
Abstract The results of a search for (0) decays to a photon and an invisible massive dark photon at the NA62 experiment at the CERN SPS are reported. From a total of 4.12 x 10(8) tagged (0) mesons, no signal is observed. Assuming a kinetic-mixing interaction, limits are set on the dark photon coupling to the ordinary photon as a function of the dark photon mass, improving on previous searches in the mass range 60-110 MeV/c(2). The present results are interpreted in terms of an upper limit of the branching ratio of the electro-weak decay 0improving the current limit by more than three orders of magnitude.
Address [Gil, E. Cortina; Kleimenova, A.; Minucci, E.; Padolski, S.; Petrov, P.; Shaikhiev, A.; Volpe, R.] Catholic Univ Louvain, Louvain, Belgium, Email: tommaso.spadaro@cern.ch;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000469459200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4028
Permanent link to this record
 
 
Author (down) NA62 collaboration (Cortina Gil, E. et al); Husek, T.
Title Searches for lepton number violating K+ decays Type Journal Article
Year 2019 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 797 Issue Pages 134794 - 9pp
Keywords
Abstract The NA62 experiment at CERN reports a search for the lepton number violating decays K+ -> pi(-)e(+)e(+) and K+ -> pi(-)mu(+)mu(+) using a data sample collected in 2017. No signals are observed, and upper limits on the branching fractions of these decays of 2.2 x 10(-10) and 4.2 x 10(-11) are obtained, respectively, at 90% confidence level. These upper limits improve on previously reported measurements by factors of 3 and 2, respectively.
Address [Gil, E. Cortina; Kleimenova, A.; Minucci, E.; Padolski, S.; Petrov, R.; Shaikhiev, A.; Volpe, R.; Perrin-Terrin, M.] Catholic Univ Louvain, B-1348 Louvain La Neuve, Belgium, Email: Evgueni.Goudzovski@cern.ch
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000488071200017 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4160
Permanent link to this record
 
 
Author (down) NA62 Collaboration (Cortina Gil, E. et al); Husek, T.
Title Search for heavy neutral lepton production in K+ decays to positrons Type Journal Article
Year 2020 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 807 Issue Pages 135599 - 9pp
Keywords
Abstract A search for heavy neutral lepton (N) production in K+ -> e(+)N decays using the data sample collected by the NA62 experiment at CERN in 2017-2018 is reported. Upper limits of the extended neutrino mixing matrix element vertical bar U-e4 vertical bar(2) are established at the level of 10(-9) over most of the accessible heavy neutral lepton mass range 144-462 MeV/c(2), with the assumption that the lifetime exceeds 50 ns. These limits improve significantly upon those of previous production and decay searches. The vertical bar U-e4 vertical bar(2) range favoured by Big Bang Nucleosynthesis is excluded up to a mass of about 340 MeV/c(2).
Address [Gil, E. Cortina; Kleimenova, A.; Minucci, E.; Padolski, S.; Petrov, P.; Shaikhiev, A.; Volpe, R.] Catholic Univ Louvain, Louvain La Neuve, Belgium, Email: Evgueni.Goudzovski@cern.ch
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000571765700067 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4544
Permanent link to this record
 
 
Author (down) NA62 Collaboration (Cortina Gil, E. et al); Husek, T.
Title An investigation of the very rare K+ -> pi+ nu nubar decay Type Journal Article
Year 2020 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 11 Issue 11 Pages 042 - 57pp
Keywords Fixed target experiments; Flavor physics; Flavour Changing Neutral Currents; Rare decay
Abstract The NA62 experiment reports an investigation of the K+-> pi+nu nu <overbar></mml:mover> mode from a sample of K+ decays collected in 2017 at the CERN SPS. The experiment has achieved a single event sensitivity of (0.389 +/- 0.024) x 10(-10), corresponding to 2.2 events assuming the Standard Model branching ratio of (8.4 +/- 1.0) x 10(-11). Two signal candidates are observed with an expected background of 1.5 events. Combined with the result of a similar analysis conducted by NA62 on a smaller data set recorded in 2016, the collaboration now reports an upper limit of 1.78 x 10(-10) for the K+-> pi+nu nu <overbar></mml:mover> branching ratio at 90% CL. This, together with the corresponding 68% CL measurement of (0.48<mml:mo>-0.48<mml:mo>+0.72) x 10(-10), are currently the most precise results worldwide, and are able to constrain some New Physics models that predict large enhancements still allowed by previous measurements.
Address [Gil, E. Cortina; Kleimenova, A.; Minucci, E.; Padolski, S.; Petrov, P.; Shaikhiev, A.; Volpe, R.; Jerhot, J.; Perrin-Terrin, M.; Lurkin, N.; Parkinson, C.] Catholic Univ Louvain, B-1348 Louvain, Belgium, Email: radoslav.marchevski@cern.ch;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000593745600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4624
Permanent link to this record
 
 
Author (down) NA48/2 Collaboration (Batley, J.R. et al); Fiorini, L.
Title Measurement of the form factors of charged kaon semileptonic decays Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 150 - 23pp
Keywords Fixed target experiments; Rare decay
Abstract A measurement of the form factors of charged kaon semileptonic decays is presented, based on 4.4 x 10(6)K(+/-) (0)e(e)(+/-) (Ke3 +/-) and 2.3 x 10(6)K(+/-) (0)+/- (K3 +/-) decays collected in 2004 by the NA48/2 experiment. The results are obtained with improved precision as compared to earlier measurements. The combination of measurements in the Ke3 +/- and K3 +/- modes is also presented.
Address [Batley, J. R.; Kalmus, G.; Lazzeroni, C.; Munday, D. J.; Slater, M. W.; Wotton, S. A.] Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England, Email: Dmitri.Madigojine@cern.ch;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000449293400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3791
Permanent link to this record
 
 
Author (down) NA48/2 Collaboration (Batley, J.R. et al); Fiorini, L.
Title First observation and study of the K-+/- -> pi(+/-)pi(0)e(+)e(-) decay Type Journal Article
Year 2019 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 788 Issue Pages 552-561
Keywords
Abstract The NA48/2 experiment at CERN reports the first observation of the K-+/- -> pi(+/-)pi(0)e(+)e(-) decay from an exposure of 1.7 x 10(11) charged kaon decays recorded in 2003-2004. A sample of 4919 candidates with 4.9% background contamination allows the determination of the branching ratio in the full kinematic region, BR(K-+/- -> pi(+/-)pi(0)e(+)e(-)) = (4.24 +/- 0.14) x 10(-6). The study of the kinematic space shows evidence for a structure dependent contribution in agreement with predictions based on chiral perturbation theory. Several P- and CP-violating asymmetries are also evaluated.
Address [Batley, J. R.; Kalmus, G.; Lazzeroni, C.; Munday, D. J.; Slater, M. W.; Wotton, S. A.; Balev, S.] Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England, Email: milena.misheva@cern.ch;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000455364400072 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3882
Permanent link to this record
 
 
Author (down) Murgui, C.; Peñuelas, A.; Jung, M.; Pich, A.
Title Global fit to b -> c tau nu transitions Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue 9 Pages 103 - 45pp
Keywords Beyond Standard Model; Effective Field Theories
Abstract We perform a general model-independent analysis of b -> c tau(nu) over bar (tau) transitions, including measurements of R-D, R-D*, their q(2) differential distributions, the recently measured longitudinal D* polarization F-L(D)*, and constraints from the B-c -> tau(nu) over bar (tau) lifetime, each of which has significant impact on the fit. A global fit to a general set of Wilson coefficients of an effective low-energy Hamiltonian is presented, the solutions of which are interpreted in terms of hypothetical new-physics mediators. From the obtained results we predict selected b -> c tau(nu) over bar (tau) observables, such as the baryonic transition Lambda(b) -> Lambda(c)tau(nu) over bar (tau), the ratio R-J/psi, the forward-backward asymmetries A(FB)(D()*()), the tau polarization asymmetries P-tau(D()*()), and the longitudinal D* polarization fraction F-L(D)*. The latter shows presently a slight tension with any new-physics model, such that an improved measurement could have an important impact. We also discuss the potential change due the very recently announced preliminary R-D(*) measurement by the Belle collaboration.
Address [Murgui, Clara; Penuelas, Ana; Pich, Antonio] Univ Valencia, IFIC, Dept Fis Teor, CSIC, Apt Correus 22085, E-46071 Valencia, Spain, Email: Clara.Murgui@ific.uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000490861200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4177
Permanent link to this record