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Author (up) Andreev, Y.M. et al; Molina Bueno, L.; Tuzi, M.
Title Measurement of the intrinsic hadronic contamination in the NA64-e high-purity e+/e- beam at CERN Type Journal Article
Year 2023 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 1057 Issue Pages 168776 - 8pp
Keywords Light dark matter; Missing-energy experiment; H4 beamline; Hadron contamination
Abstract We present the measurement of the intrinsic hadronic contamination at the CERN SPS H4 beamline configured to transport electrons and positrons at 100 GeV/c. The analysis, performed using data collected by the NA64-e experiment in 2022, is based on calorimetric measurements, exploiting the different interaction mechanisms of electrons and hadrons in the NA64 detector. We determined the contamination by comparing the results obtained using the nominal electron/positron beamline configuration with those from a dedicated setup, in which only hadrons impinged on the detector. We also obtained an estimate of the relative protons, antiprotons and pions yield by exploiting the different absorption probabilities of these particles in matter. We cross-checked our results with a dedicated Monte Carlo simulation for the hadron production at the primary T2 target, finding a good agreement with the experimental measurements.
Address [Andreev, Yu. M.; Chumakov, A. G.; Dermenev, A. V.; Donskov, S. V.; Dusaev, R. R.; Enik, T.; Frolov, V. N.; Gerassimov, S. G.; Gninenko, S. N.; Kachanov, V. A.; Kambar, Y.; Karneyeu, A. E.; Kirsanov, M. M.; Kolosov, V. N.; Gertsenberger, S. V.; Kasianova, E. A.; Kramarenko, V. A.; Kravchuk, L. V.; Krasnikov, N. V.; Lyubovitskij, V. E.; Lysan, V.; Matveev, V. A.; Mikhailov, Yu. V.; Bueno, L. Molina; Peshekhonov, D. V.; Polyakov, V. A.; Salamatin, K.; Samoylenko, V. D.; Shchukin, D.; Tikhomirov, V. O.; Tlisova, I.; Toropin, A. N.; Trifonov, A. Yu.; Vasilishin, B. I.; Volkov, P. V.; Volkov, V. Yu.; Voronchikhin, I. V.; Zhevlakov, A. S.] CERN, Geneva, Switzerland, Email: pietro.bisio@ge.infn.it
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 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:001154863600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5923
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Author (up) 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 (up) 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 (up) NA64 Collaboration (Andreev, Y.M. et al); Molina Bueno, L.
Title Search for pseudoscalar bosons decaying into e(+)e(-) pairs in the NA64 experiment at the CERN SPS Type Journal Article
Year 2021 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 104 Issue 11 Pages L111102 - 5pp
Keywords
Abstract We report the results of a search for a light pseudoscalar particle a that couples to electrons and decays to e(+) e(-) perfbnned using the high-energy CERN SPS H4 electron beam. If such light pseudoscalar exists, it could explain the ATOMKI anomaly (an excess of e(+) e(-) pairs in the nuclear transitions of Be-8 and 4 He nuclei at the invariant mass similar or equal to 17 MeV observed by the experiment at the 5 MV Van de Graaff accelerator at ATOMKI, Hungary). We used the NA64 data collected in the “visible mode” configuration with a total statistics corresponding to 8.4 x 10(10) electrons on target (EOT) in 2017 and 2018. In order to increase sensitivity to small coupling parameter epsilon we also used the data collected in 2016-2018 in the “invisible mode” configuration of NA64 with a total statistics corresponding to 2.84 x 10(11) EOT. The background and efficiency estimates for these two configurations were retained from our previous analyses searching for light vector bosons and axionlike particles (ALP) (the latter were assumed to couple predominantly to gamma). In this work we recalculate the signal yields, which are different due to different cross section and lifetime of a pseudoscalar particle a, and perform a new statistical analysis. As a result, the region of the two dimensional parameter space m(a) – epsilon in the mass range from 1 to 17.1 MeV is excluded. At the mass of the central value of the ATOMKI anomaly (the first result obtained on the beryllium nucleus, 16.7 MeV) the values of epsilon in the range 2.1 x 10(-4) < epsilon < 3.2 x 10(-4) are excluded.
Address [Hoesgen, M.; Ketzer, B.] Univ Bonn, Helmholtz Inst Strahlen & Kernphys, D-53115 Bonn, Germany
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:000738796900005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5071
Permanent link to this record
 

 
Author (up) NA64 Collaboration (Andreev, Y.M. et al); Molina Bueno, L.
Title Improved exclusion limit for light dark matter from e(+) e(-) annihilation in NA64 Type Journal Article
Year 2021 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 104 Issue 9 Pages L091701 - 7pp
Keywords
Abstract The current most stringent constraints for the existence of sub-GeV dark matter coupling to Standard Model via a massive vector boson A' were set by the NA64 experiment for the mass region m(A') less than or similar to 250 MeV, by analyzing data from the interaction of 2.84 x 10(11) 100-GeV electrons with an active thick target and searching for missing-energy events. In this work, by including A' production via secondary positron annihilation with atomic electrons, we extend these limits in the 200-300 MeV region by almost an order of magnitude, touching for the first time the dark matter relic density constrained parameter combinations. Our new results demonstrate the power of the resonant annihilation process in missing energy dark-matter searches, paving the road to future dedicated e(+) beam efforts.
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: andrea.celentano@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:000744291500008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5090
Permanent link to this record
 

 
Author (up) NA64 Collaboration (Andreev, Y.M. et al); Molina Bueno, L.; Tuzi, M.
Title Probing light dark matter with positron beams at NA64 Type Journal Article
Year 2024 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 109 Issue 3 Pages L031103 - 6pp
Keywords
Abstract We present the results of a missing-energy search for light dark matter which has a new interaction with ordinary matter transmitted by a vector boson, called dark photon A'. For the first time, this search is performed with a positron beam by using the significantly enhanced production of A' in the resonant annihilation of positrons with atomic electrons of the target nuclei, followed by the invisible decay of A' into dark matter. No events were found in the signal region with (10.1 +/- 0.1) x 109 positrons on target with 100 GeV energy. This allowed us to set new exclusion limits that, relative to the collected statistics, prove the power of this experimental technique. This measurement is a crucial first step toward a future exploration program with positron beams, whose estimated sensitivity is here presented.
Address [Andreev, Yu. M.; Dermenev, A. V.; Donskov, S. V.; Dusaev, R. R.; Enik, T.; Frolov, V. N.; Kachanov, V. A.; Karneyeu, A. E.; Kirpichnikov, D. V.; Kirsanov, M. M.; Kolosov, V. N.; Gertsenberger, S. V.; Kasianova, E. A.; Kramarenko, V. A.; Kravchuk, L. V.; Krasnikov, N. V.; Lysan, V.; Matveev, V. A.; Samoylenko, V. D.; Shchukin, D.; Tikhomirov, V. O.; Tlisova, I.; Toropin, A. N.; Volkov, P. V.; Volkov, V. Yu.; Voronchikhin, I. V.; Zhevlakov, A. S.] CERN, Meyrin, Switzerland, Email: pietro.bisio@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:001180160500008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6009
Permanent link to this record
 

 
Author (up) NA64 Collaboration (Andreev, Y.M. et al); Molina Bueno, L.; Tuzi, M.
Title Search for Light Dark Matter with NA64 at CERN Type Journal Article
Year 2023 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 131 Issue 16 Pages 161801 - 7pp
Keywords
Abstract Thermal dark matter models with particle chi masses below the electroweak scale can provide an explanation for the observed relic dark matter density. This would imply the existence of a new feeble interaction between the dark and ordinary matter. We report on a new search for the sub-GeV chi production through the interaction mediated by a new vector boson, called the dark photon A ' , in collisions of 100 GeV electrons with the active target of the NA64 experiment at the CERN SPS. With 9.37 x 10(11) electrons on target collected during 2016-2022 runs NA64 probes for the first time the well-motivated region of parameter space of benchmark thermal scalar and fermionic dark matter models. No evidence for dark matter production has been found. This allows us to set the most sensitive limits on the A ' couplings to photons for masses m(A ') less than or similar to 0.35 GeV, and to exclude scalar and Majorana dark matter with the chi – A ' coupling alpha(D) <= 0.1 for masses 0.001 less than or similar to m(chi) less than or similar to 0.1 GeV and 3m(chi) <= m(A ').
Address [Andreev, Yu. M.; Chumakov, A. G.; Dermenev, A. V.; Donskov, S. V.; Dusaev, R. R.; Enik, T.; Frolov, V. N.; Gertsenberger, S. V.; Gninenko, S. N.; Kachanov, V. A.; Karneyeu, A. E.; Kasianova, E. A.; Kekelidze, G. D.; Kramarenko, V. A.; Kravchuk, L. V.; Krasnikov, N. V.; Lyubovitskij, V. E.; Lysan, V.; Matveev, V. A.; Peshekhonov, D., V; Polyakov, V. A.; Salamatin, K. M.; Samoylenko, V. D.; Shchukin, D. A.; Tikhomirov, V. O.; Tlisova, I.; Toropin, A. N.; Vasilishin, B. I.; Volkov, P. V.; Volkov, V. Yu.; Voronchikhin, I. V.; Zhevlakov, A. S.] CERN, Geneva, Switzerland, Email: sergei.gninenko@cern.ch
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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:001098606400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5805
Permanent link to this record