• A
  • A
  • A
  • ABC
  • ABC
  • ABC
  • А
  • А
  • А
  • А
  • А
Regular version of the site
Of all publications in the section: 97
Sort:
by name
by year
Article
Аушев Т. А., Мизюк Р. В., Pakhlov P. et al. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2018. Vol. 97. No. 11. P. 1-16.

The first search for double charged charmoniumlike state production in Ï?(1S) and Ï?(2S) decays and in e+e- annihilation at s=10.52, 10.58, and 10.867 GeV is conducted using data collected with the Belle detector at the KEKB asymmetric energy electron-positron collider. No significant signals are observed in any of the studied modes, and the 90% credibility level upper limits on their product branching fractions in Ï?(1S) and Ï?(2S) decays [B(Ï?(1S,2S)→Zc+Zc(′)-)×B(Zc+→π++cc) (cc=J/ψ, χc1(1P), ψ(2S))] and the product of Born cross section and branching fraction for e+e-→Zc+Zc(′)- (σ(e+e-→Zc+Zc(′)-)×B(Zc+→π++cc)) at s=10.52, 10.58, and 10.867 GeV are determined. Here, Zc refers to the Zc(3900) and Zc(4200) observed in the πJ/ψ final state, the Zc1(4050) and Zc2(4250) in the πχc1(1P) final state, and the Zc(4050) and Zc(4430) in the πψ(2S) final state. © 2018 American Physical Society.

Added: Oct 28, 2020
Article
Аушев Т. А., Мизюк Р. В., Pakhlov P. et al. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2019. Vol. 100. No. 3. P. 1-11.

Using data samples of e+e- collisions collected at the I(1S), I(2S), and I(3S) resonances with the Belle detector, we search for the three-body decay of the ω(2012) baryon to KπΞ. This decay is predicted to dominate for models describing the ω(2012) as a KΞ(1530) molecule. No significant ω(2012) signals are observed in the studied channels, and 90% credibility level upper limits on the ratios of the branching fractions relative to KΞ decay modes are obtained. © 2019 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.

Added: Oct 28, 2020
Article
Akhmedov E., Бурда Ф. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2012. Vol. 86.

We propose an ansatz which solves the Dyson-Schwinger equation for the real scalar fields in Poincare patch of de Sitter space in the IR limit. The Dyson-Schwinger equation for this ansatz reduces to the kinetic equation, if one considers scalar fields from the principal series. Solving the latter equation we show that under the adiabatic switching on and then off the coupling constant the Bunch-Davies vacuum relaxes in the future infinity to the state with the flat Gibbons-Hawking density of out-Jost harmonics on top of the corresponding de Sitter invariant out-vacuum.

Added: Feb 17, 2013
Article
Аушев Т. А., Мизюк Р. В., Pakhlov P. et al. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2020. Vol. 101. No. 5. P. 1-8.

Using a data sample of 772×106 BB pairs collected on the Ï'(4S) resonance with the Belle detector at the KEKB asymmetric energy e+e-collider, we report the observation of B0→ppπ+π- A nd the first observation of B+→ppπ+π0. We measure a decay branching fraction of (0.83±0.17±0.17)×10-6 in B0→ppπ+π-for Mπ+π-<1.22 GeV/c2 with a significance of 5.5 standard deviations. The contribution from B0→ppK0 is excluded. We measure a decay branching fraction of (4.58±1.17±0.67)×10-6 for B+→ppπ+π0 with Mπ+π0<1.3 GeV/c2 with a significance of 5.4 standard deviations. We study the difference of the Mpp distributions in B0→ppπ+π- A nd B+→ppπ+π0. © 2020 authors.

Added: Oct 28, 2020
Article
Aushev T., Mizuk R., Pakhlov P. et al. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2020. P. 071103.

Using 980 fb−1 of data collected with the Belle detector operating at the KEKB asymmetric-energy e^+e^- collider, we report a study of the electromagnetic decays of excited {charmed baryons} Ξc(2790) and Ξc(2815). A clear signal (8.6 standard deviations) is observed for Ξc(2815)0→Ξ0cγ, and we measure: Bc(2815)0→Ξ0cγ]/Bc(2815)0→Ξc(2645)+π−→Ξ0cπ+π−]=0.41±0.05±0.03. We also present evidence (3.8 standard deviations) for the similar decay of the Ξc(2790)0 and measure: Bc(2790)0→Ξ0cγ]/Bc(2790)0→Ξ′+cπ−→Ξ+cγπ−]=0.13±0.03±0.02. The first quoted uncertainties are statistical and the second systematic. We find no hint of the analogous decays of the Ξc(2815)+ and Ξc(2790)+ baryons and set upper limits at the 90% confidence level of: Bc(2815)+→Ξ+cγ]/Bc(2815)+→Ξc(2645)0π+→Ξ+cππ+]<0.09, and Bc(2790)+→Ξ+cγ]/Bc(2790)+→Ξ′0cπ+→Ξ0cγπ+]<0.06. Approximate values of the partial widths of the decays are extracted, which can be used to discriminate between models of the underlying quark structure of these excited states.

Added: Nov 27, 2020
Article
Аушев Т. А., Мизюк Р. В., Pakhlov P. et al. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2018. Vol. 97. No. 5. P. 1-20.

We report a measurement of the cross section for KS0 pair production in single-tag two-photon collisions, γ∗γ→KS0KS0, for Q2 up to 30 GeV2, where Q2 is the negative of the invariant mass squared of the tagged photon. The measurement covers the kinematic range 1.0 GeV<W<2.6 GeV and |cosθ∗|<1.0 for the total energy and kaon scattering angle, respectively, in the γ∗γ center-of-mass system. These results are based on a data sample of 759 fb-1 collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. For the first time, the transition form factor of the f2′(1525) meson is measured separately for the helicity-0, -1, and -2 components and also compared with theoretical calculations. We have derived the cross section for the process for W<2.6 GeV from 121 signal candidate events. Finally, the γ∗γ partial decay widths of the χc0 and χc2 mesons are measured as a function of Q2 based on 10 candidate events in total. © 2018 authors.

Added: Oct 28, 2020
Article
Borisyak M., Derkach D., Belavin V. et al. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2020. Vol. 102. No. 9.

A study of the lineshape of theχc1ð3872Þstate is made using a data sample corresponding to anintegrated luminosity of3fb−1collected inppcollisions at center-of-mass energies of 7 and 8 TeV withthe LHCb detector. Candidateχc1ð3872Þandψð2SÞmesons fromb-hadron decays are selected in theJ=ψπþπ−decay mode. Describing the lineshape with a Breit-Wigner function, the mass splitting betweentheχc1ð3872Þandψð2SÞstates,Δm, and the width of theχc1ð3872Þstate,ΓBW, are determined to beΔm¼185.5980.0670.068MeV;ΓBW¼1.390.240.10MeV;where the first uncertainty is statistical and the second systematic. Using a Flatt ́e-inspired model, the mode and full width at half maximum of the lineshape are determined to bemode¼3871.69þ0.00þ0.05−0.04−0.13MeV;FWHM¼0.22þ0.07þ0.11−0.06−0.13MeV:An investigation of the analytic structure of the Flatt ́e amplitude reveals a polestructure, which is compatible with a quasiboundD0 ̄D0state but a quasivirtual state is still allowed at thelevel of 2 standard deviations.

Added: Dec 6, 2020
Article
Burrage C., Copeland E. J., Käding Christian et al. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2019. Vol. 99. No. 4. P. 1-11.

Scalar fields coupled to gravity through the Ricci scalar have been considered both as dark matter candidates and as a possible modified gravity explanation for galactic dynamics. It has recently been demonstrated that the dynamics of baryonic matter in disk galaxies may be explained, in the absence of particle dark matter, by a symmetron scalar field that mediates a fifth force. The symmetron provides a concrete and archetypal field theory within which to explore how large a role modifications of gravity can play on galactic scales. In this article, we extend these previous works by asking whether the same symmetron field can explain the difference between the baryonic and lens masses of galaxies through a modification of gravity. We consider the possibilities for minimal modifications of the model and find that this difference cannot be explained entirely by the symmetron fifth force without extending the field content of the model. Instead, we are pushed toward a regime of parameter space where one scalar field both mediates a fifth force and stores enough energy density that it also contributes to the galaxy’s gravitational potential as a dark matter component, a regime which remains to be fully explored.

Added: Sep 24, 2019
Article
Barinov V. V., Burenin R.A., Gorbunov D. S. et al. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2021. Vol. 103. No. 6.

We investigate the prospects of the Spectrum-Roentgen-Gamma (SRG) mission in search for the keV-scale mass sterile neutrino dark matter radiatively decaying into active neutrinos and photons. The ongoing all-sky x-ray survey of the SRG space observatory with data acquired by the ART-XC and eROSITA telescopes can provide a possibility to fully explore the resonant production mechanism of the dark matter sterile neutrino, which exploits the lepton asymmetry in the primordial plasma consistent with cosmological limits from the big bang nucleosynthesis. In particular, it is shown that at the end of the four year all-sky survey, the sensitivity of the eROSITA telescope near the 3.5 keV line signal reported earlier can be comparable to that of the XMM-Newton with all collected data, which will allow one to carry out another independent study of the possible sterile neutrino decay signal in this area. In the energy range below ≈2.4 keV , the expected constraints on the model parameters can be significantly stronger than those obtained with the XMM-Newton. From the ART-XC data, in the energy range approximately from 5 to 20 keV, it can be possible to get more stringent constraints than those obtained with NuSTAR so far. We conclude that the SRG mission has a very high potential in testing the sterile neutrino dark matter hypothesis.

 

Added: Mar 25, 2021
Article
Аушев Т. А., Мизюк Р. В., Pakhlov P. et al. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2019. Vol. 99. No. 11. P. 1-15.

We report measurements of the production cross sections of charged pions, kaons, and protons as a function of fractional energy, the event-shape variable called thrust, and the transverse momentum with respect to the thrust axis. These measurements access the transverse momenta created in the fragmentation process, which are of critical importance to the understanding of any transverse-momentum-dependent distribution and fragmentation functions. The low transverse-momentum part of the cross sections can be well described by Gaussians in transverse momentum as is generally assumed but the fractional-energy dependence is nontrivial and different hadron types have varying Gaussian widths. The width of these Gaussians decreases with thrust and shows an initially rising, then decreasing fractional-energy dependence. The widths for pions and kaons are comparable within uncertainties, while those for protons are significantly narrower. These single-hadron cross sections and Gaussian widths are obtained from a 558 fb-1 data sample collected at the (4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. © 2019 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the »https://creativecommons.org/licenses/by/4.0/» Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Added: Oct 28, 2020
Article
Ofengeim D. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2020. Vol. 101. No. 10. P. 103029.

I have demonstrated the existence of a tight correlation between the mass, radius, central density, and pressure of maximum-mass neutron stars modeled using diverse baryonic equations of state. A possible explanation for these correlations is provided. Simple analytic forms of such correlations are suggested and compared with observational constraints on the maximum mass of neutron stars and their radii. This gives a valuable tool to constrain maximum pressure and density that could be reached in stable neutron stars, assuming their equation of state is baryonic.

Added: Nov 11, 2020
Article
Borisyak M., Derkach D., Guschin M. et al. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2020. Vol. 101. No. 1. P. 1-12.

A search for decay-time-dependent charge-parity (CP) asymmetry in D0→K+K− and D0→π+π− decays is performed at the LHCb experiment using proton-proton collision data recorded at a center-of-mass energy of 13TeV, and corresponding to an integrated luminosity of 5.4fb−1. The D0 mesons are required to originate from semileptonic decays of b hadrons, such that the charge of the muon identifies the flavor of the neutral D meson at production. The asymmetries in the effective decay widths of D0 and D¯¯¯¯0 mesons are determined to be AΓ(K+K−)=(−4.3±3.6±0.5)×10−4 and AΓ(π+π−)=(2.2±7.0±0.8)×10−4, where the uncertainties are statistical and systematic, respectively. The results are consistent with CP symmetry and, when combined with previous LHCb results, yield AΓ(K+K−)=(−4.4±2.3±0.6)×10−4 and AΓ(π+π−)=(2.5±4.3±0.7)×10−4.

Added: Sep 17, 2020
Article
Аушев Т. А., Мизюк Р. В., Pakhlov P. et al. Physical Review D - Particles, Fields, Gravitation and Cosmology. 2020. Vol. 101. No. 9. P. 1-13.

We report new measurements of the production cross sections of pairs of charged pions and kaons as a function of their fractional energies using various fractional-energy definitions. Two different fractional-energy definitions were used and compared to the conventional fractional-energy definition reported previously. The new variables aim at either identifying dihadron cross sections in terms of single-hadron fragmentation functions, or to provide a means of characterizing the transverse momentum created in the fragmentation process. The results were obtained applying the updated initial-state radiation correction used in other recent Belle publications on light-hadron production cross sections. In addition, production cross sections of single charged pions, kaons, and protons were also updated using this initial-state radiation correction. The cross sections are obtained from a 558 fb-1 data sample collected at the γ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. © 2020 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/" Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3

Added: Oct 28, 2020