| Records |
| Author |
Cottin, G.; Helo, J.C.; Hirsch, M.; Titov, A.; Wang, Z.S. |
| Title |
Heavy neutral leptons in effective field theory and the high-luminosity LHC |
Type |
Journal Article |
| Year |
2021 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
09 |
Issue  |
9 |
Pages |
039 - 34pp |
| Keywords |
Beyond Standard Model; Effective Field Theories; Neutrino Physics |
| Abstract |
Heavy neutral leptons (HNLs) with masses around the electroweak scale are expected to be rather long-lived particles, as a result of the observed smallness of the active neutrino masses. In this work, we study long-lived HNLs in NRSMEFT, a Standard Model (SM) extension with singlet fermions to which we add non-renormalizable operators up to dimension-6. Operators which contain two HNLs can lead to a sizable enhancement of the production cross sections, compared to the minimal case where HNLs are produced only via their mixing with the SM neutrinos. We calculate the expected sensitivities for the ATLAS detector and the future far-detector experiments: AL3X, ANUBIS, CODEX-b, FASER, MATHUSLA, and MoEDAL-MAPP in this setup. The sensitive ranges of the HNL mass and of the active-heavy mixing angle are much larger than those in the minimal case. We study both, Dirac and Majorana, HNLs and discuss how the two cases actually differ phenomenologically, for HNL masses above roughly 100 GeV. |
| Address |
[Cottin, Giovanna] Univ Adolfo Ibanez, Fac Artes Liberales, Dept Ciencias, Diagonal Las Torres 2640, Santiago, Chile, Email: giovanna.cottin@uai.cl; |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
WOS:000694840800001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4970 |
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| Author |
Ling, P.; Dai, X.H.; Du, M.L.; Wang, Q. |
| Title |
Prompt production of the hidden charm pentaquarks in the LHC |
Type |
Journal Article |
| Year |
2021 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
| Volume |
81 |
Issue |
9 |
Pages |
819 - 15pp |
| Keywords |
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| Abstract |
Motivated by the observation of the first hidden charm pentaquarks by the LHCb collaboration in 2015 and the updated analysis with an order-of-magnitude larger data set in 2019, we estimate their cross sections for the prompt production as well as their heavy quark spin partners, in the Sigma(()(c)*()) (D) over bar (()*()) hadronic molecular picture, at the center-of-mass energy 7 TeV in the pp collision. Their cross sections are several nb and we would expect several tens hidden charm pentaquark events in the LHC based on its current integrated luminosity. The cross sections show a sizable deviation of the cross sections for hidden charm pentaquarks with the third isospin component Iz = + 1/2 (P-c(+)) from those with Iz = – 1/2 (P-c(0)). The cross sections decrease dramatically with the increasing transverse momentum. Our study can also tell where to search for the missing hidden charm pentaquarks. The confirmation of the complete hidden charm pentaquarks in the heavy quark symmetry would further verify their Sigma(()(c)*()) (D) over bar (()*()) molecular interpretation. In addition, the relative strength among these cross sections for pentaquarks can help us to identify the quantum numbers of the P-c(4440) and P-c(4457). |
| Address |
[Ling, Pan; Dai, Xiao-Hu; Wang, Qian] South China Normal Univ, Inst Quantum Matter, Guangdong Prov Key Lab Nucl Sci, Guangzhou 510006, Peoples R China, Email: du.menglin@ific.uv.es; |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1434-6044 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
WOS:000696534900002 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4972 |
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| Author |
van Beekveld, M.; Caron, S.; Hendriks, L.; Jackson, P.; Leinweber, A.; Otten, S.; Patrick, R.; Ruiz de Austri, R.; Santoni, M.; White, M. |
| Title |
Combining outlier analysis algorithms to identify new physics at the LHC |
Type |
Journal Article |
| Year |
2021 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
09 |
Issue |
9 |
Pages |
024 - 33pp |
| Keywords |
Phenomenological Models; Supersymmetry Phenomenology |
| Abstract |
The lack of evidence for new physics at the Large Hadron Collider so far has prompted the development of model-independent search techniques. In this study, we compare the anomaly scores of a variety of anomaly detection techniques: an isolation forest, a Gaussian mixture model, a static autoencoder, and a beta-variational autoencoder (VAE), where we define the reconstruction loss of the latter as a weighted combination of regression and classification terms. We apply these algorithms to the 4-vectors of simulated LHC data, but also investigate the performance when the non-VAE algorithms are applied to the latent space variables created by the VAE. In addition, we assess the performance when the anomaly scores of these algorithms are combined in various ways. Using supersymmetric benchmark points, we find that the logical AND combination of the anomaly scores yielded from algorithms trained in the latent space of the VAE is the most effective discriminator of all methods tested. |
| Address |
[van Beekveld, Melissa] Clarendon Lab, Rudolf Peierls Ctr Theoret Phys, 20 Pks Rd, Oxford OX1 3PU, England, Email: mcbeekveld@gmail.com; |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000695421600003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4973 |
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| Author |
LHCb Collaboration (Aaij, R. et al); Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J. |
| Title |
Search for the doubly heavy baryons Omega(0)(bc) and Xi(0)(bc) decaying to Lambda(+)(c)pi(-) and Xi(+)(c)pi- |
Type |
Journal Article |
| Year |
2021 |
Publication |
Chinese Physics C |
Abbreviated Journal |
Chin. Phys. C |
| Volume |
45 |
Issue |
9 |
Pages |
093002 - 12pp |
| Keywords |
B physics; quarkonium; spectroscopy; heavy quark production |
| Abstract |
The first search for the doubly heavy Omega(0)(bc) baryon and a search for the Xi(0)(bc) baryon are performed using collision data collected via the experiment from 2016 to 2018 at a centre-of-mass energy of, corresponding to an integrated luminosity of 5.2 fb(-1). The baryons are reconstructed via their decays to Lambda(+)(-)(c)(pi) and Xi(+)(c)pi(-). No significant excess is found for invariant masses between 6700 and 7300 MeV/c(2), in a rapidity range from 2.0 to 4.5 and a transverse momentum range from 2 to 20 MeV/c. Upper limits are set on the ratio of the Omega(0)(bc) and Xi(0)(bc) production cross-section times the branching fraction to Lambda(+)(c)pi(-)(Xi(+)(c)pi(-)) relative to that of the Lambda(0)(b)(Xi(0)(b)) baryon, for different lifetime hypotheses, at 95% confidence level. The upper limits range from 0.5x10(-4) to 2.5x10(-4) for the Omega(0)(bc) -> Lambda(+)(c)pi(-) (Xi(0)(bc) -> Lambda(+)(c)pi(-)) decay, pending on the considered mass and lifetime of the Omega(0)(bc) (Xi(0)(bc)) baryon. |
| Address |
[Leite, J. Baptista; Bediaga, I.; Torres, M. Cruz; De Miranda, J. M.; dos Reis, A. C.; Gomes, A.; Massafferri, A.; Machado, D. Torres] Ctr Brasileiro Pesquisas Fis CBPF, Rio De Janeiro, Brazil, Email: shiyang.li@cern.ch |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1674-1137 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000693209400001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4974 |
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| Author |
Reig, M. |
| Title |
The stochastic axiverse |
Type |
Journal Article |
| Year |
2021 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
09 |
Issue |
9 |
Pages |
207 - 40pp |
| Keywords |
Cosmology of Theories beyond the SM; Beyond Standard Model; Compactification and String Models |
| Abstract |
In addition to spectacular signatures such as black hole superradiance and the rotation of CMB polarization, the plenitude of axions appearing in the string axiverse may have potentially dangerous implications. An example is the cosmological overproduction of relic axions and moduli by the misalignment mechanism, more pronounced in regions where the signals mentioned above may be observable, that is for large axion decay constant. In this work, we study the minimal requirements to soften this problem and show that the fundamental requirement is a long period of low-scale inflation. However, in this case, if the inflationary Hubble scale is lower than around O(100) eV, no relic DM axion is produced in the early Universe. Cosmological production of some axions may be activated, via the misalignment mechanism, if their potential minimum changes between inflation and today. As a particular example, we study in detail how the maximal-misalignment mechanism dilutes the effect of dangerous axions and allows the production of axion DM in a controlled way. In this case, the potential of the axion that realises the mechanism shifts by a factor increment theta = pi between the inflationary epoch and today, and the axion starts to oscillate from the top of its potential. We also show that axions with masses m(a) similar to O(1 – 100) H-0 realising the maximal-misalignment mechanism generically behave as dark energy with a decay constant that can take values well below the Planck scale, avoiding problems associated to super-Planckian scales. Finally, we briefly study the basic phenomenological implications of the mechanism and comment on the compatibility of this type of maximally-misaligned quintessence with the swampland criteria. |
| Address |
[Reig, Mario] Univ Valencia, CSIC, Inst Fis Corpuscular, C Catedratico Jose Beltran 2, E-46980 Paterna, Valencia, Spain, Email: mario.reig@ifis.uv.es |
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Thesis |
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| Publisher |
Springer |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1029-8479 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000702371800004 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
4977 |
| Permanent link to this record |
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| Author |
Godbole, R.M.; Maharathy, S.P.; Mandal, S.; Mitra, M.; Sinha, N. |
| Title |
Interference effect in lepton number violating and conserving meson decays for a left-right symmetric model |
Type |
Journal Article |
| Year |
2021 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
104 |
Issue |
9 |
Pages |
095009 - 22pp |
| Keywords |
|
| Abstract |
We study the effect of interference on the lepton number violating (LNV) and lepton number conserving (LNC) three-bodymeson decaysM(1)(+)-> l(i) (+) l(j)(+)pi(+/-) that arise in a TeV-scale left-right symmetric model (LRSM) with degenerate or nearly degenerate right-handed (RH) neutrinos. The LRSM contains three RH neutrinos and a RH gauge boson. The RH neutrinos with masses in the range of M-N similar to (MeV-few GeV) can give resonant enhancement in the semileptonic LNV and LNC meson decays. In the case where only one RH neutrino contributes to these decays, the predicted new physics branching ratios of semileptonic LNV and LNC meson decaysM(1)(+)-> l(i)(+) l(j)(+) pi(-) andM(+) 1 -> l(i)(+)l(j)(-) pi(+) are equal. We find that with at least two RH neutrinos contributing to the process, the LNV and LNC decay rates can differ. Depending on the neutrino mixing angles and CP-violating phases, the branching ratios of LNVand LNC decay channelsmediated by the heavy neutrinos can be either enhanced or suppressed, and the ratio of these two rates can differ from unity. |
| Address |
[Godbole, Rohini M.] Indian Inst Sci, Ctr High Energy Phys, Bengaluru 560012, India, Email: rohini@iisc.ac.in; |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2470-0010 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000719315600005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5028 |
| Permanent link to this record |
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| Author |
LHCb Collaboration (Aaij, R. et al); Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J. |
| Title |
Observation of excited Omega(0)(c) baryons in Omega(-)(b) -> Xi(+)(c) K-pi(-) decays |
Type |
Journal Article |
| Year |
2021 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
104 |
Issue |
9 |
Pages |
L091102 - 14pp |
| Keywords |
|
| Abstract |
The first observation of the Omega(-)(b) -> Xi(+)(c) K-pi(-) decay is reported using p p collision data at center of mass energies of 7, 8, and 13 TeV collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb(-1). Four excited Omega(0)(c) baryons are observed in the Xi K-+(c)- mass projection of the Omega(-)(b) -> Xi K-+(c)-pi(-) decays with the significance of each exceeding five standard deviations. They coincide with the states previously observed in prompt pp and e(+)e(-) production. Relative production rates, masses, and natural widths of the states are measured, and a test of spin hypotheses is performed. Moreover, the branching ratio of Omega(-)(b) -> Xi K-+(c)-pi(-) is measured relative to the Omega(-)(b) -> Omega(0)(c)pi(-) decay mode and a precise measurement of the Omega(-)(b) mass of 6044.3 +/- 1.2 +/- 1.1(-0.22)(+0.19) MeV is obtained. |
| Address |
[Leite, J. Baptista; Bediaga, I; Torres, M. Cruz; De Miranda, J. M.; dos Reis, A. C.; Gomes, A.; Massafferri, A.; Machado, D. Torres] Ctr Brasileiro Pesquisas Fis CBPF, Rio De Janeiro, Brazil |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
2470-0010 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000725005800001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5045 |
| Permanent link to this record |
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| Author |
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 |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
2470-0010 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000744291500008 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5090 |
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| Author |
BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A. |
| Title |
Search for Lepton Flavor Violation in Upsilon(3S) -> e(+/-)mu(-/+) |
Type |
Journal Article |
| Year |
2022 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
| Volume |
128 |
Issue |
9 |
Pages |
091804 - 7pp |
| Keywords |
|
| Abstract |
We report on the first search for electron-muon lepton flavor violation (LFV) in the decay of a b quark and b antiquark bound state. We look for the LFV decay Upsilon(3S) -> e(+/-) mu(-/+) in a sample of 118 million gamma(3S) mesons from 27 fb(-1) of data collected with the BABAR detector at the SLAC PEP-II e(+) e(-) collider operating with a 10.36 GeV center-of-mass energy. No evidence for a signal is found, and we set a limit on the branching fraction B[Upsilon(3S) -> e(+/-) mu(-/+)] < 3.6 x 10(-7) at 90% C. L. This result can be interpreted as a limit Lambda(NP)/g(NP)(2) > 80 TeV on the energy scale Lambda(NT) divided by the coupling-squared g(NP)(2) of relevant new physics (NP). |
| Address |
[Lees, J. P.; Poireau, V; Tisserand, V] Univ Savoie, Lab Annecy le Vieux Phys Particules LAPP, CNRS IN2P3, F-74941 Annecy Le Vieux, France |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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English |
Summary Language |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0031-9007 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
WOS:000766760100005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5164 |
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| Author |
Mandal, S.; Miranda, O.G.; Sanchez Garcia, G.; Valle, J.W.F.; Xu, X.J. |
| Title |
Toward deconstructing the simplest seesaw mechanism |
Type |
Journal Article |
| Year |
2022 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
105 |
Issue |
9 |
Pages |
095020 - 32pp |
| Keywords |
|
| Abstract |
The triplet or type-II seesaw mechanism is the simplest way to endow neutrinos with mass in the Standard Model (SM). Here we review its associated theory and phenomenology, including restrictions from S, T, U parameters, neutrino experiments, charged lepton flavor violation as well as collider searches. We also examine restrictions coming from requiring consistency of electroweak symmetry breaking, i.e., perturbative unitarity and stability of the vacuum. Finally, we discuss novel effects associated to the scalar mediator of neutrino mass generation namely, (i) rare processes, e.g., l(alpha)-> l(beta)gamma decays, at the intensity frontier, and also (ii) four-lepton signatures in colliders at the high-energy frontier. These can be used to probe neutrino properties in an important way, providing a test of the absolute neutrino mass and mass ordering, as well as of the atmospheric octant. They may also provide the first evidence for charged lepton flavor violation in nature. In contrast, neutrino nonstandard interaction strengths are found to lie below current detectability. |
| Address |
[Mandal, Sanjoy] Korea Inst Adv Study, Seoul 02455, South Korea, Email: smandal@kias.re.kr; |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
2470-0010 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000807778600004 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5249 |
| Permanent link to this record |
