| Records |
| Author |
Garcia Martin, L.M.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Roy, S.; Sain, R.; Sinha, R. |
| Title |
Radiative b-baryon decays to measure the photon and b-baryon polarization |
Type |
Journal Article |
| Year |
2019 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
| Volume |
79 |
Issue |
7 |
Pages |
634 - 10pp |
| Keywords |
|
| Abstract |
The radiative decays of b-baryons facilitate the direct measurement of photon helicity in b -> s gamma transitions thus serving as an important test of physics beyond the Standard Model. In this paper we analyze the complete angular distribution of ground state b-baryon radiative decays to multibody final states assuming an initially polarized b-baryon sample. Our sensitivity study suggests that the photon polarization asymmetry can be extracted to a good accuracy along with a simultaneous measurement of the initial b-baryon polarization. With higher yields of b-baryons, achievable in subsequent runs of the Large Hadron Collider (LHC), we find that the photon polarization measurement can play a pivotal role in constraining different new physics scenarios. |
Address  |
[Garcia Martin, Luis Miguel; Jashal, Brij; Martinez Vidal, Fernando; Oyanguren, Arantza] Univ Valencia, CSIC, IFIC, Apt Correus 22085, Valencia 46071, Spain, Email: Luis.Miguel.Garcia@ific.uv.es; |
| 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 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 |
1434-6044 |
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:000477914900005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4079 |
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| Author |
BABAR Collaboration (del Amo Sanchez, P. et al); Lopez-March, N.; Martinez-Vidal, F.; Oyanguren, A. |
| Title |
Measurements of branching fractions, polarizations, and direct CP-violation asymmetries in B+ -> rho K-0*(+) and B+ -> f(0)(980)K*(+) decays |
Type |
Journal Article |
| Year |
2011 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
83 |
Issue |
5 |
Pages |
051101 - 8pp |
| Keywords |
|
| Abstract |
We present measurements of the branching fractions, longitudinal polarization, and direct CP-violation asymmetries for the decays B+ -> rho K-0*(+) and B+ -> f(0)(980)K*(+) with a sample of (467 +/- 5) x 10(6)B (B) over bar pairs collected with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at the SLAC National Accelerator Laboratory. We observe B+ -> rho K-0*(+) with a significance of 5: 3 sigma and measure the branching fraction B(B+ -> rho K-0*(+)) = (4.6 +/- 1.0 +/- 0.4) x 10(-6), the longitudinal polarization f(L) = 0.78 +/- 0.12 +/- 0.03, and the CP-violation asymmetry A(CP) = 0.31 +/- 0.13 +/- 0.03. We observe B+ -> f(0)(980)K*(+) and measure the branching fraction B(B+ -> f(0)(980)K*(+)) x B(f(0)(980) -> pi(+)pi(-)) = (4.2 +/- 0.6 +/- 0.3) x 10(-6) and the CP-violation asymmetry A(CP) = 0.15 +/- 0.12 +/- 0.03. The first uncertainty quoted is statistical and the second is systematic. |
| Address |
[Garra Tico, J.; Grauges, E.] Univ Barcelona, Fac Fis, Dept ECM, E-08028 Barcelona, Spain |
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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 |
1550-7998 |
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 |
ISI:000288121000001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
548 |
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| Author |
Gorkavenko, V.; Jashal, B.K.; Kholoimov, V.; Kyselov, Y.; Mendoza, D.; Ovchynnikov, M.; Oyanguren, A.; Svintozelskyi, V.; Zhuo, J.H. |
| Title |
LHCb potential to discover long-lived new physics particles with lifetimes above 100 ps |
Type |
Journal Article |
| Year |
2024 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
| Volume |
84 |
Issue |
6 |
Pages |
608 - 15pp |
| Keywords |
|
| Abstract |
For years, it has been believed that the main LHC detectors can play only a limited role of a lifetime frontier experiment exploring the parameter space of long-lived particles (LLPs)-hypothetical particles with tiny couplings to the Standard Model. This paper demonstrates that the LHCb experiment may become a powerful lifetime frontier experiment if it uses the new Downstream algorithm reconstructing tracks that do not allow hits in the LHCb vertex tracker. In particular, for many LLP scenarios, LHCb may be as sensitive as the proposed experiments beyond the main LHC detectors for various LLP models, including heavy neutral leptons, dark scalars, dark photons, and axion-like particles. |
| Address |
[Gorkavenko, Volodymyr; Kholoimov, Valerii; Kyselov, Yehor; Svintozelskyi, Volodymyr] Taras Shevchenko Natl Univ Kyiv, Kiev, Ukraine, Email: gorkavol@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 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 |
1434-6044 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:001246005200001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
6145 |
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| Author |
LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
| Title |
Search for the lepton-flavour violating decay D-0 -> e(+/-)mu(-/+) |
Type |
Journal Article |
| Year |
2016 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
754 |
Issue |
|
Pages |
167-175 |
| Keywords |
|
| Abstract |
A search for the lepton-flavour violating decay D-0 -> e(+/-)mu(-/+) is made with a dataset corresponding to an integrated luminosity of 3.0 fb(-1) of proton-proton collisions at centre-of-mass energies of 7 TeV and 8 TeV, collected by the LHCb experiment. Candidate D-0 mesons are selected using the decay D*(+) -> D-0 pi(+) and the D-0 -> e(+/-)mu(+) branching fraction is measured using the decay mode D-0 -> K-pi(+) as a normalization channel. No significant excess of D-0 -> e(+/-)mu(-/+) candidates over the expected background is seen, and a limit is set on the branching fraction, B(D-0 -> e(+/-)mu(-/+)) < 1.3 x10(-8), at 90% confidence level. This is an order of magnitude lower than the previous limit and it further constrains the parameter space in some leptoquark models and in supersymmetric models with R-parity violation. |
| Address |
[Gutierrez, O. Aquines; Bediaga, I.; De Miranda, J. M.; Rodrigues, F. Ferreira; Gomes, A.; Massafferri, A.; Rodrigues, B. Osorio; Rodrigues, A. B.] CBPF, Rio De Janeiro, Brazil, Email: george.lafferty@manchester.ac.uk |
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Thesis |
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| Publisher |
Elsevier Science Bv |
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 |
0370-2693 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000369601000027 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2571 |
| Permanent link to this record |
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| Author |
CMS and LHCb Collaborations (Khachatryan, V. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
| Title |
Observation of the rare B-s(0)->mu(+)mu(-) decay from the combined analysis of CMS and LHCb data |
Type |
Journal Article |
| Year |
2015 |
Publication |
Nature |
Abbreviated Journal |
Nature |
| Volume |
522 |
Issue |
7554 |
Pages |
68-72 |
| Keywords |
|
| Abstract |
The standard model of particle physics describes the fundamental particles and their interactions via the strong, electromagnetic and weak forces. It provides precise predictions for measurable quantities that can be tested experimentally. The probabilities, or branching fractions, of the strange B meson (B-s(0)) and the B-0 meson decaying into two oppositely charged muons (mu(+) and mu(-)) are especially interesting because of their sensitivity to theories that extend the standard model. The standard model predicts that the B-s(0)->mu(+)mu(-) and B-0 ->mu(+)mu(-) decays are very rare, with about four of the former occurring for every billion B-s(0) mesons produced, and one of the latter occurring for every ten billion B-0 mesons(1). A difference in the observed branching fractions with respect to the predictions of the standard model would provide a direction in which the standard model should be extended. Before the Large Hadron Collider (LHC) at CERN2 started operating, no evidence for either decay mode had been found. Upper limits on the branching fractions were an order of magnitude above the standard model predictions. The CMS (Compact Muon Solenoid) and LHCb(Large Hadron Collider beauty) collaborations have performed a joint analysis of the data from proton-proton collisions that they collected in 2011 at a centre-of-mass energy of seven teraelectronvolts and in 2012 at eight teraelectronvolts. Here we report the first observation of the B-s(0)->mu(+)mu(-) decay, with a statistical significance exceeding six standard deviations, and the best measurement so far of its branching fraction. Furthermore, we obtained evidence for the B-0 ->mu(+)mu(-) decay with a statistical significance of three standard deviations. Both measurements are statistically compatible with standard model predictions and allow stringent constraints to be placed on theories beyond the standard model. The LHC experiments will resume taking data in 2015, recording proton-proton collisions at a centre-of-mass energy of 13 teraelectronvolts, which will approximately double the production rates of B-s(0) and B-0 mesons and lead to further improvements in the precision of these crucial tests of the standard model. |
| Address |
[Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.] Yerevan Phys Inst, Yerevan 375036, Armenia |
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Thesis |
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| Publisher |
Nature Publishing Group |
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 |
0028-0836 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000355543400030 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2250 |
| Permanent link to this record |
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| Author |
DELPHI Collaboration (Abdallah, J. et al); Costa, M.J.; Ferrer, A.; Fuster, J.; Garcia, C.; Oyanguren, A.; Perepelitsa, V.; Salt, J.; Tortosa, P. |
| Title |
Measurement of the electron structure function F-2(e) at LEP energies |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
737 |
Issue |
|
Pages |
39-47 |
| Keywords |
|
| Abstract |
The hadronic part of the electron structure function F-2(e) has been measured for the first time, using e(+)e(-) data collected by the DELPHI experiment at LEP, at centre-of-mass energies of root s = 91.2-209.5 GeV. The data analysis is simpler than that of the measurement of the photon structure function. The electron structure function F-2(e) data are compared to predictions of phenomenological models based on the photon structure function. It is shown that the contribution of large target photon virtualities is significant. The data presented can serve as a cross-check of the photon structure function F-2(gamma) analyses and help in refining existing parameterizations. |
| Address |
[Lamsa, J.] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier Science Bv |
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 |
0370-2693 |
ISBN |
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Medium |
|
| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000342757700008 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1965 |
| Permanent link to this record |
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| Author |
DELPHI Collaboration (Abdallah, J. et al); Costa, M.J.; Ferrer, A.; Fuster, J.; Garcia, C.; Oyanguren, A.; Perepelitsa, V.; Salt, J.; Tortosa, P. |
| Title |
Search for single top quark production via contact interactions at LEP2 |
Type |
Journal Article |
| Year |
2011 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
| Volume |
71 |
Issue |
2 |
Pages |
1555 - 13pp |
| Keywords |
|
| Abstract |
Single top quark production via four-fermion contact interactions associated to flavour-changing neutral currents was searched for in data taken by the DELPHI detector at LEP2. The data were accumulated at centre-of-mass energies ranging from 189 to 209 GeV, with an integrated luminosity of 598.1 pb(-1). No evidence for a signal was found. Limits on the energy scale Lambda, were set for scalar-, vector- and tensor-like coupling scenarios. |
| Address |
[Lamsa, J.] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA, Email: timmerma@mail.cern.ch |
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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 |
1434-6044 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
ISI:000291694100014 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
654 |
| Permanent link to this record |
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| Author |
DELPHI Collaboration (Abdallah, J. et al); Costa, M.J.; Ferrer, A.; Fuster, J.; Garcia, C.; Oyanguren, A.; Perepelitsa, V.; Salt, J.; Tortosa, P. |
| Title |
A study of the b-quark fragmentation function with the DELPHI detector at LEP I and an averaged distribution obtained at the Z Pole |
Type |
Journal Article |
| Year |
2011 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
| Volume |
71 |
Issue |
2 |
Pages |
1557 - 29pp |
| Keywords |
|
| Abstract |
The nature of b-quark jet hadronisation has been investigated using data taken at the Z peak by the DELPHI detector at LEP. Two complementary methods are used to reconstruct the energy of weakly decaying b-hadrons, E-B(weak). The average value of x(B)(weak) = E-B(weak)/E-beam is measured to be 0.699 +/- 0.011. The resulting x(B)(weak) distribution is then analysed in the framework of two choices for the perturbative contribution (parton shower and Next to Leading Log QCD calculation) in order to extract measurements of the non-perturbative contribution to be used in studies of b-hadron production in other experimental environments than LEP. In the parton shower framework, data favour the Lund model ansatz and corresponding values of its parameters have been determined within PYTHIA 6.156 from DELPHI data: a = 1.84(-0.21)(+0.23) and b = 0.642(-0.063)(+0.073) GeV-2, with a correlation factor rho = 92.2%. Combining the data on the b-quark fragmentation distributions with those obtained at the Z peak by ALEPH, OPAL and SLD, the average value of x(B)(weak) is found to be 0.7092 +/- 0.0025 and the non-perturbative fragmentation component is extracted. Using the combined distribution, a better determination of the Lund parameters is also obtained: a = 1.48(-0.10)(+0.11) and b = 0.509(-0.023)(+0.024) GeV-2, with a correlation factor rho = 92.6%. |
| Address |
[Lamsa, J.] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA, Email: timmerma@mail.cern.ch |
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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 |
1434-6044 |
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 |
ISI:000291694100016 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
655 |
| Permanent link to this record |
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| Author |
BABAR and Belle Collaborations (Abdesselam, A. et al); Martinez-Vidal, F.; Oyanguren, A. |
| Title |
First Observation of CP Violation in (B)over-bar(0) -> D(CP)((*))h(0) Decays by a Combined Time-Dependent Analysis of BABAR and Belle Data |
Type |
Journal Article |
| Year |
2015 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
| Volume |
115 |
Issue |
12 |
Pages |
121604 - 10pp |
| Keywords |
|
| Abstract |
We report a measurement of the time-dependent CP asymmetry of (B) over bar (0) -> D(CP)((*))h(0) decays, where the light neutral hadron h(0) is a pi(0), eta , or omega meson, and the neutral D meson is reconstructed in the CP eigenstates K+K-, K-S(0)pi(0) or K-S(0)omega. The measurement is performed combining the final data samples collected at the Upsilon(4S) resonance by the BABAR and Belle experiments at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471 +/- 3) x 10(6) B (B) over bar pairs recorded by the BABAR detector and (772 +/- 11) x 10(6) B (B) over bar pairs recorded by the Belle detector. We measure the CP asymmetry parameters -eta S-f = +0.66 +/- 0.10(stat) +/- 0.06(syst) and C = -0.02 +/- 0.07(stat) +/- 0.03(syst). These results correspond to the first observation of CP violation in (B) over bar (0) -> D(CP)((*))h(0) decays. The hypothesis of no mixing-induced CP violation is excluded in these decays at the level of 5.4 standard deviations. |
| Address |
[Lee, M. J.; 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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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 |
0031-9007 |
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:000361316500005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2390 |
| Permanent link to this record |
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| |
| Author |
BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A. |
| Title |
Tests of CPT symmetry in B-0-(B)over-bar(0) mixing and in B-0 -> c(c)over-barK(0) decays |
Type |
Journal Article |
| Year |
2016 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
94 |
Issue |
1 |
Pages |
011101 - 7pp |
| Keywords |
|
| Abstract |
Using the eight time dependences e(-Gamma t)(1+C(i)cos Delta mt+S(i)sin Delta mt) for the decays Upsilon (4S) -> B-0(B) over bar (0) -> f(j)f(k), with the decay into a flavor-specific state f(j) = l(+/-)X before or after the decay into a CP eigenstate f(k) = c (c) over barK(S,L), as measured by the BABAR experiment, we determine the three CPT-sensitive parameters Re(z) and Im(z) in B-0-(B) over bar (0) mixing and vertical bar(A) over bar /A vertical bar in B-0 -> c (c) over barK(0) decays. We find Im(z) = 0.010 +/- 0.030 +/- 0.013, Re(z) = -0.065 +/- 0.028 +/- 0.014, and vertical bar(A) over bar /A vertical bar = 0.999 +/- 0.023 +/- 0.017, in agreement with CPT symmetry. |
| Address |
[Lees, J. P.; Calcaterra, A.; Gaz, A.; Filippi, A.; Beaulieu, A.] Univ Savoie, CNRS IN2P3, LAPP, F-74941 Annecy Le Vieux, France |
| Corporate Author |
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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:000380111000001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2768 |
| Permanent link to this record |
