Records |
Author |
Albertus, C.; Hernandez, E.; Nieves, J. |
Title |
Hyperfine mixing in electromagnetic decay of doubly heavy bc baryons |
Type |
Journal Article |
Year |
2010 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
690 |
Issue |
3 |
Pages |
265-271 |
Keywords |
Hyperfine mixing; Double heavy bc baryons |
Abstract |
We investigate the role of hyperfine mixing in the electromagnetic decay of ground state doubly heavy bc baryons. As in the case of a previous calculation on b -> c semileptonic decays of doubly heavy baryons, we find large corrections to the electromagnetic decay widths due to this mixing. Contrary to the weak case just mentioned, we find here that one cannot use electromagnetic width relations obtained in the infinite heavy quark mass limit to experimentally extract information on the admixtures in a model independent way. |
Address |
[Albertus, C.; Hernandez, E.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain, Email: gajatee@usal.es |
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 |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000279388800012 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ elepoucu @ |
Serial |
416 |
Permanent link to this record |
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Author |
CDF Collaboration (Aaltonen, T. et al); Cabrera, S. |
Title |
Search for new color-octet vector particle decaying to t(t)over-bar in p(p)over-bar collisions at root s=1.96 TeV |
Type |
Journal Article |
Year |
2010 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
691 |
Issue |
4 |
Pages |
183-190 |
Keywords |
Massive gluon; Top quark |
Abstract |
We present the result of a search for a massive color-octet vector particle, (e.g. a massive gluon) decaying to a pair of top quarks in proton-antiproton collisions with a center-of-mass energy of 1.96 TeV. This search is based on 1.9 fb(-1) of data collected using the CDF detector during Run II of the Tevatron at Fermilab. We study t (t) over bar events in the lepton + jets channel with at least one b-tagged jet. A massive gluon is characterized by its mass, decay width, and the strength of its coupling to quarks. These parameters are determined according to the observed invariant mass distribution of top quark pairs. We set limits on the massive gluon coupling strength for masses between 400 and 800 GeV/c(2) and width-to-mass ratios between 0.05 and 0.50. The coupling strength of the hypothetical massive gluon to quarks is consistent with zero within the explored parameter space. |
Address |
[Nara, K.; Kim, S. H.; Kurata, M.; Miyake, H.; Nagai, Y.; Naganoma, J.; Nakamura, K.; Sato, K.; Shimojima, M.; Takeuchi, Y.; Tomura, T.; Ukegawa, F.] Univ Tsukuba, Tsukuba, Ibaraki 305, Japan, Email: junji@fnal.gov |
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 |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000280328200002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
278 |
Permanent link to this record |
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Author |
CDF Collaboration (Aaltonen, T. et al); Cabrera, S. |
Title |
Measurement of d sigma/dy of Drell-Yan e(+)e(-) pairs in the Z mass region from p(p)over-bar collisions at root s=1.96 TeV |
Type |
Journal Article |
Year |
2010 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
692 |
Issue |
4 |
Pages |
232-239 |
Keywords |
Z boson; Rapidity d sigma/dy; PDFs |
Abstract |
We report on a CDF measurement of the total cross section and rapidity distribution, d sigma/dy, for gamma*/Z -> e(+)e(-) events in the Z boson mass region (66 < M-ee < 116 GeV/c(2)) produced in p (p) over bar collisions at root s = 1.96 TeV with 2.1 fb(-1) of integrated luminosity. The measured cross section of 257 +/- 16 pb and d sigma/dy distribution are compared with Next-to-Leading-Order (NLO) and Next-to-Next-to-Leading-Order (NNLO) QCD theory predictions with CTEQ and MRST/MSTW parton distribution functions (PDFs). There is good agreement between the experimental total cross section and d sigma/dy measurements with theoretical calculations with the most recent NNLO PDFs. |
Address |
[Bodek, A.; Boisvert, V.; Budd, H. S.; Chung, Y. S.; de Barbaro, P.; Gimmell, J. L.; Han, B. -Y.; Han, J. Y.; McFarland, K. S.; Sakumoto, W. K.] Univ Rochester, Rochester, NY 14627 USA, Email: bodek@pas.rochester.edu |
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 |
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Area |
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Expedition |
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Conference |
|
Notes |
ISI:000282249400003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
271 |
Permanent link to this record |
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Author |
Horvat, S.; Magas, V.K.; Strottman, D.D.; Csernai, L.P. |
Title |
Entropy development in ideal relativistic fluid dynamics with the Bag Model equation of state |
Type |
Journal Article |
Year |
2010 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
692 |
Issue |
4 |
Pages |
277-280 |
Keywords |
Quark deconfinement; Quark-gluon plasma production; Phase transitions; Relativistic heavy-ion collisions; Hydrodynamic models |
Abstract |
We consider an idealized situation where the Quark-Gluon Plasma (QGP) is described by a perfect, (3 + 1)-dimensional fluid dynamic model starting from an initial state and expanding until a final state where freeze-out and/or hadronization takes place. We study the entropy production with attention to effects of (i) numerical viscosity, (ii) late stages of flow where the Bag Constant and the partonic pressure are becoming similar, (iii) and the consequences of final freeze-out and constituent quark matter formation. |
Address |
[Horvat, Sz; Csernai, L. P.] Univ Bergen, Inst Phys & Technol, N-5007 Bergen, Norway, Email: szhorvat@ift.uib.no |
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 |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000282249400011 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
375 |
Permanent link to this record |
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Author |
Aristizabal Sierra, D.; Bazzocchi, F.; de Medeiros Varzielas, I.; Merlo, L.; Morisi, S. |
Title |
Tri/Bi-maximal lepton mixing and leptogenesis |
Type |
Journal Article |
Year |
2010 |
Publication |
Nuclear Physics B |
Abbreviated Journal |
Nucl. Phys. B |
Volume |
827 |
Issue |
1-2 |
Pages |
34-58 |
Keywords |
|
Abstract |
In models with flavour symmetries added to the gauge group of the Standard Model the CP-violating asymmetry necessary for leptogenesis may be related with low-energy parameters. A particular case of interest is when the flavour symmetry produces exact Tri/Bi-maximal lepton mixing leading to a vanishing CP-violating asymmetry. In this paper we present a model-independent discussion that confirms this always occurs for unflavoured leptogenesis in type I see-saw scenarios, noting however that Tri/Bi-maximal mixing does not imply a vanishing asymmetry in general scenarios where there is interplay between type I and other see-saws. We also consider a specific model where the exact Tri/Bi-maximal mixing is lifted by corrections that can be parametrised by a small number of degrees of freedom and analyse in detail the existing link between low and high-energy parameters – focusing on how the deviations from Tri/Bi-maximal are connected to the parameters governing leptogenesis. |
Address |
[Merlo, L.] Univ Padua, Dipartimento Fis G Galilei, Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy, Email: daristi@lnf.infn.it |
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 |
0550-3213 |
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:000272669900002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
512 |
Permanent link to this record |