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1.
Phys Rev Lett ; 115(15): 152002, 2015 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-26550717

RESUMO

The rare decay B→πℓ^{+}ℓ^{-} arises from b→d flavor-changing neutral currents and could be sensitive to physics beyond the standard model. Here, we present the first ab initio QCD calculation of the B→π tensor form factor f_{T}. Together with the vector and scalar form factors f_{+} and f_{0} from our companion work [J. A. Bailey et al., Phys. Rev. D 92, 014024 (2015)], these parametrize the hadronic contribution to B→π semileptonic decays in any extension of the standard model. We obtain the total branching ratio BR(B^{+}→π^{+}µ^{+}µ^{-})=20.4(2.1)×10^{-9} in the standard model, which is the most precise theoretical determination to date, and agrees with the recent measurement from the LHCb experiment [R. Aaij et al., J. High Energy Phys. 12 (2012) 125].


Assuntos
Partículas Elementares , Modelos Teóricos , Física Nuclear , Prótons
2.
Phys Rev Lett ; 104(25): 251802, 2010 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-20867365

RESUMO

The use of semileptonic decays has become standard in constraining the unitarity triangle. Since precise calculations of these are very challenging, we propose an entirely new approach. The ε{K} constraint, which depends extremely sensitively on |V{cb}|, is replaced by the interplay between ε{K}, BR(B→τν), and ΔM{B{s}}. Improvements on the B→τν branching ratio and on the lattice determinations of f{B{s}}B{s}{1/2} and f{B} can increase the effectiveness of this method significantly.

3.
Eur Phys J C Part Fields ; 77(2): 112, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29033670

RESUMO

We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle-physics community. More specifically, we report on the determination of the light-quark masses, the form factor [Formula: see text], arising in the semileptonic [Formula: see text] transition at zero momentum transfer, as well as the decay constant ratio [Formula: see text] and its consequences for the CKM matrix elements [Formula: see text] and [Formula: see text]. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of [Formula: see text] and [Formula: see text] Chiral Perturbation Theory. We review the determination of the [Formula: see text] parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. The latter quantities are an addition compared to the previous review. For the heavy-quark sector, we provide results for [Formula: see text] and [Formula: see text] (also new compared to the previous review), as well as those for D- and B-meson-decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. Finally, we review the status of lattice determinations of the strong coupling constant [Formula: see text].

4.
Chir Organi Mov ; 75(1): 51-7, 1990.
Artigo em Inglês, Italiano | MEDLINE | ID: mdl-2369854

RESUMO

Traumatic dislocation of the patella is an infrequent occurrence favored by dysplasia of the extensor apparatus of the knee. The problem of diagnosis is at the basis of a choice of treatment, as any pre-existing dysplasia may be worsened by traumatic dislocation. Furthermore, the presence of a patellar or femoral osteochondral fragment, a more frequent finding than is generally believed as demonstrated by arthroscopy, influences surgical treatment. The results of 37 cases are reported, and several details related to surgical method discussed.


Assuntos
Luxações Articulares/cirurgia , Patela/lesões , Adolescente , Adulto , Artroscopia , Feminino , Fraturas Ósseas/complicações , Fraturas Ósseas/diagnóstico , Fraturas Ósseas/cirurgia , Humanos , Luxações Articulares/complicações , Masculino , Patela/cirurgia
5.
Eur Phys J C Part Fields ; 74(9): 2890, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25972762

RESUMO

We review lattice results related to pion, kaon, [Formula: see text]- and [Formula: see text]-meson physics with the aim of making them easily accessible to the particle-physics community. More specifically, we report on the determination of the light-quark masses, the form factor [Formula: see text], arising in semileptonic [Formula: see text] transition at zero momentum transfer, as well as the decay-constant ratio [Formula: see text] of decay constants and its consequences for the CKM matrix elements [Formula: see text] and [Formula: see text]. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of [Formula: see text] and [Formula: see text] Chiral Perturbation Theory and review the determination of the [Formula: see text] parameter of neutral kaon mixing. The inclusion of heavy-quark quantities significantly expands the FLAG scope with respect to the previous review. Therefore, we focus here on [Formula: see text]- and [Formula: see text]-meson decay constants, form factors, and mixing parameters, since these are most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. In addition we review the status of lattice determinations of the strong coupling constant [Formula: see text].

6.
Ital J Orthop Traumatol ; 19(1): 79-86, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8567261

RESUMO

The authors analyse the method used between 1983 and 1990 in 161 patients with chronic anterior laxity of the knee treated by 162 ligament reconstructions utilizing synthetic ligament prostheses. Tearing of the prosthetic ligament is the most feared and frequent complication. This may be due to technical error, wear of the material or, to a lesser extent, new trauma. With a follow-up of up to 80 months, the number of tears seems excessively high. This means that artificial ligaments cannot today be considered a satisfactory surgical technique. The considerable technical improvements in autologous reconstructive surgery make the biological approach preferable even today.


Assuntos
Ligamento Cruzado Anterior/cirurgia , Instabilidade Articular/cirurgia , Complicações Pós-Operatórias , Próteses e Implantes , Adulto , Doença Crônica , Feminino , Seguimentos , Humanos , Masculino , Falha de Prótese , Falha de Tratamento
7.
Ital J Orthop Traumatol ; 18(4): 485-90, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1345641

RESUMO

Arthroscopic surgery is generally considered to be free of any significant complications. In particular, there is a much lower incidence of vascular complications as compared with open surgery of the knee. A careful examination of the literature, made by the authors, and an in-depth analysis of a significant sample (790 patients over 2 years) out of a total of more than 2200 knee arthroscopies performed over 7 years, has shown that thrombophlebitis is in fact an important complication especially in patients over the age of forty. The need for an accurate preliminary study to identify the patients at risk and for regular and specific out-patient check-ups to prevent the onset of severe vascular and thrombophlebitic complications is stressed.


Assuntos
Artroscopia/efeitos adversos , Articulação do Joelho/cirurgia , Tromboflebite/etiologia , Adolescente , Adulto , Fatores Etários , Idoso , Feminino , Seguimentos , Heparina/uso terapêutico , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Estudos de Amostragem , Índice de Gravidade de Doença , Tromboflebite/diagnóstico , Tromboflebite/epidemiologia , Tromboflebite/prevenção & controle , Fatores de Tempo , Torniquetes/efeitos adversos
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