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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 First Observation of the Decay B-s(0) -> K-mu(+)nu(mu) and a Measurement of vertical bar V-ub vertical bar/vertical bar V-cb vertical bar Type Journal Article
Year 2021 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 126 Issue 8 Pages (down) 081804 - 11pp
Keywords
Abstract The first observation of the suppressed semileptonic B-s(0) -> K-mu(+)nu(mu) decay is reported. Using a data sample recorded in pp collisions in 2012 with the LHCb detector, corresponding to an integrated luminosity of 2 fb(-1), the branching fraction B(B-s(0) -> K-mu(+)nu(mu)) is measured to be [1.06 +/- 0.05(stat) +/- 0.08(syst)] x 10(-4), where the first uncertainty is statistical and the second one represents the combined systematic uncertainties. The decay B-s(0) -> D-s(-)mu(+)nu(mu), where D-s(-) is reconstructed in the final state K+K-pi(-), is used as a normalization channel to minimize the experimental systematic uncertainty. Theoretical calculations on the form factors of the B-s(0) -> K- and B-s(0) -> D-s(-) transitions are employed to determine the ratio of the Cabibbo-Kobayashi-Maskawa matrix elements vertical bar V-ub vertical bar/vertical bar V-cb vertical bar at low and high B-s(0) -> K- momentum transfer.
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
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000621595400003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4719
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Author Navarro-Salas, J.; Pla, S.
Title (F, G)-summed form of the QED effective action Type Journal Article
Year 2021 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 103 Issue 8 Pages (down) L081702 - 7pp
Keywords
Abstract We conjecture that the proper-time series expansion of the one-loop effective Lagrangian of quantum electrodynamics can be summed in all terms containing the field-strength invariants F = 1/4F F-mu nu(mu nu) (x), G = 1/4 (F) over tilde F-mu nu(mu nu) (x), including those also possessing derivatives of the electromagnetic field strength. This partial resummation is exactly encapsulated in a factor with the same form as the Heisenberg-Euler Lagrangian density, except that now the electric and magnetic fields can depend arbitrarily on spacetime coordinates. We provide strong evidence for this conjecture, which is proved to sixth order in the proper time. Furthermore, and as a byproduct, we generate some solvable electromagnetic backgrounds. We also discuss the implications for a generalization of the Schwinger formula for pair production induced by nonconstant electric fields. Finally, we briefly outline the extension of these results in the presence of gravity.
Address [Navarro-Salas, Jose; Pla, Silvia] Univ Valencia, Dept Fis Teor, Valencia 46100, Spain, Email: jnavarro@ific.uv.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000649081100005 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4834
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Author Kirpichnikov, D.V.; Sieber, H.; Molina Bueno, L.; Crivelli, P.; Kirsanov, M.M.
Title Probing hidden sectors with a muon beam: Total and differential cross sections for vector boson production in muon bremsstrahlung Type Journal Article
Year 2021 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 104 Issue 7 Pages (down) 076012 - 13pp
Keywords
Abstract Vector bosons, such as dark photon A' or Z', can couple to muons and be produced in the bremsstrahlung reaction mu(-) + N -> mu(-) + N + A'(Z'). Their possible subsequent invisible decay can be detected in fixed target experiments through missing energy/momentum signature. In such experiments, not only is the energy transfer to A'(Z') important but also the recoil muon angle psi μ0. In this paper, we derive the total and the double differential cross sections involved in this process using the phase space Weizsacker-Williams and improved Weizsacker-Williams approximations, as well as using exact-tree-level calculations. As an example, we compare the derived cross sections and resulting signal yields in the NA64 μexperiment that uses a 160 GeV muon beam at the CERN Super Proton Synchrotron accelerator. We also discuss its impact on the NA64 μexpected sensitivity to explore the (g – 2)(mu) anomaly favored region with a Z' boson considering 10(12) muons accumulated on target.
Address [Kirpichnikov, D., V; Kirsanov, M. M.] Inst Nucl Res, Moscow 117312, Russia, Email: kirpich@ms2.inr.ac.ru;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000707478200010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5008
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Author Forero, D.V.; Giunti, C.; Ternes, C.A.; Tortola, M.
Title Nonunitary neutrino mixing in short and long-baseline experiments Type Journal Article
Year 2021 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 104 Issue 7 Pages (down) 075030 - 11pp
Keywords
Abstract Nonunitary neutrino mixing in the light neutrino sector is a direct consequence of type-I seesaw neutrino mass models. In these models, light neutrino mixing is described by a submatrix of the full lepton mixing matrix and, then, it is not unitary in general. In consequence, neutrino oscillations are characterized by additional parameters, including new sources of CP violation. Here we perform a combined analysis of short and long-baseline neutrino oscillation data in this extended mixing scenario. We did not find a significant deviation from unitary mixing, and the complementary data sets have been used to constrain the nonunitarity parameters. We have also found that the T2K and NOvA tension in the determination of the Dirac CP-phase is not alleviated in the context of nonunitary neutrino mixing.
Address [Forero, D. V.] Univ Medellin, Carrera 87 N 30-65, Medellin, Colombia, Email: dvanegas@udem.edu.co;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000753716600006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5121
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Author Yang, Z.; Cao, X.; Guo, F.K.; Nieves, J.; Pavon Valderrama, M.
Title Strange molecular partners of the Z(c)(3900) and Z(c)(4020) Type Journal Article
Year 2021 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 103 Issue 7 Pages (down) 074029 - 8pp
Keywords
Abstract Quantum chromodynamics presents a series of exact and approximate symmetries which can be exploited to predict new hadrons from previously known ones. The Z(c)(3900) and Z(c)(4020), which have been theorized to be isovector D*(D) over bar and D*(D) over bar* molecules [I-G(J(PC)) = 1(-)(1)(+-))], are no exception. Here we argue that from SU(3)-flavor symmetry, we should expect the existence of strange partners of the Z(c)'s with hadronic molecular configurations D*(D) over bar (s) – D (D) over bar*(s) and D*(D) over bar*(s) (or, equivalently, quark content c (c) over bars (q) over bar, with q = u, d). The quantum numbers of these Z(cs) and Z(cs)* structures would be I(J(P)) = 1/2 (1(+)). The predicted masses of these partners depend on the details of the theoretical scheme used, but they should be around the D*(D) over bar (s) – D (D) over bar*(s) and D*(D) over bar*(s) thresholds, respectively. Moreover, any of these states could be either a virtual pole or a resonance. We show that, together with a possible triangle singularity contribution, such a picture nicely agrees with the very recent BESIII data of the e(+)e(-) -> K+((Ds-D*0) + D*D--(s)0).
Address [Yang, Zhi] Univ Elect Sci & Technol China, Sch Phys, Chengdu 610054, Peoples R China, Email: zhiyang@uestc.edu.cn;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000648581900002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4832
Permanent link to this record