RETRACTED: Implications of BNL measurement of δa on a class of scalar leptoquark interactions

Mahanta, Uma

doi:10.1016/s0370-2693(01)00865-6

Cited by 8 publications

(2 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Leptoquark-quark loops can induce flavour diagonal lepton dipole operators, such as (g−2) µ [48,49]. However, it is easy to see that the contribution to (g−2) µ is always negligeable.…”

Section: Jhep11(2010)073mentioning

confidence: 99%

“Minimal Flavour Violation” for leptoquarks

Davidson

Descotes-Genon

2010

J. High Energ. Phys.

View full text Add to dashboard Cite

Scalar leptoquarks, with baryon and lepton number conserving interactions, could have TeV scale masses, and be produced at colliders or contribute to a wide variety of rare decays. In pursuit of some insight as to the most sensitive search channels, we assume that the leptoquark-lepton-quark coupling can be constructed from the known mass matrices. We estimate the rates for selected rare processes in three cases: leptoquarks carrying lepton and quark flavour, leptoquarks with quark flavour only, and unflavoured leptoquarks. We find that leptoquark decay to top quarks is an interesting search channel.

show abstract

Section: Jhep11(2010)073mentioning

confidence: 99%

“Minimal Flavour Violation” for leptoquarks

Davidson

Descotes-Genon

2010

J. High Energ. Phys.

View full text Add to dashboard Cite

show abstract

“…For the existing constraints on leptoquarks from low-energy precision experiments, see Refs. [31][32][33][34][35][36][37][38][39][40]. These bounds are especially severe for leptoquarks which couple to both left-and right-handed quarks simultaneously, like S † 1/2 in Table 1 [31].…”

Section: Modelmentioning

confidence: 99%

Signatures of leptoquarks at the LHC and right-handed neutrinos

Evans

2015

Phys. Rev. D

View full text Add to dashboard Cite

In this paper, we argue that an extension of the Standard Model with a single leptoquark and three right-handed neutrinos can explain the excess in the firstgeneration leptoquark search at the LHC. We also find that when the leptoquark has similarly sized couplings to all three generations, it produces additional signals which will soon be tested in the second and third generation leptoquark searches, as well as in decay channels consisting of two mixed flavor leptons and two jets. If the leptoquark only couples to the first generation, on the other hand, two of the righthanded neutrinos need to be fairly degenerate in mass with the leptoquark while the other right-handed neutrinos mass should be much lighter. This hierarchical structure could explain dark matter and the baryon asymmetry of the Universe. These simple models may be regarded as a benchmark models for explaining the excess, which can be tested in the next stage of the LHC running.

show abstract

Muon anomalous magnetic moment, two-Higgs-doublet model, and supersymmetry

2001

View full text Add to dashboard Cite

The recent measurement of the muon anomalous magnetic moment a µ shows a 2.6σ deviation from the standard model value. We show that it puts strong constraints on the parameter space of the two-Higgs doublet model (2HDM) II. The dominant contribution of the Higgs bosons comes at the two-loop level, and in order to explain the data it favors a pseudoscalar A with a light mass range and a large tanβ. At 95% C.L., the upper limit for m A is 29 (55) (85) GeV for tanβ = 30 (45) (60), and tanβ is bounded below at 17. This is in sharp contrast to the conclusion one draws from considering one-loop Higgs contributions alone. Finally, we also discuss the role of the Higgs contributions in the minimal supersymmetric standard model. * E-mail: cheung@phys.cts.nthu.edu.tw † E-mail: chouch@phys.sinica.edu. which may suggest the presence of contributions from physics beyond the SM. Taking the above numbers at face value, the range of ∆a µ at 95% C.L. (±1.96σ) is given by 10.3 × 10 −10 < ∆a µ < 74.9 × 10 −10 .Most of the extensions of the SM start with an extended Higgs sector, the simplest of which is the two-Higgs-doublet model (2HDM). In particular, the more interesting model II [3] shares the same Higgs structure as the minimal supersymmetric standard model (MSSM). Hence, going beyond the SM to look for extra contributions to a µ , the 2HDM should be among the first to be examined seriously.In this Rapid Communication, we investigate the contributions from the 2HDM II. Stringent constraints are thus obtained on the parameter space of the model. The results are summarized as follows. In the 2HDM II, the dominant contribution actually comes at the two-loop level, and in order to explain the data ∆a µ is preferred to come from the Higgs pseudoscalar A, the mass of which is required to be less than 29 (55) (85) GeV for tanβ = 30 (45) (60) by the 95% C.L. range of Eq.(2). Moreover, tanβ has to be larger than 17. Recently, there has been some work on the same subject [4]; however, the paper only considered the one-loop contributions from the Higgs bosons, which become smaller than their corresponding two-loop contributions when the Higgs bosons are heavier than a few GeV and substantially smaller for heavier Higgs bosons. It is important to note that the two-loop contributions considered here dramatically change the story of the Higgs sector contributions to a µ and invalidate most of the results of the one-loop studies. Although we focus on the 2HDM II here, a similar conclusion holds for most models with possible large contributions from the Higgs sector. In models with flavor-changing Higgs couplings, in particular, there are potentially 1-loop contributions substantially larger than the flavorconserving ones [5]. However, the Barr-Zee type 2-loop contributions would still have an important role to play and should be taken into consideration. This fact has often been overlooked in the literature.In the MSSM, the dominant contribution comes from the chargino-sneutrino-loop diagrams and it has been shown [6] that to sat...

show abstract

RETRACTED: Implications of BNL measurement of δa on a class of scalar leptoquark interactions

Cited by 8 publications

References 4 publications

“Minimal Flavour Violation” for leptoquarks

“Minimal Flavour Violation” for leptoquarks

Signatures of leptoquarks at the LHC and right-handed neutrinos

Muon anomalous magnetic moment, two-Higgs-doublet model, and supersymmetry

Contact Info

Product

Resources

About