New ways to search for right-handed current in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo stretchy="false">→</mml:mo><mml:mi>ρ</mml:mi><mml:mo>ℓ</mml:mo><mml:mover accent="true"><mml:mi>ν</mml:mi><mml:mo accent="true" stretchy="false">¯</mml:mo></mml:mover></mml:math>decay

Bernlochner, F. U.; Ligeti, Zoltan; Turczyk, Sascha

doi:10.1103/physrevd.90.094003

Cited by 35 publications

(33 citation statements)

References 56 publications

(136 reference statements)

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“…First studies have estimated the potential impact of right-handed currents both in inclusive [42][43][44] as well as exclusive b → c ν transitions [45], still allowing for a few percent of a right-handed current admixture. A recent LHCb analysis [46] using a baryonic decay mode disfavours this New Physics (NP) interpretation of the tension in b → u transitions, 1 while there has been a possible solution prior to this measurement [47].…”

Section: Jhep04(2016)131mentioning

confidence: 99%

“…Hence their conclusion to exclude right-handed currents purely to a deviation from their derived uncertainty band at the one sigma level is too strong. In a first order approximation in [47] we have taken into account such effects to reinterpret the Neyman belt using the same experimental data, in the valid theoretical range of low q 2 for the form factor predictions. In this analysis right-handed currents may not be excluded, yet.…”

Section: Jhep04(2016)131mentioning

confidence: 99%

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Additional information on heavy quark parameters from charged lepton forward-backward asymmetry

Turczyk

2016

J. High Energ. Phys.

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The determination of |V cb | using inclusive and exclusive (semi-)leptonic decays exhibits a long-standing tension of varying O(3σ) significance. For the inclusive determination the decay rate is expanded in 1/m b using heavy quark expansion, and from moments of physical observables the higher order heavy quark parameters are extracted from experimental data in order to assess |V cb | from the normalisation. The drawbacks are high correlations both theoretically as well as experimentally among these observables. We will scrutinise the inclusive determination in order to add a new and less correlated observable. This observable is related to the decay angle of the charged lepton and can help to constrain the important heavy quark parameters in a new way. It may validate the current seemingly stable extraction of |V cb | from inclusive decays or hints to possible issues, and even may be sensitive to New Physics operators.

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Section: Jhep04(2016)131mentioning

confidence: 99%

Section: Jhep04(2016)131mentioning

confidence: 99%

Additional information on heavy quark parameters from charged lepton forward-backward asymmetry

Turczyk

2016

J. High Energ. Phys.

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“…The determination of |V ub | from the measured ratio of branching fractions depends on the size of a possible right-handed coupling 36 . This can clearly be seen in Fig.…”

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confidence: 99%

Determination of the quark coupling strength |Vub| using baryonic decays

Sutcliffe¹

2015

Nature Phys

150

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In the Standard Model of particle physics, the strength of the couplings of the b quark to the u and c quarks, |V ub | and |V cb |, are governed by the coupling of the quarks to the Higgs boson. Using data from the LHCb experiment at the Large Hadron Collider, the probability for the Λ 0 b baryon to decay into the pµ − ν µ final state relative to the Λ + c µ − ν µ final state is measured. Combined with theoretical calculations of the strong interaction and a previously measured value of |V cb |, the first |V ub | measurement to use a baryonic decay is performed. This measurement is consistent with previous determinations of |V ub | using B meson decays to specific final states and confirms the existing incompatibility with those using an inclusive sample of final states.I n the Standard Model (SM) of particle physics, the decay of one quark to another by the emission of a virtual W boson is described by the 3 × 3 unitary Cabibbo-Kobayashi-Maskawa (CKM) matrix 1,2 . This matrix arises from the coupling of the quarks to the Higgs boson. Although the SM does not predict the values of the four free parameters of the CKM matrix, the measurements of these parameters in different processes should be consistent with each other. If they are not, it is a sign of physics beyond the SM. In global fits combining all available measurements 3,4 , the sensitivity of the overall consistency check is limited by the precision in the measurements of the magnitude and phase of the matrix element V ub , which describes the transition of a b quark to a u quark.The magnitude of V ub can be measured via the semileptonic quark-level transition b → u − ν . Semileptonic decays are used to minimize the uncertainties arising from the interaction of the strong force, described by quantum chromodynamics (QCD), between the final-state quarks. For the measurement of the magnitude of V ub , as opposed to measurements of the phase, all decays of the b quark, and the equivalent b quark, can be considered together. There are two complementary methods to perform the measurement. From an experimental point of view, the simplest is to measure the branching fraction (probability to decay to a given final state) of a specific (exclusive) decay. An example is the decay of a B 0 (bd) meson to the final state π + − ν, where the influence of the strong interaction on the decay, encompassed by a B 0 → π + form factor, is predicted by non-perturbative techniques such as lattice QCD (LQCD; ref. baryons are not produced at an e + e − B-factory; however, at the LHC, they constitute around 20% of the b-hadrons produced 19 . These measurements together with recent LQCD calculations 20 allow for the determination of |V ub | 2 /|V cb | 2 according towhere B denotes the branching fraction and R FF is a ratio of the relevant form factors, calculated using LQCD. This is then converted into a measurement of |V ub | using the existing measurements of |V cb | obtained from exclusive decays. The normalization to the Λ 0 b → Λ + c µ − ν µ decay cancels many experimental unce...

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“…Understanding the QCD dynamics of semileptonic B decays is also important, because the theoretical tools coincide with those used in inclusive and exclusive b → sγ and b → s ¯ decays. While I have also entertained modifications of these CKM measurements due to NP (such as right-handed currents [47]), many known theoretical and experimental improvements can take place in the future, such as doing all measurements in events where the other B is fully reconstructed.…”

Section: Status Of Flavor Physicsmentioning

confidence: 99%

Flavor Constraints on New Physics

Ligeti¹

2016

Proceedings of XXVII International Symposium on Lepton Photon Interactions at High Energies — PoS(LeptonPhoton2015)

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This talk highlights, from a theoretical point of view, some recent exciting results in flavor physics, as well as future prospects. We discuss possible implications of a subset of the experimental results in tension with the standard model, such as the 4σ deviation in the B → D ( * ) τν decay rates, and recent improvements in the constraints on axion portal dark matter models. We use the examples of constraining new physics contributions to neutral meson mixing and the search for possible vector-like fermions to illustrate the expected progress over the next decade to increase the sensitivity to new physics at shorter distance scales. We also speculate about the ultimate limitations of (quark) flavor physics probes of new physics.

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New ways to search for right-handed current inB→ρℓν¯decay

Cited by 35 publications

References 56 publications

Additional information on heavy quark parameters from charged lepton forward-backward asymmetry

Additional information on heavy quark parameters from charged lepton forward-backward asymmetry

Determination of the quark coupling strength |Vub| using baryonic decays

Flavor Constraints on New Physics

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