$$ {R}_{D^{\left(*\right)}} $$ in custodial warped space

Journal Article · 07 December 2018 · Journal of High Energy Physics (Online)

DOI: https://doi.org/10.1007/JHEP12(2018)043 · OSTI ID:1487057

Carena, Marcela ^[1]; Megías, Eugenio  ^[2]; Quirós, Mariano ^[3]; Wagner, Carlos ^[4]

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1. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Univ. of Chicago, Chicago, IL (United States)
2. Univ. de Granada, Granada (Spain)
3. Institut de Fisica d'Altes Energies (IFAE) and BIST, Barcelona (Spain); Univ. of Notre Dame, Notre Dame, IN (United States)
4. Univ. of Chicago, Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)

Here, flavor physics experiments allow to probe the accuracy of the Standard Model (SM) description at low energies, and are sensitive to new heavy gauge bosons that couple to quarks and leptons in a relevant way. The apparent anomaly in the ratios of the decay of $$B$$-mesons into $$D$$-mesons and different lepton flavors, $$R_{D^{(\ast)}} = \mathcal B(B \to D^{(\ast)} \tau \nu)/ \mathcal B(B \to D^{(\ast)} \ell \nu )$$ is particularly intriguing, since these decay processes occur at tree-level in the SM. Recently, it has been suggested that this anomaly may be explained by new gauge bosons coupled to right-handed currents of quarks and leptons, involving light right-handed neutrinos. In this work we present a well-motivated ultraviolet complete realization of this idea, embedding the SM in a warped space with an $$SU(2)_L \otimes SU(2)_R \otimes U(1)_{B-L}$$ bulk gauge symmetry. Besides providing a solution to the hierarchy problem, we show that this model, which has an explicit custodial symmetry, can explain the $$R_{D^{(\ast)}}$$ anomaly and at the same time allow for a solution to the $$R_{K^{(\ast)}}$$ anomalies, related to the decay of $$B$$-mesons into $$K$$-mesons and leptons, $$R_{K^{(*)}} = \mathcal B(B\to K^{(*)} \mu \mu)/ \mathcal B(B \to K^{(*)} e e)$$. In addition, a model prediction is an anomalous value of the forward-backward asymmetry $$A^b_{FB}$$, driven by the $$Z\bar b_R b_R$$ coupling, in agreement with LEP data.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Univ. of Chicago, IL (United States)
• Sponsoring Organization: Catalan Government; National Science Foundation (NSF); USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
• Grant/Contract Number: AC02-06CH11357; AC02-07CH11359; SC0009924
• OSTI ID: 1487057
• Report Number(s): EFI--18-9; FERMILAB-PUB--18-386-T; UAB-FT--777; arXiv:1809.01107; 1692568
• Journal Information: Journal of High Energy Physics (Online), Journal Name: Journal of High Energy Physics (Online) Journal Issue: 12 Vol. 2018; ISSN 1029-8479
• Publisher: Springer BerlinCopyright Statement
• Country of Publication: United States
• Language: English