SciPost Submission Page
Implications of new physics in \lambda_b \to \lambda_c \ell \nu_{\ell} decay processes
by Aishwarya Bhatta
Submission summary
| Authors (as registered SciPost users): | Aishwarya Bhatta |
| Submission information | |
|---|---|
| Preprint Link: | scipost_202202_00039v1 (pdf) |
| Date submitted: | 2022-02-22 09:22 |
| Submitted by: | Bhatta, Aishwarya |
| Submitted to: | SciPost Physics Proceedings |
| Proceedings issue: | 16th International Workshop on Tau Lepton Physics (TAU2021) |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approaches: | Theoretical, Phenomenological |
Abstract
Several indications of lepton non-universality ratios, R(D*), R(J/\psi), and the measurements on hadronic and \tau longitudinal polarization in b \to c \ell \bar{\nu} processes have attracted a lot of attention. By considering the most general effective Lagrangian, we carry out a model-independent analysis of the semileptonic \lambda_b decays, to inspect the nature of new physics. We constraint the new physics parameter space by using the chi-square fitting. We study the implications of constrained new couplings on the observable such as branching fractions, forward-backward asymmetries, lepton non-universality parameter, and \lambda_c and lepton longitudinal polarization fractions of the decay modes.
Current status:
Reports on this Submission
Strengths
- none
Weaknesses
- if truly a proceeding, no reference to original work or any future work
- incomplete description of the analysis (likelihood, observables)
- incorrect treatment of hadronic uncertainties
Report
Given the lack of reference to an original work or future work, I must assume that this is an attempt to shoehorn an analysis into a conference's proceedings. The description of the analysis is incomplete, starting with the lack of chi2 and dof, both of which are needed to compute a p value. (Only their ratio is given). There is no statement on how the "SM uncertainty" is treated, which I assume is the hadronic uncertainty in the observables. The author implicitly uses a scheme for the treatment of theory uncertainties that regularly fails for LFU searches: the hadronic uncertainties are functions of the BSM parameter (here, the Wilson coefficients). This makes their treatment as part of the chi^2 ill-defined. They must be treated as nuisance parameters instead.
Requested changes
Assuming this will be resubmitted as a paper rather than a proceedings article, I recommend to
- rework the treatment of the hadronic uncertainties as nuisance parameters with suitable theory constraints (e.g., gaussian priors from lattice QCD)
- be clear which parameters are varied in which scenario
From that point forward, one can discuss suitability for a journal.