{
  "abstract": "We study a portal of a $Z_2$-odd singlet scalar and a vector like down quark, in which a right handed flavor breaking spurion extends the portal coupling from $b_R$ to $d_R$ and $s_R$. This single coupling vector links the $b\\to s$, $b\\to d$, and $s\\to d$ transitions. We compute the one loop dipole and $ΔF=2$ Wilson coefficients, and show that a real scalar generates no $ΔF=2$ amplitude at one loop. Using a seven observable profile likelihood of $B$ meson mixing, $ε_K$, and radiative decays, with the CKM, lattice, and short distance inputs treated as nuisance parameters, we compare a generic spurion, minimal $U(2)^3$ with a free size of the light quark couplings, and a CKM-aligned ansatz. We have found that the present data cannot yet test the flavor structure: the Standard Model is compatible with the data, with a pseudo experiment $p$-value of $0.20$, and no direction of the light quark couplings can be excluded at 95% CL. For $M_D\\simeq m_{\\mathcal{S}}=1$ TeV and $|λ_b|=1$, the relative light quark coupling $ε_R$ is bounded at 95% CL by $0.227$ for a generic spurion and by $0.211$ for minimal $U(2)^3$. More precise measurements of the $B_s$ mixing phase at the LHC and of $\\sin2β$ at LHCb and Belle-II, together with improved lattice and CKM inputs, can make the minimality of the flavor structure testable if a deviation from the Standard Model is observed.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.15911",
  "author_total": 1,
  "authors": [
    {
      "name": "Qazi Maaz Us Salam"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/esks7w8qjpj58.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.15911",
  "fulltext_url": null,
  "id": "esks7w8qjpj58",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.15911",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "openalex",
      "3106|Particle physics theoretical and experimental studies"
    ]
  ],
  "openalex": "W7221809122",
  "pdf_url": "https://arxiv.org/pdf/2610.15911",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-11",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/esks7w8qjpj58.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:06Z",
      "native_id": "2610.15911",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.15911"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Testing Minimal $U(2)^3$ Right-Handed Flavor Breaking in a Singlet-Scalar Vector-Like Quark Portal",
  "title_text": "Testing Minimal U(2)^3 Right-Handed Flavor Breaking in a Singlet-Scalar Vector-Like Quark Portal",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:06Z",
  "url": "https://research.draconitic.com/paper/esks7w8qjpj58",
  "venue": "arXiv",
  "versions": []
}