We report the first observation of the two-body baryonic decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>+</mo></msup><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Σ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2455</mn><msup><mo stretchy="false">)</mo><mrow><mo>+</mo><mo>+</mo></mrow></msup><msubsup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">¯</mo></mover><mi>c</mi><mo>−</mo></msubsup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mn>0</mn></msup><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Σ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2455</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup><msubsup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">¯</mo></mover><mi>c</mi><mn>0</mn></msubsup></math> with significances of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>7.3</mn><mi>σ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>6.2</mn><mi>σ</mi></math>, respectively, including statistical and systematic uncertainties. The branching fractions are measured to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msup><mi>B</mi><mo>+</mo></msup><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Σ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2455</mn><msup><mo stretchy="false">)</mo><mrow><mo>+</mo><mo>+</mo></mrow></msup><msubsup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">¯</mo></mover><mi>c</mi><mo>−</mo></msubsup><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>5.74</mn><mo>±</mo><mn>1.11</mn><mo>±</mo><mn>0.4</mn><msubsup><mn>2</mn><mrow><mo>−</mo><mn>1.53</mn></mrow><mrow><mo>+</mo><mn>2.47</mn></mrow></msubsup><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msup><mi>B</mi><mn>0</mn></msup><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Σ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2455</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup><msubsup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">¯</mo></mover><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>4.83</mn><mo>±</mo><mn>1.12</mn><mo>±</mo><mn>0.3</mn><msubsup><mn>7</mn><mrow><mo>−</mo><mn>0.60</mn></mrow><mrow><mo>+</mo><mn>0.72</mn></mrow></msubsup><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math>. The first and second uncertainties are statistical and systematic, respectively, while the third ones arise from the absolute branching fractions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">¯</mo></mover><mi>c</mi><mo>−</mo></msubsup></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">¯</mo></mover><mi>c</mi><mn>0</mn></msubsup></math> decays. The data samples used for this analysis have integrated luminosities of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>711</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>365</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>, and were collected at the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">ϒ</mi><mo stretchy="false">(</mo><mn>4</mn><mi>S</mi><mo stretchy="false">)</mo></math> resonance by the Belle and Belle II detectors operating at the KEKB and SuperKEKB asymmetric-energy <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> colliders, respectively.

M. Abumusabh

I. Adachi

L. Aggarwal

H. Ahmed

Y. Ahn

H. Aihara

N. Akopov

S. Alghamdi

M. Alhakami

A. Aloisio

N. Althubiti

K. Amos

N. Anh Ky

D.M. Asner

H. Atmacan

T. Aushev

V. Aushev

R. Ayad

V. Babu

H. Bae

N.K. Baghel

S. Bahinipati

P. Bambade

Sw. Banerjee

M. Barrett

M. Bartl

J. Baudot

A. Baur

A. Beaubien

F. Becherer

J. Becker

J.V. Bennett

F.U. Bernlochner

V. Bertacchi

M. Bertemes

E. Bertholet

M. Bessner

S. Bettarini

V. Bhardwaj

B. Bhuyan

F. Bianchi

D. Biswas

A. Bobrov

D. Bodrov

A. Bondar

G. Bonvicini

J. Borah

A. Boschetti

A. Bozek

M. Bračko

P. Branchini

R.A. Briere

T.E. Browder

A. Budano

S. Bussino

Q. Campagna

M. Campajola

L. Cao

G. Casarosa

C. Cecchi

M.C. Chang

P. Cheema

L. Chen

B.G. Cheon

K. Chilikin

J. Chin

K. Chirapatpimol

H.E. Cho

K. Cho

S.J. Cho

S.K. Choi

S. Choudhury

L. Corona

J.X. Cui

E. De La Cruz-Burelo

S.A. De La Motte

G. De Nardo

G. De Pietro

R. de Sangro

M. Destefanis

S. Dey

A. Di Canto

J. Dingfelder

Z. Doležal

I. Domínguez Jiménez

T.V. Dong

X. Dong

M. Dorigo

K. Dugic

G. Dujany

P. Ecker

D. Epifanov

J. Eppelt

R. Farkas

P. Feichtinger

T. Ferber

T. Fillinger

C. Finck

G. Finocchiaro

F. Forti

Observation of the decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>+</mo></msup><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Σ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2455</mn><msup><mo stretchy="false">)</mo><mrow><mo>+</mo><mo>+</mo></mrow></msup><msubsup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">¯</mo></mover><mi>c</mi><mo>−</mo></msubsup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mn>0</mn></msup><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Σ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2455</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup><msubsup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">¯</mo></mover><mi>c</mi><mn>0</mn></msubsup></math>

An axionlike particle <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>a</mi></math> (ALP) can explain the excess of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>K</mi><mo>+</mo><mtext>invisible</mtext></math> events at Belle II. However, many analyses of ALP scenarios are oversimplified. We revisit the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>K</mi><mi>a</mi></math> transition rate in a popular minimal and UV complete model with two Higgs doublets (2HDM) and a complex singlet [Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) model]. To this end we compare our results with previous studies which derived the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover><mi>s</mi><mi>a</mi></math> vertex from the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover><mi>s</mi><mi>A</mi></math> vertex, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>A</mi></math> is the heavy pseudoscalar of the 2HDM, in terms of an <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>a</mi><mo>−</mo><mi>A</mi></math> mixing angle. We find this approach to work only at the leading one-loop order, while it fails at the two-loop level. Furthermore, while an approximate <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mn>2</mn></msub></math> symmetry suppresses the leading-order amplitude by a factor of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mo>/</mo><mi>tan</mi><mi>β</mi></math>, which is the ratio of the two vacuum expectation values of the Higgs doublets, we find the two-loop contribution unsuppressed and phenomenologically relevant for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>tan</mi><mi>β</mi><mo>≳</mo><mn>5</mn></math>. We determine the allowed parameter space and underline the importance of better searches for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">ϒ</mi><mo stretchy="false">→</mo><mi>γ</mi><mo>+</mo><mi>invisible</mi></mrow></math> and for a possible excess in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>K</mi><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></math>. We further study the low-energy axion effective theory which leads to a divergent and basis-dependent amplitude. As a conceptual result, we clarify the ambiguities and identify which low-energy framework is consistent with the DFSZ model.

Germany

Xiyuan Gao

Ulrich Nierste

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>K</mi><mo>+</mo></math> axionlike particles: Effective versus UV-complete models and enhanced two-loop contributions

Spain

Daniel Castillo

Canada

Lotta Jokiniemi

Pablo Soriano

Javier Menéndez

Corrigendum to “Neutrinoless ββ decay nuclear matrix elements complete up to N 2LO in heavy nuclei&#8221; [Physics Letters B 860 (2025) 139181]

Mass and full width of the heavy scalar molecule <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">M</mi></math> composed of the mesons <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>c</mi><mo>+</mo></msubsup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>c</mi><mo>−</mo></msubsup></math> are calculated in the QCD sum rule framework. To find its mass and current coupling, we apply the two-point sum rule method. The width of the hadronic molecule <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">M</mi><mo>=</mo><msubsup><mi>B</mi><mi>c</mi><mo>+</mo></msubsup><msubsup><mi>B</mi><mi>c</mi><mo>−</mo></msubsup></math> is evaluated by taking into account its dissociation to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>η</mi><mi>c</mi></msub><msub><mi>η</mi><mi>b</mi></msub><mo>,</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mi mathvariant="normal">ϒ</mi></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>c</mi><mo>+</mo></msubsup><msubsup><mi>B</mi><mi>c</mi><mo>−</mo></msubsup></math> mesons. Decays into <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> meson pairs with appropriate charges and quantum numbers triggered by <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover><mi>b</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover><mi>c</mi></math> annihilations to light quark-antiquarks are also included in the analyses. Because the partial widths of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">M</mi></math> molecule’s decay channels depend on the strong couplings at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">M</mi></math>-meson-meson vertices, we estimate them by invoking tools of the three-point sum rule method. Our predictions <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>m</mi><mo>=</mo><mo stretchy="false">(</mo><mn>12725</mn><mo>±</mo><mn>85</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>MeV</mi></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">Γ</mi><mo stretchy="false">[</mo><mi mathvariant="script">M</mi><mo stretchy="false">]</mo><mo>=</mo><mo stretchy="false">(</mo><mn>155</mn><mo>±</mo><mn>23</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>MeV</mi></mrow></math> for the parameters of the molecule <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">M</mi></mrow></math> provide useful information for experimental studies of numerous heavy resonances.

Azerbaijan

S.S. Agaev

Iran

Türkiye

K. Azizi

H. Sundu

Heavy scalar molecule <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>c</mi><mo>+</mo></msubsup><msubsup><mi>B</mi><mi>c</mi><mo>−</mo></msubsup></math>

We present measurements of $\textit{B → K}$ (892)$\textit{γ}$ decays using 365 fb of data collected from 2019 to 2022 by the Belle II experiment at the SuperKEKB asymmetric-energy $\textit{e}$ $\textit{e}$ collider. The data sample contains (387 $\textit{±}$ 6) $\textit{×}$ 10 Υ(4$\textit{S}$) events. We measure branching fractions ( $$\mathcal{B}$$ ) and CP asymmetries ( $${\mathcal{A}}_{CP}$$ ) for both $\textit{B}$ $\textit{→ K}$ $\textit{γ}$ and $\textit{B}$ $\textit{→ K}$ $\textit{γ}$ decays. The difference in CP asymmetries ( $$\Delta {\mathcal{A}}_{CP}$$ ) and the isospin asymmetry (∆ ) between these neutral and charged channels are also measured. We obtain the following branching fractions and $\textit{CP}$ asymmetries: $$\mathcal{B}\left({B}^{0}\to {K}^{*0}\gamma \right)=\left(4.14\pm 0.10\pm 0.11\right)\times {10}^{-5}$$ , $$\mathcal{B}\left({B}^{+}\to {K}^{*+}\gamma \right)=\left(4.04\pm {0.13}_{-0.15}^{+0.13}\right)\times {10}^{-5}$$ , $${\mathcal{A}}_{CP}\left({B}^{0}\to {K}^{*0}\gamma \right)=\left(-3.3\pm 2.3\pm 0.4\right)\%$$ , and $${\Delta}{\mathcal{A}}_{CP}\left({B}^{+}\to {K}^{*+}\gamma \right)=\left(-0.7\pm 2.9\pm 0.5\right)\%$$ . The measured difference in $\textit{CP}$ asymmetries is $${\Delta}{\mathcal{A}}_{CP}=\left(+{2}.{6}\pm {3}.{8}\pm 0.{6}\right)\%$$ , and the measured isospin asymmetry is ∆ = (+4.8 ± 2.0 ± 1.8)%. The first uncertainties listed are statistical and the second are systematic. These results are consistent with world-average values and theory predictions.

D. Asner

M. Aversano

N. Baghel

S. Bansal

J. Bennett

F. Bernlochner

L. Bierwirth

T. Bilka

A. Bolz

R. Briere

T. Browder

J. Cerasoli

P. Chang

R. Cheaib

C. Chen

B. Cheon

J. Cochran

J. Cui

F. Dattola

E. Cruz-Burelo

S. Motte

G. Marino

G. Nardo

G. Pietro

R. Sangro

R. Dhamija

A. Canto

F. Capua

T. Dong

K. Dort

D. Dossett

S. Dubey

M. Eliachevitch

Measurement of $\textit{B → K}$

The Cabibbo–Kobayashi–Maskawa matrix element $$|V_{\textrm{cb}}|$$ is an important Standard Model parameter, whose value can be determined by using the semi-leptonic decay $$B\rightarrow D^{*}\ell {\bar{\nu }}_\ell $$ . The perturbative QCD (pQCD) corrections to the $$B \rightarrow D^{*}$$ transform form factor $${{\mathcal {F}}}(w)$$ has been known up to the $$\hbox {N}^3$$ LO level, whose magnitude remains sensitive to the choice of renormalization scale $$\mu _r$$ . To improve the precision of $${{\mathcal {F}}}(w)$$ and hence $$|V_{\textrm{cb}}|$$ , we first apply the single-scale approach of Principle of Maximum Conformality (PMC) to eliminate the conventional (Conv.) renormalization scale dependence of the short-distance parameter $$\eta _A$$ and then predict the contribution of its unknown $$\hbox {N}^4$$ LO term via Bayesian analysis. In this paper, we adopt two probabilistic models for Bayesian analysis: the Cacciari–Houdeau model (CH model) and the geometric behavior model (GB model). It is shown that by using the PMC series in combination with Bayesian analysis, one can achieve high degree of reliability in estimating unknown higher-order terms. A more convergent behavior is achieved by applying the PMC, confirmed by the predicted $$\hbox {N}^4$$ LO contributions: for the CH model, $$\eta _A|_{\mathrm{Conv.}}^{\text {N}^{4}\text {LO}}=\{-\,0.0032,+\,0.0052\}$$ and $$\eta _A|_{\textrm{PMC}}^{\text {N}^{4}\text {LO}}=\{-\,0.0004,+\,0.0004\}$$ ; for the GB model, $$\eta _A|_{\mathrm{Conv.}}^{\text {N}^{4}\text {LO}}=\{-\,0.0049,+\,0.0075\}$$ and $$\eta _A|_{\textrm{PMC}}^{\text {N}^{4}\text {LO}}= \{-\,0.0007,+\,0.0007\}$$ . Comparing with the latest experimental measurements, we obtain $$|V_{\textrm{cb}}||_{\textrm{PMC}}=(40.58^{+0.53}_{-0.57})\times 10^{-3}$$ , which is consistent for both CH and GB models and in good agreement with the PDG world average, $$|V_{\textrm{cb}}|_{\textrm{PDG}}=(41.1\pm 1.2)\times 10^{-3}$$ within errors.

China

Wang Li

Xing-Gang Wu

Hua Zhou

Xu-Chang Zheng

Determination of $$|V_{\textrm{cb}}|$$ using Bayesian analysis of the $$B \rightarrow D^{*}\ell {\bar{\nu }}_\ell $$ semileptonic decay width with four-loop QCD corrections

The Kaon bag parameter $$ {\hat{B}}_K $$ plays a critical role in constraining the parameters of the CKM matrix and in probing physics beyond the Standard Model. In this work, we improve the precision of $$ {\hat{B}}_K $$ to next-to-next-to-leading order (NNLO) and provide world averages for both 3- and 4-flavour theories. In the course of this, as our main technical development, we carry out the two-loop matching between the RI-(S)MOM and $$ \overline{\textrm{MS}} $$ schemes. Our world averages combine all available lattice data, including conversion between the 3- and 4-flavour theories as appropriate. We obtain the result $$ {\hat{B}}_K^{\left(f=3\right)}=0.7627(60) $$ , which comprises the complete set of 3- and 4-flavour lattice results and can be used directly in phenomenological applications. The error is dominated by lattice uncertainties and missing higher-order corrections (residual scale dependence). Our averages include a PDG rescaling factor of 1.28 reflecting a mild tension among the lattice inputs after inclusion of NNLO corrections in the scheme conversion and matching across flavour thresholds. Our averages imply an updated value |$\textit{ϵ}$ | = 2$\textit{.}$171(65) (71) (153) × 10 . We briefly discuss applications of our results to $\textit{D}$-meson mixing.

United Kingdom

Martin Gorbahn

Sebastian Jäger

Sandra Kvedaraitė

RI-(S)MOM to $$ \overline{\textrm{MS}} $$ conversion for $\textit{B}$

We present a method to measure time-dependent <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> violation in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mn>0</mn></msup></math> decays produced in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><mi mathvariant="normal">ϒ</mi><mo stretchy="false">(</mo><mn>4</mn><mi>S</mi><mo stretchy="false">)</mo></mrow><mo stretchy="false">→</mo><msup><mrow><mi>B</mi></mrow><mrow><mn>0</mn></mrow></msup><mrow><msup><mrow><mover accent="true"><mrow><mi>B</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mn>0</mn></mrow></msup></mrow></mrow></math> events at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> factories without reconstructing the signal decay vertex. The method exploits the sensitivity of the tag <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mover accent="true"><mi>B</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msup></math> decay time to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> violation in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mn>0</mn></msup></math> signal. It relies on a compact <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> interaction region and excellent vertex resolution, which enable precise measurement of the displacement between production and decay vertices of the tag meson. We study an application to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mn>0</mn></msup><mo stretchy="false">→</mo><msup><mi>π</mi><mn>0</mn></msup><msup><mi>π</mi><mn>0</mn></msup></math> decays using a simplified simulation that approximates the conditions of the Belle II experiment at the SuperKEKB collider. Our approach achieves a sensitivity on mixing-induced <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> violation that would require 20 times larger samples with standard approaches. When incorporated into the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>π</mi><mi>π</mi></math> isospin analysis, the expected results would reduce the degeneracy of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ϕ</mi><mn>2</mn></msub></math> solutions and significantly increase precision. This work opens a path to previously inaccessible <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math>-violation studies enhancing and accelerating the reach of Belle II and future flavor physics programs.

Italy

S. Raiz

D. Tonelli

R. Žlebčík

Unlocking time-dependent <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> violation without signal vertexing at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>B</mi></mrow></math> factories

We report measurements of the ratios of branching fractions <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">R</mi><mo stretchy="false">(</mo><msup><mrow><mi>D</mi></mrow><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo><mo>+</mo></mrow></msup><mo stretchy="false">)</mo><mo>=</mo><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msup><mrow><mover accent="true"><mrow><mi>B</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mn>0</mn></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>D</mi></mrow><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo><mo>+</mo></mrow></msup><msup><mrow><mi>τ</mi></mrow><mrow><mo>−</mo></mrow></msup><msub><mrow><mover accent="true"><mrow><mi>ν</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mi>τ</mi></mrow></msub><mo stretchy="false">)</mo><mo>/</mo><mspace linebreak="goodbreak"></mspace><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msup><mrow><mover accent="true"><mrow><mi>B</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mn>0</mn></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>D</mi></mrow><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo><mo>+</mo></mrow></msup><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>−</mo></mrow></msup><msub><mrow><mover accent="true"><mrow><mi>ν</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mo>ℓ</mo></mrow></msub><mo stretchy="false">)</mo></mrow></math>, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>ℓ</mo></math> denotes either an electron or a muon. These ratios test the universality of the charged-current weak interaction. The results are based on a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>365</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> data sample collected with the Belle II detector at the SuperKEKB <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> collider, which operates at a center-of-mass energy corresponding to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">ϒ</mi><mo stretchy="false">(</mo><mn>4</mn><mi>S</mi><mo stretchy="false">)</mo></math> resonance, just above the threshold for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mover accent="true"><mi>B</mi><mo stretchy="false">¯</mo></mover></math> production. Signal candidates are reconstructed by selecting events in which the companion <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> meson from the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">ϒ</mi><mo stretchy="false">(</mo><mn>4</mn><mi>S</mi><mo stretchy="false">)</mo><mo stretchy="false">→</mo><mi>B</mi><mover accent="true"><mi>B</mi><mo stretchy="false">¯</mo></mover></math> decay is identified in semileptonic modes. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math> lepton is reconstructed via its leptonic decays. We obtain <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">R</mi><mo stretchy="false">(</mo><msup><mrow><mi>D</mi></mrow><mrow><mo>+</mo></mrow></msup><mo stretchy="false">)</mo><mo>=</mo><msubsup><mrow><mn>0.418</mn></mrow><mrow><mo>−</mo><mn>0.073</mn></mrow><mrow><mo>+</mo><mn>0.075</mn></mrow></msubsup><msubsup><mrow><mo stretchy="false">(</mo><mi>stat</mi><mo stretchy="false">)</mo></mrow><mrow><mo>−</mo><mn>0.056</mn></mrow><mrow><mo>+</mo><mn>0.049</mn></mrow></msubsup><mrow><mo stretchy="false">(</mo><mi>syst</mi><mo stretchy="false">)</mo></mrow></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">R</mi><mo stretchy="false">(</mo><msup><mrow><mi>D</mi></mrow><mrow><mo>*</mo><mo>+</mo></mrow></msup><mo stretchy="false">)</mo><mo>=</mo><msubsup><mrow><mn>0.306</mn></mrow><mrow><mo>−</mo><mn>0.033</mn></mrow><mrow><mo>+</mo><mn>0.035</mn></mrow></msubsup><msubsup><mrow><mo stretchy="false">(</mo><mi>stat</mi><mo stretchy="false">)</mo></mrow><mrow><mo>−</mo><mn>0.018</mn></mrow><mrow><mo>+</mo><mn>0.016</mn></mrow></msubsup><mrow><mo stretchy="false">(</mo><mi>syst</mi><mo stretchy="false">)</mo></mrow></mrow></math>, which are consistent with world average values. Accounting for the correlation between them, these values differ from the Standard Model expectation by a collective significance of 1.7 standard deviations.

K. Adamczyk

M. Angelsmark

C. Antonioli

I. Consigny

F. Di Capua

Test of lepton flavor universality with measurements of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>R</mi><mo stretchy="false">(</mo><msup><mi>D</mi><mo>+</mo></msup><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>R</mi><mo stretchy="false">(</mo><msup><mi>D</mi><mrow><mo>*</mo><mo>+</mo></mrow></msup><mo stretchy="false">)</mo></math> using semileptonic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> tagging at the Belle II experiment

In this paper, we study one-loop corrections to the neutrino mass matrix in the N-B-LSSM. We obtain the N-B-LSSM from the U(1) extension of the minimal supersymmetric standard model (MSSM). By adding three generation right-handed neutrino superfields and three Higgs singlets, the model generates tiny neutrino masses at the tree level through the first type seesaw mechanism. However, one-loop corrections are essential for understanding neutrino masses and mixing angles. In our calculations, the one-loop corrections contribute approximately 10% to the total result. We calculate the neutrino mass variance and mixing angle from both normal order neutrino mass spectrum and inverse order neutrino mass spectrum. Crucially, these corrections are 3–5 times larger than current experimental uncertainties. And they have implications for future neutrino oscillation experiments. This study provides new theoretical support for exploring the mechanism of neutrino mass generation in the supersymmetric model and provides clues for exploring new physics beyond the Standard Model (SM).