We present a measurement of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><msub><mi>V</mi><mrow><mi>u</mi><mi>b</mi></mrow></msub><mo stretchy="false">|</mo></math> from a simultaneous study of the charmless semileptonic decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>B</mi></mrow><mrow><mn>0</mn></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>+</mo></mrow></msup><msub><mrow><mi>ν</mi></mrow><mrow><mo>ℓ</mo></mrow></msub></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>B</mi></mrow><mrow><mo>+</mo></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>ρ</mi></mrow><mrow><mn>0</mn></mrow></msup><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>+</mo></mrow></msup><msub><mrow><mi>ν</mi></mrow><mrow><mo>ℓ</mo></mrow></msub></mrow></math>, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>ℓ</mo><mo>=</mo><mi>e</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>μ</mi></mrow></math>. This measurement uses a data sample of 387 million <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> meson pairs recorded by the Belle II detector at the SuperKEKB electron-positron collider between 2019 and 2022. The two decays are reconstructed without identifying the partner <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> mesons. We simultaneously measure the differential branching fractions of <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><mo>−</mo></msup><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>+</mo></msup><mo stretchy="false">→</mo><msup><mi>ρ</mi><mn>0</mn></msup><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> decays as functions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>q</mi><mn>2</mn></msup></math> (momentum transfer squared). From these, we obtain total branching fractions <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msup><mrow><mi>B</mi></mrow><mrow><mn>0</mn></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>+</mo></mrow></msup><msub><mrow><mi>ν</mi></mrow><mrow><mo>ℓ</mo></mrow></msub><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>1.516</mn><mo>±</mo><mn>0.042</mn><mo stretchy="false">(</mo><mrow><mi>stat</mi></mrow><mo stretchy="false">)</mo><mo>±</mo><mn>0.059</mn><mo stretchy="false">(</mo><mrow><mi>syst</mi></mrow><mo stretchy="false">)</mo><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msup><mrow><mi>B</mi></mrow><mrow><mo>+</mo></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>ρ</mi></mrow><mrow><mn>0</mn></mrow></msup><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>+</mo></mrow></msup><msub><mrow><mi>ν</mi></mrow><mrow><mo>ℓ</mo></mrow></msub><mo stretchy="false">)</mo><mo>=</mo><mspace linebreak="goodbreak"></mspace><mo stretchy="false">(</mo><mn>1.625</mn><mo>±</mo><mn>0.079</mn><mo stretchy="false">(</mo><mrow><mi>stat</mi></mrow><mo stretchy="false">)</mo><mo>±</mo><mn>0.180</mn><mo stretchy="false">(</mo><mrow><mi>syst</mi></mrow><mo stretchy="false">)</mo><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math>. By fitting the measured <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><mo>−</mo></msup><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> partial branching fractions as functions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>q</mi><mn>2</mn></msup></math>, together with constraints on the nonperturbative hadronic contribution from lattice QCD calculations, we obtain <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><msub><mi>V</mi><mrow><mi>u</mi><mi>b</mi></mrow></msub><mo stretchy="false">|</mo><mo>=</mo><mo stretchy="false">(</mo><mn>3.93</mn><mo>±</mo><mn>0.09</mn><mo>±</mo><mn>0.13</mn><mo>±</mo><mn>0.19</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></math>. Here, the first uncertainty is statistical, the second is systematic, and the third is theoretical.

I. Adachi

L. Aggarwal

H. Aihara

N. Akopov

A. Aloisio

N. Althubiti

N. Anh Ky

D.M. Asner

H. Atmacan

T. Aushev

V. Aushev

M. Aversano

R. Ayad

V. Babu

H. Bae

S. Bahinipati

P. Bambade

Sw. Banerjee

S. Bansal

M. Barrett

J. Baudot

M. Bauer

A. Baur

A. Beaubien

F. Becherer

J. Becker

J.V. Bennett

F.U. Bernlochner

V. Bertacchi

M. Bertemes

E. Bertholet

M. Bessner

S. Bettarini

B. Bhuyan

F. Bianchi

L. Bierwirth

T. Bilka

D. Biswas

A. Bobrov

D. Bodrov

A. Bolz

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

J. Cerasoli

M.C. Chang

P. Chang

R. Cheaib

P. Cheema

B.G. Cheon

K. Chilikin

K. Chirapatpimol

H.E. Cho

K. Cho

S.J. Cho

S.K. Choi

S. Choudhury

L. Corona

J.X. Cui

F. Dattola

E. De La Cruz-Burelo

S.A. De La Motte

G. De Nardo

M. De Nuccio

G. De Pietro

R. de Sangro

M. Destefanis

S. Dey

R. Dhamija

A. Di Canto

F. Di Capua

J. Dingfelder

Z. Doležal

I. Domínguez Jiménez

T.V. Dong

M. Dorigo

D. Dorner

K. Dort

D. Dossett

S. Dreyer

S. Dubey

K. Dugic

G. Dujany

P. Ecker

M. Eliachevitch

P. Feichtinger

T. Ferber

T. Fillinger

C. Finck

Determination of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><msub><mi>V</mi><mrow><mi>u</mi><mi>b</mi></mrow></msub><mo stretchy="false">|</mo></math> from simultaneous measurements of untagged <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><mo>−</mo></msup><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>+</mo></msup><mo stretchy="false">→</mo><msup><mi>ρ</mi><mn>0</mn></msup><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> decays

The valence quark parton distribution functions (PDFs) of all ground state heavy mesons composed of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>c</mi></math> quarks, are discussed; namely, the pseudoscalar <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>η</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>1</mn><mi>S</mi><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>η</mi><mi>b</mi></msub><mo stretchy="false">(</mo><mn>1</mn><mi>S</mi><mo stretchy="false">)</mo></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>c</mi></msub></math>, together with the corresponding vector ones, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">ϒ</mi><mo stretchy="false">(</mo><mn>1</mn><mi>S</mi><mo stretchy="false">)</mo></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>c</mi><mo>*</mo></msubsup></math>. We use a quantum chromodynamics (QCD)-inspired constituent quark model, which has been applied with success to conventional heavy mesons, so that one advantage here is that all parameters have already been fixed by previous studies. The wave functions of the heavy mesons in the rest frame are obtained by solving the Schrödinger equation, then boosted to its light-front, based on Susskind’s Lorentz transformation. The PDFs at the hadron scale, are then obtained by integrating out the transverse momenta of the modulus square of the light-front wave function. Our study shows how the valence quark distributions differ between pseudoscalar and vector mesons, as well as among charmonia, bottomonia and bottom-charmed mesons. Comparisons with other theoretical calculations demonstrate that the PDFs obtained herein are in general narrower but align well with the expected patterns. Moreover, each PDF’s pointwise behavior is squeezed with respect to the scale-free partonlike PDF.

China

Qian Wu

Zhu-Fang Cui

Spain

Jorge Segovia

Parton distribution functions of ground state mesons composed of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>c</mi></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math> quarks

The detection of primordial B-modes, a key probe of cosmic inflation, is increasingly challenged by contamination from weak gravitational lensing B-modes induced by large-scale structure (LSS). We present a delensing pipeline designed to enhance the sensitivity to the inflationary parameter $\textit{r}$, minimizing reliance on foreground mitigation during lensing reconstruction. Using simulations of Simons Observatory-like CMB observations and $\textit{Euclid}$-like LSS surveys in the Northern hemisphere, we demonstrate that excluding low- $$\ell $$ modes ( $$\ell <200$$ ) effectively mitigates foreground biases, enabling robust lensing potential reconstruction using observed CMB polarization maps. We reconstruct the lensing potential with a minimum-variance (MV) quadratic estimator (QE) applied to CMB polarization data and combine this with external LSS tracers to improve delensing efficiency. Two complementary methods – the gradient-order template and the Inverse-lensing approach – are used to generate lensing B-mode templates, which are cross-correlated with observed B-modes. This achieves a 40% reduction in the uncertainty of r with CMB-only reconstruction, improving to 60% when incorporating external LSS tracers. We validate our results using both the Hamimeche and Lewis likelihood and a Gaussian approximation, finding consistent constraints on $\textit{r}$. Our work establishes a streamlined framework for ground-based CMB experiments, demonstrating that synergies with LSS surveys significantly enhance sensitivity to primordial gravitational waves.

Wen-Zheng Chen

Yang Liu

Yi-Ming Wang

Hong Li

Delensing for precision cosmology: optimizing future CMB B-mode surveys to constrain $\textit{r}$

In this study, we conduct an enhanced investigation of pure annihilation-type charmless hadronic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> decays within the framework of the perturbative QCD approach. Specifically, we account for the quark-loop enhanced contribution to various decay processes at the next-to-leading order (NLO) in the strong coupling constant <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>α</mi><mi>s</mi></msub></math>. The NLO amplitudes possess large imaginary parts that have signs opposite to those of the leading-order amplitudes. This cancellation effect implies that the NLO contribution does not significantly influence the branching ratios of the processes under consideration. However, the NLO effect explored in this work constitutes an important source of the strong phases in the weak-annihilation nonleptonic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>B</mi><mo stretchy="false">¯</mo></mover><mi>q</mi></msub></math>-meson decay amplitudes. As a result, it can have a substantial impact on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math>-violating observables such as the direct <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> asymmetry <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="script">A</mi><mrow><mi>C</mi><mi>P</mi></mrow><mrow><mi>dir</mi></mrow></msubsup></math> and mixing-induced <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> asymmetry <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="script">A</mi><mrow><mi>C</mi><mi>P</mi></mrow><mrow><mi>mix</mi></mrow></msubsup></math>. The numerical result evidently revealed that NLO QCD correction significantly enhances both <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="script">A</mi><mrow><mi>C</mi><mi>P</mi></mrow><mrow><mi>dir</mi></mrow></msubsup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="script">A</mi><mrow><mi>C</mi><mi>P</mi></mrow><mrow><mi>mix</mi></mrow></msubsup></math> of the pure annihilation-type <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> decay processes.

Hong-Yuan Sheng

Feng-Chen Chu

Yue-Long Shen

Zhi-Tian Zou

Enhanced quark-loop contribution to pure annihilation nonleptonic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math>-meson decays in the PQCD approach

The long-standing flavor anomalies in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>s</mi><msup><mo>ℓ</mo><mo>+</mo></msup><msup><mo>ℓ</mo><mo>−</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>c</mi><mo>ℓ</mo><mi>ν</mi></math> persist. In this work, we explore a specific flavor-gauged two-Higgs-doublet model (FG2HDM) extended by a scalar singlet, with an imposed <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></math> flavor symmetry. Compared to the standard model (SM), four additional scalars and one neutral gauge boson <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Z</mi><mo>′</mo></msup></math> are added to the particle spectrum. The special Yukawa coupling matrices, due to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></math> symmetry, lead to flavor-changing neutral Higgs interactions uniquely occurring in the down-type quark sector, while the new gauge boson <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Z</mi><mo>′</mo></msup></math> induces flavor-changing neutral current interactions in the down-type quark sector as well. The two distinct types of anomalies can be accommodated simultaneously in such a model. Incorporating scalar and vector contributions to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>s</mi><msup><mo>ℓ</mo><mo>+</mo></msup><msup><mo>ℓ</mo><mo>−</mo></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>s</mi></msub><mo stretchy="false">→</mo><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>s</mi><mn>0</mn></msubsup><mo>−</mo><msubsup><mover accent="true"><mi>B</mi><mo stretchy="false">¯</mo></mover><mi>s</mi><mn>0</mn></msubsup></math> mixing, charged Higgs contributions to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>c</mi><mo>ℓ</mo><mi>ν</mi></math>, along with electroweak precision observables and Higgs fermionic decays, we investigate the parameter space in FG2HDM and find substantial room in the solution space. Specifically, in the SM-like model setup, the data suggest that <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msup><mi>Z</mi><mo>′</mo></msup></msub><mo>&lt;</mo><mn>450</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>tan</mi><mi>β</mi><mo>&lt;</mo><mn>28</mn></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>g</mi><mo>′</mo></msup><mo>/</mo><msub><mi>m</mi><msup><mi>Z</mi><mo>′</mo></msup></msub><mo>&gt;</mo><mn>3.5</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>GeV</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>, while there are fewer constraints on heavy scalars, which can be further tested by a combination of other observables.

Qiaoyi Wen

Fanrong Xu

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>B</mi></mrow></math> anomalies in a two-Higgs-doublet model with flavor symmetry

We investigate the sextet <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math>-baryon decay processes <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ω</mi><mi>b</mi></msub><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><msup><mi mathvariant="normal">Ω</mi><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msup></math>, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi mathvariant="normal">Ω</mi><mo>*</mo></msup></math> represents the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>-, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>D</mi></math>- and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>S</mi></math>-wave excited <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Ω</mi></math> hyperons in the spectroscopy. Using the constituent quark model, we obtain <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msub><mi mathvariant="normal">Ω</mi><mi>b</mi></msub><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mi mathvariant="normal">Ω</mi><mo stretchy="false">)</mo><mo>=</mo><mn>8.8</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math>, which agrees with the previous studies to the order of magnitude. By identifying <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Ω</mi><mo stretchy="false">(</mo><mn>2012</mn><mo stretchy="false">)</mo></math> as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">Ω</mi><mo stretchy="false">(</mo><msup><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></msup><msub><mrow><mi>P</mi></mrow><mrow><mn>3</mn><mo>/</mo><msup><mrow><mn>2</mn></mrow><mrow><mo>−</mo></mrow></msup></mrow></msub><mo stretchy="false">)</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msub><mi mathvariant="normal">Ω</mi><mi>b</mi></msub><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mi mathvariant="normal">Ω</mi><mo stretchy="false">(</mo><mn>2012</mn><mo stretchy="false">)</mo><mo stretchy="false">)</mo><mo>=</mo><mn>1.1</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></math> can be similarly significant. Additionally, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Ω</mi><mo stretchy="false">(</mo><msup><mn>1</mn><mn>2</mn></msup><msub><mi>D</mi><mrow><mn>5</mn><mo>/</mo><msup><mn>2</mn><mo>+</mo></msup></mrow></msub><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Ω</mi><mo stretchy="false">(</mo><msup><mn>1</mn><mn>4</mn></msup><msub><mi>D</mi><mrow><mn>3</mn><mo>/</mo><msup><mn>2</mn><mo>+</mo></msup></mrow></msub><mo>,</mo><msup><mn>1</mn><mn>4</mn></msup><msub><mi>D</mi><mrow><mn>5</mn><mo>/</mo><msup><mn>2</mn><mo>+</mo></msup></mrow></msub><mo stretchy="false">)</mo></math> states exhibit production rates of 0.5, and (0.6, 0.8), respectively, relative to their ground-state counterpart. Notably, our findings suggest that <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msub><mi mathvariant="normal">Ω</mi><mi>b</mi></msub><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mi mathvariant="normal">Ω</mi><mo stretchy="false">(</mo><msup><mn>2</mn><mn>2</mn></msup><msub><mi>S</mi><mrow><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>+</mo></msup></mrow></msub><mo>,</mo><msup><mn>2</mn><mn>4</mn></msup><msub><mi>S</mi><mrow><mn>3</mn><mo>/</mo><msup><mn>2</mn><mo>+</mo></msup></mrow></msub><mo stretchy="false">)</mo><mo stretchy="false">)</mo></math> are as large as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mn>4.5</mn><mo>,</mo><mn>20</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math>, making them accessible to experiments at LHCb.

Kai-Lei Wang

Juan Wang

Yu-Kuo Hsiao

Xian-Hui Zhong

Excited <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Ω</mi></math> hyperon in charmful <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ω</mi><mi>b</mi></msub></math> weak decays

A precise determination of the CKM angle $\textit{γ}$ from $$ {B}_s^0 $$ oscillations in $$ {B}_s^0\to {D}_s^{\mp }{K}^{\pm } $$ decays offers a critical test of the Standard Model and probes for new physics. We present a comprehensive study on the prospects of measuring $\textit{γ}$ at a future Tera-$\textit{Z}$ factory, utilizing the baseline detector concept of the Circular Electron Positron Collider (CEPC). A two-dimensional simultaneous fit framework, incorporating flavor tagging, decay time resolution modeling, and acceptance corrections, is developed using full Monte Carlo simulations of $$ {B}_s^0\to {D}_s^{\mp}\left(\to {K}^{\mp }{K}^{\pm }{\pi}^{\mp}\right){K}^{\pm } $$ decays and inclusive background processes. The effective flavor tagging power reaches 23.6%, while the decay time resolution is determined to be 26 fs. Projecting to full statistics of signal events across three dominant $$ {D}_s^{-} $$ decay channels, we estimate a statistical precision of $\textit{σ}$($\textit{γ}$) = 0$\textit{.}$69 , which corresponds to 4.1 Tera-$\textit{Z}$ boson equivalent data. This study has established the feasibility of sub-degree level $\textit{γ}$ measurements at a $\textit{Z}$ factory, highlighting its unique advantages in time-dependent $\textit{CP}$ violation studies through ultra-precise vertexing and background suppression capabilities.

Ji Peng

Mingrui Zhao

Xiaolin Wang

Manqi Ruan

Hengne Li

Shanzhen Chen

Prospect for measurement of $\textit{CP}$-violating observables in $$ {B}_s^0\to {D}_s^{\mp }{K}^{\pm } $$ decays at a future $\textit{Z}$ factory

We perform a detailed analysis of the semileptonic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Ξ</mi><mi>c</mi></msub><msup><mo>ℓ</mo><mo>−</mo></msup><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mo>ℓ</mo></msub></math> decays within the perturbative QCD framework. In our study, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Ξ</mi><mi>c</mi></msub></math> transition form factors are calculated using several popular models for baryonic light-cone distribution amplitudes. These form factors are then employed to analyze a range of observable quantities for the semileptonic processes via the helicity formalism. Our work presents predictions for the branching fractions of these decays for both the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>e</mi></math> channels. Notably, the obtained lepton flavor universality ratio, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">R</mi><msub><mi mathvariant="normal">Ξ</mi><mi>c</mi></msub></msub><mo>≈</mo><mn>0.3</mn></math>, may offer new insights into the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi mathvariant="script">R</mi><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msup></math> puzzle. Furthermore, we investigate various angular observables, such as forward-backward asymmetries, lepton-side convexity parameters, and polarization asymmetries, which provide complementary information regarding potential new physics in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math>-baryonic semileptonic transitions. The numerical results for these angular observables are presented as both functions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>q</mi><mn>2</mn></msup></math> and as averaged values. We observe that the lepton mass plays a significant role in shaping the angular distributions, affecting most of the observables under consideration. These results are expected to be valuable for both current and future experimental investigations of semileptonic heavy-to-heavy baryon decays.

Zhou Rui

Ya Li

Ying Li

Semileptonic baryon decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Ξ</mi><mi>c</mi></msub><msup><mo>ℓ</mo><mo>−</mo></msup><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mo>ℓ</mo></msub></math> in perturbative QCD

We study the modifications to decay amplitudes in heavy to heavy semileptonic decays with multiple hadrons in the final state due to intermediate heavy hadrons being off-shell or having a finite width. Combining Heavy Hadron Chiral Perturbation Theory (HH$\textit{χ}$PT) with a BCFW on-shell factorization formula, we show that these effects induce $$ \mathcal{O} $$ (1/$\textit{M}$) corrections to the standard results computed in the narrow-width approximation and therefore are important in extracting form factors from data. A combination of perturbative unitarity, analyticity, and reparameterization invariance fully determine these corrections in terms of known Isgur-Wise functions without the need to introduce new form factors. In doing so, we develop a novel technique to compute the boundary term at complex infinity in the BCFW formula for theories with derivatively coupled scalars. While we have used the $$ \overline{B} $$ → $\textit{Dπℓν}$ decay as an example, these techniques can generally be applied to effective field theories with (multiple) distinct reference vectors.

United States

Michele Papucci

Ryan Plestid

Off-shell vertices in heavy particle effective theories and B $\textit{→}$ D$\textit{πℓν}$

F. Gil-Domínguez

R. Molina

Corrigendum to “Quark mass dependence of the low-lying charmed mesons at one loop in HH <math altimg='si77.svg'><mi>&#967;</mi></math> <italic>PT</italic>&#8221; [Physics Letters B Volume 843, 10 August 2023, 137997]