A search for the decay $ B^+\to D_s^+ K^+K^- $ has been reported by the LHCb Collaboration using $ pp $ collision data corresponding to an integrated luminosity of $4.8\;{\rm{fb}}^{-1}$ , collected at center-of-mass energies of 7, 8, and 13 TeV, in which no amplitude analysis of the $ K^+K^- $ subsystem was performed. In this work, we study the resonant contributions to the decay $ B^+\to D_s^+ K^+K^- $ within the perturbative QCD (PQCD) factorization framework. Contributions from the $\textit{S}$-wave resonances $ f_0(980) $ , $ f_0(1370) $ , and $ f_0(1500) $ , the $\textit{P}$-wave resonance $ \phi(1020) $ , and the $\textit{D}$-wave resonances $ f_2(1270) $ and $ f_2(1525) $ are taken into account. By introducing the corresponding two-meson distribution amplitudes for the $ K^+K^- $ system, we perform a complete perturbative analysis of the quasi-two-body decays $ B^+\to D_s^+(R\to)K^+K^- $ , where $\textit{R}$ denotes an intermediate resonance, and present the first PQCD predictions for the associated branching fractions. Using the narrow-width approximation, we further extract the branching fractions of the corresponding two-body decays $ B^+\to D_s^+R $ . Our results are consistent with the available experimental measurements and previous theoretical studies. Finally, we find that direct CP asymmetries vanish for these quasi-two-body decays within the Standard Model, so that any experimentally observed nonzero CP asymmetry would constitute a clear signal of physics beyond the Standard Model.

China

Zhi-Tian Zou

Jun-Peng Wang

Rui Zhou

Ying Li

Quasi-two-body decays $ {B^+\to D_s^+ (R\to) K^+K^-} $ in the perturbative QCD approach * Supported in part by the National Science Foundation of China (12375089, 12435004, 12075086), and the Natural Science Foundation of Shandong province (ZR2022ZD26, ZR2022MA035)

The recent measurement of the branching ratio of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>+</mo></msup><mo stretchy="false">→</mo><msup><mi>K</mi><mo>+</mo></msup><mo>+</mo><mi>inv</mi></math> (where “inv” denotes invisible states) by the Belle II Collaboration is enhanced relative to the standard model expectation by <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2.7</mn><mi>σ</mi></mrow></math>. An older puzzle persists in measurements of the branching ratios and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> asymmetries of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>π</mi><mi>K</mi></math> decays. We address these two anomalies in flavor-changing neutral current <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> decays, with a short-lived axionlike particle (ALP) with mass close to that of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mn>0</mn></msup></math>. In the model with the minimum number of new couplings, the ALP has couplings to the photon, top quark and a heavy sterile neutrino. The ALP contributes to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><msup><mi>π</mi><mn>0</mn></msup><mi>K</mi></math> decays by mixing with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mn>0</mn></msup></math>. It contributes to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>+</mo></msup><mo stretchy="false">→</mo><msup><mi>K</mi><mo>+</mo></msup><mo>+</mo><mi>inv</mi></math> by its off-shell coupling to sterile neutrino pairs. The model can explain the excess in the total rate, but not the observed distribution of signal events. We make predictions for all <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><msup><mi>K</mi><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msup><mo>+</mo><mi>inv</mi></math> modes and for the rare kaon decays, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>+</mo></msup><mo stretchy="false">→</mo><msup><mi>π</mi><mo>+</mo></msup><mo>+</mo><mi>inv</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>K</mi><mi>L</mi></msub><mo stretchy="false">→</mo><msup><mi>π</mi><mn>0</mn></msup><mo>+</mo><mi>inv</mi></math>. We find an appreciable contribution to the magnetic moment of the muon, and negligible contributions to the magnetic moment of the electron and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>s</mi><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math>.

United States

Bhubanjyoti Bhattacharya

Alakabha Datta

Girish Kumar

Danny Marfatia

Axionlike particles and sterile neutrinos solve the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>B</mi><mo stretchy="false">→</mo><mi>K</mi><mi>ν</mi><mover accent="true"><mrow><mi>ν</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>B</mi><mo stretchy="false">→</mo><mi>π</mi><mi>K</mi></mrow></math> puzzles

Based on the effective Lagrangian approach, we investigate the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mover accent="true"><mi>p</mi><mo stretchy="false">¯</mo></mover><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><mover accent="true"><mi mathvariant="normal">Λ</mi><mo stretchy="false">¯</mo></mover></math> reaction. Within this framework, we provide a dynamical explanation by analyzing its total and differential cross sections, as well as the polarization of the produced <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi></math> hyperon. Incorporating the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi></math>-channel exchange of the scalar <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>K</mi><mn>0</mn><mo>*</mo></msubsup><mo stretchy="false">(</mo><mn>700</mn><mo stretchy="false">)</mo></math> and pseudoscalar <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>K</mi></math> mesons, complemented by an <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>s</mi></math>-channel contribution from the vector excited state, we can reproduce the current experimental data fairly well in a wide energy region. Compared to the conventional <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>K</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>*</mo></msup><mo stretchy="false">(</mo><mn>892</mn><mo stretchy="false">)</mo></math> mesons exchange, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>K</mi><mn>0</mn><mo>*</mo></msubsup><mo stretchy="false">(</mo><mn>700</mn><mo stretchy="false">)</mo></math> meson exchange plays a more essential role in simultaneously capturing the observed features of the total and differential cross sections. The introduction of the vector <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>s</mi></math>-channel resonance improves the description of the spin observables. This work gives a perspective to inspect the role of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>K</mi><mn>0</mn><mo>*</mo></msubsup><mo stretchy="false">(</mo><mn>700</mn><mo stretchy="false">)</mo></math> and serves as a test to search for the resonances in the reaction <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mover accent="true"><mi>p</mi><mo stretchy="false">¯</mo></mover><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><mover accent="true"><mi mathvariant="normal">Λ</mi><mo stretchy="false">¯</mo></mover></math> at threshold.

Japan

Hao-Nan Wang

Cheng Chen

Xing-Yi Ji

De-Min Li

Yue Ma

En Wang

Ju-Jun Xie

Role of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>K</mi><mn>0</mn><mo>*</mo></msubsup><mo stretchy="false">(</mo><mn>700</mn><mo stretchy="false">)</mo></math> exchange in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mover accent="true"><mi>p</mi><mo stretchy="false">¯</mo></mover><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><mover accent="true"><mi mathvariant="normal">Λ</mi><mo stretchy="false">¯</mo></mover></math> reaction

Recent measurements of the charge-parity asymmetry in the decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mn>0</mn></msup><mo stretchy="false">→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup></math> by CMS Collaboration, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>A</mi><mrow><mi>C</mi><mi>P</mi></mrow></msub><mo stretchy="false">(</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>6.2</mn><mo>±</mo><mn>3.0</mn><mo>±</mo><mn>0.2</mn><mo>±</mo><mn>0.8</mn><mo stretchy="false">)</mo><mo>%</mo></math>, and by LHCb, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>A</mi><mrow><mi>C</mi><mi>P</mi></mrow></msub><mo stretchy="false">(</mo><msup><mi>D</mi><mn>0</mn></msup><mo stretchy="false">→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>1.86</mn><mo>±</mo><mn>1.04</mn><mo>±</mo><mn>0.41</mn><mo stretchy="false">)</mo><mo>%</mo></math>, suggest possible deviations from Standard Model expectations, which predict asymmetries below the percent level. This singly Cabibbo-suppressed decay is particularly sensitive to new physics, as the leading amplitudes vanish in the exact U-spin symmetry limit and the process is dominated by W-exchange topologies. We investigate scalar diquark contributions to this decay, comparing color-sextet and color-triplet representations. We find that the color-sextet diquark, characterized by a symmetric color structure <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><msubsup><mi>C</mi><mn>1</mn><mi>NP</mi></msubsup><mo>=</mo><msubsup><mi>C</mi><mn>2</mn><mi>NP</mi></msubsup><mo stretchy="false">)</mo></math>, avoids color suppression and can generate <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> asymmetries in the range 0.5%–1.5% for a diquark mass of order 1 TeV. In contrast, the color-triplet contribution is strongly suppressed due to destructive interference from its antisymmetric color structure. We further show that a flavor hierarchy in the sextet couplings, with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>λ</mi><mrow><mi>u</mi><mi>d</mi></mrow></msub><mo>&gt;</mo><msub><mi>λ</mi><mrow><mi>u</mi><mi>s</mi></mrow></msub></math>, can simultaneously account for the observed deviation from the U-spin sum rule in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mn>0</mn></msup><mo stretchy="false">→</mo><msup><mi>K</mi><mo>+</mo></msup><msup><mi>K</mi><mo>−</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mn>0</mn></msup><mo stretchy="false">→</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup></math> and the measured <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> asymmetry in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mn>0</mn></msup><mo stretchy="false">→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup></math>. These results identify color-sextet scalar diquarks as viable candidates for explaining enhanced <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> violation in charm decays.

Mexico

David Delepine

Egypt

Shaaban Khalil

Colombia

Carlos A. Ramirez

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">→</mo><mi>K</mi><mi>K</mi></math> decays: A comparative analysis of triplet and sextet diquarks

This Letter presents the first evidence of the simultaneous production of two <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi></math> bosons and one photon with the ATLAS detector at the Large Hadron Collider. The measurement is performed using the full Run-2 dataset, recorded from 2015 to 2018, of proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>140</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math>. The fully leptonic final state with four leptons and one photon is analyzed, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>p</mi><mi>p</mi><mo stretchy="false">→</mo><mi>Z</mi><mi>Z</mi><mi>γ</mi><mo stretchy="false">→</mo><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>′</mo><mo>+</mo></mrow></msup><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>′</mo><mo>−</mo></mrow></msup><mi>γ</mi></mrow></math> with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>ℓ</mo><mo>,</mo><msup><mo>ℓ</mo><mo>′</mo></msup><mo>=</mo><mi>e</mi></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>μ</mi></math>. This final state is measured in a fiducial region where photon final-state radiation is minimized, and the photon has a transverse momentum of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi>p</mi></mrow><mrow><mi mathvariant="normal">T</mi></mrow><mrow><mi>γ</mi></mrow></msubsup><mo>&gt;</mo><mn>20</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math>. Eight events are selected, with a background estimate of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>0.92</mn><mo>±</mo><mn>0.15</mn></math>. This results in an observed (expected) significance of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi><mi>Z</mi><mi>γ</mi></math> final state of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>4.4</mn><mi>σ</mi></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>4.0</mn><mi>σ</mi></math>). The measured cross section for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>p</mi><mi>p</mi><mo stretchy="false">→</mo><mi>Z</mi><mi>Z</mi><mi>γ</mi><mo stretchy="false">→</mo><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>′</mo><mo>+</mo></mrow></msup><msup><mrow><mo>ℓ</mo></mrow><mrow><mo>′</mo><mo>−</mo></mrow></msup><mi>γ</mi></mrow></math> in the fiducial region is <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>σ</mi></mrow><mrow><mi>Z</mi><mi>Z</mi><mi>γ</mi></mrow></msub><mo>=</mo><mn>0.14</mn><msubsup><mrow><mn>4</mn></mrow><mrow><mo>−</mo><mn>0.051</mn></mrow><mrow><mo>+</mo><mn>0.065</mn></mrow></msubsup><msubsup><mrow><mo stretchy="false">(</mo><mi>stat</mi><mo stretchy="false">)</mo></mrow><mrow><mo>−</mo><mn>0.004</mn></mrow><mrow><mo>+</mo><mn>0.008</mn></mrow></msubsup><mrow><mo stretchy="false">(</mo><mi>syst</mi><mo stretchy="false">)</mo></mrow><mtext> </mtext><mtext> </mtext><mi>fb</mi></mrow></math>, in agreement with the standard model prediction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi>σ</mi></mrow><mrow><mi>fid</mi></mrow><mrow><mi>SM</mi></mrow></msubsup><mo>=</mo><mn>0.130</mn><mo>±</mo><mn>0.006</mn><mtext> </mtext><mtext> </mtext><mi>fb</mi></mrow></math>.

France

G. Aad

Norway

E. Aakvaag

B. Abbott

United Arab Emirates

S. Abdelhameed

Germany

K. Abeling

N.J. Abicht

S.H. Abidi

M. Aboelela

Morocco

A. Aboulhorma

Israel

H. Abramowicz

Italy

B.S. Acharya

A. Ackermann

C. Adam Bourdarios

Poland

L. Adamczyk

S.V. Addepalli

United Kingdom

M.J. Addison

J. Adelman

Türkiye

A. Adiguzel

T. Adye

A.A. Affolder

Y. Afik

Spain

M.N. Agaras

A. Aggarwal

Romania

C. Agheorghiesei

A. Ahmad

F. Ahmadov

S. Ahuja

X. Ai

G. Aielli

A. Aikot

M. Ait Tamlihat

Sweden

T.P.A. Åkesson

D. Akiyama

N.N. Akolkar

S. Aktas

G.L. Alberghi

Canada

J. Albert

Switzerland

U. Alberti

P. Albicocco

S. Alderweireldt

Z.L. Alegria

CERN

M. Aleksa

I.N. Aleksandrov

C. Alexa

Greece

T. Alexopoulos

F. Alfonsi

M. Algren

M. Alhroob

Czechia

B. Ali

H.M.J. Ali

S. Ali

S.W. Alibocus

South Africa

M. Aliev

G. Alimonti

C. Allaire

B.M.M. Allbrooke

D.R. Allen

J.S. Allen

J.F. Allen

Australia

C.S. Alley

E.R. Almazan

A. Aloisio

Argentina

F. Alonso

C. Alpigiani

A. Alvarez Fernandez

M. Alves Cardoso

M.G. Alviggi

M. Aly

Brazil

Y. Amaral Coutinho

A. Ambler

C. Amelung

M. Amerl

T. Amezza

B. Amini

K. Amirie

A. Amirkhanov

D. Amperiadou

S. An

C. Anastopoulos

T. Andeen

J.K. Anders

A.C. Anderson

A. Andreazza

S. Angelidakis

A. Angerami

A.V. Anisenkov

A. Annovi

C. Antel

E. Antipov

M. Antonelli

F. Anulli

M. Aoki

T. Aoki

M.A. Aparo

L. Aperio Bella

M. Apicella

C. Appelt

A. Apyan

M. Arampatzi

Evidence of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>Z</mi><mi>Z</mi><mi>γ</mi></mrow></math> Production with the ATLAS Detector

Using <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>20.3</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> of <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> collision data taken at the center-of-mass energy of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>3.773</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math>, we report the first experimental constraint on the scalar current in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>D</mi></mrow><mrow><mn>0</mn><mo stretchy="false">(</mo><mo>+</mo><mo stretchy="false">)</mo></mrow></msup><mo stretchy="false">→</mo><mover accent="true"><mrow><mi>K</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover><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> transitions, based on a simultaneous fit to the first measured forward-backward asymmetries and precisely determined partial decay rates. The parameters of the scalar current are determined to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>Re</mi><mo stretchy="false">(</mo><msubsup><mrow><mi>c</mi></mrow><mrow><mi>S</mi></mrow><mrow><mi>μ</mi></mrow></msubsup><mo stretchy="false">)</mo><mo>=</mo><mn>0.017</mn><mo>±</mo><mn>0.00</mn><msub><mrow><mn>8</mn></mrow><mrow><mi>stat</mi></mrow></msub><mo>±</mo><mn>0.00</mn><msub><mrow><mn>6</mn></mrow><mrow><mi>syst</mi></mrow></msub></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>Im</mi><mo stretchy="false">(</mo><msubsup><mrow><mi>c</mi></mrow><mrow><mi>S</mi></mrow><mrow><mi>μ</mi></mrow></msubsup><mo stretchy="false">)</mo><mo>=</mo><mo>±</mo><mo stretchy="false">(</mo><mn>0.077</mn><mo>±</mo><mn>0.01</mn><msub><mrow><mn>1</mn></mrow><mrow><mi>stat</mi></mrow></msub><mo>±</mo><mn>0.00</mn><msub><mrow><mn>9</mn></mrow><mrow><mi>syst</mi></mrow></msub><mo stretchy="false">)</mo></mrow></math>, which deviates from the standard model by a significance of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.3</mn><mi>σ</mi></math>. The branching fractions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mrow><mn>0</mn><mo stretchy="false">(</mo><mo>+</mo><mo stretchy="false">)</mo></mrow></msup><mo stretchy="false">→</mo><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math>, the hadronic form factor <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>f</mi><mo>+</mo></msub><mo stretchy="false">(</mo><mn>0</mn><mo stretchy="false">)</mo></math>, and the modulus of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>c</mi><mo stretchy="false">→</mo><mi>s</mi></math> Cabibbo-Kobayahsi-Maskawa matrix element <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><msub><mi>V</mi><mrow><mi>c</mi><mi>s</mi></mrow></msub><mo stretchy="false">|</mo></math> are also determined with improved precision. In addition, lepton flavor universality is tested via the ratios of the decay rates between semimuonic and semielectronic decays in the full momentum transfer range and in subranges.

M. Ablikim

Russia

M.N. Achasov

P. Adlarson

X.C. Ai

C.S. Akondi

R. Aliberti

A. Amoroso

Q. An

Y.H. An

Y. Bai

JINR

O. Bakina

Y. Ban

H.R. Bao

X.L. Bao

V. Batozskaya

Mongolia

K. Begzsuren

N. Berger

M. Berlowski

M.B. Bertani

D. Bettoni

F. Bianchi

E. Bianco

A. Bortone

I. Boyko

R.A. Briere

A. Brueggemann

D. Cabiati

H. Cai

M.H. Cai

X. Cai

A. Calcaterra

G.F. Cao

N. Cao

S.A. Cetin

X.Y. Chai

J.F. Chang

T.T. Chang

G.R. Che

Y.Z. Che

C.H. Chen

Chao Chen

G. Chen

First Experimental Constraint on the Scalar Current in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mrow><mn>0</mn><mo stretchy="false">(</mo><mo>+</mo><mo stretchy="false">)</mo></mrow></msup><mo stretchy="false">→</mo><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><msup><mo>ℓ</mo><mo>+</mo></msup><msub><mi>ν</mi><mo>ℓ</mo></msub></math> Transition