The Cabibbo-favored decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi>n</mi><msup><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msup><msup><mi>π</mi><mo>+</mo></msup></math> offers a unique window to explore unresolved puzzles in the low-energy baryon spectroscopy and the isospin dynamics of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><mi>N</mi></math> system. Recent experimental results present a, for now, contradiction: LHCb and Belle analyses of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi>p</mi><msup><mi>K</mi><mo>−</mo></msup><msup><mi>π</mi><mo>+</mo></msup></math> suggest the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><msup><mi>K</mi><mo>−</mo></msup></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>0</mn></math>) component dominates, while the Beijing Spectrometer III (BESIII) hints at significant contributions from both isospin 0 and 1 in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>n</mi><msup><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msup></math> system of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi>n</mi><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>π</mi><mo>+</mo></msup></math>. Furthermore, the measured branching fraction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi>n</mi><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>π</mi><mo>+</mo></msup></math> exceeds SU(3) symmetry predictions by a factor of 3–4, signaling strong contributions from low-lying resonances. In this work, we provide a theoretical analysis of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi>n</mi><msup><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msup><msup><mi>π</mi><mo>+</mo></msup></math> within the coupled-channel chiral unitary approach, where the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo stretchy="false">(</mo><mn>1535</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><mo stretchy="false">(</mo><mn>1670</mn><mo stretchy="false">)</mo></math> can be dynamically generated. Our calculations show a narrow peak from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo stretchy="false">(</mo><mn>1535</mn><mo stretchy="false">)</mo></math> in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>+</mo></msup><mi>n</mi></math> invariant mass spectrum and a distinct dip from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><mo stretchy="false">(</mo><mn>1670</mn><mo stretchy="false">)</mo></math> in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msup><mi>n</mi></math> spectrum. The dip structure is qualitatively consistent with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><mo stretchy="false">(</mo><mn>1670</mn><mo stretchy="false">)</mo></math> manifestation in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><mi>N</mi><mo stretchy="false">→</mo><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><mi>N</mi></math> scattering, supporting its molecular interpretation. This study not only connects the experimental observations but also highlights <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi>n</mi><msup><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msup><msup><mi>π</mi><mo>+</mo></msup></math> as a crucial process to disentangle the nature of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo stretchy="false">(</mo><mn>1535</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><mo stretchy="false">(</mo><mn>1670</mn><mo stretchy="false">)</mo></math>. Future precise measurements of this decay channel by the BESIII, Belle II, LHCb, and the proposed Super Tau-Charm Facility are strongly encouraged.

China

Meng-Yuan Li

Guan-Ying Wang

Neng-Chang Wei

De-Min Li

En Wang

Probing the isospin structure and low-lying resonances in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi>n</mi><msup><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msup><msup><mi>π</mi><mo>+</mo></msup></math> decays

In this work, we study the radiative decays of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Σ</mi><mi>c</mi></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mo>′</mo></msubsup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ω</mi><mi>c</mi></msub></math> charmed baryons, which belong to the flavor sextet (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mn mathvariant="bold">6</mn><mi mathvariant="normal">F</mi></msub></math>), within the constituent quark model formalism. The electromagnetic transitions are calculated from the ground and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi></math>-wave states to ground states, as well as from the second shell states to both the ground and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi></math>-wave final states. These decays play a crucial role in confirming the existence of certain resonances when strong decays are not allowed. Moreover, electromagnetic decay widths are particularly useful for identifying resonances when states have the same mass and total decay width. A relevant case is the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ω</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>3327</mn><mo stretchy="false">)</mo></math> state, whose branching ratios between the strong decay channels are comparable; thus, the radiative decay widths may help assign this state. We also make the assignment of the recently discovered <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mo>′</mo></msubsup><mo stretchy="false">(</mo><mn>2923</mn><msup><mo stretchy="false">)</mo><mo>+</mo></msup></math> baryon, which is consistent with being the isospin partner of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mo>′</mo></msubsup><mo stretchy="false">(</mo><mn>2923</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup></math>. This study presents, for the first time, the calculation of electromagnetic decays for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>D</mi><mi>ρ</mi></msub></math>-wave states, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi><mo>−</mo><mi>λ</mi></math> mixed states, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi></math>-mode radially excited states in the charm sector. Throughout our calculations, we account for uncertainties arising from both experimental and model-dependent errors.

Mexico

A. Dávila-Rivera

H. García-Tecocoatzi

A. Ramirez-Morales

Italy

Ailier Rivero-Acosta

E. Santopinto

Carlos Alberto Vaquera-Araujo

Radiative decays of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Σ</mi><mi>c</mi></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mo>′</mo></msubsup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ω</mi><mi>c</mi></msub></math> charmed baryons

The observation of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation in the difference of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> asymmetries between <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><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"><mi>D</mi><mo stretchy="false">→</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup></math> has raised a debate whether the observed asymmetries can be regarded as a signal of physics beyond the standard model (SM). In this paper we obtain all the topological amplitudes and isospin amplitudes directly from measured observables for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">→</mo><mi>π</mi><mi>π</mi></math>. These results unambiguously imply a very large penguin contribution, having a central value 4.74 times the magnitude of the amplitude for <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>. This fitted central value differs from a reasonable SM estimate of 10% with a significance greater than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3.3</mn><mi>σ</mi></math>. In contrast to previous studies, we present model-independent arguments based only on unitarity of rescattering amplitudes to show that large penguins cannot arise from rescattering alone and likely indicate physics beyond the SM. In a model-independent approach we show how a very small contribution from physics beyond the SM with a large weak phase alleviates the problem.

United States

India

Rahul Sinha

Thomas E. Browder

N.G. Deshpande

Poland

Dibyakrupa Sahoo

Nita Sinha

Implications of the evidence for direct <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><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup></math> decays

A novel machine-learning-based flavor-tagging algorithm combining same-side and opposite-side tagging is used to obtain the equivalent of 27 500 tagged <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>s</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi>J</mi><mo stretchy="false">/</mo><mi>ψ</mi><mi>ϕ</mi><mo stretchy="false">(</mo><mn>1020</mn><mo stretchy="false">)</mo></math> decays from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi></math> collisions at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>, collected by the CMS experiment and corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>96.5</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>. A time- and flavor-dependent angular analysis of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow><mrow><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></mrow></math> final state, consistent with a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><mi>ϕ</mi><mo stretchy="false">(</mo><mn>1020</mn><mo stretchy="false">)</mo></mrow><mo stretchy="false">→</mo><mrow><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></mrow></math> decay, is used to measure parameters of the <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 accent="true" stretchy="false">¯</mo></mover><mi>s</mi><mn>0</mn></msubsup></math> system. The weak phase is measured to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>ϕ</mi></mrow><mrow><mi mathvariant="normal">s</mi></mrow></msub><mo>=</mo><mrow><mo>−</mo><mn>73</mn></mrow><mo>±</mo><mn>22</mn><mrow><mo stretchy="false">(</mo><mi>stat</mi><mo stretchy="false">)</mo></mrow><mo>±</mo><mn>10</mn><mrow><mo stretchy="false">(</mo><mi>syst</mi><mo stretchy="false">)</mo></mrow><mtext> </mtext><mtext> </mtext><mi>mrad</mi></mrow></math>, which, combined with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>8</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math> CMS result, gives <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>ϕ</mi></mrow><mrow><mi mathvariant="normal">s</mi></mrow></msub><mo>=</mo><mrow><mo>−</mo><mn>75</mn></mrow><mo>±</mo><mn>23</mn><mtext> </mtext><mtext> </mtext><mi>mrad</mi></mrow></math>. This value differs from zero by 3.2 standard deviations, providing the first evidence for mixing-induced <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"><msubsup><mi>B</mi><mi>s</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi>J</mi><mo stretchy="false">/</mo><mi>ψ</mi><mi>ϕ</mi><mo stretchy="false">(</mo><mn>1020</mn><mo stretchy="false">)</mo></math> decays. All measured physics parameters are found to agree with standard model predictions where available.

Armenia

A. Hayrapetyan

A. Tumasyan

Austria

W. Adam

J.W. Andrejkovic

L. Benato

T. Bergauer

S. Chatterjee

K. Damanakis

M. Dragicevic

P.S. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

I. Mikulec

J. Schieck

R. Schöfbeck

D. Schwarz

M. Sonawane

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

T. Van Laer

P. Van Mechelen

N. Breugelmans

J. D’Hondt

S. Dansana

A. De Moor

M. Delcourt

F. Heyen

S. Lowette

I. Makarenko

D. Müller

S. Tavernier

M. Tytgat

G.P. Van Onsem

S. Van Putte

D. Vannerom

B. Bilin

B. Clerbaux

A.K. Das

I. De Bruyn

G. De Lentdecker

H. Evard

L. Favart

P. Gianneios

J. Jaramillo

A. Khalilzadeh

F.A. Khan

K. Lee

A. Malara

S. Paredes

M.A. Shahzad

L. Thomas

M. Vanden Bemden

C. Vander Velde

P. Vanlaer

M. De Coen

D. Dobur

G. Gokbulut

Y. Hong

J. Knolle

L. Lambrecht

D. Marckx

K. Mota Amarilo

K. Skovpen

N. Van Den Bossche

J. van der Linden

L. Wezenbeek

A. Benecke

A. Bethani

G. Bruno

C. Caputo

J. De Favereau De Jeneret

C. Delaere

I.S. Donertas

A. Giammanco

A.O. Guzel

Sa. Jain

V. Lemaitre

J. Lidrych

P. Mastrapasqua

T.T. Tran

Brazil

G.A. Alves

E. Coelho

G. Correia Silva

C. Hensel

T. Menezes De Oliveira

C. Mora Herrera

P. Rebello Teles

M. Soeiro

A. Vilela Pereira

W.L. Aldá Júnior

M. Barroso Ferreira Filho

H. Brandao Malbouisson

W. Carvalho

J. Chinellato

E.M. Da Costa

G.G. Da Silveira

D. De Jesus Damiao

First Evidence for Mixing-Induced <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"><msubsup><mi>B</mi><mi>s</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mi>ϕ</mi><mo stretchy="false">(</mo><mn>1020</mn><mo stretchy="false">)</mo></math> Decays in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi></math> Collisions at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math>

We study the processes <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>τ</mi></msub><mi>n</mi><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><msup><mi>τ</mi><mo>−</mo></msup><mo stretchy="false">(</mo><msup><mi>π</mi><mo>−</mo></msup><msub><mi>ν</mi><mi>τ</mi></msub><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>τ</mi></msub><mi>p</mi><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mi>τ</mi><mo>+</mo></msup><mo stretchy="false">(</mo><msup><mi>π</mi><mo>+</mo></msup><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>τ</mi></msub><mo stretchy="false">)</mo></math>, with particular emphasis on the pion energy and angular distributions, as a possible signal for lepton flavor universality violation, and in general of physics beyond the Standard Model (SM), as well as a sensitive probe of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math> polarization vector. We work within an effective low-energy extension of the SM with all dimension-six four-fermion operators. In this framework, complex Wilson coefficients which encode new physics can generate <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math>-violating contributions. We propose an observable that provides a genuine <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math>-odd signal due to its sensitivity to particular transverse components of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math> polarization vector. Namely, we show that the asymmetry in the azimuthal-angle distribution of the pion in the decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>τ</mi><mo>±</mo></msup><mo stretchy="false">→</mo><msup><mi>π</mi><mo>±</mo></msup><msub><mi>ν</mi><mi>τ</mi></msub></math> constitutes a smoking-gun prediction of such a beyond the SM scenario. We estimate the strength of this effect extrapolating nucleon-hyperon form factors recently obtained from lattice QCD calculations.

Spain

E. Hernández

J. Nieves

Sweden

J.E. Sobczyk

Probing new physics and <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"><msub><mi>ν</mi><mi>τ</mi></msub><mi>n</mi><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><msup><mi>τ</mi><mo>−</mo></msup><mo stretchy="false">(</mo><msup><mi>π</mi><mo>−</mo></msup><msub><mi>ν</mi><mi>τ</mi></msub><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>τ</mi></msub><mi>p</mi><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mi>τ</mi><mo>+</mo></msup><mo stretchy="false">(</mo><msup><mi>π</mi><mo>+</mo></msup><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>τ</mi></msub><mo stretchy="false">)</mo></math>

In this work, we perform a systematic investigation of the hidden-charm tetraquark states with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>I</mi><mi>G</mi></msup><mo stretchy="false">(</mo><msup><mi>J</mi><mrow><mi>P</mi><mi>C</mi></mrow></msup><mo stretchy="false">)</mo><mo>=</mo><msup><mn>1</mn><mo>+</mo></msup><mo stretchy="false">(</mo><msup><mn>1</mn><mrow><mo>+</mo><mo>−</mo></mrow></msup><mo stretchy="false">)</mo></math> within the hadronic molecular picture, placing particular emphasis on systems composed of an <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mi>D</mi><mo>,</mo><msup><mi>D</mi><mo>*</mo></msup><mo stretchy="false">)</mo></math> meson and a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">[</mo><msubsup><mrow><mi>D</mi></mrow><mrow><mn>0</mn></mrow><mrow><mo>*</mo></mrow></msubsup><mo stretchy="false">(</mo><mn>2300</mn><mo stretchy="false">)</mo><mo>,</mo><msub><mrow><mi>D</mi></mrow><mrow><mn>1</mn></mrow></msub><mo stretchy="false">(</mo><mn>2430</mn><mo stretchy="false">)</mo><mo>,</mo><msub><mrow><mi>D</mi></mrow><mrow><mn>1</mn></mrow></msub><mo stretchy="false">(</mo><mn>2420</mn><mo stretchy="false">)</mo><mo>,</mo><msubsup><mrow><mi>D</mi></mrow><mrow><mn>2</mn></mrow><mrow><mo>*</mo></mrow></msubsup><mo stretchy="false">(</mo><mn>2460</mn><mo stretchy="false">)</mo><mo stretchy="false">]</mo></mrow></math> meson. Adopting the one-boson exchange potential, we solve the Schrödinger equation in momentum space via the complex scaling method. A crucial feature of our approach is the rigorous treatment of the unstable nature of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi></math>-wave constituents by incorporating three-body decay effects arising from self-energy corrections and the static limit approximation. Our results demonstrate that these three-body dynamics play a crucial role in determining the pole positions, specifically in reproducing the large decay widths observed experimentally. We identify several broad resonances in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>*</mo></msup><msub><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mn>1</mn></msub><mo stretchy="false">(</mo><mn>2420</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>*</mo></msup><msubsup><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mn>2</mn><mo>*</mo></msubsup><mo stretchy="false">(</mo><mn>2460</mn><mo stretchy="false">)</mo></math> systems as candidates for the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>4430</mn><mo stretchy="false">)</mo></math>, while the significantly broader resonances in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><msubsup><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mn>0</mn><mo>*</mo></msubsup><mo stretchy="false">(</mo><mn>2300</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><msub><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mn>1</mn></msub><mo stretchy="false">(</mo><mn>2430</mn><mo stretchy="false">)</mo></math> sectors are suggested as candidates for the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>4200</mn><mo stretchy="false">)</mo></math>. Focusing on the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>*</mo></msup><msubsup><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mn>2</mn><mo>*</mo></msubsup><mo stretchy="false">(</mo><mn>2460</mn><mo stretchy="false">)</mo></math> assignment as a specific case study, we further analyze the line shape of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>4430</mn><mo stretchy="false">)</mo></math> candidate using a Flatté-like parametrization with energy-dependent self-energy terms, providing predictions for its open-charm decay modes to guide future experimental searches.

Jian-Bo Cheng

Zi-Yang Lin

Jun-Zhang Wang

Shi-Lin Zhu

Decoding <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>4430</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>Z</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>4200</mn><mo stretchy="false">)</mo></math>: The role of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi></math>-wave charmed mesons

We consider planar codimension-one defects and interfaces in $$ \mathcal{N} $$ = 4 supersymmetric Yang-Mills (SYM) theory, realized by the D3/D5-brane intersection. Working in the probe limit, where the number of D5-branes is small compared to the number of D3-branes, we obtain analytic results for the holographic entanglement entropy of a ball-shaped region centered on the defect. A defect renormalization group flow is triggered by giving the defect hypermultiplets a mass, which corresponds to separating the D3- and D5-branes. Along this flow the entanglement C-function decreases monotonically. We also allow the D5-branes to carry worldvolume flux corresponding to dissolved D3-branes, in which case the setup describes an interface between two copies of $$ \mathcal{N} $$ = 4 SYM theory with different gauge groups, where an RG flow is triggered by placing one side of the interface onto the Coulomb branch. Here we again find monotonic behavior of the entanglement C-function, although its interpretation as a measure of effective degrees of freedom is problematic. We investigate possible alternative measures of degrees of freedom.

Finland

Niko Jokela

Germany

Jani Kastikainen

José Penín

Ronnie Rodgers

Helime Ruotsalainen

Entanglement C-functions of defects and interfaces in $$ \mathcal{N} $$ = 4 supersymmetric Yang-Mills theory

We analyze the rare semileptonic decays $$B_{c}^+ \rightarrow D^{*+}(\rightarrow P_1 P_2)\ell ^{+}\ell ^{-}$$ , with $$P_1 P_2 = D^+ \pi ^0$$ or $$D^0 \pi ^+$$ , and $$\ell =\mu , \tau $$ . We focus on the impact of weak annihilation contributions alongside penguin, box, and long-distance effects. Using the effective Hamiltonian for $$b \rightarrow d \ell ^+ \ell ^-$$ transitions and $$B_c \rightarrow D^{*}$$ form factors from covariant confined quark model inputs, we compute the differential branching ratios, forward–backward asymmetry, longitudinal helicity fraction of the $$D^{*}$$ , and various normalized angular coefficients. The results of the observables show that weak annihilation effects are sizable, particularly at low $$q^2$$ , significantly modifying several observables and shifting zero-crossings. Resonance effects dominate at high $$q^2$$ , restricting reliable analysis windows. We conclude that the inclusion of weak annihilation is essential for precise Standard Model predictions and for isolating possible New Physics effects in $$B_c^+ \rightarrow D^{*+} \ell ^+ \ell ^-$$ decays.

Pakistan

Zohaib Aarfi

Qazi Salam

Ishtiaq Ahmed

Faisal Bhutta

M. Paracha

Weak annihilation contribution to angular observables in $$B_{c}^+\rightarrow D^{*+}\ell ^{+}\ell ^{-}$$ decays

In experiments exotic meson resonance $$T_{c\bar{c}}(4020)$$ lies above the $$D^{*}\bar{D}^{*}$$ threshold, and in principle one can not explain $$T_{c\bar{c}}(4020)$$ as a meson-meson bound state because meson-meson bound state must lie below the $$D^{*}\bar{D}^{*}$$ threshold. In this work, exotic resonance $$T_{c\bar{c}}(4020)$$ is considered as an unstable meson-meson molecular state $$D^{*}\bar{D}^{*}$$ , and the developed Bethe–Salpeter theory for dealing with unstable state is applied to investigate resonance $$T_{c\bar{c}}(4020)$$ . We calculate the mass and width of unstable meson-meson molecular state $$D^{*}\bar{D}^{*}$$ in the framework of relativistic quantum field theory and find that this unstable meson-meson molecular state lies above the $$D^{*}\bar{D}^{*}$$ threshold, which is consistent with experimental values of resonance $$T_{c\bar{c}}(4020)$$ .

Xiaozhao Chen

Xiaofu Lü

Xiurong Guo

Zonghua Shi

Mass and width of $$T_{c\bar{c}}(4020)$$ in the developed Bethe–Salpeter theory

The first observation of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mi>χ</mi><mrow><mi>c</mi><mn>1</mn></mrow></msub><mo stretchy="false">(</mo><mn>3872</mn><mo stretchy="false">)</mo></mrow><mo stretchy="false">→</mo><mrow><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></mrow></math> decay is reported using proton-proton collision data recorded with the LHCb detector corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>9</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math>. The decay mode is observed for the first time, with a significance of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>6.5</mn><mi>σ</mi></math>. Its branching fraction is measured relative to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mi>χ</mi><mrow><mi>c</mi><mn>1</mn></mrow></msub><mo stretchy="false">(</mo><mn>3872</mn><mo stretchy="false">)</mo></mrow><mo stretchy="false">→</mo><mrow><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup></mrow></math> decay mode <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mfrac><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><mrow><msub><mrow><mi>χ</mi></mrow><mrow><mi>c</mi><mn>1</mn></mrow></msub><mo stretchy="false">(</mo><mn>3872</mn><mo stretchy="false">)</mo></mrow><mo stretchy="false">→</mo><mrow><mrow><mi>J</mi><mo stretchy="false">/</mo><mi>ψ</mi></mrow><msup><mrow><mi>μ</mi></mrow><mrow><mo stretchy="false">+</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo stretchy="false">−</mo></mrow></msup></mrow><mo stretchy="false">)</mo></mrow><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><mrow><msub><mrow><mi>χ</mi></mrow><mrow><mi>c</mi><mn>1</mn></mrow></msub><mo stretchy="false">(</mo><mn>3872</mn><mo stretchy="false">)</mo></mrow><mo stretchy="false">→</mo><mrow><mrow><mi>J</mi><mo stretchy="false">/</mo><mi>ψ</mi></mrow><msup><mrow><mi>π</mi></mrow><mrow><mo stretchy="false">+</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo stretchy="false">−</mo></mrow></msup></mrow><mo stretchy="false">)</mo></mrow></mfrac><mo>=</mo><mrow><mo stretchy="false">(</mo><mn>1.68</mn><mo>±</mo><mn>0.32</mn><mo>±</mo><mn>0.05</mn><mo stretchy="false">)</mo></mrow><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></mrow></math>, where the first uncertainty includes both statistical contributions and systematic contributions which are uncorrelated between data-taking periods, and the second represents the systematic contributions that are correlated between data-taking periods.

Netherlands

R. Aaij

United Kingdom

A.S.W. Abdelmotteleb

Switzerland

C. Abellan Beteta

F. Abudinén

T. Ackernley

A.A. Adefisoye

B. Adeva

M. Adinolfi

P. Adlarson

France

C. Agapopoulou

C.A. Aidala

Z. Ajaltouni

S. Akar

K. Akiba

M. Akthar

P. Albicocco

J. Albrecht

R. Aleksiejunas

CERN

F. Alessio

P. Alvarez Cartelle

R. Amalric

S. Amato

J.L. Amey

Y. Amhis

L. An

Observation of the decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mrow><mi>c</mi><mn>1</mn></mrow></msub><mo stretchy="false">(</mo><mn>3872</mn><mo stretchy="false">)</mo><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></math>