The photoleptonic decay $$ {B}^{-}\to \gamma {\ell}^{-}\overline{\nu} $$ is the simplest low-energy process that probes the substructure of the $\textit{B}$ meson, making it an excellent candidate to determine the parameters of $\textit{B}$-meson light-cone distribution amplitudes from experimental data. More recently, the decay $$ {B}^{-}\to {\gamma}^{\ast}\left(\to {\ell}^{\prime -}{\ell}^{\prime +}\right){\ell}^{-}\overline{\nu} $$ has received attention as an alternative probe of these parameters. Both decays are described through a common set of hadronic form factors, which, if computed within the framework of QCD factorization, give rise to the sensitivity to the $\textit{B}$-meson light-cone distribution amplitudes. Nevertheless, in this case the form factors still receive so-called soft contributions that can only be estimated but not rigorously computed. In this work, we provide results for the QCD factorization expressions for the form factors, including terms at next-to-leading power in the $\textit{b}$ quark mass and in the photon energy. We further use these results to estimate the soft contributions within a light-cone sum rule setup. Finally, using numerical results obtained from a benchmark model of the light-cone distribution amplitudes, we show that the soft contributions are under significantly better theoretical control at a mildly spacelike photon virtuality.

France

Aoife Bharucha

United Kingdom

Danny Dyk

Eduardo Velásquez

On soft contributions to the $\textit{B}$ $\textit{−}$ $\textit{→ γ}$ * form factors

To shed light on the inner structure of the observed single-bottom strange baryons, in this work we systematically study the Okubo-Zweig-Iizuka allowed strong decay properties of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>- and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>S</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>′</mo></msubsup></math> baryons within the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>j</mi><mtext>−</mtext><mi>j</mi></math> coupling scheme in the framework of the quark pair creation model. For a comparison, we also give the predictions of the chiral quark model. The calculations indicate that (i) The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>λ</mi></math>-mode <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub></math> states <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><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo>,</mo><mn>1</mn><msub><mo stretchy="false">⟩</mo><mi>λ</mi></msub></math> and <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><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><mn>3</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo>,</mo><mn>1</mn><msub><mo stretchy="false">⟩</mo><mi>λ</mi></msub></math> are highly promising candidates for the observed state <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><mn>6087</mn><mo stretchy="false">)</mo></math> and <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><mn>6095</mn><mo stretchy="false">)</mo><mo>/</mo><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub><mo stretchy="false">(</mo><mn>6100</mn><mo stretchy="false">)</mo></math>, respectively. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>λ</mi></math>-mode <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>′</mo></msubsup></math> states <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>′</mo></msubsup><mo stretchy="false">|</mo><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><mn>3</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo>,</mo><mn>2</mn><msub><mo stretchy="false">⟩</mo><mi>λ</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>′</mo></msubsup><mo stretchy="false">|</mo><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><mn>5</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo>,</mo><mn>2</mn><msub><mo stretchy="false">⟩</mo><mi>λ</mi></msub></math> are likely candidates for the state <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><mn>6227</mn><mo stretchy="false">)</mo></math>. Meanwhile, we cannot rule out the possibility that <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><mn>6227</mn><mo stretchy="false">)</mo></math> could be a candidate of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi></math>-mode <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub></math> state <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><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><mn>3</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo>,</mo><mn>2</mn><msub><mo stretchy="false">⟩</mo><mi>ρ</mi></msub></math> or <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><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><mn>5</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo>,</mo><mn>2</mn><msub><mo stretchy="false">⟩</mo><mi>ρ</mi></msub></math>. (ii) For the other <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi></math>-mode <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub></math> states and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>λ</mi></math>-mode <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>′</mo></msubsup></math> states, they may be moderate states with a width of several tens of MeV. Their main decay channels are <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub><mi>π</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>′</mo></msubsup><mi>π</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>*</mo></msubsup><mi>π</mi></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>b</mi></msub><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover></math>. The width of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi></math>-mode <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>′</mo></msubsup></math> states are slightly broader, approximately several tens to over one hundred MeV, and the dominant decay channels are <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>′</mo></msubsup><mi>π</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>*</mo></msubsup><mi>π</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Σ</mi><mi>b</mi></msub><mi>K</mi></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Σ</mi><mi>b</mi><mo>*</mo></msubsup><mi>K</mi></math>. (iii) The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>S</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>λ</mi></math>-mode <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>′</mo></msubsup></math> states are most likely to be relatively narrow state with a width of only a few to around ten MeV, and they mainly decay into <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>′</mo></msubsup><mi>π</mi></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>*</mo></msubsup><mi>π</mi></math>. Meanwhile, the decay process of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>S</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>λ</mi></math>-mode <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>′</mo></msubsup></math> states into the final states containing <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub></math> baryons should not be overlooked either. We hope that the theoretical results can provide some reference for future experimental investigations.

China

Yu-Bin Zhang

Yi-Heng Wang

Hui-Hua Zhong

Li-Ye Xiao

Probing the inner structures of the observed <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>b</mi><mo>′</mo></msubsup></math> resonances

We consider realizations of a gauged B-L symmetry in the context of the Dark Dimension scenario, where the SM lives on a codimension one brane in 5d spacetime. The B-L can naturally be a bulk gauge symmetery leading to a global symmetry on the SM brane, and have its gauge anomaly canceled by charged bulk modes. This naturally leads to the existence of 3 right-handed neutrinos propagating in the dark dimension. Allowing for Higgsing of B-L by a bulk scalar at the Higgs scale, results in a massive gauge field with $\textit{m}$ ~ 100 GeV and weak coupling $\textit{g}$ ~ 10 which is allowed by current bounds. The model also predicts a natural matching $\textit{m}$ ~ $\textit{m}$ ~ Λ , thereby providing a theoretical explanation for the observed coincidence between neutrino masses and the Dark Energy scale. It also predicts a tower of sterile right-handed neutrinos in the $\textit{keV}$ mass range.

Spain

Miguel Montero

United States

Cumrun Vafa

Switzerland

Irene Valenzuela

Neutrinos, B-L symmetry and the dark dimension

The dynamical content of equations resulting from rank-two covariant derivatives in $\textit{B}$ Coxeter theory in AdS are analyzed in terms of $\textit{σ}$ -complexes. Primary fields and gauge-invariant differential operators on primary fields are classified for ($\textit{adj}$ ⊗ $\textit{adj}$) one-form fields $\textit{ω}$ and ($\textit{tw}$ ⊗ $\textit{adj}$) zero-form fields $\textit{C}$. It is shown that one-forms $\textit{ω}$ in the ($\textit{adj}$ ⊗ $\textit{adj}$) sector encode symmetric massless fields and partially massless fields of all spins and depth of masslessness. Gluing of the one-form module to the zero-form modules at the linear vertices is studied.

Russia

A. Tarusov

K. Ushakov

The $\textit{σ}$ $\textit{−}$ cohomology analysis for Coxeter higher spin $\textit{B}$ 2 model

The ratio between the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mi>B</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></mrow><msup><mi>τ</mi><mo>+</mo></msup><msub><mi>ν</mi><mi>τ</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mi>B</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></mrow><msup><mi>μ</mi><mo>+</mo></msup><msub><mi>ν</mi><mi>μ</mi></msub></math> branching fractions is measured using a data sample of proton-proton collisions collected by CMS at a center-of-mass energy of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math> in the years 2016–2018 and corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>138</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> meson is identified through its <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow><mo stretchy="false">→</mo><mrow><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></mrow></math> decay and the tau lepton is reconstructed in the hadronic three-prong final state. The measured ratio of branching fractions in this tau decay mode, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="script">R</mi><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow><mi>had</mi></msubsup><mo>=</mo><mn>1.0</mn><msubsup><mn>4</mn><mrow><mo>−</mo><mn>0.44</mn></mrow><mrow><mo>+</mo><mn>0.50</mn></mrow></msubsup></math>, is combined with the previous analysis based on the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>τ</mi></mrow><mrow><mo>+</mo></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup><msub><mrow><mi>ν</mi></mrow><mrow><mi>μ</mi></mrow></msub><msub><mrow><mover accent="true"><mrow><mi>ν</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mi>τ</mi></mrow></msub></mrow></math> leptonic decay channel, leading to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">R</mi><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></msub><mo>=</mo><mrow><mn>0.49</mn><mo>±</mo><mn>0.26</mn></mrow></math>. As this result is consistent with the standard model prediction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>0.258</mn><mo>±</mo><mn>0.004</mn></math>, no evidence of lepton flavor universality violation is found.

Armenia

V. Chekhovsky

A. Hayrapetyan

V. Makarenko

A. Tumasyan

Austria

W. Adam

J.W. Andrejkovic

L. Benato

T. Bergauer

K. Damanakis

M. Dragicevic

C. Giordano

P.S. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

I. Mikulec

J. Schieck

R. Schöfbeck

D. Schwarz

M. Shooshtari

M. Sonawane

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

H. Kwon

T. Van Laer

P. Van Mechelen

J. Bierkens

N. Breugelmans

J. D’Hondt

S. Dansana

A. De Moor

M. Delcourt

F. Heyen

Y. Hong

S. Lowette

I. Makarenko

D. Müller

J. Song

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

A. Khalilzadeh

F.A. Khan

A. Malara

M.A. Shahzad

L. Thomas

M. Vanden Bemden

C. Vander Velde

P. Vanlaer

F. Zhang

M. De Coen

D. Dobur

G. Gokbulut

J. Knolle

L. Lambrecht

D. Marckx

K. Skovpen

N. Van Den Bossche

J. van der Linden

J. Vandenbroeck

L. Wezenbeek

S. Bein

A. Benecke

A. Bethani

G. Bruno

A. Cappati

J. De Favereau De Jeneret

C. Delaere

A. Giammanco

A.O. Guzel

Sa. Jain

V. Lemaitre

J. Lidrych

P. Mastrapasqua

S. Turkcapar

Brazil

G.A. Alves

E. Coelho

G. Correia Silva

C. Hensel

T. Menezes De Oliveira

C. Mora Herrera

P. Rebello Teles

M. Soeiro

E.J. Tonelli Manganote

A. Vilela Pereira

W.L. Aldá Júnior

M. Barroso Ferreira Filho

H. Brandao Malbouisson

Measurement of the ratio of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><msup><mi>τ</mi><mo>+</mo></msup><msub><mi>ν</mi><mi>τ</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>B</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><msup><mi>μ</mi><mo>+</mo></msup><msub><mi>ν</mi><mi>μ</mi></msub></math> branching fractions using three-prong <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math> lepton decays

In this work, the potential parameters of the independent quark model are systematically reduced using previously determined inputs from a broad range of baryons. The reduced-parameter formulation, developed within the relativistic Dirac formalism and employing a Martin-like potential, is then applied to the spectroscopy of the singly heavy baryons $$\Xi _c^0$$ and $$\Xi _b^-$$ in anti-triplet( $$\bar{\textbf{3}}$$ ) and sextet( $$\textbf{6}$$ ) representations. This enables an explicit verification of the linear relation obtained between the potential parameters. Radially and orbitally excited state masses are calculated accordingly, and the resulting Regge trajectories are used to assign spin-parity of experimentally observed states. The observed states $$\Xi _c^0(2882)$$ , $$\Xi _c^0(2923)$$ , and $$\Xi _c^0(2970)$$ are interpreted as $$J^P = \tfrac{3}{2}^-$$ states, where $$\Xi _c^0(2882)$$ is assigned to the anti-triplet ( $$\bar{\textbf{3}}$$ ) configuration, while $$\Xi _c^0(2923)$$ and $$\Xi _c^0(2970)$$ are identified as sextet ( $$\textbf{6}$$ ) states. In the bottom sector, the $$\Xi _b^-(6227)$$ state is interpreted either as a $$\bar{\textbf{3}}$$ baryon with $$J^P = \tfrac{5}{2}^+$$ or as a $$\textbf{6}$$ baryon with $$J^P = \tfrac{3}{2}^+$$ . To investigate the electromagnetic structure of these baryons, their magnetic moments and radiative decay widths are computed. Additionally, the two-body weak decay branching ratios of $$\Xi _c^0$$ are evaluated and compared with experimental data to assess the robustness of the approach. The two-body nonleptonic decays of $$\Xi _b^{'-}$$ are also analyzed, providing predictions for branching ratios that may be tested in future experiments. Overall, the results demonstrate the effectiveness of the parameter-reduction procedure and support its applicability in the spectroscopy of heavy flavor baryons.

India

Rameshri Patel

Manan Shah

Bhoomika Pandya

Singly heavy cascade baryon $$\Xi ^0_{c}$$ , $$\Xi ^{'0}_{c}$$ , $$\Xi ^-_{b}$$ & $$\Xi ^{'-}_{b}$$ spectroscopy in the relativistic framework of independent quark model

The inclusive photoproduction of heavy mesons in ultraperipheral <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>P</mi><mi>b</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi><mi>b</mi><mi>P</mi><mi>b</mi></math> collisions at the LHC energies is investigated considering the color-dipole <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi></math>-matrix formalism and assuming distinct models for the unintegrated gluon distribution, based on different assumptions for the description of the QCD dynamics. In particular, predictions for the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mn>0</mn></msup></math>-meson photoproduction are presented here for the first time. The study of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mn>0</mn></msup></math>-meson photoproduction is revisited by estimating the impact of the treatment of the heavy charm fragmentation on the predictions and extended for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>P</mi><mi>b</mi></math> collisions. Moreover, the contribution associated with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mo stretchy="false">→</mo><msup><mi>D</mi><mn>0</mn></msup></math> transition is estimated. Our results indicate that a future experimental analysis of the heavy meson photoproduction will provide important constraints on the description of the hadronic structure at high energies.

Victor P. Gonçalves

Luana Santana

Poland

Wolfgang Schäfer

Inclusive heavy meson photoproduction in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>P</mi><mi>b</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi><mi>b</mi><mi>P</mi><mi>b</mi></math> collisions

Recent Belle II data on <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><msub><mi>E</mi><mrow><mi>miss</mi></mrow></msub></math> show an excess consistent with a two-body decay involving a light invisible particle with mass around 2.1 GeV. We present a UV-complete explanation based on a Higgsed <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msup><mo stretchy="false">)</mo><mo>′</mo></msup></math> gauge symmetry with a light vector boson <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Z</mi><mo>′</mo></msup></math> and a vectorlike top partner, which naturally enhances <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>s</mi></math> transitions. While the minimal model can reproduce the required <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><msup><mi>Z</mi><mo>′</mo></msup></math> rate, it is excluded by LHCb searches for resonant dimuon decays due to unavoidable loop-induced couplings of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Z</mi><mo>′</mo></msup></math> to charged leptons. We show that a minimal extension with an additional light <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msup><mo stretchy="false">)</mo><mo>′</mo></msup></math>-charged singlet fermion allows <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Z</mi><mo>′</mo></msup></math> to decay dominantly invisibly, evades existing constraints coming also from dark photon and collider searches as well as Higgs measurements, and can simultaneously account for the Belle II excess and the observed dark matter abundance through resonant thermal freeze-out.

Slovenia

Patrick D. Bolton

Jernej F. Kamenik

Martín Novoa-Brunet

Dark light shining on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>B</mi><mo stretchy="false">→</mo><msup><mrow><mi>K</mi></mrow><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msup><msub><mrow><mi>E</mi></mrow><mrow><mrow><mi>miss</mi></mrow></mrow></msub></mrow></math>

Using the pinch technique, we determine the one-loop vertices of weak interactions in the B-LSSM and incorporate their pinch contributions into the gauge boson self-energies. Compared to the definitions of the $\textit{S}$, $\textit{T}$, and $\textit{U}$ parameters in the Standard Model based on the $S U(2)_L \otimes U(1)_Y$ group, the corresponding parameters in the local B-L gauge symmetry (B-LSSM) are modified. We present these redefined $\textit{S}$, $\textit{T}$, and $\textit{U}$ parameters and demonstrate the convergence of the results. In the framework of the low-energy effective Lagrangian for weak interactions, the $\textit{S}$, $\textit{T}$, and $\textit{U}$ parameters can be expressed as functions of specific parameters in the B-LSSM. The updated experimental and fitting results strongly constrain the parameter space of the B-LSSM.

Sheng-Kai Cui

Ke-Sheng Sun

Yu-Li Yan

Jin-Lei Yang

Tai-Fu Feng

$\textit{S}$, $\textit{T}$, $\textit{U}$ parameters in the B-LSSM * Supported by the Natural Science Foundation of Guangxi Autonomous Region (2022GXNSFDA035068), the Natural Science Foundation of Hebei Province (A2022104001), and the Foundation of Baoding University (2023Z01)

We analyze the isovector vector form factors of $$D, D^{*}, B,$$ and $$B^{*}$$ mesons at low energies. We employ all constraints due to chiral and heavy-quark symmetry, and include the physics of resonant pion–pion rescattering in a model-independent way, using dispersion theory. Special attention is paid to the analytic properties of these form factors, which include anomalous thresholds due to triangle diagrams that are located on the physical Riemann sheets in some of the form factors. We extract the couplings of the $$\rho (770)$$ resonance to all these heavy mesons by determining the appropriate pole residues.

Germany

Simon Mutke

Leon Heuser

Ingrid Dax

Bastian Kubis

Sweden

Stefan Leupold

Dispersive analysis of $\textit{D}$- and $\textit{B}$-meson form factors with chiral and heavy-quark constraints