We explore baryon-number-violating (|∆$\textit{B}$| = 2) processes beyond the well-known neutron-antineutron ( $$ n-\overline{n} $$ ) oscillations, focusing on the $$ \Lambda -\overline{\Lambda} $$ system. The presence of a strange quark in the Λ baryon introduces a new set of six-quark operators roughly of the form ($\textit{uds}$) , which are different from the ($\textit{udd}$) operators responsible for $$ n-\overline{n} $$ oscillations. Using the Standard Model Effective Field Theory (SMEFT), we classify all dimension-9 operators that cause |∆$\textit{B}$| = 2 transitions and study their UV completions mediated by exotic scalar fields with trilinear interactions. We demonstrate that in these models, $$ \Lambda -\overline{\Lambda} $$ oscillations can occur at tree level, with $$ n-\overline{n} $$ mixing potentially appearing at higher loop levels. We employ a chiral effective theory to constrain the effective mass mixing $\textit{δm}$ , deriving bounds from current experimental limits on $$ n-\overline{n} $$ oscillations and dinucleon decays such as $\textit{pp}$ → $\textit{K}$ $\textit{K}$ . These bounds indicate that $$ \Lambda -\overline{\Lambda} $$ oscillations probe a complementary parameter space, sensitive to baryon-number violation at scales up to 10 − 10 TeV. We show that the existing indirect bounds make it challenging to provide a competitive bound on $\textit{δm}$ at BESIII.

Spain

Arnau Beneito

Slovenia

Svjetlana Fajfer

United States

Alexey Petrov

New avenues for $\textit{|}$∆$\textit{B|}$ = 2 processes beyond neutron-antineutron oscillations

Studying heavy-quark hadrons is crucial due to the nonperturbative nature of low-energy QCD, with Heavy-Quark Symmetry (HQS) serving as a key framework for understanding their spin and flavor symmetries. However, a key issue is that the theoretically expected $$B^{(*)}\bar{K}$$ molecular states have not yet been observed, although they are considered the bottom-quark counterparts of the observed $$\bar{D}^{(*)}\bar{K}$$ molecular states (corresponding to $$D_{s0}(2317/2460)^{-}$$ ), which challenges the universality of HQS. The main goal of this work is to search for the theoretically predicted $$B\bar{K}$$ and $$B^{*}\bar{K}$$ molecular states, namely $$B_{s0}^{*}(5725)$$ and $$B_{s1}^{*}(5778)$$ , via the reactions $$K^{-}p \rightarrow \varLambda _{b}^{0} B_{s0}^{*}$$ and $$K^{-}p \rightarrow \varLambda _{b}^{0} B_{s1}^{*}$$ . Within an effective Lagrangian framework, we compute the relevant cross sections, considering $\textit{t}$-channel $$B^{(*)}$$ exchanges and $$K^{-}p$$ initial-state interactions (ISI). The results show that the production cross sections of $$B_{s0}^{*}(5725)$$ and $$B_{s1}^{*}(5778)$$ can reach the order of 0.01 nb, and we suggest that experiments searching for $$B_{s0}^{*}(5725)$$ are best performed at $$P_{K^{-}} = 12.18~\textrm{GeV}$$ , while higher energies are most favorable for producing $$B_{s1}^{*}(5778)$$ . The ISI play a crucial role, as they not only significantly enhance the production cross sections of $$B_{s0}^{*}(5725)$$ and $$B_{s1}^{*}(5778)$$ (by roughly one order of magnitude) but also markedly affect the angular distributions of the produced particles. We also calculated the production cross sections of the conventional quark–antiquark states $$B_{s0}^*(5700)$$ and $$B_{s1}^*(5720)$$ , which are found to be nearly the same as those of $$B_{s0}^{*}(5725)$$ and $$B_{s1}^{*}(5778)$$ . Although their internal structures remain ambiguous, these results can inform future experimental searches at CERN and J-PARC.

China

Min Yuan

Yin Huang

A search for $$B_{s0}^{*}$$ and $$B^{*}_{s1}$$ through the $$K^{-}p$$ interaction

We propose boundary terms for the action of the NS sector of supergravity on $\textit{M}$ × $\textit{S}$ × $\textit{T}$ spacetimes — where $\textit{M}$ is an AdS or a linear dilaton background — that render the Brown-York stress tensor and the on-shell action finite. For AdS backgrounds, we show that the on-shell action yields a free energy with chemical potentials determined by the $\textit{B}$-field. TsT (T-duality + shift + T-duality) transformations of these backgrounds generate classes of linear dilaton backgrounds distinguished by their boundary conditions. Among them, there is one class of backgrounds that reproduces features of the single-trace $$ T\overline{T} $$ deformation. These backgrounds have additional chemical potentials that can be turned off by large gauge transformations of the $\textit{B}$-field. We show that the Brown-York stress tensor of these backgrounds reproduces the energies and the trace flow equation of $$ T\overline{T} $$ -deformed CFTs. We also show that the on-shell action matches the $$ T\overline{T} $$ partition function and discuss the interpretation of these results.

Luis Apolo

The on-shell action of supergravity & the $\textit{B}$-side of TsT and single-trace $$ T\overline{T} $$

We compute next-to-next-to-leading order corrections to the decay width difference of mass eigenstates and the charge-parity (CP) asymmetry $\textit{a}$ in flavour-specific decays of neutral $\textit{B}$ mesons. We include both current-current and penguin operators at three-loop order. All input integrals in the transition amplitude are reduced to a small set of master integrals which depend on the ratio of the charm and bottom quark masses. The latter are computed using semi-analytic methods which provide deep expansions around properly selected values of $\textit{m}$ $\textit{/m}$ . We provide numerical results for ∆Γ and ∆Γ$\textit{/}$∆$\textit{M}$, both for the $\textit{B}$ and $\textit{B}$ system, including a detailed uncertainty analysis. Using the experimental value for the mass difference ∆$\textit{M}$ we predict ∆Γ = (0$\textit{.}$078 ± 0$\textit{.}$015) ps . For the CP asymmetries we find $$ {a}_{\textrm{fs}}^s=\left(2.27\pm 0.13\right)\times {10}^{-5} $$ and $$ {a}_{\textrm{fs}}^d=-\left(5.19\pm 0.30\right)\times {10}^{-4} $$ . Furthermore, we show that the ratios (∆Γ $\textit{/}$∆$\textit{M}$ )$\textit{/}$(∆Γ $\textit{/}$∆$\textit{M}$ ) and ∆Γ $\textit{/}$∆Γ can be predicted with high precision. The former quantity permits the prediction ∆Γ = (0$\textit{.}$00215 ± 0$\textit{.}$00013) ps from the measurements of ∆$\textit{M}$ and ∆Γ . We further discuss the impact of ∆Γ $\textit{/}$∆Γ on the CKM unitarity triangle and present ready-to-use formulae which permit improved predictions once updated results for the operator matrix elements are available.

Germany

Ulrich Nierste

Pascal Reeck

Vladyslav Shtabovenko

Matthias Steinhauser

Complete next-to-next-to-leading order QCD corrections to the decay matrix in $\textit{B}$-meson mixing at leading power

We investigate the discovery potential of the $$3~\textrm{TeV}$$ Compact Linear Collider (CLIC) for a singlet vector-like bottom partner $\textit{B}$ decaying via $$B \rightarrow tW.$$ Focusing on the fully hadronic final state $$B\bar{B} \rightarrow tW\,tW,$$ we reconstruct boosted top and $\textit{W}$ candidates using large-$\textit{R}$ Valencia jets, supplemented by a merging strategy for partially resolved decays. A systematic scan of the jet-radius parameter identifies $$R=0.8$$ as the optimal choice, balancing boosted-jet containment with jet multiplicity. Using a cut-based analysis optimized for the $$(2t+2W)$$ topology and an integrated luminosity of $$5~\textrm{ab}^{-1},$$ CLIC can achieve sensitivity to $$m_B \lesssim 1.5~\textrm{TeV}.$$ These results highlight CLIC’s excellent capability to probe heavy vector-like quarks in high jet multiplicity environments, extending well beyond the reach of current hadron collider searches.

Shuo Yang

Baoxia Wang

Australia

Pengxuan Zhu

Exploring vector-like $\textit{B}$-quark pair production at CLIC in fully hadronic final states

The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Z</mi><mn>0</mn></msup></math> bosons produced in electron-positron collisions at the potential Future Circular Collider (FCC-ee) provide unique opportunities for flavor physics. The nonzero polarization of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>b</mi><mn>0</mn></msubsup></math> baryons produced in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Z</mi><mn>0</mn></msup></math> decays enables access to a much larger set of observables than at the LHC, where the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>b</mi><mn>0</mn></msubsup></math> baryons are produced unpolarized. This paper presents a toy angular analysis of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>b</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mrow><mi mathvariant="normal">Λ</mi><mo stretchy="false">(</mo><mo stretchy="false">→</mo><mi>p</mi><msup><mi>π</mi><mo>−</mo></msup><mo stretchy="false">)</mo><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></mrow></math> decays using simulation samples of collisions at the FCC-ee reconstructed using the IDEA detector concept and assuming a dataset of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>6</mn><mo>×</mo><msup><mn>10</mn><mn>12</mn></msup></math> <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>Z</mi><mn>0</mn></msup></math> bosons. While the statistical sensitivity achieved for individual angular observables is not expected to significantly exceed that from the LHCb Upgrade II experiment, the addition of the polarized observables leads to a significant improvement of the knowledge on the Wilson coefficients <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>C</mi><msup><mn>9</mn><mrow><mo stretchy="false">(</mo><mo>′</mo><mo stretchy="false">)</mo></mrow></msup></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>C</mi><mrow><msup><mn>10</mn><mrow><mo stretchy="false">(</mo><mo>′</mo><mo stretchy="false">)</mo></mrow></msup></mrow></msub></math>.

Anja Beck

Mero Elmarassy

Asher Sabbagh

United Kingdom

Michal Kreps

Eluned Smith

Constraints on new physics from decays of polarized <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>b</mi><mn>0</mn></msubsup></math> baryons at the FCC-ee

We propose to search for <math altimg='si25.svg'><msubsup><mstyle mathvariant='normal'><mi>&#926;</mi></mstyle><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup></math> in the decay <math altimg='si26.svg'><mrow><msub><mstyle mathvariant='normal'><mi>&#923;</mi></mstyle><mi>b</mi></msub><mo>&#8594;</mo><msubsup><mstyle mathvariant='normal'><mi>&#926;</mi></mstyle><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup><msup><mi>D</mi><mo>&#8722;</mo></msup></mrow></math>, which serves as a tagged and reconstructible source of <math altimg='si25.svg'><msubsup><mstyle mathvariant='normal'><mi>&#926;</mi></mstyle><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup></math>. A possible fully charged final state is <math altimg='si27.svg'><mrow><msub><mrow><mo>[</mo><msub><mrow><mo>(</mo><mi>p</mi><msup><mi>K</mi><mo>&#8722;</mo></msup><msup><mi>K</mi><mo>&#8722;</mo></msup><msup><mi>&#960;</mi><mo>+</mo></msup><mo>)</mo></mrow><msubsup><mstyle mathvariant='normal'><mi>&#926;</mi></mstyle><mi>c</mi><mn>0</mn></msubsup></msub><msup><mi>&#960;</mi><mo>+</mo></msup><mo>]</mo></mrow><msubsup><mstyle mathvariant='normal'><mi>&#926;</mi></mstyle><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup></msub><mspace width='0.16em' /><msub><mrow><mo>(</mo><msup><mi>K</mi><mo>+</mo></msup><msup><mi>&#960;</mi><mo>&#8722;</mo></msup><msup><mi>&#960;</mi><mo>&#8722;</mo></msup><mo>)</mo></mrow><msup><mi>D</mi><mo>&#8722;</mo></msup></msub></mrow></math>, where the subscripts indicate the parent hadron in the decay chain. We estimate the branching fraction to be <math altimg='si28.svg'><mrow><mi mathvariant='script'>B</mi><mrow><mo>(</mo><msub><mstyle mathvariant='normal'><mi>&#923;</mi></mstyle><mi>b</mi></msub><mo>&#8594;</mo><msubsup><mstyle mathvariant='normal'><mi>&#926;</mi></mstyle><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup><msup><mi>D</mi><mo>&#8722;</mo></msup><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><mrow><mo>(</mo><mn>5.1</mn><mo>&#177;</mo><mn>3.9</mn><mo>)</mo></mrow><mo linebreak='goodbreak'>&#215;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>4</mn></mrow></msup></mrow></math>, while the fully charged final state corresponds to an effective branching fraction of order <math altimg='si29.svg'><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>8</mn></mrow></msup></math>. These results indicate that LHCb has the potential to discover <math altimg='si25.svg'><msubsup><mstyle mathvariant='normal'><mi>&#926;</mi></mstyle><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup></math>. The prospects for observing <math altimg='si30.svg'><msubsup><mstyle mathvariant='normal'><mi>&#937;</mi></mstyle><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup></math> are also briefly discussed.

Chao-Qiang Geng

Xiang-Nan Jin

Chia-Wei Liu

Xin-Yi Liu

Xiao Yu

Potential of discovering <math altimg='si25.svg'><msubsup><mstyle mathvariant='normal'><mi>&#926;</mi></mstyle><mrow><mi>c</mi><mi>c</mi></mrow><mo>+</mo></msubsup></math> in &#923; <inf><italic>b</italic></inf> decays

The process of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mrow><mi>b</mi><mi>c</mi></mrow><mo>+</mo></msubsup><mo stretchy="false">→</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mo>+</mo></msubsup><mi>J</mi><mo>/</mo><mi>ψ</mi></math> is among the most favored modes for searching for bottom-charm baryons. However, its branching fraction has never been studied in theory. In this work, we investigate the branching fraction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mrow><mi>b</mi><mi>c</mi></mrow><mo>+</mo></msubsup><mo stretchy="false">→</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mo>+</mo></msubsup><mi>J</mi><mo>/</mo><mi>ψ</mi></math> in the final-state-interaction approach, as it is dominated by the color-suppressed nonfactorizable contributions. A similar process, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>b</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><msup><mi mathvariant="normal">Λ</mi><mn>0</mn></msup><mi>J</mi><mo>/</mo><mi>ψ</mi></math>, is used as a control mode to fix the model parameter. Consequently, the branching fraction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mrow><mi>b</mi><mi>c</mi></mrow><mo>+</mo></msubsup><mo stretchy="false">→</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mo>+</mo></msubsup><mi>J</mi><mo>/</mo><mi>ψ</mi></math> is predicted to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mn>1.5</mn><msubsup><mn>5</mn><mrow><mo>−</mo><mn>0.42</mn></mrow><mrow><mo>+</mo><mn>0.50</mn></mrow></msubsup><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math>. With the production rate of bottom-charm baryons and the detection efficiencies of the final states, it is expected for considerable signal events to observe <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mrow><mi>b</mi><mi>c</mi></mrow><mo>+</mo></msubsup></math> in the near future.

Xiao-Hui Hu

Cai-Ping Jia

Ye Xing

Fu-Sheng Yu

Branching fraction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mrow><mi>b</mi><mi>c</mi></mrow><mo>+</mo></msubsup><mo stretchy="false">→</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mo>+</mo></msubsup><mi>J</mi><mo>/</mo><mi>ψ</mi></math> in the final-state-interaction approach

An analysis of baryogenesis and stochastic gravitational wave production is presented for an extension of the Standard Model where the dark sector consists of dark matter particles charged under a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi>x</mi></msub></math> gauge symmetry, while a subset of dark fields also carry lepton number but no <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi>x</mi></msub></math> charge. We demonstrate that, with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation induced by Yukawa couplings, equal and opposite lepton asymmetries are generated in the visible and hidden sectors. Subsequent evolution preserves the lepton number separately in each sector, and sphaleron interactions partially convert the lepton asymmetry into baryon asymmetry near the temperature of the first-order phase transition. Furthermore, we discuss stochastic gravitational wave background production for the first-order phase transition using a gauge-independent bubble nucleation dynamics which yields spectra also valid in the supercooled low-temperature regime with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mi>p</mi></msub><mo>/</mo><msub><mi>m</mi><msub><mi>A</mi><mi>x</mi></msub></msub><mo>≪</mo><mn>1</mn></math>, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mi>p</mi></msub></math> is the percolation temperature and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msub><mi>A</mi><mi>x</mi></msub></msub></math> is the dark photon mass. A parameter-space scan identifies regions that simultaneously account for cogenesis of baryon asymmetry and dark matter and predict stochastic gravitational wave signals within reach of current (NANOGrav, EPTA, and PPTA) and future detectors at higher frequencies, providing a unified framework for cogenesis and associated gravitational wave production.

Wan-Zhe Feng

Jinzheng Li

Pran Nath

Zong-Huan Ye

Gauge-independent gravitational waves from cogenesis in a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo>−</mo><mi>L</mi></math> conserving universe

This paper presents a detailed analysis of the three-body final state interactions in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>+</mo></msup><mo stretchy="false">→</mo><mi>D</mi><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><msup><mi>K</mi><mo>+</mo></msup></math> process, whose phase space is sufficient small. To precisely extract the resonance parameters, for instance the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mrow><mi>c</mi><mn>0</mn><mo>/</mo><mn>2</mn></mrow></msub><mo stretchy="false">(</mo><mn>3930</mn><mo stretchy="false">)</mo></math> in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover></math> invariant mass distributions, in this process, one has to take into account final state interaction, especially the three-body final state interaction. We employ the dispersive Khuri-Treiman formalism, combined with a parametrization of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover></math> interaction based on heavy quark spin symmetry. By performing a simultaneous fit to the experimental data from LHCb, BABAR, and Belle collaborations, the scheme with three-body interaction successfully describes the invariant mass distributions of the three two-body subsystems. We precisely extract the pole structures of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mrow><mi>c</mi><mn>0</mn></mrow></msub><mo stretchy="false">(</mo><mn>3930</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ψ</mi><mo stretchy="false">(</mo><mn>3770</mn><mo stretchy="false">)</mo></math> as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>3.913</mn><mo>−</mo><mn>0.016</mn><mi>i</mi><mtext> </mtext><mi>GeV</mi></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>3.761</mn><mo>−</mo><mn>0.006</mn><mi>i</mi><mtext> </mtext><mi>GeV</mi></mrow></math> in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>+</mo></msup></math> decay. By performing the pole trajectory analysis on a uniformized complex plane, we find that both of them stem from the input bare state.

Xin-Yue Hu

Jiahao He

Pengyu Niu

Japan

Qian Wang

Thailand

Yupeng Yan

Three-body final state interactions in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>+</mo></msup><mo stretchy="false">→</mo><mi>D</mi><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><msup><mi>K</mi><mo>+</mo></msup></math> decays