We study the nonleptonic weak decays of doubly charmed baryons (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">B</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub></math>) into singly charmed baryons (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">B</mi><mi>c</mi></msub></math>) and vector mesons (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>V</mi></math>), denoted as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">B</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub><mo stretchy="false">→</mo><msub><mi mathvariant="script">B</mi><mi>c</mi></msub><mi>V</mi></math>. The short-distance contributions are calculated within the naive factorization hypothesis, while the long-distance final-state interaction effects are modeled via hadronic triangle diagrams. Unlike previous approaches, which compute only the imaginary part using the Cutkosky cutting rule, we evaluate the complete loop integrals to obtain both the real and imaginary parts of the amplitudes. These provide the nontrivial strong phases essential for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation. The model parameters are determined using experimental data. With this improved calculation method, we predict the branching ratios and decay asymmetry parameters for various decay channels, as well as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violations for short-distance dominated and singly Cabibbo-suppressed channels. This strengthens our theoretical framework for future study of doubly charmed baryons. Certain decays, primarily driven by long-distance effects, have been calculated, and their observation in future experiments could help clarify the role of final-state interactions in charm baryon decays. Therefore, our calculation of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">B</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub><mo stretchy="false">→</mo><msub><mi mathvariant="script">B</mi><mi>c</mi></msub><mi>V</mi></math> provides crucial predictions for branching ratios, decay asymmetry parameters, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation, which are essential for guiding experimental study at LHCb.

China

Xiao-Hui Hu

Fu-Sheng Yu

Ye Xing

Final-state rescattering mechanism of doubly-charmed baryon decays: <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">B</mi><mrow><mi>c</mi><mi>c</mi></mrow></msub><mo stretchy="false">→</mo><msub><mi mathvariant="script">B</mi><mi>c</mi></msub><mi>V</mi></math>

<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>p</mi><mi>t</mi></msub></math>-differential quantity <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>v</mi><mn>2</mn></msub><mrow><mo>(</mo><msub><mi>p</mi><mi>t</mi></msub><mo>)</mo></mrow></mrow></math> is meant to measure elliptic flow manifested by a dense QCD medium formed in high-energy nucleus-nucleus collisions. Elliptic flow may be referred to more neutrally as a cylindrical quadrupole component of the transverse motion of particle sources within a collision. As defined, <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>v</mi><mn>2</mn></msub><mrow><mo>(</mo><msub><mi>p</mi><mi>t</mi></msub><mo>)</mo></mrow></mrow></math> relies on an implicit assumption that almost all produced particles emerge from a single source. This article describes a detailed study of the algebraic structure of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>v</mi><mn>2</mn></msub><mrow><mo>(</mo><msub><mi>p</mi><mi>t</mi></msub><mo>)</mo></mrow></mrow></math>. A procedure is developed to derive a common monopole boost (“radial flow”) value and quadrupole <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>p</mi><mi>t</mi></msub></math> spectra for several hadron species. The method is applied to <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>v</mi><mn>2</mn></msub><mrow><mo>(</mo><msub><mi>p</mi><mi>t</mi></msub><mo>)</mo></mrow></mrow></math> data for four hadron species from 2.76-TeV Pb-Pb collisions. According to available <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>v</mi><mn>2</mn></msub><mrow><mo>(</mo><msub><mi>p</mi><mi>t</mi></msub><mo>)</mo></mrow></mrow></math> data the assumption of a single dominant particle source within <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>A</mi></mrow><mtext>−</mtext><mrow><mi>A</mi></mrow></math> collisions is unjustified. Combined with a previous study of quadrupole amplitude variation for 200-GeV <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>p</mi><mtext>−</mtext><mi>p</mi></mrow></math> collisions these results demonstrate that quadrupole structure is related to a novel QCD process separate from projectile-nucleon dissociation and jet production. Given quadrupole evolution it is unlikely that a hydrodynamic description is relevant to that process.

United States

Thomas A. Trainor

Quadrupole spectra derived from 2.76-TeV Pb-Pb identified-hadron <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>v</mi><mn>2</mn></msub><mrow><mo>(</mo><msub><mi>p</mi><mi>t</mi></msub><mo>)</mo></mrow></mrow></math> data

We present hydrodynamic predictions for the new observable <italic>v</italic> <inf>02</inf>( <italic>p<inf>T</inf></italic>), which measures the correlation of particle spectra with elliptic flow. We implement a data-driven correction so as to match hydrodynamic calculations to elliptic flow ( <italic>v</italic> <inf>2</inf>( <italic>p<inf>T</inf></italic>)) data. The corrected results are in fair agreement with <italic>v</italic> <inf>0</inf>( <italic>p<inf>T</inf></italic>) data up to high <italic>p<inf>T</inf></italic>. We make predictions for <italic>v</italic> <inf>02</inf>( <italic>p<inf>T</inf></italic>) of unidentified charged hadrons up to <math altimg='si2.svg'><mrow><msub><mi>p</mi><mi>T</mi></msub><mo linebreak='goodbreak'>=</mo><mn>10</mn></mrow></math> GeV/ <italic>c</italic>, and of pions, kaons and protons up to <math altimg='si3.svg'><mrow><msub><mi>p</mi><mi>T</mi></msub><mo linebreak='goodbreak'>=</mo><mn>5</mn><mo linebreak='goodbreak'>&#8722;</mo><mn>6</mn></mrow></math> GeV/ <italic>c</italic>, in several centrality windows, for Pb+Pb collisions at <math altimg='si4.svg'><mrow><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo linebreak='goodbreak'>=</mo><mn>5.02</mn></mrow></math> TeV. We predict a decrease of <italic>v</italic> <inf>02</inf>( <italic>p<inf>T</inf></italic>) of charged hadrons for <italic>p<inf>T</inf></italic>&#8239;&gt;&#8239;4 GeV/ <italic>c</italic> and meson-baryon splitting for <italic>p<inf>T</inf></italic>&#8239;&gt;&#8239;3 GeV/ <italic>c</italic> in mid-central collisions. We also predict a non-monotonic variation of <italic>v</italic> <inf>02</inf>( <italic>p<inf>T</inf></italic>) for protons at low <italic>p<inf>T</inf></italic> above 30% centrality. This is a specific feature of this new observable, which is not observed for the usual flow observables <italic>v</italic> <inf>2</inf>( <italic>p<inf>T</inf></italic>) and <italic>v</italic> <inf>0</inf>( <italic>p<inf>T</inf></italic>).

Poland

Rupam Samanta

Tribhuban Parida

France

Jean-Yves Ollitrault

Enhanced hydrodynamic predictions for <italic>v</italic> <inf>02</inf>( <italic>p<inf>T</inf></italic>)

Within the NRQCD factorization framework, we investigate the color-singlet contribution to $$ {e}^{+}{e}^{-}\to J/\psi +{X}_{\mathrm{non}\ c\overline{c}} $$ at B factories, computing the 𝒪($\textit{α}$ ), 𝒪($\textit{v}$ ), and 𝒪($\textit{α}$ $\textit{v}$ ) corrections to both the unpolarized cross section and the $\textit{J}$/$\textit{ψ}$ angular distribution. The 𝒪($\textit{α}$ $\textit{v}$ ) correction is obtained for the first time, and the validity of NRQCD factorization at this order is explicitly verified. Using the differential equation method, the short-distance coefficients are obtained as asymptotic expansions in $$ r={m}_c/\sqrt{s} $$ up to $\textit{r}$ , which reproduce exact results with high precision at B factory energies, achieving relative errors around 10 for the cross section and around 10 for the angular distribution. Notably, with the same input parameters, our 𝒪($\textit{α}$ ) and 𝒪($\textit{v}$ ) corrections are consistent with those reported in the literature. Phenomenologically, the 𝒪($\textit{α}$ ) correction (with $$ {\mu}_R=\sqrt{s}/2 $$ ) reaches about 50% of the leading-order cross section, while the 𝒪($\textit{v}$ ) and 𝒪($\textit{α}$ $\textit{v}$ ) corrections are accidentally small. After including feeddown contributions from $\textit{ψ}$(2$\textit{S}$), the predicted cross section $$ {0.523}_{-0.197}^{+0.285} $$ pb agrees with the Belle measurement within uncertainties. However, the predicted angular distribution parameter $$ {0.120}_{-0.036}^{+0.041} $$ deviates from the experimental value 5.71 ± 2.51 by more than 2$\textit{σ}$, calling for further experimental and theoretical investigations.

Cong Li

Hao-Yang Liu

Xu-Dong Huang

Wen-Long Sang

Semi-analytical results for $$ {e}^{+}{e}^{-}\to J/\psi +{X}_{\mathrm{non}\ c\overline{c}} $$ up to 𝒪($\textit{α}$ $\textit{s}$ $\textit{v}$ 2) at B factories

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi></math> meson decays into neutral kaons involve both Cabibbo-favored and doubly Cabibbo-suppressed amplitudes as well as final-state kaon mixing, providing abundant sources of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> violation. In this work, we analyze <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> asymmetries in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">→</mo><msubsup><mi>K</mi><mrow><mi>S</mi><mo>,</mo><mi>L</mi></mrow><mn>0</mn></msubsup><mi>P</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">→</mo><msubsup><mi>K</mi><mrow><mi>S</mi><mo>,</mo><mi>L</mi></mrow><mn>0</mn></msubsup><mi>V</mi></math> decays, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>V</mi></math> denote pseudoscalar and vector mesons, respectively. The formulas of the time-dependent and time-integrated <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> asymmetries in these modes are derived, in which the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>D</mi></mrow><mrow><mn>0</mn></mrow></msup><mo>−</mo><msup><mrow><mover accent="true"><mrow><mi>D</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mn>0</mn></mrow></msup></mrow></math> mixing effects and the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>K</mi><mi>L</mi><mn>0</mn></msubsup></math> modes are considered for the first time. The hadronic parameters that determine <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> asymmetries are extracted by the global fit of branching fractions within the topological diagram approach. A significant result is that the tension between theoretical predictions and experimental data for the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><mo>−</mo><msubsup><mi>K</mi><mi>L</mi><mn>0</mn></msubsup></math> asymmetries 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><mrow><mi>S</mi><mo>,</mo><mi>L</mi></mrow><mn>0</mn></msubsup><mi>ω</mi></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><msubsup><mi>K</mi><mrow><mi>S</mi><mo>,</mo><mi>L</mi></mrow><mn>0</mn></msubsup><mi>ϕ</mi></math> modes is mitigated. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math>-violating effects arising from the interference between Cabibbo-favored and doubly Cabibbo-suppressed amplitudes with neutral kaon mixing could reach to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup><mo stretchy="false">)</mo></math> order in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>+</mo></msup><mo stretchy="false">→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>π</mi><mo>+</mo></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>D</mi><mi>s</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>K</mi><mo>+</mo></msup></math>, <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><msup><mi>ρ</mi><mn>0</mn></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><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><mi>ϕ</mi></math> modes. The difference between the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> asymmetries in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>+</mo></msup><mo stretchy="false">→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>π</mi><mo>+</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>D</mi><mi>s</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>K</mi><mo>+</mo></msup></math> modes will be available on LHCb and Belle II in the near future.

Ying-Xin Lai

Di Wang

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> asymmetries in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">→</mo><msubsup><mi>K</mi><mrow><mi>S</mi><mo>,</mo><mi>L</mi></mrow><mn>0</mn></msubsup><mi>P</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">→</mo><msubsup><mi>K</mi><mrow><mi>S</mi><mo>,</mo><mi>L</mi></mrow><mn>0</mn></msubsup><mi>V</mi></math> decays

We present a precise and systematic analysis of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">→</mo><mi>V</mi><mi>V</mi></math> decays within the factorization-assisted topological-amplitude approach, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi></math> denotes the set <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">{</mo><msup><mi>D</mi><mn>0</mn></msup><mo>,</mo><msup><mi>D</mi><mo>+</mo></msup><mo>,</mo><msubsup><mi>D</mi><mi>s</mi><mo>+</mo></msubsup><mo stretchy="false">}</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>V</mi></math> represents the vector mesons <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>*</mo></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ω</mi></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ϕ</mi></math>. Given the limited current experimental data, the factorization-assisted topological-amplitude approach serves as a available phenomenological framework for predicting charmed meson decays to both vector mesons. In this framework, incorporating flavor SU(3) symmetry-breaking effects, we can express nonfactorizable contributions of different modes as a minimal set of universal parameters globally fitted to experimental data. Utilizing 36 experimental data points for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">→</mo><mi>V</mi><mi>V</mi></math> decays, we precisely extract ten nonfactorizable parameters associated with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>E</mi></math> topological diagrams with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>χ</mi><mn>2</mn></msup><mo>/</mo><mrow><mi mathvariant="normal">d</mi><mo>.</mo><mi mathvariant="normal">o</mi><mo>.</mo><mi mathvariant="normal">f</mi><mo>.</mo></mrow><mo>=</mo><mn>8.43</mn></math>. We find that a large strong phase in the longitude <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>E</mi></math> amplitude causes strong destructive interference with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi></math> longitudinal component, yielding <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>f</mi><mo stretchy="false">∥</mo></msub><mo>&gt;</mo><msub><mi>f</mi><mi>L</mi></msub></math>, contrary to the naive factorization predictions. Additionally, for modes processing exclusively by the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>E</mi></math> diagram, the amplitude hierarchy <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><mi>S</mi><mo stretchy="false">|</mo><mo>&lt;</mo><mo stretchy="false">|</mo><mi>D</mi><mo stretchy="false">|</mo></math> leads to a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi></math>-wave branching fraction larger than that of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi></math> wave. This explains recent observations that contradict <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi></math>-wave dominance predictions. The predicted branching fractions and polarizations for 28 decay modes are consistent with existing experimental data. Unobserved modes, especially those with branching fractions of the order of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup><mi>–</mi><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></math>, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi></math>-wave-dominated modes, and modes exhibiting <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>f</mi><mo stretchy="false">∥</mo></msub><mo>&gt;</mo><msub><mi>f</mi><mi>L</mi></msub></math>, await measurement by BESIII, STCF, Belle II, and LHCb.

Jing Ou-Yang

Hui Zheng

Run-Hui Li

Si-Hong Zhou

Precise theoretical prediction on branching fractions and polarizations of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">→</mo><mi>V</mi><mi>V</mi></math> decays

A search is presented for massive narrow-width resonances in the mass range of 1–4.5 $$\,\text {Te}\hspace{-.08em}\text {V}$$ , decaying into pairs of Higgs bosons (HH). The search uses proton–proton collision data at a center-of-mass energy of 13 $$\,\text {Te}\hspace{-.08em}\text {V}$$ collected with the CMS detector at the CERN LHC during 2016–2018, corresponding to an integrated luminosity of 138 $$\,\text {fb}^{-1}$$ . The analysis targets final states where one Higgs boson decays into a pair of bottom quarks and the other into a pair of tau leptons, $${\text {X}} \rightarrow {\text {HH}} \rightarrow \text {b}{\bar{\text {b}}}\,\tau ^{+}\tau ^{-} $$ . It uses a single large radius jet to reconstruct the $${\text {H}} \rightarrow \text {b}{\bar{\text {b}}}$$ decay, while the $${\text {H}} \rightarrow \tau ^{+}\tau ^{-} $$ decay products can either be contained within a single large radius jet or appear as two isolated tau leptons. The observed data are consistent with standard model background expectations. Upper limits at 95% confidence level are set on the production cross section for resonant HH production for masses between 1 and 4.5 $$\,\text {Te}\hspace{-.08em}\text {V}$$ . This analysis sets the most sensitive limits to date on $${\text {X}} \rightarrow {\text {HH}} \rightarrow \text {b}\bar{\hbox {b}}\, \tau ^{+}\tau ^{-} $$ decays in the mass range of 1.4–4.5 $$\,\text {Te}\hspace{-.08em}\text {V}$$

Armenia

A. Hayrapetyan

V. Makarenko

A. Tumasyan

Austria

W. Adam

L. Benato

T. Bergauer

M. Dragicevic

P. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

M. Matthewman

J. Schieck

R. Schöfbeck

M. Shooshtari

M. Sonawane

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

H. Kwon

D. Ocampo Henao

T. Laer

P. Mechelen

J. Bierkens

N. Breugelmans

J. D’Hondt

S. Dansana

A. Moor

M. Delcourt

F. Heyen

Y. Hong

P. Kashko

S. Lowette

I. Makarenko

D. Müller

S. Tavernier

M. Tytgat

G. Onsem

S. Putte

D. Vannerom

B. Bilin

B. Clerbaux

A. Das

I. Bruyn

G. Lentdecker

H. Evard

L. Favart

P. Gianneios

A. Khalilzadeh

F. Khan

A. Malara

M. Shahzad

A. Sharma

L. Thomas

M. Vanden Bemden

C. Vander Velde

P. Vanlaer

F. Zhang

M. Coen

D. Dobur

C. Giordano

G. Gokbulut

K. Kaspar

D. Kavtaradze

D. Marckx

K. Skovpen

A. Tomaru

N. Bossche

J. Linden

J. Vandenbroeck

H. Aarup Petersen

S. Bein

A. Benecke

A. Bethani

G. Bruno

A. Cappati

J. Jeneret

C. Delaere

F. Gameiro Casalinho

A. Giammanco

A. Guzel

V. Lemaitre

J. Lidrych

P. Malek

P. Mastrapasqua

S. Turkcapar

Brazil

G. Alves

M. Barroso Ferreira Filho

E. Coelho

C. Hensel

D. Matos Figueiredo

T. Oliveira

C. Mora Herrera

P. Rebello Teles

M. Soeiro

E. Tonelli Manganote

A. Vilela Pereira

W. Aldá Júnior

H. Brandao Malbouisson

Search for heavy resonances decaying into two Higgs bosons in the $$\text {b}{\bar{\text {b}}} \tau ^{+} \tau ^{-} $$ final state in proton–proton collisions at $$\sqrt{s} = 13\,\text {Te}\hspace{-.08em}\text {V} $$

The observation of resonant di-Higgs production, which would strongly suggest the existence of a new heavy neutral scalar <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi></math>, has been searched for extensively at the LHC. In the two-Higgs doublet model (2HDM) with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>H</mi></msub><mo>≫</mo><msub><mi>m</mi><mi>h</mi></msub></math>, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>h</mi></math> is the Higgs boson of mass 125 GeV observed at the LHC, we show that a direct correlation emerges between <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Br</mi><mo stretchy="false">(</mo><mi>H</mi><mo stretchy="false">→</mo><mi>h</mi><mi>h</mi><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Br</mi><mo stretchy="false">(</mo><mi>H</mi><mo stretchy="false">→</mo><mi>V</mi><mi>V</mi><mo stretchy="false">)</mo></math>, with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>V</mi><mo>=</mo><mi>Z</mi></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>W</mi></mrow></math>, which depends only on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>H</mi></msub></math> (and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>V</mi></msub></math>). In particular, for heavy scalar masses between 500 GeV and 1 TeV, we find that <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>Br</mi><mo stretchy="false">(</mo><mi>H</mi><mo stretchy="false">→</mo><mi>h</mi><mi>h</mi><mo stretchy="false">)</mo><mo>/</mo><mi>Br</mi><mo stretchy="false">(</mo><mi>H</mi><mo stretchy="false">→</mo><mi>Z</mi><mi>Z</mi><mo stretchy="false">)</mo><mo>≈</mo><mn>9.4</mn><mo>±</mo><mn>0.25</mn></mrow></math>. Moreover, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mi>h</mi><mi>h</mi></math> is a dominant decay mode over a significant region of the parameter space and serves as the primary probe for a heavy scalar resonance at current and future hadron colliders. The origin of these predictions is most transparent in the Higgs basis, where the term in the scalar potential proportional to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="script">H</mi><mn>1</mn><mi>†</mi></msubsup><msub><mi mathvariant="script">H</mi><mn>1</mn></msub><msubsup><mi mathvariant="script">H</mi><mn>1</mn><mi>†</mi></msubsup><msub><mi mathvariant="script">H</mi><mn>2</mn></msub></math> (and its Hermitian conjugate) generates the leading contributions to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>h</mi><mi>h</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>h</mi><mi>h</mi><mi>h</mi></math> couplings in the decoupling limit of the 2HDM. Additionally, the latter coupling governs the resonant prompt tri-Higgs production via <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mi>h</mi><mi>h</mi><mi>h</mi></math>, which is also directly correlated to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mi>h</mi><mi>h</mi></math> (and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mi>V</mi><mi>V</mi></math>), and can yield rates large enough to be measured at the High-Luminosity LHC.

Italy

Guglielmo Coloretti

Spain

Andreas Crivellin

Howard E. Haber

Correlating resonant di-Higgs and tri-Higgs production to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mi>V</mi><mi>V</mi></math> in the two-Higgs-doublet model

Superallowed (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>0</mn><mo>+</mo></msup><mo stretchy="false">→</mo><msup><mn>0</mn><mo>+</mo></msup></math>) beta decays currently provide the most precise extraction of quark mixing in the Standard Model. Their interpretation as a measurement of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><msub><mi>V</mi><mrow><mi>u</mi><mi>d</mi></mrow></msub><mo stretchy="false">|</mo></math> relies on a reliable first-principles computation of QED radiative corrections expressed as a series in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi><mi>α</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>α</mi></math>. In this work, we provide the first model-independent result for two-loop, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>O</mi><mo stretchy="false">(</mo><mi>Z</mi><msup><mi>α</mi><mn>2</mn></msup><mo stretchy="false">)</mo></math>, long-distance radiative corrections where the nuclei are treated as heavy pointlike particles. We use renormalization group analysis to obtain new results at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>O</mi><mo stretchy="false">(</mo><mi>Z</mi><msup><mi>α</mi><mn>3</mn></msup><mo stretchy="false">)</mo></math> for the coefficient of double logarithms in the ratio of the maximal beta energy to the inverse nuclear size, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>E</mi><mi>m</mi></msub><mo>/</mo><msup><mi>R</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>. We use the Kinoshita-Lee-Nauenberg theorem to obtain new results at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>O</mi><mo stretchy="false">(</mo><msup><mi>Z</mi><mn>2</mn></msup><msup><mi>α</mi><mn>3</mn></msup><mo stretchy="false">)</mo></math> for the coefficient of logarithms in the ratio of maximal beta energy to the electron mass, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>log</mi><mo stretchy="false">(</mo><mn>2</mn><msub><mi>E</mi><mi>m</mi></msub><mo>/</mo><mi>m</mi><mo stretchy="false">)</mo></math>. We identify a structure-dependent, and, therefore, short-distance, contribution to the traditional <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi><msup><mi>α</mi><mn>2</mn></msup></math> correction that should be revisited. We provide the first comprehensive update to the long-distance corrections in almost 40 years and comment on the impact of our findings for extractions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><msub><mi>V</mi><mrow><mi>u</mi><mi>d</mi></mrow></msub><mo stretchy="false">|</mo></math>. We find that shifts in the long-distance corrections are <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.5</mn><mo>×</mo></math> larger than past estimates of their uncertainty, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1.5</mn><mo>×</mo></math> larger than the statistical uncertainty from the combined fit of superallowed decays, and about <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mo>/</mo><mn>2</mn></math> the size of estimated systematic error, which stems dominantly from nuclear structure effects.

Zehua Cao

Richard J. Hill

CERN

Ryan Plestid

Peter Vander Griend

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi><msup><mi>α</mi><mn>2</mn></msup></math> correction to superallowed beta decays in effective field theory and implications for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><msub><mi>V</mi><mrow><mi>u</mi><mi>d</mi></mrow></msub><mo stretchy="false">|</mo></math>

We analyze the charmless two-body decays of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> meson into a pseudoscalar and a vector meson, referred to as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>P</mi><mi>V</mi></math> decay, within the framework of the modified perturbative QCD (PQCD) approach, which was originally developed to solve the long-standing puzzles, the so-called <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi><mi>π</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi><mi>K</mi></math> puzzles. In this method, based on the conventional PQCD calculations, soft form factors and contributions arising from color-octet quark-antiquark components in the final state are introduced, which involve essentially nonperturbative dynamics. By employing the flavor SU(3) symmetry and its breaking effect, the parameters describing soft contributions are correlated and subsequently reduced into a more concise set of SU(3) parameters. Through a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>χ</mi><mn>2</mn></msup></math> analysis procedure applied to the experimental data, these parameters are determined, from which the corresponding theoretical results for the branching ratios and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> asymmetries in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>P</mi><mi>V</mi></math> decays are derived. Within this framework, it is demonstrated that the theoretical calculations align well with experimental measurements, suggesting that the method developed for solving <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi><mi>π</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi><mi>K</mi></math> puzzles can be extended to more decay modes of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> meson. The numerical analysis shows that these soft contributions have a significant influence on the theoretical results. Furthermore, more precise experimental data are needed for deeper investigations of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> asymmetries.

Sheng Lü

Ru-Xuan Wang

Mao-Zhi Yang

Phenomenological analysis of charmless <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo stretchy="false">→</mo><mi>P</mi><mi>V</mi></math> decays in the modified perturbative QCD approach