We perform a detailed study of the current phenomenological status of baryon number violating operators within the framework of the $\textit{R}$-parity violating Minimal Supersymmetric Standard Model (RPV-MSSM). This study aims to identify any gaps in the experimental coverage of the RPV landscape. We identify the unique final states for all possible LSPs decaying via four different benchmark UDD operators. Both the direct production of the LSP and its production via gauge-cascades are considered. For each LSP, we assume that only one UDD coupling is non-zero at a time and confront the signals with existing ATLAS and CMS searches implemented in the recasting framework CheckMATE 2. We find that the UDD colored LSP sector is well covered with the mass bounds on the gluino LSP being the strongest, and with possible improvements for some of the right-handed squark LSPs. We also point out that there is limited coverage for electroweakino and slepton LSPs with UDD decays. This limitation may be due to the lack of targeted experimental searches for these specific final states or the appropriate recasting of existing searches.

Germany

Herbi Dreiner

United States

Michael Hank

Sweden

Yong Koay

Martin Schürmann

Rhitaja Sengupta

Apoorva Shah

Nadja Strobbe

Evelyn Thomson

The ABC of RPV. Part II. Classification of R-parity violating signatures from UDD couplings and their coverage at the LHC

The detection of primordial B-modes, a key probe of cosmic inflation, is increasingly challenged by contamination from weak gravitational lensing B-modes induced by large-scale structure (LSS). We present a delensing pipeline designed to enhance the sensitivity to the inflationary parameter $\textit{r}$, minimizing reliance on foreground mitigation during lensing reconstruction. Using simulations of Simons Observatory-like CMB observations and $\textit{Euclid}$-like LSS surveys in the Northern hemisphere, we demonstrate that excluding low- $$\ell $$ modes ( $$\ell <200$$ ) effectively mitigates foreground biases, enabling robust lensing potential reconstruction using observed CMB polarization maps. We reconstruct the lensing potential with a minimum-variance (MV) quadratic estimator (QE) applied to CMB polarization data and combine this with external LSS tracers to improve delensing efficiency. Two complementary methods – the gradient-order template and the Inverse-lensing approach – are used to generate lensing B-mode templates, which are cross-correlated with observed B-modes. This achieves a 40% reduction in the uncertainty of r with CMB-only reconstruction, improving to 60% when incorporating external LSS tracers. We validate our results using both the Hamimeche and Lewis likelihood and a Gaussian approximation, finding consistent constraints on $\textit{r}$. Our work establishes a streamlined framework for ground-based CMB experiments, demonstrating that synergies with LSS surveys significantly enhance sensitivity to primordial gravitational waves.

China

Wen-Zheng Chen

Yang Liu

Yi-Ming Wang

Hong Li

Delensing for precision cosmology: optimizing future CMB B-mode surveys to constrain $\textit{r}$

Polarization is a prominent feature of gravitational wave observations and can be used to distinguish between different modified gravity theories. Compared to General Relativity, $\textit{f}$($\textit{R}$) gravity exhibits an additional polarization originating from a scalar field, which is a combination of the longitudinal and breathing modes. When the scalar mass of $\textit{f}$($\textit{R}$) is zero, the mixed mode will reduce to a pure breathing mode with the disappearance of the longitudinal mode. However, this reducing seems to be disallowed because a positive scalar mass is often required to maintain the stability of the cosmological perturbation. In fact, the massless scalar case can provide a stable perturbation, but more detailed constraints need to be considered. For the completeness of the polarization analysis, we explore the possibility that there are stable massless scalar polarizations in viable dark energy $\textit{f}$($\textit{R}$) models. We find that the existence of stable massless scalar polarization depends on the structure of $\textit{f}$($\textit{R}$) model and can be used to distinguish different models in $\textit{f}$($\textit{R}$) gravity.

Xin-Dong Du

Peng-Cheng Li

Stable massless scalar polarization of $\textit{f}$($\textit{R}$) gravity

In this article, we explore an anisotropic model to describe the Buchdahl compact star with a spherically symmetric matter distribution within the framework of modified <math altimg='si1.svg'><mi>f</mi><mo stretchy='false'>(</mo><mi>R</mi><mo stretchy='false'>)</mo></math> gravity. To achieve this, we consider the Starobinsky model <math altimg='si2.svg'><mi>f</mi><mo stretchy='false'>(</mo><mi>R</mi><mo stretchy='false'>)</mo><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><mi>R</mi><mo linebreak='goodbreak' linebreakstyle='after'>+</mo><mi>&#945;</mi><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math>, where <italic>&#945;</italic> is a model parameter. To solve the Einstein Field equations, we adopt the embedded class-I geometry that satisfies the Karmarkar condition. Our analysis includes the generalized Darmois-Israel junction conditions, which are crucial for seamlessly matching the star's interior to the Schwarzschild exterior metric at the boundary in <math altimg='si1.svg'><mi>f</mi><mo stretchy='false'>(</mo><mi>R</mi><mo stretchy='false'>)</mo></math> gravity. These conditions have been employed to calculate the constant parameters by analyzing observational data from multiple compact stars, including <italic>Cen X-3, PSR J1903+327, Vela X-1</italic>, and <italic>PSR J1614-2230</italic>. This novel approach enables us to conduct a detailed analysis of Buchdahl compact star models and assess their physical viability. We also perform various physical tests, including equilibrium conditions and stability to evaluate the models' validity. The analysis of mass and radius reveals that the <math altimg='si3.svg'><mi>M</mi><mo linebreak='goodbreak' linebreakstyle='after'>&#8722;</mo><mi>R</mi></math> relationship is based on the Buchdahl limit and is sensitive to variations in the parameter <italic>&#945;</italic>. With <math altimg='si4.svg'><mi>&#945;</mi><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><mn>0</mn></math> representing General Relativity, the maximum mass and radius for different <italic>&#945;</italic> values were calculated and compared with observational data from the five aforementioned neutron stars. The range of maximum mass and radii are: <math altimg='si5.svg'><mo stretchy='false'>[</mo><mn>2.51</mn><mo linebreak='badbreak' linebreakstyle='after'>&#8722;</mo><mn>2.54</mn><mspace width='0.25em' /><msub><mrow><mi>M</mi></mrow><mrow><mo>&#8857;</mo></mrow></msub><mo stretchy='false'>]</mo></math> and <math altimg='si6.svg'><mn>8.71</mn><mo linebreak='goodbreak' linebreakstyle='after'>&#8722;</mo><mn>9.33</mn><mspace width='0.25em' /><mtext>km</mtext></math>. The obtained values of radii align well with observed neutron star radii in X-ray binaries from spectroscopic studies, confirming the validity of the model.

India

Rajesh Kumar

Azerbaijan

Oman

S.K. Maurya

Y. Sekhmani

Saudi Arabia

Akram Ali

Uzbekistan

Farruh Atamurotov

Anisotropic compact stars in quadratic <italic>f</italic>( <italic>R</italic>) gravity and influence of quadratic parameter on properties of compact stars

Based on a previously derived superstring model possessing a cosmological sector that mimics Starobinsky inflation, we analyze several questions addressed in the recent literature: the generation of an effective $\textit{R}$ -term, the stability of the sgoldstino, the modular symmetry of the inflaton potential and the large distance swampland conjecture. We first show that the presence of the string dilaton stabilizes the sgoldstino direction in the supersymmetric case and no modification of the Kähler potential is needed. This is a generic property of a large class of Starobinsky type models within the framework of no-scale supergravity. We then present an explicit example of a string derived inflaton potential where the large values of the inflaton field during inflation imply a decompactification of two extra dimensions, while the scale of inflation is generated by higher order $\textit{α}$ -corrections via expectation values that cancel the D-term of an anomalous U(1) symmetry and break the modular symmetry of the scalar potential. As a result, the scale of inflation is much lower than the compactification scale which at the end of inflation is fixed at the free-fermionic self-dual point at an (approximate) supersymmetric minimum.

France

Thailand

Ignatios Antoniadis

Greece

Switzerland

Dimitri Nanopoulos

Keith Olive

An angular analysis of $\textit{B}$ $\textit{→ K}$ $\textit{e}$ $\textit{e}$ decays is presented using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb . The analysis is performed in the region of the dilepton invariant mass squared of 1.1–6.0 GeV /$\textit{c}$ . In addition, a test of lepton flavour universality is performed by comparing the obtained angular observables with those measured in $\textit{B}$ $\textit{→ K}$ $\textit{μ}$ $\textit{μ}$ decays. In general, the angular observables are found to be consistent with the Standard Model expectations as well as with global analyses of other $\textit{b → sℓ}$ $\textit{ℓ}$ processes, where $\textit{ℓ}$ is either a muon or an electron. No sign of lepton-flavour-violating effects is observed.

Netherlands

R. Aaij

United Kingdom

A. Abdelmotteleb

C. Abellan Beteta

F. Abudinén

T. Ackernley

A. Adefisoye

Spain

B. Adeva

M. Adinolfi

P. Adlarson

C. Agapopoulou

C. Aidala

Z. Ajaltouni

S. Akar

K. Akiba

Italy

P. Albicocco

J. Albrecht

F. Alessio

Z. Aliouche

P. Alvarez Cartelle

R. Amalric

Brazil

S. Amato

J. Amey

Y. Amhis

L. An

L. Anderlini

M. Andersson

A. Andreianov

P. Andreola

M. Andreotti

D. Andreou

A. Anelli

D. Ao

F. Archilli

M. Argenton

Costa Rica

S. Arguedas Cuendis

A. Artamonov

M. Artuso

E. Aslanides

R. Ataíde Da Silva

M. Atzeni

B. Audurier

D. Bacher

I. Bachiller Perea

S. Bachmann

M. Bachmayer

J. Back

P. Baladron Rodriguez

V. Balagura

W. Baldini

L. Balzani

H. Bao

J. Baptista de Souza Leite

C. Barbero Pretel

M. Barbetti

I. Barbosa

R. Barlow

M. Barnyakov

S. Barsuk

W. Barter

M. Bartolini

J. Bartz

J. Basels

Poland

S. Bashir

G. Bassi

B. Batsukh

P. Battista

A. Bay

A. Beck

M. Becker

F. Bedeschi

I. Bediaga

N. Behling

S. Belin

V. Bellee

K. Belous

I. Belov

I. Belyaev

G. Benane

G. Bencivenni

E. Ben-Haim

A. Berezhnoy

R. Bernet

S. Bernet Andres

A. Bertolin

C. Betancourt

F. Betti

J. Bex

Ia. Bezshyiko

J. Bhom

M. Bieker

N. Biesuz

P. Billoir

A. Biolchini

M. Birch

F. Bishop

A. Bitadze

A. Bizzeti

T. Blake

F. Blanc

J. Blank

Angular analysis of B

The 3 <italic>&#945;</italic> reaction plays a crucial role in stellar nucleosynthesis, as it is responsible for synthesizing carbon from helium. This reaction overcomes the <math altimg='si1.svg'><mi>A</mi><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><mn>5</mn></math> and <math altimg='si2.svg'><mi>A</mi><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><mn>8</mn></math> mass gaps, allowing the synthesis of heavier elements in stars. Additionally, this reaction significantly influences the evolution of the first-generation stars, accreting white dwarfs, and neutron stars. The relevant temperature range spans from 0.01 to 10 GK. Prior rate evaluations of the sequential process [ <italic>&#945;</italic>+ <italic>&#945;</italic>&#8594; 8Be( <italic>&#945;</italic>, <italic>&#947;</italic>) 12C] have primarily focused on the uncertainties associated with the resonance parameters in 8Be and 12C states. Since direct measurement data for the 8Be( <italic>&#945;</italic>, <italic>&#947;</italic>) 12C capture reaction is unavailable, the effect of interference between the direct (non-resonant) and resonance capture components of the 8Be( <italic>&#945;</italic>, <italic>&#947;</italic>) 12C capture reaction remains uncertain in the sequential 3 <italic>&#945;</italic> path. In particular, previous studies have not taken into account the uncertainty arising from this interference effect. In this work, a phenomenological <italic>R</italic>-matrix model has been employed to analyze the required <italic>&#945;</italic>+ <italic>&#945;</italic> scattering and the 8Be( <italic>&#945;</italic>, <italic>&#947;</italic>) 12C capture excitation functions. The present rate evaluation method incorporates uncertainties from both interference effects and resonance/bound-state parameters, utilizing updated nuclear data on 12C. The revised 3 <italic>&#945;</italic> reaction rate exhibits significantly greater uncertainty than previous evaluations due to the inclusion of interference effects in the 8Be( <italic>&#945;</italic>, <italic>&#947;</italic>) 12C reaction. Interference effects contribute approximately 75% to the total uncertainty. When considering only parameter uncertainties, the present rate aligns well with previous studies within the 0.1&#8211;2 GK temperature range. The present upper limits of the 3 <italic>&#945;</italic> rate are two orders of magnitude lower than the astrophysical limits.

Rajkumar Santra

Sk Mustak Ali

New limits on the 3 <italic>&#945;</italic> reaction rate from <italic>R</italic>-matrix modeling

A search for the decay $$ {B}_c^{+} $$ $\textit{→ χ}$ (3872)$\textit{π}$ is reported using proton-proton collision data collected with the LHCb detector between 2011 and 2018 at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of 9 fb . No significant signal is observed. Using the decay $$ {B}_c^{+} $$ → $\textit{ψ}$(2$\textit{S}$)$\textit{π}$ as a normalisation channel, an upper limit for the ratio of branching fractions

M. Alexander

A. Balboni

Search for the $$ {B}_c^{+} $$ $\textit{→ χ}$

We search for the leptonic decay $ D^+\to e^+\nu_{e} $ using an $ e^+e^- $ collision data sample with an integrated luminosity of 20.3 fb $ ^{-1} $ collected with the BESIII detector at a center-of-mass energy of 3.773 GeV. Significant signal is not observed, and an upper limit on the branching fraction of $ D^+\to e^+\nu_{e} $ is set as $ 9.7 \times 10^{-7} $ , at a confidence level of 90%. Our upper limit is an order of magnitude smaller than the previous limit for this decay mode.

M. Ablikim

Russia

M.N. Achasov

O. Afedulidis

X.C. Ai

R. Aliberti

A. Amoroso

Q. An

Y. Bai

O. Bakina

I. Balossino

Y. Ban

H.R. Bao

V. Batozskaya

Mongolia

K. Begzsuren

N. Berger

M. Berlowski

M. Bertani

D. Bettoni

F. Bianchi

E. Bianco

A. Bortone

I. Boyko

R.A. Briere

A. Brueggemann

H. Cai

X. Cai

A. Calcaterra

G.F. Cao

N. Cao

Türkiye

S.A. Cetin

X.Y. Chai

J.F. Chang

G.R. Che

Y.Z. Che

G. Chelkov

C. Chen

Search for the leptonic decay ${\boldsymbol D^{\bf +}{\bf\to}{\boldsymbol e}^{\bf +}\boldsymbol\nu_{\boldsymbol e}}$ * Supported in part by the National Key R&D Program of China (2023YFA1606000, 2020YFA0406400, 2020YFA0406300), the National Natural Science Foundation of China(NSFC) (11635010, 11735014, 11935015, 11935016, 11875054, 11935018, 12025502, 12035009, 12035013, 12061131003, 12192260, 12192261, 12192262, 12192263, 12192264, 12192265, 12221005, 12225509, 12235017, 12361141819), the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program, the CAS Center for Excellence in Particle Physics (CCEPP), the Joint Large-Scale Scientific Facility Funds of the NSFC and CAS (U2032104, U1832207), the 100 Talents Program of CAS, the Excellent Youth Foundation of Henan Scientific Commitee (242300421044), the Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology, the German Research Foundation DFG (FOR5327), the Istituto Nazionale di Fisica Nucleare, Italy, the Knut and Alice Wallenberg Foundation (2021.0174, 2021.0299), the Ministry of Development of Turkey (DPT2006K-120470), the National Research Foundation of Korea (NRF-2022R1A2C1092335), the National Science and Technology Fund of Mongolia, the National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources & Institutional Development, Research, and Innovation of Thailand (B16F640076, B50G670107), the Polish National Science Center (2019/35/O/ST2/02907), the Swedish Research Council (2019.04595), the Swedish Foundation for International Cooperation in Research and Higher Education (CH2018-7756), and the US Department of Energy (DE-FG02-05ER41374).