The IceCube Neutrino Observatory has observed a diffuse flux of high-energy astrophysical neutrinos for more than a decade. A relevant background to the astrophysical flux is prompt atmospheric neutrinos, originating from the decay of charmed mesons produced in cosmic-ray-induced air showers. The production rate of charmed mesons in the very forward phase space of hadronic interactions, and consequently, the prompt neutrino flux, remains uncertain and has not yet been observed by neutrino detectors. An accurate measurement of this flux would enhance our understanding of fundamental particle physics such as hadronic interactions in high-energy cosmic-ray-induced air showers and the nucleon structure. Furthermore, an experimental characterization of this background flux will improve the precision of astrophysical neutrino flux spectral measurements. In this work, we perform a combined fit of cascade-like and track-like neutrino events in IceCube to constrain the prompt atmospheric neutrino flux. Given that the prompt flux is a sub-dominant contribution, treating systematic uncertainties arising from the potential mis-modeling of the conventional and astrophysical neutrino fluxes is critical for its measurement. Our analysis yields a non-zero best-fit result, which is, however, consistent with the null hypothesis of no prompt flux within one standard deviation. Consequently, we establish an upper bound on the flux at $$4\times 10^{-16}$$ (GeV m $$^2$$ s sr) $$^{-1}$$ at 10TeV.

United States

R. Abbasi

Germany

M. Ackermann

New Zealand

J. Adams

India

S. Agarwalla

Belgium

J. Aguilar

Denmark

M. Ahlers

J. Alameddine

S. Ali

N. Amin

K. Andeen

C. Argüelles

Y. Ashida

S. Athanasiadou

S. Axani

R. Babu

X. Bai

J. Baines-Holmes

A. V.

S. Barwick

S. Bash

V. Basu

R. Bay

J. Beatty

Sweden

J. Tjus

P. Behrens

J. Beise

C. Bellenghi

S. Benkel

S. BenZvi

D. Berley

Italy

E. Bernardini

D. Besson

E. Blaufuss

L. Bloom

S. Blot

I. Bodo

F. Bontempo

J. Motzkin

C. Meneguolo

S. Böser

O. Botner

J. Böttcher

J. Braun

B. Brinson

Canada

Z. Brisson-Tsavoussis

Australia

R. Burley

D. Butterfield

M. Campana

K. Carloni

J. Carpio

S. Chattopadhyay

N. Chau

Z. Chen

D. Chirkin

S. Choi

B. Clark

P. Coleman

G. Collin

D. Borja

A. Connolly

J. Conrad

D. Cowen

C. Clercq

J. DeLaunay

D. Delgado

T. Delmeulle

S. Deng

P. Desiati

K. de Vries

G. de Wasseige

T. DeYoung

J. Díaz-Vélez

S. DiKerby

T. Ding

M. Dittmer

A. Domi

L. Draper

L. Dueser

D. Durnford

K. Dutta

M. DuVernois

T. Ehrhardt

L. Eidenschink

A. Eimer

C. Eldridge

P. Eller

E. Ellinger

D. Elsässer

R. Engel

H. Erpenbeck

W. Esmail

S. Eulig

J. Evans

P. Evenson

K. Fan

K. Fang

Japan

K. Farrag

A. Fazely

Taiwan

A. Fedynitch

N. Feigl

Constraining the Prompt Atmospheric Neutrino Flux combining IceCube’s Cascade and Track samples

The four-body decays $$D^+ \rightarrow K^-\pi ^+e^+\nu _e$$ ( $$D_{e4}^+$$ ) and $$D^0\rightarrow \overline{K^0}\pi ^-e^+\nu _e$$ ( $$D^0_{e4}$$ ) are studied in a model where the momentum-dependence of the hadronic matrix elements are described in terms of $$K^*(892)$$ and $$D^*(2010)$$ pole contributions. From fits to the recent data of the BESIII collaboration we find that the $$D^*$$ -pole can mimic the effect of the $\textit{S}$-wave contribution of the $$K\pi $$ system to the branching fraction. Implications for the determination of the $$|V_{cs}|$$ quark mixing matrix element are discussed.

Mexico

J. Santiago

G. Castro

Semileptonic $$D_{e4}$$ decays: hadronic dynamics and the determination of $$|V_{cs}|$$

Within a model-independent framework that includes an $\textit{SU}$(2) singlet vector-like top quark (VLQ-$\textit{T}$), we investigate the prospects for detecting pair production of the VLQ-$\textit{T}$ in $$e^+e^-$$ collisions at the 3 TeV Compact Linear Collider (CLIC). We focus on signal final states from the $$T \rightarrow Wb$$ decay channel, with the resulting $\textit{W}$ bosons decaying hadronically. We show that the TeV-scale mass of the VLQ-$\textit{T}$ leads to highly boosted $\textit{W}$ bosons, which manifest as collimated fat jets. These serve as distinctive experimental signatures for signal identification. By performing a full simulation of the signal processes and the relevant Standard Model backgrounds, we respectively derive the $$2\sigma $$ exclusion limits on the VLQ-$\textit{T}$ mass and the $$5\sigma $$ discovery prospects for the $$T \rightarrow Wb$$ branching ratio.

China

Jin-Zhong Han

Jing-Yun Li

Zhou-Run Zhu

Shang-Li Zhao

Shuai Xu

Pair production of the vector-like top partner at the 3 TeV CLIC in fully hadronic final states

A search is presented for emerging jets using $$140~\textrm{fb}^{-1}$$ of proton–proton collision data at $$\sqrt{s} = 13~\textrm{TeV}$$ , collected by the ATLAS experiment between 2015 and 2018. The search looks for the existence of a dark sector with symmetries similar to those in quantum chromodynamics. This dark sector is populated with dark quarks, which undergo showering similar to quarks in the Standard Model, leading to a high multiplicity of long-lived dark hadrons within a dark jet. These dark hadrons subsequently decay to Standard Model particles via a new heavy scalar mediating particle $$\phi $$ . This results in jets which contain multiple displaced vertices, known as emerging jets. This analysis targets four-jet topologies, with two emerging jets and two Standard Model jets, resulting from the decay of pair-produced scalar mediators. No significant excess above the Standard Model background is observed. For dark pion proper decay lengths of $$20~\textrm{mm}$$ , mediator masses are excluded between 1 and $$2~\textrm{TeV}$$ assuming a dark pion mass of $$20~\textrm{GeV}$$ .

France

G. Aad

Norway

E. Aakvaag

B. Abbott

United Arab Emirates

S. Abdelhameed

K. Abeling

N. Abicht

S. Abidi

M. Aboelela

Morocco

A. Aboulhorma

Israel

H. Abramowicz

Y. Abulaiti

United Kingdom

B. Acharya

A. Ackermann

C. Bourdarios

Poland

L. Adamczyk

S. Addepalli

M. Addison

J. Adelman

Türkiye

A. Adiguzel

T. Adye

A. Affolder

Y. Afik

Spain

M. Agaras

A. Aggarwal

Romania

C. Agheorghiesei

Azerbaijan

F. Ahmadov

S. Ahuja

X. Ai

G. Aielli

A. Aikot

M. Tamlihat

B. Aitbenchikh

T. Åkesson

A. Akimov

D. Akiyama

N. Akolkar

S. Aktas

G. Alberghi

J. Albert

Switzerland

U. Alberti

P. Albicocco

G. Albouy

S. Alderweireldt

Z. Alegria

M. Aleksa

I. Aleksandrov

C. Alexa

Greece

T. Alexopoulos

F. Alfonsi

M. Algren

M. Alhroob

Czechia

B. Ali

Saudi Arabia

H. Ali

S. Alibocus

South Africa

M. Aliev

G. Alimonti

W. Alkakhi

Search for emerging jets in $\textit{pp}$ collisions at $$\sqrt{s} = 13~\textrm{TeV}$$ with the ATLAS experiment