The Real Higgs Triplet model, known as the $$\varDelta $$ SM, is a minimal extension of the Standard Model (SM) obtained by adding a hypercharge 0 triplet ( $$\varDelta $$ ). This simple model is motivated by the multi-lepton anomalies and excesses in di-photon, $$Z\gamma $$ , and $\textit{WW}$ spectra at $$\approx 152$$ GeV. The model contains, in addition to the SM particle content, a $\textit{CP}$-even neutral Higgs ( $$\varDelta ^0$$ ) and a charged state ( $$\varDelta ^\pm $$ ), which are quasi-degenerate in mass. Observing the charged scalar at the LHC and measuring its mass is very challenging, since it dominantly decays to $\textit{WZ}$, $\textit{tb}$, and $$\tau \nu $$ . In this article, we consider the discovery prospects of the charged Higgs with mass 150 GeV at future electron-positron colliders. Taking into account $$e^+e^- \rightarrow \gamma ^*,Z^* \rightarrow \varDelta ^\pm \varDelta ^\mp $$ as the production mechanism and the dominant decay modes, we define three signal regions (SR) to study the 150 GeV charged Higgs properties: SR1: $$\ge 3j + 1\ell $$ , SR2: $$\ge 3\ell + \tau _{\text {had}}$$ , SR3: $$\ge 4j + \tau _{\text {had}}$$ . For $$m_{\varDelta ^\pm }=150\,\text {GeV}$$ , a $$5\sigma $$ significance can be achieved in SR1 with an integrated luminosity of less than $$1\text {~fb}^{-1}$$ . SR2 is very clean with leptonic final states having low background and small systematic uncertainties. Furthermore, SR3 is crucial for reconstructing the charged scalar invariant mass, which can be measured with $$\mathcal {O}(1)$$ GeV accuracy with an integrated luminosity of $$500\text {~fb}^{-1}$$ .

South Africa

India

Siddharth Maharathy

Phodiso Maroeshe

Paballo Ndhlovu

Srimoy Bhattacharya

Switzerland

Andreas Crivellin

Mukesh Kumar

Rachid Mazini

Bruce Mellado

Discovery prospects for the 150 GeV charged scalar at future $$e^+e^-$$ colliders

<p>A search is performed for a new resonance <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>X</mi></math> decaying into a Higgs boson and a new scalar boson <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Y</mi></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>Y</mi></math>) including the case where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Y</mi></math> is assumed to be a second Higgs boson (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>H</mi></math>), using proton-proton collision data collected at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>, 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>. This study performs a comprehensive exploitation of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mi>b</mi><mi>Z</mi><mi>Z</mi></math> events, encompassing the following decay topologies. One <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi></math> candidate is identified through its decay into a bottom quark-antiquark pair, while the other <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi></math> or the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Y</mi></math> candidate is selected through its decay into a pair of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi></math> bosons. One <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi></math> boson is required to decay leptonically and the other, to decay into a pair of quarks or neutrinos. Events of interest are categorized based on the Lorentz boosts of the hadronically decaying <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi></math> bosons. Machine-learning-based discriminants, together with the reconstructed resonance mass, are employed across the different categories to separate signal from backgrounds, and their corresponding distributions are included in a simultaneous fit. No significant deviations from the standard model predictions are observed. Upper limits at the 95% confidence level are set on the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>Y</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>H</mi></math> production cross sections. For <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>Y</mi></math> production, the upper limit on the cross section of the process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi><mo stretchy="false">→</mo><mi>X</mi><mo stretchy="false">→</mo><mrow><mi>H</mi><mi>Y</mi></mrow><mo stretchy="false">→</mo><mi>b</mi><mi>b</mi><mi>Z</mi><mi>Z</mi></math> ranges from 500 to 5 fb, with the most stringent constraints achieved for high-mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>X</mi></math> resonances and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Y</mi></math> masses near the threshold for decay into a pair of massive vector bosons. This is comparable to the sensitivity achieved in other analyses, which focus on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi></math> decays to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>γ</mi></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi><mi>τ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Y</mi></math> decays into a pair of bottom quarks or massive vector bosons. For resonant <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>H</mi></math> production, the upper limit on the cross section of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi><mo stretchy="false">→</mo><mi>X</mi><mo stretchy="false">→</mo><mrow><mi>H</mi><mi>H</mi></mrow></math> production is 1 pb for a high-mass resonance.</p>

Armenia

A. Hayrapetyan

V. Makarenko

A. Tumasyan

Austria

W. Adam

L. Benato

T. Bergauer

M. Dragicevic

P.S. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

M. Matthewman

J. Schieck

R. Schöfbeck

M. Shooshtari

M. Sonawane

N. Van Den Bossche

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

H. Kwon

D. Ocampo Henao

T. Van Laer

P. Van Mechelen

D. Ahmadi

J. Bierkens

N. Breugelmans

J. D’Hondt

S. Dansana

A. De Moor

M. Delcourt

C. Gupta

F. Heyen

Y. Hong

P. Kashko

S. Lowette

I. Makarenko

S. Nandakumar

S. Tavernier

M. Tytgat

G.P. Van Onsem

S. Van Putte

D. Vannerom

A. Beshr

B. Bilin

F. Caviglia Roman

B. Clerbaux

A.K. Das

I. De Bruyn

G. De Lentdecker

E. Ducarme

H. Evard

L. Favart

A. Khalilzadeh

A. Malara

M.A. Shahzad

A. Sharma

L. Thomas

M. Vanden Bemden

C. Vander Velde

P. Vanlaer

F. Zhang

A. Cauwels

M. De Coen

D. Dobur

C. Giordano

G. Gokbulut

K. Kaspar

D. Kavtaradze

D. Marckx

K. Skovpen

A.M. Tomaru

J. van der Linden

J. Vandenbroeck

H. Aarup Petersen

S. Bein

A. Benecke

A. Bethani

G. Bruno

A. Cappati

J. De Favereau De Jeneret

C. Delaere

F. Gameiro Casalinho

A. Giammanco

A.O. Guzel

V. Lemaitre

J. Lidrych

P. Malek

S. Turkcapar

Brazil

G.A. Alves

M. Barroso Ferreira Filho

E. Coelho

C. Hensel

D. Matos Figueiredo

T. Menezes De Oliveira

C. Mora Herrera

P. Rebello Teles

M. Soeiro

E.J. Tonelli Manganote

Search for a new resonance decaying to a Higgs boson and a scalar boson in events with two <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math> jets and two <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi></math> bosons in proton-proton collisions at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>

<p>The first search for the lepton-flavor violating decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>B</mi></mrow><mrow><mo>+</mo></mrow></msup><mo stretchy="false">→</mo><mrow><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>±</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>∓</mo></mrow></msup></mrow></mrow></math> in proton-proton collisions is presented, using data collected by the LHCb experiment between 2011 and 2018, corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>9</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math>. No significant signal is observed and an upper limit on the branching fraction is set at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><mrow><msup><mrow><mi>B</mi></mrow><mrow><mo>+</mo></mrow></msup><mo stretchy="false">→</mo><mrow><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>±</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>∓</mo></mrow></msup></mrow></mrow><mo stretchy="false">)</mo><mo>&lt;</mo><mn>1.8</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>9</mn></mrow></msup></mrow></math> at the 90% confidence level, 2 orders of magnitude more restrictive than the most stringent upper limit to date. This is the first constraint on lepton-flavor violating <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mo stretchy="false">→</mo><mi>d</mi></math> quark transitions at the LHC and also sets the most stringent upper limits to date on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi><mo stretchy="false">→</mo><mrow><mi>d</mi><msup><mi>μ</mi><mo>±</mo></msup><msup><mi>e</mi><mo>∓</mo></msup></mrow></math> transitions. Limits on left-handed and scalar scenarios beyond the standard model are also reported.</p>

Netherlands

R. Aaij

United States

M. Abdelfatah

United Kingdom

A.S.W. Abdelmotteleb

C. Abellan Beteta

F. Abudinén

T. Ackernley

A.A. Adefisoye

Spain

B. Adeva

M. Adinolfi

Poland

P. Adlarson

France

C. Agapopoulou

C.A. Aidala

S. Akar

K. Akiba

Italy

P. Albicocco

Germany

J. Albrecht

R. Aleksiejunas

CERN

F. Alessio

P. Alvarez Cartelle

S. Amato

J.L. Amey

Y. Amhis

China

L. An

L. Anderlini

M. Andersson

P. Andreola

M. Andreotti

S. Andres Estrada

A. Anelli

D. Ao

C. Arata

F. Archilli

Z. Areg

M. Argenton

Costa Rica

S. Arguedas Cuendis

L. Arnone

M. Artuso

E. Aslanides

R. Ataíde Da Silva

M. Atzeni

B. Audurier

J.A. Authier

D. Bacher

I. Bachiller Perea

S. Bachmann

M. Bachmayer

J.J. Back

Z.B. Bai

V. Balagura

A. Balboni

W. Baldini

Z. Baldwin

L. Balzani

H. Bao

J. Baptista de Souza Leite

C. Barbero Pretel

M. Barbetti

I.R. Barbosa

R.J. Barlow

M. Barnyakov

S. Baron

S. Barsuk

W. Barter

J. Bartz

S. Bashir

B. Batsukh

P.B. Battista

A. Bavarchee

A. Bay

A. Beck

Search for the Lepton-Flavor Violating Decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>B</mi></mrow><mrow><mo>+</mo></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>±</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>∓</mo></mrow></msup></mrow></math>