International Workshop on Future Linear Colliders, LCWS2024

Session

Higgs, Electroweak

9 Jul 2024, 09:00

The University of Tokyo, Japan

Conveners

Higgs, Electroweak: 1

• Manqi RUAN (IHEP-LLR/CERN)
• Shinya Kanemura (Osaka University)

Higgs, Electroweak: joint with BSM/GI

• Manqi RUAN (IHEP-LLR/CERN)
• Shinya Kanemura (Osaka University)

Higgs, Electroweak: 2

• Georg Ralf Weiglein (Deutsches Elektronen-Synchrotron (DE))
• Shinya Kanemura (Osaka University)

Higgs, Electroweak: 3

• Graham Wilson
• Georg Ralf Weiglein (Deutsches Elektronen-Synchrotron (DE))

Higgs, Electroweak: 4

• Graham Wilson
• Georg Ralf Weiglein (Deutsches Elektronen-Synchrotron (DE))

255. Higgs measurements at the LHC and HL-LHC (Invited)

Dengfeng Zhang (University of Sheffield (GB))

09/07/2024, 09:00

Higgs, Electro-Weak

Oral presentation (in person)

Invited talk on Higgs measurements at the LHC and HL-LHC

88. Determination of CP-violating Higgs couplings with transversely-polarized beams at the ILC

Dr Cheng Li (Sun-Yat-Sen University)

09/07/2024, 09:30

Higgs, Electro-Weak

Oral presentation (remote)

We study possible CP-violation effects of the Higgs to $Z$-boson coupling
at a future $e^{+}{e}^{-}$ collider, e.g. the International Linear Collider (ILC). We find that the azimuthal angular distribution of the muon pair, produced by $e^{+}{e}^{-}\to HZ->H{\mu }^{+}{\mu }^{-}$, can be sensitive to such a CP-violation effect when we apply initial transversely polarized beams. Based on this angular...

113. Prospects of measuring quantum entanglement in H->tautau at a future e+e- Higgs factory

Mr Cedric Breuning (University of Bonn)

09/07/2024, 09:50

Higgs, Electro-Weak

Oral presentation (in person)

Final states with spin-correlations allow the measurement of quantum entanglement at collider energies. The $H\to \tau \tau$ process is an excellent probe for this, due to the scalar nature of the Higgs boson, and the direct access to the $\tau$-lepton helicity through the angular distributions of the $\tau$-lepton decay products. We will present the prospects of such a measurement a future...

181. Decoding Higgs Boson Branching Ratios from Event Shape Variables

Daniel Reichelt

09/07/2024, 10:10

Higgs, Electro-Weak

Oral presentation (remote)

In this talk I will discuss a novel strategy [1] for the simultaneous measurement of Higgs-boson branching ratios into gluons and light quarks at a future lepton collider operating in the Higgs-factory mode. The method is based on template fits to global event-shape observables, and in particular fractional energy correlations, thereby exploiting differences in the QCD radiation patterns of...

85. Collider Tests of Nanohertz Gravitational Waves

Dr Shaoping Li (Osaka U.)

09/07/2024, 11:00

Higgs, Electro-Weak

Oral presentation (in person)

Recently, compelling evidence of nanohertz gravitational waves is indicated by the pulsar timing array collaborations. In this talk, I will present an MeV-scale first-order phase transition from a minimal dark sector to explain the gravitation waves, with a focus on the collider tests via a minimal Higgs portal. I will demonstrate that to explain the observed gravitational waves, the Higgs...

115. Searching for heavy neutral leptons in electron positron colliders

Arindam Das

09/07/2024, 11:15

Higgs, Electro-Weak

Oral presentation (remote)

The origin of neutrino mass is a long standing puzzle. Plethora of models have been proposed to explain the origin of small neutrino mass. Among them tree level seesaw and inverse seesaw scenarios are the simplest ones where Standard Model (SM) is extended by SM-singlet heavy Right Handed Neutrinos (RHNs). If the RHN masses are $\mathcal{O}$(TeV) scale, they could be produced in lepton...

135. Testing the gauged U(1)B-L model for loop induced neutrino mass with dark matter at future colliders

GUOHAO YING (Osaka University)

09/07/2024, 11:30

Higgs, Electro-Weak

Oral presentation (in person)

We present a new viable benchmark scenario under the current experimental data for the model which can explain the tiny mass of active neutrinos and dark matter. Majorana masses of right handed neutrinos are given by the spontaneous breaking of the U(1)B-L gauge symmetry at the TeV scale, and tiny neutrino mass are radiatively induced by quantum effects of particles of the dark sector...

218. Higgs Production at \mu^+ \mu^+ Colliders

Mr Lukas Treuer (KEK, The Gaduate U. Adv. Studies (SOKENDAI))

09/07/2024, 11:45

Higgs, Electro-Weak

Oral presentation (in person)

Muon colliders offer exciting new opportunities to explore the Standard Model and beyond by unifying the energy and precision frontiers, thus also facilitating deeper insight into the Higgs sector central to the Standard Model. In this work, motivated by recent developments in anti-muon cooling, we explore the prospects of Higgs production at \mu^+ \mu^+ colliders. At high energies, Higgs...

122. Exploring new physics by loop-corrected decays of additional Higgs bosons

Mariko KIKUCHI (Nihon University)

09/07/2024, 12:00

Higgs, Electro-Weak

Oral presentation (in person)

In order to test and discriminate the extended Higgs models, it is quite important to include radiative corrections to the analyses for the synergy between the precise measurements of the discovered Higgs boson (h125) and the direct searches for additional Higgs bosons. Deviations of couplings of h125 from the standard model (SM) predictions give the upper limit on masses of additional Higgs...

101. $4b+X$ via electroweak multi-Higgs production as smoking gun signal for the Type-I 2HDM at the LHC

Dr Prasenjit Sanyal (Konkuk University)

09/07/2024, 12:15

Higgs, Electro-Weak

Oral presentation (remote)

The existence of additional Higgs bosons, besides the one
discovered by the LHC, already a decade ago, is predicted by most
frameworks of new physics. Observation of a second Higgs boson
(charged or neutral) will thus provide a firm evidence that the
underlying manifestation of the Electroweak Symmetry Breaking (EWSB)
mechanism is a non-minimal one. The majority of analyses,...

254. Electroweak measurements at the LHC and HL-LHC (Invited)

Anne-Marie Magnan (Imperial College (GB))

10/07/2024, 09:00

Higgs, Electro-Weak

Oral presentation (in person)

Invited talk on the electroweak measurements at the LHC and HL-LHC.

207. Searching for new physics in WW and single-W events

Jenny List (Deutsches Elektronen-Synchrotron (DE))

10/07/2024, 09:30

Higgs, Electro-Weak

Oral presentation (in person)

Pair- and single-production of W bosons provide many opportunities to look for new physics via precision measurements, for instance via scrutinizing the involved triple-gauge vertices or by measuring CKM matrix elements in an environment very complementary to B hadron decays. This contribution presents the ongoing work based on full simulation of the ILD detector concept, exploiting the...

61. Higher-order initial state radiation in e+e- annihilation

Andrej Arbuzov (Joint Institute for Nuclear Research)

10/07/2024, 09:50

Higgs, Electro-Weak

Oral presentation (in person)

Radiative corrections due to initial state radiation in electron-positron
annihilation are calculated within the QED structure function approach. NLO QED parton distribution functions are derived analytically. Results are shown in the next-to-leading logarithmic approximation up to $\mathcal{O}({\alpha }^4{L}^3)$ order, where $L=\ln (s/m_e^2)$ is the large logarithm. Several mistakes in previous...

107. New renormalization scheme in extended Higgs sectors for Higgs precision measurements

Kei Yagyu (Osaka University)

10/07/2024, 10:10

Higgs, Electro-Weak

Oral presentation (in person)

We propose a new renormalization scheme in extended Higgs sectors for the coming new era of the Higgs precise measurements at future lepton colliders. In this new scheme, we use a precisely measured value of the discovered Higgs boson coupling, e.g., hZZ, as an input of the renormalization condition. We demonstrate how the other Higgs boson couplings (e.g., hWW) can be predicted. in this new...

67. Searching for Charged Higgs Bosons via $e^{+}{e}^{-}\to H^{+}{H}^{-}\to c\overline{b}\overline{c}b$ at Linear Colliders

George W.-S. Hou (National Taiwan University)

10/07/2024, 11:00

Higgs, Electro-Weak

Oral presentation (in person)

We study a search for the charged Higgs boson via $e^{+}{e}^{-}\to H^{+}{H}^{-}\to c\overline{b}\overline{c}b$ at the 500 GeV ILC. In a general two Higgs doublet model without $Z_2$ symmetry, extra Yukawa couplings ${\rho }_{tc}$ and ${\rho }_{tt}$ can drive electroweak baryogenesis, but searches at the HL-LHC may still go empty-handed if the couplings are relatively weak. Taking $m_{H^{+}}\simeq m_H\simeq$ $m_A\simeq...

174. Impact of quark flavor violating SUSY on h(125) decays at future lepton colliders

Prof. Keisho Hidaka (Tokyo Gakugei University)

10/07/2024, 11:20

Higgs, Electro-Weak

Oral presentation (remote)

We study the CP-even neutral Higgs boson decays h -> c \bar{c}, b \bar{b},
b \bar{s}, \gamma \gamma, g g in the Minimal Supersymmetric Standard Model (MSSM)
with general quark flavor violation (QFV) due to squark generation mixings,
identifying the h as the Higgs boson with a mass of 125 GeV. We compute the widths
of the h decays to c \bar c, b \bar b, b \bar s (s \bar b) at full...

208. Towards an update of the ILD ZHH analysis

Bryan Bliewert

10/07/2024, 11:40

Higgs, Electro-Weak

Oral presentation (remote)

The double Higgs-strahlungs process ee -> ZHH allows to access the Higgs self-coupling at energies above ~450 GeV. It exhibits a very different BSM behaviour than fusion-type processes like gluon-gluon fusion at LHC (and future hadron colliders) and WW / ZZ fusion at higher energy lepton colliders. Therefore it adds unique information to the picture, in particular should the value of the Higgs...

161. Higher-order effects in the trilinear Higgs coupling for future collider experiments

Shuhei Ohzawa (University of Toyama)

10/07/2024, 11:55

Higgs, Electro-Weak

Oral presentation (in person)

Although the Higgs boson has been discovered, the couplings with the Higgs boson have room for deviation from the Standard Model (SM) prediction. Each extended Higgs model is characterized by its Higgs potential. Nearly aligned models where the shape of the Higgs potential is described by one classical field include the classical scale invariance model (CSI), the pseudo-Nambu-Goldstone model,...

98. Loop induced H±W±Z vertex in CP violating two Higgs doublet model and its impact on collider phenomenology

Yushi Mura (Osaka Univ.)

10/07/2024, 12:10

Higgs, Electro-Weak

Oral presentation (in person)

The two Higgs doublet model, which can serve enough CP violation and first order electroweak phase transition, is often introduced to realize electroweak baryogenesis.
If CP symmetry is violated in the two Higgs doublet model, it does not have custodial symmetry, which is remnant of global symmetry of SU(2)L × SU(2)R.
It has been known that H±W±Z vertex is induced at the loop level due to...

148. BSM Triple Higgs couplings at the ILC/CLIC

Francisco Arco, Sven Heinemeyer (Consejo Superior de Investigaciones Cientificas (CSIC) (ES))

10/07/2024, 16:00

BSM, Global Interpretations

Oral presentation (in person)

To explain the baryon asymmetry in the universe a First Order Electroweak Phase Transition (FOEWPT) in the early universe is favored. This requires a BSM Higgs sector, which introduces additional Higgs bosons as well as the corresponding additional trilinear Higgs couplings (THCs). Taking the 2HDM as a concrete example, we discuss how such BSM THCs might be accessible at the ILC/CLIC via...

257. ECFA Study: Higgs Self-coupling

Sven Heinemeyer (Consejo Superior de Investigaciones Cientificas (CSIC) (ES))

10/07/2024, 16:25

Higgs, Electro-Weak

Oral presentation (in person)

Invited talks on the ECFA Topic: Higgs self-coupling

109. New collider implications on a strongly first order EWPT.

Ricardo Florentino

10/07/2024, 16:45

Higgs, Electro-Weak

Oral presentation (in person)

In order to understand the early history of the universe, and to test baryogenesis models, determining the nature of the electroweak phase transition is imperative. The order and strength of this transition is strongly correlated to relatively large deviations in the $hhh$ coupling. In models where a considerable part of the $hhh$ coupling deviation is caused by charged particle loops, the...

167. Double Higgs production in composite two Higgs doublet model

Kodai Sakurai (Tohoku University)

10/07/2024, 17:00

Higgs, Electro-Weak

Oral presentation (in person)

The precise measurement of the 125 GeV Higgs boson is one of the powerful ways to probe new physics. In particular, it is known that a large deviation from the SM predictions can appear in the di-Higgs production process e.g., via new physics effects of the triple Higgs boson coupling.
In this talk, we discuss the theoretical behavior of the di-Higgs production cross section in the composite...

264. Higgs self coupling: Theory status

Matthew Mccullough (CERN)

10/07/2024, 17:15

Higgs, Electro-Weak

Oral presentation (remote)

Invited talk on the status of the theory of the Higgs self coupling