scholarly journals Testing the $$R_{D^{(*)}}$$ anomaly at the LHeC

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Georges Azuelos ◽  
Oliver Fischer ◽  
Sudip Jana
Keyword(s):  
Standard Model ◽  
B Physics ◽  
First Generation ◽  
Theoretical Frameworks ◽  
Final State ◽  
Discovery Potential ◽  
O 10

AbstractB-Physics anomalies have recently raised renewed interest in leptoquarks, predicted in several theoretical frameworks. Under simplifying but conservative assumptions, we show that the current limits from LHC searches together with the requirement to explain the observed value for $$R_{D^{(*)}}$$ R D ( ∗ ) constrain the $$R_2$$ R 2 leptoquark mass to be in the range of $$800 \le m_{R_2} \le 1000$$ 800 ≤ m R 2 ≤ 1000  GeV. We study the search for $$R_2$$ R 2 at the LHeC via its resonance in the $$b\tau $$ b τ final state by performing a cut-and-count analysis of the signal and the dominant Standard Model backgrounds. We find that the LHeC has an excellent discovery potential for the $$R_2$$ R 2 leptoquark even for couplings to the first generation as small as $${\mathcal {O}}(10^{-2})$$ O ( 10 - 2 ) .

scholarly journals Charged lepton flavor violation at the EIC

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Vincenzo Cirigliano ◽  
Kaori Fuyuto ◽  
Christopher Lee ◽  
Emanuele Mereghetti ◽  
Bin Yan
Keyword(s):  
Cross Sections ◽  
Charged Lepton ◽  
Hadron Collider ◽  
Effective Field ◽  
Background Suppression ◽  
Lepton Flavor Violation ◽  
Final State ◽  
Lepton Flavor ◽  
Flavor Violation ◽  
Discovery Potential

Abstract We present a comprehensive analysis of the potential sensitivity of the Electron-Ion Collider (EIC) to charged lepton flavor violation (CLFV) in the channel ep→τX, within the model-independent framework of the Standard Model Effective Field Theory (SMEFT). We compute the relevant cross sections to leading order in QCD and electroweak corrections and perform simulations of signal and SM background events in various τ decay channels, suggesting simple cuts to enhance the associated estimated efficiencies. To assess the discovery potential of the EIC in τ-e transitions, we study the sensitivity of other probes of this physics across a broad range of energy scales, from pp→eτX at the Large Hadron Collider to decays of B mesons and τ leptons, such as τ→eγ, τ→eℓ+ℓ−, and crucially the hadronic modes τ→eY with Y∈π, K, ππ, Kπ, …. We find that electroweak dipole and four-fermion semi-leptonic operators involving light quarks are already strongly constrained by τ decays, while operators involving the c and b quarks present more promising discovery potential for the EIC. An analysis of three models of leptoquarks confirms the expectations based on the SMEFT results. We also identify future directions needed to maximize the reach of the EIC in CLFV searches: these include an optimization of the τ tagger in hadronic channels, an exploration of background suppression through tagging b and c jets in the final state, and a global fit by turning on all SMEFT couplings, which will likely reveal new discovery windows for the EIC.

scholarly journals Highly boosted Higgs bosons and unitarity in vector-boson fusion at future hadron colliders

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Wolfgang Kilian ◽  
Sichun Sun ◽  
Qi-Shu Yan ◽  
Xiaoran Zhao ◽  
Zhijie Zhao
Keyword(s):  
Pair Production ◽  
Vector Boson ◽  
New Physics ◽  
Higgs Bosons ◽  
Vector Boson Fusion ◽  
Final State ◽  
Proton Proton ◽  
Effective Lagrangian ◽  
Discovery Potential ◽  
New Interactions

Abstract We study the observability of new interactions which modify Higgs-pair production via vector-boson fusion processes at the LHC and at future proton-proton colliders. In an effective-Lagrangian approach, we explore in particular the effect of the operator $$ {h}^2{W}_{\mu \nu}^a{W}^{a,\mu \nu} $$ h 2 W μν a W a , μν , which describes the interaction of the Higgs boson with transverse vector-boson polarization modes. By tagging highly boosted Higgs bosons in the final state, we determine projected bounds for the coefficient of this operator at the LHC and at a future 27 TeV or 100 TeV collider. Taking into account unitarity constraints, we estimate the new-physics discovery potential of Higgs pair production in this channel.

scholarly journals RECENT τ LEPTON RESULTS FROM BABAR

2014 ◽  
Vol 35 ◽  
pp. 1460440
Author(s):  
ALBERTO LUSIANI
Keyword(s):  
Standard Model ◽  
Branching Fractions ◽  
Charged Particles ◽  
Babar Collaboration ◽  
Final States ◽  
Final State ◽  
Experimental Knowledge ◽  
Electron Positron ◽  
The Standard Model ◽  
Positron Collisions

We report recent measurements on τ leptons obtained by the BABAR collaboration using the entire recorded sample of electron-positron collisions at and around the Υ(4S) (about 470fb-1). The events were recorded at the PEP-II asymmetric collider at the SLAC National Accelerator Laboratory. The measurements include high multiplicity τ decay branching fractions with 3 or 5 charged particles in the final state, a search for the second class current the τ decay τ → πη′ν, τ branching fractions into final states containing two KS mesons, [Formula: see text], with h = π, K, and preliminary measurements of hadronic spectra of τ decays with three hadrons (τ- → h-h+h-ντ decays, where h = π, K). The results improve the experimental knowledge of the τ lepton properties and can be used to improve the precision tests of the Standard Model.

SEARCH FOR NEW PHYSICS IN eμX DATA AT THE TEVATRON USING SLEUTH: A QUASI-MODEL-INDEPENDENT SEARCH STRATEGY FOR NEW PHYSICS

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 888-890
Author(s):  
◽  
BRUCE KNUTESON
Keyword(s):  
Standard Model ◽  
Search Strategy ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Final States ◽  
Final State ◽  
The Standard Model ◽  
Model Independent

We present a quasi-model-independent search for physics beyond the standard model. We define final states to be studied, and construct a rule that identifies a set of variables appropriate for any particular final state. A new algorithm ("Sleuth") searches for regions of excess in the space of those variables and quantifies the significance of any detected excess. After demonstrating the sensititvity of the method, we apply it to the semi-inclusive channel eμX collected in ≈108 pb -1 of [Formula: see text] collisions at [Formula: see text] at the DØ experiment at the Fermilab Tevatron. We find no evidence of new high pT physics in this sample.

scholarly journals B PHYSICS AT LHCb

2008 ◽  
Vol 23 (32) ◽  
pp. 5117-5136 ◽  
Author(s):  
MONICA PEPE ALTARELLI ◽  
FREDERIC TEUBERT
Keyword(s):  
Large Hadron Collider ◽  
Standard Model ◽  
B Physics ◽  
Hadron Collider ◽  
New Physics ◽  
Concise Review ◽  
The Standard Model ◽  
And Performance ◽  
Detector Design

LHCb is a dedicated detector for b physics at the LHC (Large Hadron Collider). In this paper we present a concise review of the detector design and performance together with the main physics goals and their relevance for a precise test of the Standard Model and search of New Physics beyond it.

New physics through interference of nonstandard interactions with Standard Model in rare decays of Bc+ meson

2018 ◽  
Vol 33 (30) ◽  
pp. 1850171
Author(s):  
Shakeel Mahmood ◽  
Farida Tahir ◽  
Azeem Mir
Keyword(s):  
Experimental Data ◽  
Standard Model ◽  
Rare Decays ◽  
New Physics ◽  
Final State ◽  
Neutrino Interactions ◽  
Bc Meson ◽  
Free Parameters

We investigate the nonstandard neutrino interactions (NSI) in the rare decays of [Formula: see text] mesons involving neutrinos in the final state. It is suggested that the interference between Standard Model and nonstandard interaction can provide sizeable contribution. We calculate the limits on NSI free parameters ([Formula: see text], [Formula: see text]) and compare them with experimental data.

Conclusions

2021 ◽  
pp. 137-148
Author(s):  
Nick Williams
Keyword(s):  
Comparative Analysis ◽  
First Generation ◽  
Theoretical Frameworks ◽  
Entrepreneurship Research ◽  
Global Migration ◽  
Post Conflict ◽  
Over Time

Chapter 9 closes the book with a comparative analysis of the key theoretical frameworks employed in the book in order to illuminate the contribution of returnee entrepreneurs to post-conflict economies. As global migration continues to grow, the role of returnees are becoming an ever more important aspect of entrepreneurship research. The chapter articulates the specific components of isolation and assimilation, detailing that while individuals are returning to complex homelands, their contribution is not currently being maximised. They are not assimilated within the economy, often avoiding policy actions designed to engage with them. This will have a lasting impact on the potential of returnees to contribute to their homeland, especially given that the emotional ties of the first generation are stronger than subsequent generations and thus interest in homeland return may diminish over time.

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