A. Yu. Korchin, E. Richter-Was, Yu. Volkotrub, Z. Was
{"title":"τ -lepton pair spin in proton-proton LHC collisions for anomalous dipole moments","authors":"A. Yu. Korchin, E. Richter-Was, Yu. Volkotrub, Z. Was","doi":"10.1103/physrevd.111.013006","DOIUrl":null,"url":null,"abstract":"The spin correlations in the pair of τ</a:mi></a:math> leptons produced in high-energy proton-proton collisions are studied. The invariant mass of the <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mi>τ</c:mi></c:math>-lepton pair is chosen close to the <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mi>Z</e:mi></e:math>-boson mass; in these conditions, <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><g:mi>Z</g:mi></g:math>-boson exchange gives the dominant contribution to the Drell-Yan mechanism. The interaction of <i:math xmlns:i=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><i:mi>Z</i:mi></i:math> bosons with <k:math xmlns:k=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><k:mi>τ</k:mi></k:math> leptons, in addition to the Standard Model couplings, can include weak anomalous magnetic and electric dipole moments (or form factors) of the <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><m:mi>τ</m:mi></m:math> lepton. The dependence of elements of the <o:math xmlns:o=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><o:mi>p</o:mi><o:mi>p</o:mi></o:math> spin-correlation matrix on the weak anomalous moments is determined for various regions of the rapidity of the <q:math xmlns:q=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><q:mi>τ</q:mi></q:math>-lepton pair. Based on this calculation, we construct a semirealistic observable built on the momenta of pions in the <s:math xmlns:s=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><s:msup><s:mi>τ</s:mi><s:mo>∓</s:mo></s:msup><s:mo stretchy=\"false\">→</s:mo><s:msup><s:mi>π</s:mi><s:mo>∓</s:mo></s:msup><s:msub><s:mi>ν</s:mi><s:mi>τ</s:mi></s:msub></s:math> and <v:math xmlns:v=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><v:msup><v:mi>τ</v:mi><v:mo>±</v:mo></v:msup><v:mo stretchy=\"false\">→</v:mo><v:msup><v:mi>ρ</v:mi><v:mo>±</v:mo></v:msup><v:msub><v:mi>ν</v:mi><v:mi>τ</v:mi></v:msub><v:mo stretchy=\"false\">→</v:mo><v:msup><v:mi>π</v:mi><v:mo>±</v:mo></v:msup><v:msup><v:mi>π</v:mi><v:mn>0</v:mn></v:msup><v:msub><v:mi>ν</v:mi><v:mi>τ</v:mi></v:msub></v:math> decay channels, and we show that this observable can be sensitive to the weak anomalous dipole moments. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20167,"journal":{"name":"Physical Review D","volume":"35 1","pages":""},"PeriodicalIF":5.0000,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physical Review D","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1103/physrevd.111.013006","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Physics and Astronomy","Score":null,"Total":0}
引用次数: 0
Abstract
The spin correlations in the pair of τ leptons produced in high-energy proton-proton collisions are studied. The invariant mass of the τ-lepton pair is chosen close to the Z-boson mass; in these conditions, Z-boson exchange gives the dominant contribution to the Drell-Yan mechanism. The interaction of Z bosons with τ leptons, in addition to the Standard Model couplings, can include weak anomalous magnetic and electric dipole moments (or form factors) of the τ lepton. The dependence of elements of the pp spin-correlation matrix on the weak anomalous moments is determined for various regions of the rapidity of the τ-lepton pair. Based on this calculation, we construct a semirealistic observable built on the momenta of pions in the τ∓→π∓ντ and τ±→ρ±ντ→π±π0ντ decay channels, and we show that this observable can be sensitive to the weak anomalous dipole moments. Published by the American Physical Society2025
期刊介绍:
Physical Review D (PRD) is a leading journal in elementary particle physics, field theory, gravitation, and cosmology and is one of the top-cited journals in high-energy physics.
PRD covers experimental and theoretical results in all aspects of particle physics, field theory, gravitation and cosmology, including:
Particle physics experiments,
Electroweak interactions,
Strong interactions,
Lattice field theories, lattice QCD,
Beyond the standard model physics,
Phenomenological aspects of field theory, general methods,
Gravity, cosmology, cosmic rays,
Astrophysics and astroparticle physics,
General relativity,
Formal aspects of field theory, field theory in curved space,
String theory, quantum gravity, gauge/gravity duality.