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Particle Theory in Innsbruck

Steven Bass / Innsbruck

RECFA, March 26 2004

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1. Subatomic Theory in Innsbruck

• HEP Theory: Steven Bass (Lise Meitner Fellow, FWF, Visiting Prof.)– QCD: Spin Structure of the Proton, Heavy Quarks, Confinement, Eta-

prime Physics, Structure of light-mass Exotic Mesons (JPC=1-+)• [Writing Rev Mod Physics ``The Spin Structure of the Proton´´]

– Electroweak baryogenesis (spin independent) topological condensate in the Early Universe (Interface with Astrophysics [S Schindler talk])

– Origin of mass and spin (related issues in Black Hole Physics)• Connections with programmes elsewhere include:

– CERN (ATLAS, TH-EP Collab. with A De Roeck, CMS)– JLAB/CSSM (AW Thomas, R Crewther: longstanding collab.)– BNL (A Deshpande on polarized colliders: RHIC, e-RHIC/EIC)– SLAC (S Brodsky on polarized photon structure function &tc)– Nuclear Physics Labs working on eta(-prime) physics:

COSY-11 (W Oelert, P Moskal), GSI (P Kienle @IMEP), …– (1999+): 22 invited talks at Int. Meetings, including 17 in plenary

session – Co-Chair with C Jarlskog + T Nilsson (Nuclei and the Standard Model

topical conference at INPC, Göteborg SE, 04), – Scientific Prog. Cttee (Physics at LHC, Vienna, 04)

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2. Field Theory Group

• A. Prof. Gebhard Grübl, • 2 PhD students (Sabine Kreidl, Stefan Mair), 3 MSc students

(Margarete Meisinger, Markus Penz, Michael Ruggenthaler) @ March 04; 6 completed M Sc´s (2000-04)– Bohmian mechanics and foundations of QFT

• Search for quantum theory of closed systems without external measurement intervention, i.e. quantum theory without observers.

» Coordinate free form of Schrödinger Eqns on Galilean space times» Do Bohmian trajectories for Klein´s paradox show particle creation ?» Bohmian mechanics of interferometry and decoherence» What is the probability to detect a particle within a given space-time

volume ? Detection probability without state reduction and quantum Zeno paradox. Time of arrival of Bohmian flow.

» Does local energy momentum conservation in relativistic quantum mechanics lead to a relativistic Bohmian flow ?

» Generalizing some NO GO theorems concerning the quantum measurement problem

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QCD: The Spin Structure of the Proton

QCD: (Spin) Structure of the proton Confinement (physical interpretation of Gribov confinement) Relation to axial U(1) problem [etaprime mass, light-mass

exotics, gluon topology, instantons, …] [36 primary research papers]

Structure of the Proton as a Lab for Non-perturbative physics Very interesting in itself (!) *plus* primary test of non-perturbative

particle theory before unexpected surprises at the LHC (strong e-weak symmetry breaking, WW, …)

``WHERE THERE IS NO MYSTERY THERE IS NO RELIGION ´´ (Rev. Septimus Harding in Barchester Towers)

SM Higgs sector (many parameters of unknown dynamical origin, 15 before neutrino masses)

Hierachy problem (SUSY, Large Extra-Dimensions), Strong CP (axions), Cosmological Constant (Universe size of a football!), …

Many of the things we vigorously seek are postulated to explain problems that arise from a (perturbative) elementary Higgs

» SOON TO START MEETING DATA !!! be prepared for something non-perturbative !

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The Spin Structure of the Proton• Polarized DIS

– Measure g_1 spin structure function– First moment Sigma = 0.2 – 0.35– ``Missing spin´´

• Many exciting ideas being checked in experiment: Gluon polarization Delta g (COMPASS, RHIC, EIC), Valence and Sea quark polarization (Jlab, HERMES, COMPASS, RHIC), … , Connection to Drell-Hearn-Gerasimov sum-rule, … Close contacts with EP groups

• Spawned vast EP programme at BNL, CERN, DESY, JLab, SLAC, …

• PLANS FOR NEW FACILITIES: JLAB @ 12 GeV, e-RHIC [SDB, De Roeck, Deshpande]

• Key result [SDB]: • Transition from current to

constituent quarks Polarized Condensate (x=0)

• Testable through nu-p elastic scattering

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Spin structure of the proton

• Transition between current and constituent quarks– Anomalous glue in DSB– Can form ``polarized condensate

´´ inside a proton some of the spin sits at x=0

– In Regge language: „fixed pole with non-polynomial residue in the spin dependent, real part of forward Compton amplitude“

Subtraction constant correction in dispersion relation (from circle at infinity)

There is no EJ sum rule for pDIS (!) but there is an EJ sum rule for nu-p

elastic scattering

Direct probe of the spin !!! (Interest in the US, R Tayloe et al)

• Test current to constituent quark transition !!!

Elastic neutrino proton scatteringlow duty cycle neutrino beamCarbon target

Heavy Quarks (Simultaneous Decoupling)[NLO Calculation: SDB, Crewther,

Steffens, Thomas, PRD 02,03]

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Etaprime phenomenology• Large etaprime mass - anomalous glue in non-p

QCD– Relation to proton spin problem

• Look at etaprime – hadron interactions …– Eta-(prime) production at threshold [Bass,

PLB]– COSY-11/CELSIUS : (pnpn eta´)/(pppp eta

´)– GSI : eta´s in nuclei …– Light mass exotics … (CERN and BNL)

• Major importance in new Jlab and GSI projects

• Lattice cannot get right (mass few-100 MeV too big)

• BS calculation with U(1) extended Chiral Lagrangian [Bass, Marco 02] Like sigma meson in nuclear physics

•

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• Anomalous commutators + electroweak baryogenesis topological condensate in the Early Universe– Condensate has spin independent component– (probably) survives cooling to present times!!

» [SDB, hep-ph/0403219]– Possible Application to Cosmology …

• *** Same fundamental physics which can give you a ``subtraction at infinity´´ correction to the proton spin sum-rule in QCD ***

» Generalization of the Crewther current problem in axial U(1) dynamics

Cosmology: Electroweak baryogenesis

topological condensate in the Early Universe

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Future: What are Spin ? Mass ?

• Black Holes (Large Extra Dimension models perhaps see at LHC, FNAL, CLIC,…)

• Famous information paradox – Well defined quantum information goes into BH– BH evaporates through (black body) thermal Hawking

radiation… – Information is missing unless some new physics (HEP meets

gravity)– Could (in principle) test with polarized beams at CLIC, TESLA,

(LHC)!!

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Summary: important and relevant to many experimental programmes at

major world Labs in Subatomic Physics

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Experiments motivated by TH• Key TH results and new experiments:

– High energy part of the GDH sum rule (Jlab, SLAC, EIC)

– Semi inclusive DIS quark sea (HERMES, COMPASS, EIC)

– Gluon polarization jets (EIC)– Polarized condensate neutrino-proton elastic

(FNAL ?)– Real photon spin sum-rule (CLIC, TESLA) – Etaprimes at threshold COSY, GSI, JLab– Light-mass exotics BNL, CERN, GSI, Jlab– Topological condensate in early Universe

Cosmology– Black Holes CLIC, LHC, TESLA, FNAL

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21st century physicist !Celine (born 18/08/03)

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Ideal place for a European Aspen!• Kitzbühel …

– Work in progress …