Neutron disappearance and regeneration from mirror stateartscimedia.case.edu/wp-content/uploads/sites/206/2016/03/19152257/... · – Enhancement of oscillation ... “Neutron disappearance

Neutron disappearance and regenerationfrom mirror state

Louis VarrianoUniversity of Tennessee Knoxville

International Workshop on Baryonamp Lepton Number Violation

May 17 2017

Mirror matter hypothesis- for a review see L B Okun Phys Usp 50 380-389 (2007)

ndash Mirror matter (MM) is a hypothetical form ofmatter and is a copy of the Standard Modelparticle content in a hidden ldquomirrorrdquo sectorwith identical self-couplings and possibly newinteractions between the two sectors

ndash MM sector has identical forces andself-interacting particles which are dark toordinary matter (OM) with gravity as acommon force

ndash Exact symmetry between the two sectorsmeans no new parameters except forpossible mixing parameters

ndash In Ltot MM might restore global paritybetween left-right in weak sector

Two identical gauge sectors (exSU(5)times SU(5)prime) with identicalfield contents couplings and

LagrangiansLtot = L+ Lprime + Lmix

Lmix could contain new particleinteractions between sectors for

neutral particles (eg γ ν netc)

1 Neutron disappearance and regeneration from mirror stateLouis Varriano

Mirror matter as dark matter

ndash No DM has yet been observed despite popularity of existing models andexperimental searches for new particles

ndash Alternative DM models should be explored

ndash MM is a natural dark matter (DM) candidate since its particles do not interactwith OM except through gravity (and perhaps some new mixing force)

ndash MM is currently not excluded by any experiment and is consistent withcosmological observation

- R Foot Int J Mod Phys A 29 1430013 (2014)

ndash MM is similar to OM but because its temperature T prime lt T has sim 25 mirrorH and sim 75 mirror He by mass

- Z Berezhiani Int J Mod Phys A 19 3775 (2004)


No DM direct detection experiments of MM yet


Neutral particles could oscillate between sectorsndash Free neutrons (no charge and colorless) could oscillate between OM and MM

sectors via new mechanism- Z Berezhiani and L Bento Phys Rev Lett 96 081801 (2006)

ndash nminusnprime could be fast (τnnprime ≳ 1 s) compared to nminusn (τnn gt 24 times 108 s) whichcould be a second-order effect

- A Addazi Z Berezhiani and Y Kamyshkov arXiv160700348 (2016)


Magnetic resonance in nminusnprime oscillations- Z Berezhiani Eur Phys J C 64 421-431 (2009)

ndash The nminusnprime Hamiltonian H =

(m+micro(minusrarrσ middotminusrarrB ) 1

τ1τ

m+micro(minusrarrσ middotminusrarrBprime)

)

ndash Enhancement of oscillationprobability if magnetic fieldsin each sector are alignedand same magnitude(ldquoresonancerdquo behavior)

ndash Direction and magnitude ofBprime unknown

ndash When microB ≫ ε thedependence of the probabilityof oscillation on angle βbetween the two magneticfield can be written

Pnrarrnprime(t) =sin2(

microB2 minus microBprime

2

)t

2τ 2(microB2 minus microBprime

2 )2[1 + cos(β)] +

sin2(

microB2 + microBprime

2

)t

2τ 2(microB2 + microBprime

2 )2[1 minus cos(β)]


Previous nminusnprime oscillation searches

ndash Three ultra-cold neutron experiments performed previously

1 G Ban et al Phys Rev Lett 99 161603 (2007)

2 A P Serebrov et al Phys Lett B 663 3 181-185 (2008)A P Serebrov et al Nucl Instr Meth Phys Res 611 2-3137-140 (2009)

3 I Altarev et al Phys Rev D 80 032003 (2009)

ndash One neutron beam regeneration-type experiment performedpreviously (unpublished)

1 U Schmidt (Heidelberg) BLNV Workshop 2007


Most persuasive experiment with ultra-cold neutrons- A P Serebrov et al Phys Lett B 663 3 181-185 (2008)

- A P Serebrov et al Nucl Instr Meth Phys Res 611 2-3 137-140 (2009)

ndash 190L volume stores sim 500 000 UCN with wallcollision rate of sim 10 per neutron per second

ndash Magnetic field varied sim 0 Gauss or plusmn02Gauss (up or down)

ndash Neutron lifetime in the trap is measured with acycle of 130 s filling 300 s storage and 130 scounting survivors

ndash Comparison of applied magnetic fieldcounting with shielded field (sim 0 G) countingcan reveal nminusnprime effect

ndash Assuming Bprime = 0 nminusnprime oscillation timeτ gt 448s (90 CL)


Most persuasive experiment with ultra-cold neutrons


Reanalysis discovered magnetic anomaly- Z Berezhiani and F Nesti Eur Phys J C 72 1974 (2012)

ndash Asymmetry

AdetB (t) = NminusB(t)minusNB(t)

NminusB(t)+NB(t)

ndash Reanalysis shows the asymmetryhas a 52σ deviation from zerodependent on the appliedmagnetic field direction

ndash This could be indication ofnon-zero Bprime field present at Earth

ndash Fitted parameter indicate B sim 01G and τβ sim few seconds

ndash A new experiment should beperformed by an alternatemethod to be sensitive to thisanomaly


UCN experiment with scanning magnetic field- I Altarev et al Phys Rev D 80 032003 (2009)

ndash Scanning over the magnetic field from+125microT to minus125microT in 25microTincrements

ndash Data shows that step size is toocoarse to observe resonance

ndash Data could be fit equally well withstraight line

ndash Low significance fit howeverindicates that Bprime sim 11microT β sim 25τ sim 20 s

ndash Experiment with finer steps inmagnetic field could revealresonance


UCN scattering can have ambiguous interpretationndash UCN scattering on trap walls

leads to higher losscoefficients than predicted bycalculation - not wellunderstood

- E A Goremychkin and Yu NPokotilovski JGU Mainz

Germany (2016)

ndash Asymmetry anomaly might besome other unexplainedphenomenon not mirrortransformation

ndash Neutron beam regenerationexperiment without neutronreflections eliminatespotentially anomalous effects


Previously - cold neutron beam regeneration at B = 0- U Schmidt (Heidelberg) BLNV Workshop 2007

ndash Previous cold neutron beam experiment compared neutron counts with appliedmagnetic field to counts with suppressed zero field

ndash New proposed experiment revives previous beam technique with addedcomponent - scanning over lab magnetic field

ldquoNeutron disappearance and regeneration from mirror staterdquoZ Berezhiani M Frost Y Kamyshkov B Rybolt and L Varriano

arXiv 1703067335 (2017)


New proposed regeneration experiment

ndash Proposed regeneration experiment tobe sensitive to τ sim 10 minus 20 sindependent of angle β

ndash Paper examines SNS as possible siteof experiment as an examplerarr Leah Broussard (next) to talkabout real experiment at HFIR


Conclusions

ndash Mirror matter offers an attractive theory to help explain several big problems inphysics including nature of dark matter and could also shed light on thebaryonic asymmetry problem

- Z Berezhiani arXiv160208599 (2016)

ndash A neutron regeneration experiment can check the anomalous UCN signalunambiguously with good control of magnetic fields and by eliminating neutronwall reflections which lack a satisfactory theoretical understanding

ndash The unique character of the resonance signal is different than simplymeasuring a UCN asymmetry which might be attributed to different effects

ndash By enhancingsuppressing the resonance signal it could be possible todetermine mirror magnetic field vector at Earth


Questions

ndash Thanks to the paper co-authors Z Berezhiani M Frost Y Kamyshkov and BRybolt

ndash Thanks to B Kerbikov L Broussard and J Barrow for many usefuldiscussions as well as the nminusnprime collaboration currently working on therealization of this experiment at HFIR



- T Tait Snowmass 2013


Parameters affecting experiment

nminusnprime disappearance is influenced by six parameters

ndash τ - nminusnprime oscillation period

ndash B - lab magnetic field strength

ndash Bprime - mirror magnetic field strength

ndash β - angle between lab magnetic field and mirror magnetic field

ndash φ isin C - Fermi pseudo-potential of residual lab gas (H2)rArr residual gas pressure

ndash φprime isin C - Fermi pseudo-potential of mirror gas (Hprime2 or Hprime

2)rArr mirror gas pressure (neglected here)


Mirror matter hypothesis- for a review see L B Okun Phys Usp 50 380-389 (2007)

ndash Mirror matter (MM) is a hypothetical form ofmatter and is a copy of the Standard Modelparticle content in a hidden ldquomirrorrdquo sectorwith identical self-couplings and possibly newinteractions between the two sectors

ndash MM sector has identical forces andself-interacting particles which are dark toordinary matter (OM) with gravity as acommon force

ndash Exact symmetry between the two sectorsmeans no new parameters except forpossible mixing parameters

ndash In Ltot MM might restore global paritybetween left-right in weak sector

Two identical gauge sectors (exSU(5)times SU(5)prime) with identicalfield contents couplings and

LagrangiansLtot = L+ Lprime + Lmix

Lmix could contain new particleinteractions between sectors for

neutral particles (eg γ ν netc)





















τ1τ


)






2

)t


2 )2[1 + cos(β)] +

sin2(


2

)t























ndash Asymmetry


NminusB(t)+NB(t)
















Germany (2016)








arXiv 1703067335 (2017)






Conclusions







Questions




































τ1τ


)






2

)t


2 )2[1 + cos(β)] +

sin2(


2

)t























ndash Asymmetry


NminusB(t)+NB(t)
















Germany (2016)








arXiv 1703067335 (2017)






Conclusions







Questions



























τ1τ


)






2

)t


2 )2[1 + cos(β)] +

sin2(


2

)t























ndash Asymmetry


NminusB(t)+NB(t)
















Germany (2016)








arXiv 1703067335 (2017)






Conclusions







Questions

























τ1τ


)






2

)t


2 )2[1 + cos(β)] +

sin2(


2

)t























ndash Asymmetry


NminusB(t)+NB(t)
















Germany (2016)








arXiv 1703067335 (2017)






Conclusions







Questions




















τ1τ


)






2

)t


2 )2[1 + cos(β)] +

sin2(


2

)t























ndash Asymmetry


NminusB(t)+NB(t)
















Germany (2016)








arXiv 1703067335 (2017)






Conclusions







Questions




































ndash Asymmetry


NminusB(t)+NB(t)
















Germany (2016)








arXiv 1703067335 (2017)






Conclusions







Questions




























ndash Asymmetry


NminusB(t)+NB(t)
















Germany (2016)








arXiv 1703067335 (2017)






Conclusions







Questions




















ndash Asymmetry


NminusB(t)+NB(t)
















Germany (2016)








arXiv 1703067335 (2017)






Conclusions







Questions


















ndash Asymmetry


NminusB(t)+NB(t)
















Germany (2016)








arXiv 1703067335 (2017)






Conclusions







Questions



























Germany (2016)








arXiv 1703067335 (2017)






Conclusions







Questions




















Germany (2016)








arXiv 1703067335 (2017)






Conclusions







Questions





















arXiv 1703067335 (2017)






Conclusions







Questions





















Conclusions







Questions

















Conclusions







Questions

















Questions








































Documents

Neutron disappearance and regeneration from mirror stateartscimedia.case.edu/wp-content/uploads/sites/206/2016/03/19152257/... · – Enhancement of oscillation ... “Neutron disappearance