,THE DECAY ,BP  ;Z_<  A BEAUTY MESON
VANISHING INTO TWO MUONS  IS THE RAREST
PARTICLE DECAY EVER OBSERVED3 IT HAPPENS
ROUGHLY ONCE IN EVERY TEN BILLION DECAYS
OF THE ,BP MESON4 ,ANNOUNCED BY THE
,L,H,CB COLLABORATION AT ,,CERN ON #C
,NOVEMBER #BJBF1 THE RESULT ENDED A
#DB-YEAR SEARCH1 PRODUCED THE FIRST
CREDIBLE SIGNAL FROM A SCALE NOW CALLED
THE ZEPTOVERSE1 AND MATTERS FAR BEYOND
ITS RARITY  BECAUSE A DECAY THIS
UNLIKELY IS THE ,STANDARD ,MODEL'S
SMALLEST1 CLEANEST LEAK1 AND PRECISELY
THE SORT OF PLACE UNDISCOVERED PHYSICS
CAN LEAK THROUGH4
,WHAT THE DECAY IS
,THE ,BP MESON IS A TWO-QUARK PARTICLE 
A BEAUTY "<BOTTOM"> QUARK BOUND TO A
DOWN ANTIQUARK4 ,BEAUTY PARTICLES RAIN
OUT OF ,,LHC COLLISIONS BY THE BILLIONS
BUT LIVE ONLY @9#A4E TRILLIONTHS OF A
SECOND BEFORE DECAYING  ALMOST ALWAYS
INTO ORDINARY HADRONIC DEBRIS4 ,IN ,BP 
1 SOMETHING TOTAL HAPPENS3 THE BEAUTY
QUARK AND THE ANTIQUARK ANNIHILATE EACH
OTHER COMPLETELY1 AND THE ENTIRE
PARTICLE CONVERTS INTO A MUONANTIMUON
PAIR  HEAVIER COUSINS OF THE ELECTRON 
LEAVING THE CLEANEST POSSIBLE SIGNATURE3
TWO MUONS RECOILING FROM A SINGLE POINT4
,IN THE ,STANDARD ,MODEL THIS CAN'T
HAPPEN DIRECTLY  THERE IS NO TREE-LEVEL
ROUTE4 ,THE DECAY MUST PROCEED THROUGH
QUANTUM LOOP DIAGRAMS1 WITH THE BEAUTY
QUARK BRIEFLY DISSOLVING INTO VIRTUAL
TOP QUARKS AND ;,W BOSONS BEFORE
RE-MATERIALIZING AS MUONS4 ,EVERY STEP
OF THAT CHAIN IS SUPPRESSED1 WHICH IS
WHY THE PREDICTED RATE IS SO TINY  AND
WHY THE PREDICTION IS SO PRECISE4 ,A
DECAY THIS RARE IS MAXIMALLY SENSITIVE
TO THE UNEXPECTED3 ANY NEW PARTICLE
CAPABLE OF JOINING THE LOOP  A SECOND
,HIGGS DOUBLET1 A DARK-SECTOR PORTAL1 A
,Z#B BOSON  CREATES A SHORTCUT THAT
MEASURABLY SHIFTS THE RATE4 ,PHYSICISTS
CALL THIS CLASS OF PROCESSES GOLDEN
CHANNELS3 RARE ENOUGH THAT NOTHING ELSE
LOOKS LIKE THEM1 CLEAN ENOUGH THAT
THEORY CAN SEE A DEVIATION4
,THE #DB-YEAR HUNT
"9 #AIHD  ,CORNELL'S ,,CLEO EXPERIMENT
BEGINS THE SEARCH FOR FLAVOR-CHANGING
NEUTRAL-CURRENT BEAUTY DECAYS2 THE ERA
OF HUNTING 8ONE IN A BILLION0 OPENS "9
#AIIJ;S#BJJJ;S  ,BELLE "<,,KEK1 ,JAPAN">
AND ,BA,BAR "<,,SLAC1 ,CALIFORNIA"> RUN
DEDICATED ;,B-FACTORIES2 UPPER LIMITS
TIGHTEN BUT NO SIGNAL "9 #BJAB#BJAC 
,,LHC EXPERIMENTS CLOSE IN2 THE SISTER
DECAY ;,B   IS OBSERVED JOINTLY BY ,,CMS
AND ,L,H,CB IN #BJAD_/#BJAE AT @9#C PER
BILLION  #BJAE  A JOINT ,,CMS"6,L,H,CB
ANALYSIS CLAIMS FIRST EVIDENCE"9 FOR ,BP
LATER UPDATES THROUGH #BJAH FAIL TO
CONFIRM IT2 THE SIGNAL RETREATS INTO THE
NOISE "9 #BJBB#BJBD  ,L,H,CB'S ,UPGRADE
,I REBUILDS THE DETECTOR3 FIVE TIMES THE
COLLISION RATE1 @9#AJJ MILLION PROTON
COLLISIONS PER SECOND1 @9#D TERABYTES OF
DATA PER SECOND1 MACHINE-LEARNING
BACKGROUND REJECTION "9 #C ,NOVEMBER
#BJBF  COMBINING #BJBD#BJBE DATA WITH
THE #BJAA#BJAH ARCHIVE1 ,L,H,CB REPORTS
EVIDENCE AT #C4B SIGMA  ABOUT A #J4C.0
CHANCE OF A FLUKE  FROM A SINGLE
EXPERIMENT FOR THE FIRST TIME4 ,THE
ANALYSIS WAS LED BY A ,CAMBRIDGE TEAM
UNDER ,DR4 ,HARRY ,CLIFF AND CO-LED BY
,,INFN'S ,MARCO ,SANTIMARIA
,WHY ONE DECAY OPENS A NEW WORLD
,THE MEASUREMENT'S POWER ISN'T JUST
CATCHING A RARE EVENT  IT'S SURVEYING A
NEW FRONTIER4 ,RARE DECAYS ARE SENSITIVE
TO PARTICLES FAR HEAVIER THAN ANY
COLLIDER CAN MAKE DIRECTLY1 BECAUSE
VIRTUAL PARTICLES DON'T OBEY ENERGY
CONSERVATION IN THE ORDINARY SENSE  THEY
CAN BORROW MASS FROM THE QUANTUM FOAM
FOR THE INSTANT OF THE DECAY4
,PHYSICISTS ESTIMATE THAT ,BP   PROBES
PHYSICS AT DISTANCES APPROACHING #AJ_<
METRES  THE ZEPTOVERSE  MAKING IT A
TELESCOPE AIMED AT TERRITORY NO
MICROSCOPE WILL EVER IMAGE4
,IF THE MEASURED RATE EVER LANDS AWAY
FROM THE ,STANDARD ,MODEL'S PREDICTION1
SOMETHING NEW IS HIDING IN THE LOOP  AND
CANDIDATES ARE EXACTLY WHAT COSMOLOGY IS
MISSING3 DARK-MATTER PARTICLES1 THE
AGENTS OF THE MATTERANTIMATTER ASYMMETRY
"<SEE WHY DOES MATTER EXIST">1 HEAVIER
,HIGGS-LIKE STATES4 ,FOR NOW THE
MEASURED VALUE IS CONSISTENT WITH THE
,STANDARD ,MODEL  WHICH TIGHTENS THE
CAGE AROUND NEW PHYSICS RATHER THAN
OPENING THE DOOR1 BUT THE DOOR IS NOW ON
ITS HINGES3 WITH ,HIGH-,LUMINOSITY ,,LHC
DATA1 THE SAME MEASUREMENT SHARPENS
UNTIL EITHER THE ,STANDARD ,MODEL IS
CONFIRMED TO UNNERVING PRECISION1 OR
SOMETHING SHOWS ITS HAND4
,AN HONEST CAVEAT
,THE RESULT IS EVIDENCE AT #C4B SIGMA1
NOT DISCOVERY  THE #E-SIGMA STANDARD IS
DELIBERATELY HARD BECAUSE PARTICLE
PHYSICS HAS BEEN BURNED BEFORE "<THE
#BJAE CLAIM ITSELF FADED">4 ,THE
MEASUREMENT HAS NOT YET COMPLETED PEER
REVIEW4 ,AND THE RATE1 SO FAR1 AGREES
WITH THEORY  NO NEW PARTICLES CAUGHT
YET4 ,WHAT IS CERTAIN IS THE MILESTONE3
A SINGLE EXPERIMENT1 FOR THE FIRST TIME1
HAS MEASURED A PROCESS THAT HAPPENS ONCE
IN TEN BILLION TRIES  AND WITH IT1
REACHED THE SMALLEST SCALE EVER
EXPLORED4
,SEE ALSO
"9 ZEPTOVERSE  THE REALM THIS DECAY
OPENED "9 ,L,H,CB  THE EXPERIMENT THAT
CAUGHT IT "9 SMALLEST THINGS EVER
MEASURED  THE LEAGUE TABLE IT TOPS "9
WHY DOES MATTER EXIST  THE BIGGER
MYSTERY IT HUNTS
,REFERENCES
- ,,CERN  8,L,H,CB FINDS EVIDENCE OF
ONE-IN-TEN-BILLION PARTICLE DECAY0 "<#C
,NOV #BJBF"> - ,UNIVERSITY OF ,CAMBRIDGE
8,PHYSICISTS KNOCK AT THE DOOR OF THE
ZEPTOVERSE0 "<#C ,NOV #BJBF"> -
,,INFN-,,LNF  8,L,H,CB IDENTIFIES A
DECAY THAT OCCURS ONCE IN TEN BILLION0
"<,NOV #BJBF"> - ,,CMS @& ,L,H,CB 
OBSERVATION OF ;,B  1 ,NATURE #EBB
"<#BJAE"> - ,AAIJ ET AL4 "<,L,H,CB"> 
RARE-DECAY PROGRAM PUBLICATIONS