R a r e F C N C b d e c a y s Ma r c - O l i v - PowerPoint PPT Presentation

R a r e F C N C b d e c a y s Ma r c - O l i v i e r B e t t l e r C a v e n d i s h L a b . C a mb r i d g e o n b e h a l f o f t h e L H C b c o l l a b o r a t i o n , i n c l u d i n g r e s u l t s f r o m A T L A S , C MS , B a B a r , B e l l e a n d C D F .

H e a v y F l a v o u r : T w o ma i n w a y s t o N e w P h y s i c s r e l t t e B r e i S M v i l O - R a r e d e c a y s c r Ma p o t e n t i a l s mo k i n g g u n F C N C d e c a y s : - f o r b i d d e n a t t r e e l e v e l C P v i o l a t i o n - p r o c e e d v i a l o o p , b o x d i a g r a ms e x t r a s o u r c e mu s t e x i s t V i r t u a l N P p a r t i c l e s c a n c o n t r i b u t e i n l o o p s I n d i r e c t p r o b e c a n a c c e s s N e w h i g h e r e n e r g y s c a l e t h a n s y d i r e c t s e a r c h e s a P h y s i c s c e d C N C F November 11 2011 B s l i d e 2

r e l t t e B r e i v i l O L a s t L H C b r e s u l t , f i r s t e v i d e n c e f o r t h e B mo d e - s c r Ma A n g u l a r a n a l y s i s , i s o s p i n a s y mme t r y , C P a s y mme t r y i n A n g u l a r a n a l y s i s o f s B r a n c h i n g f r a c t i o n o f y a c e d C B r a n c h i n g f r a c t i o n o f N C F November 11 2011 B s l i d e 3

B F C N C d e c a y s Ma r c - O l i v i e r B e t t l e r November 11 2011 s l i d e 4

s t a t u s C MS 5 f b - 1 [ J H E P 0 4 ( 2 0 1 2 ) 0 3 3 ] r e l t t e B r e i v i l O - c r Ma [ P R D 8 7 ( 2 0 1 3 ) 0 7 2 0 0 6 ] [ P R D 8 7 ( 2 0 1 3 ) 0 7 2 0 0 3 ] s y a [ P R L 1 1 0 ( 2 0 1 3 ) 0 2 1 8 0 1 ] c e d C - 1 A T L A S 2 . 4 f b N C [ P L B 7 1 3 ( 2 0 1 2 ) 3 8 7 ] F November 11 2011 1 0 - 9 B s l i d e 5

a t L H C b L H C b [ P R L 1 1 0 ( 2 0 1 3 ) 0 2 1 8 0 1 ] r e l t t e B r e i v i l O - c r Ma A n a l y s i s c o mb i n i n g t w o d a t a s e t s : - 1 1 . 0 f b o f d a t a t a k e n i n 2 0 1 1 a t √ s = 7 T e V ( r e - a n a l y s e d w i t h i mp r o v e me n t s ) s y a c e - 1 1 . 1 f b o f d a t a t a k e n i n 2 0 1 2 a t √ s = 8 T e V d C ( 5 0 % o f a v a i l a b l e s t a t i s t i c s ) N C F November 11 2011 B s l i d e 6

A n a l y s i s s t r a t e g y L H C b [ P R L 1 1 0 ( 2 0 1 3 ) 0 2 1 8 0 1 ] r e l t C l a s s i f i c a t i o n o f a n d c a n d i d a t e s i n a 2 D t e B s p a c e r e i ma s s o f t h e µµ p a i r c o mb i n a t i o n v i l O mu l t i v a r i a t e d i s c r i mi n a n t , B D T - c r Ma B : I P , i s o l a t i o n , p T , . . 2 mu o n s : i s o l a t i o n , I P χ w r t P V s , mi n ( p ) , . . . T U s e o f c o n t r o l c h a n n e l s t o c a l i b r a t e t h e e x p e c t a t i o n s U s e o f n o r ma l i s a t i o n c h a n n e l s s y a c C o mp a r e e x p e c t a t i o n s w i t h o b s e r v e d d i s t r i b u t i o n o f e v e n t s e d t o s e t a l i mi t o n t h e b r a n c h i n g f r a c t i o n C N t o g e t a b r a n c h i n g f r a c t i o n me a s u r e me n t v i a a f i t C F November 11 2011 B s l i d e 7

D i s c r i mi n a n t c a l i b r a t i o n L H C b [ P R L 1 1 0 ( 2 0 1 3 ) 0 2 1 8 0 1 ] T h e s i g n a l ma s s d i s t r i b u t i o n i s mo d e l e d a s a G a u s s i a n ( w i t h a r e l t r a d i a t i v e t a i l ) . T h e p a r a me t e r s o f t h i s mo d e l a r e d e t e r mi n e d f r o m d a t a t e B u s i n g c o n t r o l c h a n n e l s . r e i v i l O T h e B D T i s t r a i n e d u s i n g s i mu l a t i o n . - c r B u t i t i s c a l i b r a t e d f r o m d a t a . Ma s i g n a l P D F i s o b t a i n e d f r o m c h a n n e l s w i t h s a m e t o p o l o g y , b a c k g r o u n d P D F i s o b t a i n e d f r o m F f i t t o t h e m a s s s i d e b a n d s . D P s y a c e d C N C F November 11 2011 B s l i d e 8

O t h e r b a c k g r o u n d s L H C b [ P R L 1 1 0 ( 2 0 1 3 ) 0 2 1 8 0 1 ] Ma i n b a c k g r o u n d s o u r c e i s r e l c o mb i n a t o r i a l f r o m b b - > µ + µ - X t t e B r e i v i l - c o n t r i b u t i o n i n t h e s i g n a l w i n d o w : O - c r 0 + - B - > h h ' w i t h b o t h h a d r o n s Ma ( s ) mi s i d e n t i f i e d . Mi s - i d f r o m d a t a , f o l d e d w i t h s i mu l a t i o n s p e c t r a . - c o n t r i b u t i o n t o t h e l o w e r ma s s s i d e b a n d : ma s s s h a p e d i f f e r e n t f r o m e x p o n e n t i a l , c o u l d b i a s t h e i n t e r p o l a t i o n o f n o t c o n s i d e r e d . s y a 0 - + + ( 0 ) + ( 0 ) + - T h r e e c o mp o n e n t s a d d e d t o t h e f i t : B - > π µ ν , B - > π µ µ a n d c e d 0 + - B - > h h ' ( s ) C N C F November 11 2011 B s l i d e 9

N o r ma l i s a t i o n L H C b [ P R L 1 1 0 ( 2 0 1 3 ) 0 2 1 8 0 1 ] n o r ma l i s a t i o n t o r e l t t e B r e i v i P D G l O - c r f r o m MC f r o m d a t a Ma c h e c k o n d a t a b f r a g me n t a t i o n me a s u r e d a t L H C b [ J H E P 0 4 ( 2 0 1 3 ) 0 0 1 ] 4 2 4 2 0 0 s t a b i l i t y c h e c k e d o n 8 T e V d a t a . ± 1 5 0 0 s y a c e d C f o r t h e 8 T e V d a t a s e t . N C F November 11 2011 B s l i d e 1 0

R e s u l t f o r t h e B F o f - 1 2 0 1 1 , 1 . 0 f b , √ s = 7 T e V S i mu l t a n e o u s r u n b i n n e d l i k e l i h o o d e l t t f i t t o 1 5 B D T b i n s . e B r e i v i C o mb i n a t o r i a l b k g , l O - c 0 B a n d B y i e l d r s Ma f r e e . A l l o t h e r p a r a me t e r s - 1 2 0 1 2 , 1 . 1 f b , √ s = 8 T e V G a u s s i a n c o n s t r a i n e d . f u l l P D F s y a c e d C N L H C b C F November 11 2011 [ P R L 1 1 0 ( 2 0 1 3 ) 0 2 1 8 0 1 ] B s l i d e 1 1

R e s u l t f o r t h e B F o f L H C b [ P R L 1 1 0 ( 2 0 1 3 ) 0 2 1 8 0 1 ] r e l t t E x c e s s o f c a n d i d a t e s e B w i t h a s i g n i f i c a n c e o f 3 . 5 s t a n d a r d r e i v i d e v i a t i o n s . l O - c - 4 ( p - v a l u e b k g - o n l y h y p . : 5 · 1 0 ) r Ma F i r s t e v i d e n c e o f t h i s d e c a y ! c o mp a t i b l e w i t h t h e S M p r e d i c t i o n , a f t e r c o r r e c t i o n f o r : [ E P J C 7 2 ( 2 0 1 2 ) 2 1 7 2 ] [ P R L 1 0 9 ( 2 0 1 2 ) 0 4 1 8 0 1 ] s 0 F o r t h e B mo d e , n o t s i g n i f i c a n t e x c e s s y a c i s f o u n d , a n u p p e r l i mi t o n t h e B F i s s e t : e d C N C F November 11 2011 B s l i d e 1 2